Clipping Audio Signals - ATTN: Audio Engineers, DJ's [Archive]

maxxpower23

08-04-2003, 12:42 AM

There is a limit to how large a signal can pass through an audio circuit undistorted. Like driving a big truck under a low overpass, if it doesn't fit, some rather ugly clipping results. So to keep our audio signal safe from harm we must keep it strong ALL the way through the mix console, but at a level low enough to prevent distortion. One of the most important tools that we have on a mix console is the audio level meters. When the audio system is running at its loudest, the output meter should peak at 'zero' or slightly above. Under these conditions the signal level at the output of the mixer is at its optimum.

WHY SHOULD I CARE ABOUT CLIPPING?

CLIPPING AND DRIVER FAILURE:
Clipping means that the tops of the signal are "clipped off" or "flat-topped" when the signal level is exceeding the maximum capability of the power amplifier or some other piece of equipment in the system. Clipping is a form of distortion. Clipping occurs when a sound signal's voltage increases past a point that the equipment cannot output. As such, instead of maintaining the real wave-form of a sound, the sound is abruptly truncated where equipment meets its limits. During the times when a signal is flat-topped, loudspeaker cones are not being "instructed" to move as it is receiving essentially a DC signal (instead of an AC signal). This means all power goes into heating up their voice coils instead of producing sound.

CLIPPING FACTS:
ANY CLIPPED SIGNAL CAN BLOW A LOUDSPEAKER. It does NOT matter if it is caused by the mixer, amplifier OR any other piece of equipment in the system OR whether the amp is at full output.
CLIPPING CANNOT BE DETECTED by electronic or built-in loudspeaker protection circuits and therefore cannot prevent damage from clipping.
LOUDSPEAKER POWER RATINGS are valid on for un-clipped input signals.
WATCH THOSE CLIP INDICATORS on every piece of equipment to avoid ANY clipping.

In practical applications, what this all means, is that when you run your mixer with the individual channel preamp gain / trim cranked, at +12-15 dB overdriven signal, and then crank your master output fader so the output is clipping heavily (in the region of +12-15 dB over Unity Gain), the signal being sent from the DJ mixer to the sound system is already heavily distorted and unnatural BEFORE AMPLIFICATION.

GARBAGE IN, GARBAGE OUT

This also means, that a DJ can damage or destroy sound equipment through excessive signal abuse.

DJ's please educate yourselves on the physics of audio line levels, overdriven preamps, and distorted / clipped signals. Your music WILL sound better to your audiences as your understanding increases.

I invite DJ's, Audio Engineers, System owners to please reply and add to the discussion. Let's raise the collective knowledge on Audio Acoustics and Physics.

peace
-caleb-

djowns

08-04-2003, 06:48 AM

Good levels are key :) (hence why I hate pioneers)

GreenAcresProd

08-04-2003, 07:23 AM

Nothing worse than an experienced DJ walking up to the mixer, and jacking the gain up so far that the signal clips out, and the sound gets all distorted. I HATE that. I have watched so many headliners do this. Especially on systems that would otherwise sound SO good at high levels.

I am in full agreement with maxx.

Joy-Stick

08-04-2003, 07:43 AM

this needs to be a sticky

and max you are right and i agree that the dj's need to realize that when they see the lights on the mixer turn red that doesnt mean turn it up more that means STOP dont turn it up any more .... if you want it louder maybe you should grab the sound guy and say hey can you turn your amps up ill turn the sound down then you turn it down to where MAYBE one red light lights up on the heavy bass hits then leave it there at the most then the sound guys turns his amps up and all is good .... but be carefull cause if you decide to cut the lows for some reason then add them again but turn em up too much then you will red light again and distort the speakers and then thats when the sound guy comes running up with a baseball bat (jk about the baseball bat :P) and tells you to turn it down

again sticky this please

skloot

08-04-2003, 09:02 AM

Originally posted by Joy-Stick
this needs to be a stickyWord!
I hate, hate, HATE seeing dj's crank the gains way the fuck up until it's nothing but redline. Gah!
Please, wont someone think of the levels? Think of the levels!

electrokid

08-04-2003, 09:45 AM

caleb's statements couldn't be more true. if the sound guy actually knows what they are doing with their system, the djs mixer should be right at green on the master. anything more than that generally results in distortion and a crappy sounding set.

the problem is that the djs turn it up at the mixer. the sound tech turns it down at their board instead of yelling at the djs to decrease the volume at the source. once it is turned down at the board, the djs turn it up more on the mixer. the end result is full bars into the red on the master of the mixer,extremely shitty sound, and potential equipment damage.

what djs have to realize is that cranking the sound up does not make the kids dance harder. instead it makes their set sound horrible and ruffles the feathers of those who enjoy a good clean sound to get down to. i have my own opinions why many djs turn up the system too loud but i'll leave it for another discussion.

if practical, i check the mixer to see how far the dj before me has it into the red. i then consult with the sound person and tell them that i'm going to turn it down at the mixer so they can turn it back up on their board. this produces a good clean sound for my set plus the monitors are more free of distortion as well.

Pipedream

08-04-2003, 10:11 AM

yep, this is all true.

and it looks like we all agree on this as a dj community... yet when put into practical circumstances, these doctrines do not seem to be followed so strictly.

as a fellow dj, i definitely appreciate that everybody wants to hear there music LOUD and crankin..that it NEEDS to be loud. cool, i understand, and even feel more or less the same way. you just have to remember that when you are starting to see red, that is an indication of the signal being overdriven, and your signal quality IS being degraded... if you are like me, you want your music to be as loud as possible, but also sound as clean and crisp as possible... green means go, red (usually) means stop.

befriend your local sound man. the discourse between sound tech and dj is one of the most valuable discussions that can happen on the production side of the event. most dj's end up fighting the sound man via levels... dont.... talk to them, get on the same page- both of you should want the same thing... loud, clean, and crisp sound.

word to your mom.

milgramShock

08-04-2003, 09:48 PM

okay... well feeling that I am the reason this discussion was started.... i feel i should respond.

1. I never jack or jacked the levels (at this last party) to an extreme point, i.e: all reds and solid.... if anything I turned it down from the dj that was before me.

1.5. at this last show I didn't actually know that the sound was turned down so low until pipedream actually said something when he got there....."yeah, paddy your set sounds good, but why is it so quiet?" .... my monitors were loud enough that I wasn't aware of the system being that quiet. I went out in front of the speakers and found the sound to be way below a level that one might hear at a party... I even play louder when I make music.

2. I have to much of my own equipment at home to break to be turning sound systems up beyond a legitimate level.

3. As I have always played on my Pioneer mixer, I make sure the levels are bouncing just into the first two reds. this has proven to sound good in all cases... including making recordings.

4. I have always appreciated a good sound person. Caleb, I think you know a lot about sound.... and I think you know about what you are doing but..... the last 45min of my set.... where did you go?

5. As jed says, I have found myself consulting with the sound person many times about turning it down on my end so he can turn it up on his end. This didn't happen this weekend..... I just kept getting turned down by various sources... and no I didn't respond by turning it up... I just dealt with it.

6. I agree with Caleb as well... But the attenuator knob on the DJM600/500 can help a lot in situations of unruly DJs..... as long as the DJ knows what they are doing and how to keep levels in a reasonable area.... The knob can protect all parts of sound systems and make it so the master level can appear to be all the way up..... giving the dj no head room..... as long as they keep the gains at a intelligent level. Don't believe this works..... try it.... It won't be distorted. there are other mixers with various forms of this knob as well and it should be something I think that everyone is attentive to, especially when you know a "ignorant DJ" is on their way. DJs, get to know your sound person, Sound persons, protect your equipment from goof balls.

-paddy

maxxpower23

08-05-2003, 12:43 AM

Milgram Shock: My recent experience with you is only the most recent occurrence of this ongoing phenomena. This post is not directed at you. It is intended to generate discourse and hopefully educate. You have not been mentioned in this post until you brought it up yourself.

Please keep this thread on-topic and Private Message me for personal communication. I have recieved your PM's, and am crafting a response as we speak. I have no wish to discuss party drama on this or other public threads.

__________________________________________________ _

Electrokid

...the problem is that the djs turn it up at the mixer. the sound tech turns it down at their board instead of yelling at the djs to decrease the volume at the source. once it is turned down at the board, the djs turn it up more on the mixer. the end result is full bars into the red on the master of the mixer,extremely shitty sound, and potential equipment damage.

Pipedream

befriend your local sound man. the discourse between sound tech and dj is one of the most valuable discussions that can happen on the production side of the event. most dj's end up fighting the sound man via levels... dont.... talk to them, get on the same page- both of you should want the same thing... loud, clean, and crisp sound.

In my experience this is the most common scenario. DJ's need to talk with your sound man and most importantly, trust him/her. You'll probably have more favorable results if you develop a rapport with your technician; a sound guy is more likely to thump it if he trusts you and feels respected. Try it, trust me, you'll like it.

Pipedream

when you are starting to see red, that is an indication of the signal being overdriven, and your signal quality IS being degraded... if you are like me, you want your music to be as loud as possible, but also sound as clean and crisp as possible... green means go, red (usually) means stop.

Electrokid

what djs have to realize is that cranking the sound up does not make the kids dance harder. instead it makes their set sound horrible and ruffles the feathers of those who enjoy a good clean sound to get down to.

Another aspect of this Clipped Signal / Overdriven Level problem is that when the tops and bottoms of the electrical waveform are being clipped off, the result is that your records do not sound as they are intended. The producers of the tracks and music we all love, use expensive mastering equipment to get the sound they want. When a DJ overdrives the signals, the quality and artistic integrity of the original intended music is degraded.

I will be posting simple diagrams of normal and clipped audio waveforms to further illustrate this concept to those of us who are more inclined to learning visually.

Please take the time to research this. Your mixes, sets and overall performance skills will benefit greatly.

Thank you
-caleb-

milgramShock

08-05-2003, 01:30 AM

Caleb.... sorry.... I was just commenting because this thread is linked directly off of the the last post of yours in the review thread (of the Dusk till dawn party)... which partially is responding to what I said. Sorry I broke the board rules.

Regardless, I think I am keeping on topic with my response..... I am just including my most recent experiences to make valid points... or ask questions of ideas that you preach, like being a good sound person... or trusting people.

I am not discussing "party drama"... I am only speaking of my most recent experiences and using them as examples to solidify points. Do you think you would have started this thread yesterday if I had not given you something to start it about? If not... cool. If so... cool, I'm just using times from our experiences to make points about how I feel about what you say here and what you actually do.

I am not here to discuss "party drama".... I think someone can have a discussion while bringing up points of time where they become relevant in that persons argument.

I refer to myself to recall the history of what I did this last weekend because i felt it was not ignorant .. furthermore, I feel that labeling djs as ignorant or "ignant" as you had (had because it seems that the title of this thread has been changed since it was originally started) put it is rather unjust and untrustworthy. And how should I trust you if you refer to DJs as "ignant"?

-paddy

Dank Rag

08-05-2003, 10:45 AM

Who is to blame? Well a lot of the blame can be placed on the fucking Pioneer mixers that everyone seems to have a hard on for. How many red lights are on those damn things? Like 6 or 7 red lights above green? That is seriously WHACK! It gives DJs the wrong ideas about the headroom on the mixer. I have a Rane mixer, do you know how many red lights it has on the readout? ONE! Allen and Heath? ONE! One is all that is necessary, red is bad, why the hell would you need 6 red lights? Why the hell does the mixer allow this kind of blatent misuse to be built into it?

As a sound engineer it is a pain in the ass to set the levels appropriately with the Pioneer mixers. You HAVE to assume that the DJs are going to be playing well into the red, setting the sound levels at maximum when the mixer is peaking out the meters. This sucks, as at this point the mixer sounds like shit and so does the sound. Unfortunately the tendancies of 90% of the DJs out there force this kind of setup to be necessary to protect the sound system. If we set the sound during sound check to comply with the green lights on the mixer, then some shitty DJ will get up there and overdrive it as soon as they can. Very rarely will I get a DJ on the system that will want to play in the greens, even when I talk to them about it before their set.

Caleb- I understand your frusteration and wanting to inform DJs out there about how to properly play with their levels set right, but that isn't going to happen. Basic principles of user interfaces indicate that we have to assume the most base user of the equipment. You cannot expect DJs to know anything about sound, electronics, or clipping. Of course this sounds rediculous, but I am sure that your experience supports this assumption. Assuming that they know nothing, in order to protect the sound system and to prevent arguing with every knob cranking DJ that plays on your system, you have to adjust the miexr levels accordingly. It will sound shitty, but that is their punishment for playing in the reds. If a DJ does want to play in the greens, you can always turn up the sound system, that's what a sound tech is there for, to monitor the situation of each DJ playing and adjust accordingly.

Why in the world does the Pioneer have that damn attenuation (gain) knob on the back of it? It only serves to allow the DJs to think that they can crank the mixer and that we should have set the knob probperly before they started playing. I have never played on another professional mixer of any quality that has a similar knob. That's what the master output knob/slider is for. Why would you possibly need two master levels? WHACK!!!

ONCE AGAIN THIS IS WHY THE FUCKING PIONEER MIXERS SUCK ASS!!!

corbettfields

08-05-2003, 12:34 PM

Originally posted by Dank Rag
Who is to blame? Well a lot of the blame can be placed on the fucking Pioneer mixers that everyone seems to have a hard on for. How many red lights are on those damn things? Like 6 or 7 red lights above green? That is seriously WHACK! It gives DJs the wrong ideas about the headroom on the mixer. I have a Rane mixer, do you know how many red lights it has on the readout? ONE! Allen and Heath? ONE! One is all that is necessary, red is bad, why the hell would you need 6 red lights? Why the hell does the mixer allow this kind of blatent misuse to be built into it?

As a sound engineer it is a pain in the ass to set the levels appropriately with the Pioneer mixers. You HAVE to assume that the DJs are going to be playing well into the red, setting the sound levels at maximum when the mixer is peaking out the meters. This sucks, as at this point the mixer sounds like shit and so does the sound. Unfortunately the tendancies of 90% of the DJs out there force this kind of setup to be necessary to protect the sound system. If we set the sound during sound check to comply with the green lights on the mixer, then some shitty DJ will get up there and overdrive it as soon as they can. Very rarely will I get a DJ on the system that will want to play in the greens, even when I talk to them about it before their set.

Caleb- I understand your frusteration and wanting to inform DJs out there about how to properly play with their levels set right, but that isn't going to happen. Basic principles of user interfaces indicate that we have to assume the most base user of the equipment. You cannot expect DJs to know anything about sound, electronics, or clipping. Of course this sounds rediculous, but I am sure that your experience supports this assumption. Assuming that they know nothing, in order to protect the sound system and to prevent arguing with every knob cranking DJ that plays on your system, you have to adjust the miexr levels accordingly. It will sound shitty, but that is their punishment for playing in the reds. If a DJ does want to play in the greens, you can always turn up the sound system, that's what a sound tech is there for, to monitor the situation of each DJ playing and adjust accordingly.

Why in the world does the Pioneer have that damn attenuation (gain) knob on the back of it? It only serves to allow the DJs to think that they can crank the mixer and that we should have set the knob probperly before they started playing. I have never played on another professional mixer of any quality that has a similar knob. That's what the master output knob/slider is for. Why would you possibly need two master levels? WHACK!!!

ONCE AGAIN THIS IS WHY THE FUCKING PIONEER MIXERS SUCK ASS!!!

yeah.. its the equipments fault .. always is...:rolleyes:

Jizosh

08-05-2003, 02:50 PM

i agree with dan...pioneer mixers are set up really lame, and whoever thought of a readout with like six red bars should be punished severaly. however, from my experience, if you set the attenuation (and lock it) and run a good compressor, there won't be too much of an issue with the levels.

milgramShock

08-05-2003, 03:18 PM

okay.... I agree.... the pioneer mixer sucks with how its laid out and its silly number of red bars on the levels... and a number of other things, like how the lines on the low end knobs are green.... a color which is impossible to see with the blinky light factor in a rave or dark club.

The sound coming from any pioneer i have ever worked with has been good as long as the levels BOUNCE just into the red just like on any mixer.

Jizosh, Exactly my point... Every time I have ever had anything to do with sound (when setting up my own equipment), I have pre set everything so the djs have headroom and the sound guy doesn't have an aneurism... if i am working with a dj I know is gonna crank it (which is usually the case) I don't have problems because the mixer is pre set and they are instructed prior to their set not to go past a point with the gains or the master.... and most comply. Trust me the attenuation knob on pioneers makes a difference if everyone knows what they are doing.

I don't have a hard on for my DJM600 but I think what I paid for it was well worth it and I know I can find enough positive things about it to drown out the dumb levels, green paint and some silly effects.

In the end.... friendly, realistic communication on both ends is key.

-paddy

djowns

08-05-2003, 03:54 PM

This is a good reflection of one of the unfortunate things about my vestax PMC-07, it's not that great at displaying your levels, infact hte display is all pre-master. That means when you may be running at -16 db the meter will be showing +6. It's a tradeoff with this mixer though, cause so much about it is bad ass that the few faults are worth dealing with.

Joy-Stick

08-06-2003, 04:51 PM

this problem is simple to solve

sound techie needs to find out who is spining and when and then about 5-10 minutes before the new dj gets on show them where the level is at and tell them flat out dont turn it up any more than that or i will eat your first born child

dj's need to value there first born child and not turn it up any more than the sound techie lets em

then there will be lots of dancing happy ppl and all will be good

dj metro

08-07-2003, 07:29 AM

i never let my sound go above one red led, and it hardly ever gets there... yellow is usually the max for me.

corbettfields

08-08-2003, 11:29 AM

Originally posted by milgramShock
okay.... I agree.... the pioneer mixer sucks with how its laid out and its silly number of red bars on the levels... and a number of other things, like how the lines on the low end knobs are green.... a color which is impossible to see with the blinky light factor in a rave or dark club.

The sound coming from any pioneer i have ever worked with has been good as long as the levels BOUNCE just into the red just like on any mixer.

Jizosh, Exactly my point... Every time I have ever had anything to do with sound (when setting up my own equipment), I have pre set everything so the djs have headroom and the sound guy doesn't have an aneurism... if i am working with a dj I know is gonna crank it (which is usually the case) I don't have problems because the mixer is pre set and they are instructed prior to their set not to go past a point with the gains or the master.... and most comply. Trust me the attenuation knob on pioneers makes a difference if everyone knows what they are doing.

I don't have a hard on for my DJM600 but I think what I paid for it was well worth it and I know I can find enough positive things about it to drown out the dumb levels, green paint and some silly effects.

In the end.... friendly, realistic communication on both ends is key.

-paddy

so what is spec'd distortion/clipping levels on Pioneer 600 when red light SAYS +3,+6 db , etc?

does anyone KNOW that distortion has started at that point? Has anyone CALIBRATED there 600's meters, or do you just believe the little flashing lights?!?!

Is the signal CLIPPING with 3 reds, or is it just THD increasing?

and what has setting the attenuater got to do with the price of cheese once you've saturated the preamps?!?! it's just the volume of distortion methinks....

Mr Shock states it right... get the system setup to give good sound, good headroom and enough room on the faders to make a difference... then 95% of folks wont NEED TO PUSH it...

I've seen setups where the poor DJ HAS to push it because the dufus sound engineer "forgot" that 300 people packing into a room act as a pretty decent muffler and no-one can hear a darn thing!

In general, if the sound guy has long hair, a Deep Purple T-shirt, is a bit deaf, and a weird accent, do what he tells you.. otherwise they probably know about as much as you do,,,, so use common sense... and yer own ears..

MustHaveLust

08-16-2003, 12:18 PM

this also applies to live audio as well. I've made the mistake myself. Like turning on an amp, after you've played a few days ago, and didn't turn your master level and instrument level off. So you get this giant fucking POP. And then your shit doesn't work. Yup. Cost me some cash, bass crates are not cheapo.

So I guess my point is that it doesn't just happen to djs, it happens to bands too. turn your shit off before you turn it on.

milgramShock

09-21-2003, 11:33 PM

Why is this still sticky.... it's apparent that some of us DJs know more than some would suspect.... and some sound guys have problems with people knowing more than them.

djowns

09-22-2003, 12:18 AM

Know whats a cool trick and a reason why I wouldn't get self powerd monitors? If the DJ is being too loud, simply drop your levels and bump the monitors. Sure fire cure :)

maxxpower23

09-22-2003, 03:44 PM

I imagine this is still a sticky because it addresses a common occurence. It seems that any new dj (or old) might be unaware of these issues and would (should) appreciate advice/input/feedback/tips.

This thread is educational in its intent. If researched and adhered to, good signal levels throughout a signal chain will truly make your mix sound better. Try it and see for yourself.

milgramShock

09-22-2003, 04:47 PM

word.

Sophistik

09-26-2003, 06:08 PM

Yeah I tend to walk up to the decks and everytime the guy before me's got the master output and every channel on the mixer jacked up to total red line city.

Then I get to back off all the channels to at least +4. I try not to let it line higher than that.

Joy-Stick

09-27-2003, 09:28 AM

hey i just came up with an idea

hook a mic up to JUST the monitors then when the dj turns the gain up too much get on the mic and say something along the lines of "excuse me sire but do you mind not trying to blow my system" or "warning gains too high ... dj must turn gains down or sound tech will turn sound system off ... warning" (corse if you do that you gotta be willing to at least fake starting to turn it off) or just a simple "hey fucknut dj turn the fucking signals down"

meh just an idea feel free to use it though

unknownp0et

09-29-2003, 09:45 PM

For a bedroom DJ (like myself) who will be exiting the boudoir coocoon soon, this discussion is incredibly valuable

When mixing, I found that many of my records have been recorded at different levels. One record is often simply quieter than another. At first I never touched the trim knobs, but my mixes suffered because the album that I was mixing in was not at the same level as the albumn playing. Then I realized that my mixer (Korg Kaos mixer) was able to moniter each channel seperately. I found that I could adjust the trim to make sure that the levels were equivelent before mixing, allowing for a much more seamless mix when one record eventually drops out.

Besides, keeping the levels below red helps a bit with beat matching (outside of the headphones) as the lights bounce. Lower levels also allow for a few more subtle nuances when playing with the track as I mix. I have trained myself, unconscious of this issue, to never allow the level indicator to bounce over the first little red light. If I want to keep my housemates awake, I will simply crank my amp rather than distorting the signal by tweaking my mixer output to max.

Just because you're being subtle doesn't mean the shit can't be bangin'.

My mix tapes sound better and I will be better prepared for the club gigs to come.

Thank you all for this discussion.

jasonbuss

11-20-2003, 08:18 AM

level managment 101 is a required course before graduating to crowd control and response...

heh

this is a good read for anyone who is lacking in this department. you can be the best dj out there, but totally ruin it for yourself due to sending to hot a signal out of the mixer...

i own a 600 and i never send any signal over 0db. even when i run sound out of my mackie cfx, i never send anything out past 0db. theres no reason to send that hot of a signal to the amps... distortion is the enemy, and most djs are never learned this aspect of playing.

its more than laying plates on a turntable and beatmatching them...

i think a major factor is nobody bothers to teach this when up and comers learn, they are afraid to look like a dumbass and ask how its supposed to be done, or they see the djs they look up to doing it and fig its the way to do it.

get your own sound equipment and you realize, its the first most important thing a dj can do on the decks and mixer is run a clean signal to the board and amps...

a lil side story - i was throwing a house party with my 600 and my mackie 450's and swa18.. a pretty well known dj in the area was getting ready to play and before him the levels were managable, with a red here and there, but overall the signal was pretty clean the whole night. untill he gets on. the first thing i notice is his technique that he did set him up to fail instantly with level managment. instead of using the upfaders to kick the sound in and out, he would use the gain knobs. nono... so by his first mix, the sound was increased by at least 6db, just from him rotating the shit out of those knobs... so with screwdriver in hand i proceded to tell him that if he didnt lower the levels i was going to attenuate his ass down. he lowered it a bit and i was content. a friend said that this guy was known to overdrive systems. i looked at him blankly... why?. so he started in increase the levels more and pretty much has the system pegged... i warned him once more. he disreguarded it. so i told him one last time, that if he doesnt lower his levels, hes gonna activate the auto shutoff on my 450s and kill the sound completly for a half an hour. as those speakers have a auto protection built in when the signal gets TOO hot. he didnt pay attention... so i nonsholantly when over and placed my hand around back and snapped off one of the speakers. and had my firend hit the other... opps no sound. immediatly i yelled at him, "goddammit, i told you not to send such a hot signal to my gear, now you have to wait a half an hour till these speaks cool down." so the floor cleared and that was that. his set was over. later that nighthe came up to me and started asking me questions about the setup and wondering why it happened.. he had no idea. no one ever told him how to manage it. so for about 20 minutes i answered his questions and explained to him that to get the system louder at 0db you turn it up at the amp level etc...

a couple other times after that, he played on my gear and i didnt have one problem. he even came to me and asked me to turn the mackies up... running green the whole time.

so the moral of this story, look both ways before crossing the street. then when you get there. let the damn dj know that level managment will make or break each record they play.

jasonbuss

Axx0

11-22-2003, 12:12 PM

<<"goddammit, i told you not to send such a hot signal to my gear, now you have to wait a half an hour till these speaks cool down." so the floor cleared and that was that. his set was over.>>

That's a great way to teach up-and-comers responsibility for their own actions--especially at a party. I've been to a few where whoever was spinning was making the awesome system sound like a diaherretic. It would have set my mind at peace if the soundguy (if there was a sound guy) came up and bitched the supertard DJ out.

DJ's can try to act like rockstars sometimes which doesn't help the new ones just starting out who don't realize that the soundsystem they're playing on costs about as much as their hospital bill would if they fried some equipment and had to face someone like an angry Yeshua with a baseball bat. :p

<<In general, if the sound guy has long hair, a Deep Purple T-shirt, is a bit deaf, and a weird accent, do what he tells you..>>

Dude, I know that guy! He runs sound for most of the funk bands in Corvallis! :D

Oh, and by the way MilgramShock, get over yourself. It's not all about you dude. ;8^>

maxxpower23

11-24-2003, 02:10 PM

jasonbuss - great tactic! I'll definitely remember that one for the future. ;)

Axx0 - <<Dude, I know that guy! He runs sound for most of the funk bands in Corvallis!>>

I work for the guy in Corvallis who installed sound at the Peacock, Bombs Away Cafe, rents sound to Club Platinum (Corvallis), sold stuff to the Roseland (PDX). This guy does a lot of the festivals in the summertime; I work with him at Oregon Country Fair main stage, Portland Gay Pride (he does main stage, I did the small stage this year) and a lot of gigs with very heinous music (country western, classic rock, blech!). His name is Doug Looney and runs a sound install and reinforcement business out of Corvallis and is pretty much a sound god in my opinion. I am deeply indebted to him for teaching me this art and look up to him as a guru. His business is called Doug Looney's Live Sound Services out of Corvallis and I highly reccomend him for work in the mid-valley area. He doesn't come cheap, but his sound is superior.

Back on topic, this man Doug Looney reccomended a book to me that has become my bible of sound for the last five years. It is thick, informative and has taken me a good while to digest it. If any of you are aspiring sound people, run out and buy this book!

"Sound Reinforcement Handbook" Gary Davis & Ralph Jones - Published by Hal Leonard Corporation - copyright 1987, 1989 - ISBN: 0-88188-900-8

peace :cool:

milgramShock

12-02-2003, 11:04 AM

Originally posted by Axx0

Oh, and by the way MilgramShock, get over yourself. It's not all about you dude. ;8^>

Not once did I ever say that this was all about me.... but caleb did start this thread just after an interesting experience that him and I had playing at a party. Dick.

ske96

01-28-2004, 10:25 PM

All Dj's need to learn about how their equipment works. What's funny is the designers of most mixers already knew of this problem. Your LED's are probably not accurate. They are usually lower so the company can say how much head room they have. this by no means justifies turning your levels pass 0db. But just to let you know, also depending on what brand you have, the levels are only measured off of one channel, usually the left. I totaly agree with everyone here. My friend use to come over and scratch with me and as soon as I see his mixer I always redo his levels. he just always cranks them, horrible.

I am usually not on this site, but something came to my attention the last couple of times that I've checked it out. Not a lot of people on this site know about equipment, which is suprising since this is more of a mix dj group and would think that sound was very important. It's just weird, because I'm usually on a asisphonics or d-styles (scratch dj site) and equipment has there own section and is probably the most visited. Most eveyone on there know a shit load about equipment, probably because as soon as we get a mixer, we take it apart to modify the fader. It was just suprising. that's all

adamjenkins80

02-20-2004, 04:18 PM

In reference to lower frequency distortion ...

it's not that you can't hear it, you're just used to hearing it. a woofer (let alone a sub!) has a HUGE amount more distortion and non-linearity characteristics than a midrange (let alone a tweeter). We are used, and don't really care about 25-45% THD in the subs anyways ... or should we? (www.velodyne.com)

>Is the signal CLIPPING with 3 reds, or is it just THD increasing?

THD doesn't increase until the signal experiences non-linearity effects -- like clipping. If the signal is not clipping, THD changes are negligable over the linear gain bandwidth..

Jenkins

Weazus

04-02-2004, 09:29 AM

This info is not only useful for DJ's, but producers as well. I now produce my songs through Reason with these facts in mind. Although there's no actual "equipment" to blow out on the computer (unless you've got your speaker volume WAY up) the effect of clipping can still be heard through the program's emulated "hardware."

Like people said, some clipping can't necessarily be "heard," but the software will detect it for you. Just look down in the lower left corner, and you'll see an indicator light called "audio out clipping." Try to keep this light OFF when creating/arranging your mix; and you'll get a nice clean sound.

Remember, if your sound levels are lacking, you can always use Wavelab or something else with VST's to boost those levels later on. This is how I achieve a nice rich Bass sound through Reason.

Thanks everyone for all this killer info! Hope I could contribute something useful in return.

peace

MYSTYK

04-08-2004, 08:47 PM

Originally posted by Notorious Abe
True "good sound" at parties will only happen if we give the DJs less freedom and let the engineers control things :P [/B]

I thought DJ's WERE sound engineers.... in a perfect world.
But I suppose someone had to buy all those badass speakers we bassin' out.

A whole truckload of good info in this string. I for one have had my fair share of ppls at my house that wanted to drive my personal rig WAAAAAY beyond niceness. A tactfully placed comment USUALLY gets the message across but sometimes the aluminium bat comes in handy....... Green Red... yeah. what I want to see is some kind of standard across the board for equipmant. dB wise and other WISE (key word I think is WISE, implying intelligence) some mixers have no PFL meter reading , some do. Some pre-fade-effects loop, some don't. I think that may be the first two reasons I am trying to build my own equipment. Nobody has made a comprehensive setup that could appeal to all dj's. Hey if you use it , FINE. If not, don't. It is still there if you feel like exanding. Commercial bullshit if you ask me. Most of the reallly good (popular) ones have a hybrid type custom setup anyhoo. costs a few G's. But 4 us it will start with strict sound control. You gotta love a crispy mix. If you want distortion......hook up an effect. Experiment, but not with my amp and speakers. PIMP
PEACE (of that ass) Love (this muthafunka) Unity(which means I am locked on that like a dog) and Respect ( the power of sound)

out

MYSTYK

04-08-2004, 08:52 PM

Seattle seems bumpin. Gotta bring the VW bus out that way soon to make some BOOM! peace to all the hedz out there.

mrtumnus

04-13-2004, 09:10 AM

Is a Hard Limiter before the amp set at like -2 dB better than a Compressor?
I thought Compressers gave an up and down levels effect?

Katapult

05-04-2004, 08:06 AM

To establish a safe recording level, go to your local hardware store. Home Depot will work in a pinch. They sell all sorts of levels and I am sure you can pick one up for around $9.99. I suggest going with a bigger more expensive one though-you know, the ones that are about the length of a yard stick. That way you can knock the DJ over the head with it. Level problem solved.

Katapult

05-05-2004, 11:59 AM

Now for something useful.

http://www.prosoundweb.com/studyhall/jbl/lowpower.php

and

http://www.prosoundweb.com/studyhall/studyjump.php?pdf=clipping

rayman

05-27-2004, 09:29 AM

BUMP
can you hear it??

Aquatic Resonance

06-20-2004, 11:18 PM

Originally posted by maxxpower23
If any of you are aspiring sound people, run out and buy this book!

"Sound Reinforcement Handbook" Gary Davis & Ralph Jones - Published by Hal Leonard Corporation - copyright 1987, 1989 - ISBN: 0-88188-900-8

Great Book!

Caleb recommended this book to me a couple years ago at the salon in eugene while setting up for a party. I'm forever grateful. It's readable, but there is no shortage of technical information. You can get it for $25 at amazon, pick up at least one.

psyclone

11-19-2004, 01:56 AM

Ok if you want the best signals from your DJ mixer - don't go over unity at all, or goto 7.

The key is to have your input levels set so they are not to high. Watch for the red light on the input levels from your decks. This might change for each record - so be on top of it before you mix in.

Then use system 7 - set your output levels to 7 and you should be putting out -10db to your stereo/amp whatever and it will sound sick. I have used this for years and it always works in Dj or Engineering situations. I start with system 7 and tweak the Eq's to the room...

Good luck

subspace

03-06-2005, 12:11 PM

Originally posted by djowns
Good levels are key :) (hence why I hate pioneers)

lol... heres to that! I am and always will be a vestax diehard. My PCV275 OWNS pioneer 600's (minus the effects unit). It is smooth, responsive, all the faders have a perfect level of resistance, the crossfader is nice and heavy, and the level indicators are a dream come true.

I highly reccomend this mixer to any trance DJ, it runs about $500 and the sound is worth $500 more than any pioneer mixer.

Starfighter

04-23-2005, 03:16 PM

i saw this thread about clipping called "whats the big deal" and thought it might help furth explain things.
http://www.djforum.com/forums/showthread.php?t=43120

djowns

05-17-2005, 01:05 PM

So I took a lot of look into speakers, signal, and electricity lately. I've been reading a ton of shit, and I am pretty sure I figured out exactly why clipping is bad. I'd like to see what people have to say about this, as all I hear is people parading around telling my that it's bad, not why. If your just going to come onto this post and just go "it's bad" than get lost! This is a thread for those who want to know why, and understand enough about how it all works to know more than just "Don't do it!"

Here's my take on it all so far:

First of all, you need to understand how a speaker works. Here's a really good break down (http://electronics.howstuffworks.com/speaker.htm) of just how it all works. Understanding a little bit about electricity helps too, so check out this as well (http://science.howstuffworks.com/electricity.htm).

After reading all that you'll understand just how the signal (An ac current) makes a speaker work. A good, non clippin signal will NEVER go into DC (a never alternating + to - travel path). Now, A signal in a cable only has so much "width" per say. -10db being RCA, 0db for unbalanced cables, and +4 db being Balanced XLR or 1/4" cables. Now when you run over that width, the excess signal beyond your peak cannot be reproduced. The signal than becomes flat until the spike alternates and returns to a reproducable level within your cable. Essentially, for a second there, you're running a DC current as it becomes a pure + to - travel with no alternation.

When it comes to the way a speaker works, this doesn't reproduce noise. As you read before the alteration in electrical flow causes the speaker to vibrate and create the noise you hear. A direct signal simply moves the speaker once (towards or away from the magnet) and therefore doesn't do much to create sound. Under light clipping, it's not such a big deal, as the amount of time spent as a DC signal is minimal. It's still not good for your speakers though, and is truthfully 100% best avoided. I will never be caught advocating clipping ;)

Now, under extreme clipping, where the signal goes DC for a prolonged period of time, you're forcing your voice coil to resist or attract towards the magnet as much as possible for long periods of time. This stresses the suspension (the spider, and the diagraphm/excursion) a large amount, and doesn't reproduce hardly any sound at all. So, a very clipped signal does not actually produce sound hardly at all, as the vibrations (alternations in signal) are few and far between . All you get when feeding a prolonged DC signal to your speaker, is stress upon your suspension, and heat from a prolonged large quanity of electicty running through your speaker.

So to compare it and put it into laymans terms, lets pretend a speaker is honda civic traveling at 30 mph, and your signal is the road. A regular signal is like a slightly bumpy road, and the civic suspension easily works with that. A clipping signal is like having a road with massive rocks and pot holes. We all know what would happen to the honda civic.

Anyone got thoughts on all this? Maybe there's somethng I missed? Like I said before, please don't come in here and just unintellgibly repeat what you've heard before eithe.r We all have heard time and time again clippng is bad This is a discssion as to the "why".

burnt

05-17-2005, 02:02 PM

clipping is bad. don't do it!

:D

misthang88

05-27-2005, 09:49 PM

I guess I'm just biased, and probably the only way that feels this way but I use a Pioneer 600 mixer and love it. Don't have a single comlaint!

milgramShock

08-17-2005, 02:51 PM

Originally posted by misthang88
I guess I'm just biased, and probably the only way that feels this way but I use a Pioneer 600 mixer and love it. Don't have a single comlaint!

i use the same mixer.

i have no complaints either. you just have to know how to use it.

DjDevilE

01-12-2006, 10:18 PM

This whole thread is extremely helpful, to absolutely no end, especially for a newbie like myself. Reading this for just a few minutes I started to understand my mixer and it's settings ten fold. Walkin into this with an eager brain to learn! So thanks for all the tips and such!

Pan@BeatChapel

01-24-2006, 05:49 PM

Ok so i been lurkin for awhile....

This was the post that got me to register!

I cant agree more how important it is to learn
a bit about signal and levels when spinning out!!!

I cant count how many DJ's I've run across
with their djm600 in the red at every meter!

Im exstatic to finally see people talking about it!

djowns

03-16-2006, 12:31 AM

Originally posted by Pan@BeatChapel
I cant count how many DJ's I've run across
with their djm600 in the red at every meter!

FYI it means absolutely nothing when a 600 is in the red. It can be in the red and outputting absolutly nothing, or be in the green and be way beyond clipping. This is due to the attenuator upon the back. There's more to a mixer, and voltage, than red just being bad... although thats exactly what it should mean and unfortunately for some reason the industry standard is that it does not. Also, the clipping everyone here describes, mostly pertains to a digital medium. Many cables (well, balanced cables) can handle +4dbu's before clipping, and can handle high voltage amounts.

What I want to know, is if a low pass filter elimantes clipping to some extent, and just sort of creates silent pauses. A clipped signal is in essence 0hz (DC power). Therefore, does a low pass filter completely remove it?

Pan@BeatChapel

03-18-2006, 11:04 PM

Originally posted by djowns
FYI it means absolutely nothing when a 600 is in the red. It can be in the red and outputting absolutly nothing, or be in the green and be way beyond clipping. This is due to the attenuator upon the back. There's more to a mixer, and voltage, than red just being bad... although thats exactly what it should mean and unfortunately for some reason the industry standard is that it does not. Also, the clipping everyone here describes, mostly pertains to a digital medium. Many cables (well, balanced cables) can handle +4dbu's before clipping, and can handle high voltage amounts.

That didnt seem to have any point but to just be insulting....

but......

Have you looked at the schematic diagram for a djm600?
If memory serves....the meter is reading 'post EQ' or is showing you signal at a point just past the EQ in that channel.....
Most mixers, like the Tascam X-9 for example, the meter is reading immediatly after the input and before any EQ.....

So an attenuator knob at the master out is not going to fix running your inputs or EQ into distortion.....

And......
on the X-9 the master output meter is reading at the balanced XLR
outputs just before the physical plugs which says 2 very important things.....
1.....a meter at +4 is running 0dBv ONLY at the balanced outputs
2......there is no accurate info to calculate how the meter relates to
the unbalanced RCA outputs

this is true for a handful of mixers as well....

Meters are very very important....
but without knowing exactly what they mean
their just pretty lights.

Pan@BeatChapel

03-18-2006, 11:44 PM

Originally posted by djowns
Many cables (well, balanced cables) can handle +4dbu's before clipping, and can handle high voltage amounts.

the cable dosent 'clip'
Balanced ins/outs/cables are
3 conductor - 1 hot 2 cold 3 ground
unbalanced signal/cable is only 2 conductor and requires sheilding
a balanced signal benefits from a much lower impedance
which means more voltage, less interferance, and longer cable lengths

B.L.U.E. is even making 4 conductor XLR

Originally posted by djowns
What I want to know, is if a low pass filter elimantes clipping to some extent, and just sort of creates silent pauses. A clipped signal is in essence 0hz (DC power). Therefore, does a low pass filter completely remove it?

A low pass filter is only a preset EQ in essence.
low pass eliminates mids and higs
a high pass eliminates lows and mids

The function of most sub harmonic filters on pro audio equipment
is to eleminate sub-harmonic frequencies.......
(usually at 30hz and below)

the benefit is that most frequencies below 30hz are generally
perceived as rumble-y and unclear at high volumes
and those frequencies are the hardest for your amps and speakers to reproduce.......
So an eq roll-off (cut) at 30hz and below can often
sharpen up the clarity of a big system and give your amps
a bit of well deserved breathing room

djowns

03-19-2006, 12:25 AM

Word up. Hi pass or subharmonic than. I always mix those two up, espsecially when trying to make songs. I'm aware of what they do. I employ it into my system, espescially as my cabinets are not tuned under 36hz (fs). Low cuts are definitely important.

I want to know why exactly balanced cables get better voltage and a lower impedance. While there is a path for ground, the signal never touches it. Most grounds just go straight to the chasis, and acts as a shield that is wrapped around the other two conductors, and absorbs outside influence from things like RF frequencies.

So why exactly would it get a lower impedance. Thats something I haven't found in my reading...

Also, on your comment about the pioneer 600, the meter you refrence are the line inputs. I'm discussing the master meter... although both just turn into christmas tress anyways.

Sad-Mans-Burd

08-07-2006, 04:20 AM

Also kids don't forget to take your record off the deck after you're done mixing it,..oh and it's also essential that the needle go ON the vinyl,..this allows the crowd to actually HEAR the music,...hmmmmmm anything else,..ummmmm,..nope that's all the secrets I can reveal atm....

I guess to sum it up I'll end with.....

"woooooaahhhhh there captain obvious lemme sit down cause you just blew my mind!" :)

I guess it all relates to people that have somehow miracuously learned to beatmatch, bought some tunes, and have now decided they're DJ's and deserve to get booked,..and do cause their friends are throwing the party. Awesome times,...awesome times.

djowns

08-07-2006, 10:40 AM

Originally posted by Pan@BeatChapel
So an eq roll-off (cut) at 30hz and below can often
sharpen up the clarity of a big system and give your amps
a bit of well deserved breathing room

Yes I meant to say low-CUT or high-pass. I used to get the terms mixed up all the time, hehe. Anyways, if clipped signal is truely DC, it is therefore 0hz in theory, although that isn't entirely true either as a square wave can alternate as welll...

I'm curious how processing would handle the signal, and what it REALLY is. Is it seen as 0hz, or is it seen as a slam on the speaker, with no movement and just pure heat transfer (no movement, plus voltage going through it).

If it is zero HZ, would the capacitors in the crossover network in say a bi-amped system completely prevent clipped signal from hitting the high's? Would a high pass remove it, as it is zero hz (theoritically speaking of course). I don't think it would, which leads me to believe that it is not infact DC signal... although everyone on here swears it is... but I kind of wrote this thread off to begin with, haha.

I've heard of four conductor XLR cables. They've had them for a while, with a double shield. My boss was discussing this with me at work.

D-Melt

10-22-2006, 10:09 AM

Thats why mixers need 2 outs with a master fader for each. One that goes to the speakers that the DJ shouldn't have to touch and one for the booth so they can turn their monitors up if they cant hear themselves. Which brings me to my question. Why do DJ's keep turning up the volume so much? Is it because they cant hear whats going on because they either have poor monitoring or none at all?

Sad-Mans-Burd

11-07-2006, 11:31 PM

They do already. Called a booth Monitor. Thay got their own nob too! :)

Lost-in-Trance

10-10-2007, 12:42 PM

Originally posted by djowns
Good levels are key :) (hence why I hate pioneers)

True. Vestex does a good job with level displays

TProphet

11-22-2007, 05:23 PM

All very good advice. I've posted some of my own in this thread (http://www.nwtekno.org/vb/showthread.php?s=&postid=2030971#post2030971), so please check it out!

Sophistik

03-14-2008, 03:38 PM

Yeah no joke. The redlining mixers and dials at 3-4 oclock are teh sucks. I thought the thread title was funny though. "ATTN Audio Engineers..." Are they really engineers if they don't understand that clipping is bad joo joo? DJs though I see do this all the time, we've all done it before I guess. Just say no to clipping signals!

whenyournex2me

02-23-2009, 04:20 PM

it only makes sence to give an amplifier a clean but strong signal. anyone who doesnt understand should step away... and let the people that do understand either teach them or let htem mix.

if you area clipper, stay the suck away from my equipment!

hey maxx, i have an interesting article on the rms and peak power rating on amplifiers.... i will cut and paste in a pm to you, you can sticky it along with this bud. people should know... all the ins and outs.... the more you know, the more you can teach others. dont be a dick... just a teacher.

peace

deformaty

02-23-2009, 09:55 PM

NOFACE-OCHO

09-11-2009, 12:10 PM

Good levels are key :) (hence why I hate pioneers)

amen to that!

Lost-in-Trance

09-11-2009, 03:44 PM

amen to that!

FUCK pioneers

that said, I have one lol

but i dont like it

bgrade

09-11-2009, 07:05 PM

Haha! I am rocking that same boat. Fucking piece of crap DJM500... that I can't afford to replace with something better.

D-Massive

06-02-2010, 02:05 PM

good levels are a must

hellnegative

06-10-2010, 10:24 AM

Good post. As a tech, I enjoyed seeing this! ;)

knobcore

06-16-2010, 01:15 AM

keone

06-17-2010, 10:30 PM

knobcore

06-18-2010, 02:29 AM

It seems like there is alot of confusion when it comes to this subject...It also relates to ground signal interfaces, or that annoying hum which is present even when all your connections appear to be "grounded".

here is a basic tutorial which does a good job of explaining the difference:

http://www.djtechtools.com/2010/05/23/know-your-connections-dj-essentials/

Using proper cables can minimize signal impedence and reduce noise along the signal path. The dynamic range of an entire system can be no better than it's weakest link.

Using a shielded cables creates a grounded signal path helps to reduce noise voltage that eminates from the power chassis and reduces output impedence, which is one reason why DJ's seem to want to crank up the levels into the red when in fact the problem lies in the connection itself and not in the hardware.

Yeah, that's always a good thing but in most cases xlr outs or DIs are used everywhere so I don't generally think it's an issue. Clipped signals usually come from lack of audio engineering skill in either not knowing what level to set it at, or by the engineer of failing to use floor monitors so the DJ can't even hear anything but the reflections and bass.

If your mixer only has RCA out you might as well just buy a DI box for yourself. Hell, you might as well just buy one if you don't have XLR out anyways, they are not that expensive.

http://www.sweetwater.com/store/detail/CleanBoxPro

vinyltap

06-18-2010, 06:45 PM

You guys are only technically right. But the simple reason most dj's clip out the mixer is because they are not educated enough to know red lights are bad:mad:. And a lot of them think if they are louder than the other dj's, that the crowd will think they rock harder! But once they start clipping the mixer, I just turn them down on my board, so they jack it up more, and so on till you can hear the girl dancing next to you fart. I tell all the dj's as they get ready for their set, exactly that. If they keep their levels good, as a profesional dj should, I'll give it all she's got captain. But alot of dj's just use a mixer like a home stereo, turn up all frequncies, gains and trims thinking "hell it's not my gear, fuck it". The weakest link in the system is most often the dj.

As for the humming it can be alot of things or combinations of things, but usualy overlooked is the ground loop problems that can arise from not having proper power distibution. Balanced or not if you have ground loops, you will likely have a buzz(and sometimes it's just the venues power that will have ground issues). But basically if you clip the mixer while you play, you shouldn't be playing out, and if you let your system run clipped you shouldn't be doing sound.

knobcore

06-19-2010, 11:58 AM

TyCast

07-10-2010, 02:44 PM

I've seen the clipping/distortion from too much wattage, or too much bass just on my little Stanton cheap mixer (not a Dj, just a hobbyist, scratching turntables and random mixing).

It seems that its always the bassline.

The technique that I use is called the "The First-Row Flicker". (I made it up)

Basically, I watch the UV output levels (shown in LED's, 3 rows of green for Good, 2 rows of Red for too loud) during the tracks play. I watch specifically the first red LED row for when the bassline/kick hits.

If the first row of red LED's "Flickers" when the bass/kick hits, then its the perfect output level.

If the first row of red LED's is solid and lit during the bassline/kick, then I know I either have to turn down the bass, or the Master volume.

Is this the proper way to prevent clipping/distortion?

Also, I know to NEVER turn up the EQ-gain for the "Lows" on my mixer. I usually have to turn it down actually, especially when mixing between 2 tracks. Have to turn it WAY down for mixing 2 bass-heavy Hip-Hop tracks, but I'm sure you guys alreay knew that. ; D

I'm sure you can get clipping with highs, but I've yet to see it on my little home stereo system. Its always the bass/low freq that do it.

Let me know...
~[8] TyCast [8]~

sea.envy

07-11-2010, 08:53 AM

TyCast

07-12-2010, 03:52 AM

im not even going to bother reading this thread, if your shit is clipping then turn it down and go get better gear at your next earliest convinced or stop complaining please. it's lie buying a vw bug (ols skool style) and wondering why you can't go faster than 67mph. its cause you only have 90hp in your motor, go get something faster. *duhs*

So, what you are saying by your bug metaphor is that older mixers tend to clip more, and the new "faster" ones, do not and have a clean output.

Hmmm...never thought about that. Well, I think its time to upgrade my Stanton Mixer...maybe i'll get a Nice Numark this time.

Age matters
~ T y C a ~

knobcore

10-06-2010, 04:46 AM

So, what you are saying by your bug metaphor is that older mixers tend to clip more, and the new "faster" ones, do not and have a clean output.

Hmmm...never thought about that. Well, I think its time to upgrade my Stanton Mixer...maybe i'll get a Nice Numark this time.

Age matters
~ T y C a ~

Actually it's the other way around. You can generally push more juice with the old stuff because it was all analogue. The new ones are all digital, so you're done at 0 dBfs. In a complete analogue world (all tube), you'll blow speakers from the loudness before you even start clipping, and all you really get is harmonic distortion at best. That's why people value tube amps so much. As for solid state stuff SSL strips have an enormous amount of gain staging, so they can also take fairly hot signals. Most allen and heath analogue boards have a maximum output of +5 dBu before clipping as well.

My main reason for explaining this, is that it's a valid argument but the science is misguided. The best thing to do in any situation is just leave it at -3 or -4 dBu. That way, there is at least 5-6 dB worth of headroom for the house engineer to play with, it's usually what their limiters are set at anyways, and generally the amplification on a house console is many times better than the amplification on a standard DJ mixer.

TyCast

10-07-2010, 02:07 PM

OK, so analog is actually better than digital, in terms of preventing clipping.

So, I had a couple questions (excuse me for my lack of knowledge on this subject).

You mentioned that analog has the unit of "dBu" and digital has the units of "dBfs".

Whats the difference between the two? And why is the clipping "limit" different for analog & digital mixers?

Also, how do you know if a mixer is analog or digital? Is it the output signal, meaning if its analog it outputs to analog and digital outputs in a digital signal?

I know some mixers say "8-bit D/A conversion Digital Mixer" or whatever, but could some modern mixers appear analog but are in fact digital?

One more important, fundamental question that confuses me till today: I notice on my mixer that there is a specific value of 0 dB then +4, +6, +8 dB above that, and of course -20, -40, -60 dB below it. What is that 0dB refering to?

I read on this technical, in-depth, somewhat confusing website about sound Decibels (dB) (http://www.phys.unsw.edu.au/jw/dB.html), that the "0 dB" value represents the "reference level".

What is the reference level of "0 dB" on mixers pertaining to? Is it related to what a analog speaker can handle in terms of voltage or power?

- - - - - -- -- -- --- - -- - -

Lastly, I heard you talk about "headroom" for the house console (which I assume is the main amp that powers the main powered speakers/monitor speakers), and that it should be in the -3 to -4 dBu.

I like to keep a "headroom" of about -6 to -8 dBu, but for mixing channels (so I don't clip during mixing of 2 tracks). Is that too low?

Should I just be more careful with mixing tracks of different loudness while *still* keeping it in that golden -3 to -4 dBu pre-amp output range?

That seems to be my biggest challenge for just mixing at home (aka I'm not a real Dj), I usually clip during mixing. Alternatively, I'm afraid of the clip, so it comes out not loud enough.

Thanks for clarifying my previous statement knobcore,
- TC

knobcore

10-11-2010, 02:43 AM

OK, so analog is actually better than digital, in terms of preventing clipping.

Yes, though some cheap analog equipment is made out of integrated circuits and doesn't have as much oomph as some of the higher end stuff so it will clip easier. Still, it's normally at least a few dB higher threshold than digital systems and especially true for professional mixing/audio equipment.

So, I had a couple questions (excuse me for my lack of knowledge on this subject).

You mentioned that analog has the unit of "dBu" and digital has the units of "dBfs".

Whats the difference between the two? And why is the clipping "limit" different for analog & digital mixers?

dBu is a measurement relative to a certain voltage, 0.7746 volts to be exact, which is 0 dBu. It's normally used on consoles and in audio engineering because it's a fast way of measuring to 1 dBv which is equal to one volt. There is also dBm for measurement, but that's by milliwatt so it would be a real chore to do the math at that scale.

dBfs is a measurement which means "decibel full scale". It's basically the measurement describing the maximum output a signal can have before clipping. In analogue equipment, it varies from console to console but on a digital system it's always at 0, or just around one volt. It's used to describe the max amplitude of a digital audio signal mostly obviously because of the limitations, but you can also calculate the full scale unit on anything using a tone generator, a professional voltmeter and a calculator. If you wish to get into the mathematics, you can play around with it here to get the hang of it, it's pretty simple actually: http://www.sengpielaudio.com/calculator-db-volt.htm

Also, how do you know if a mixer is analog or digital? Is it the output signal, meaning if its analog it outputs to analog and digital outputs in a digital signal?

It's getting harder to tell now, because so much of it is hybrid. Also ICs have just about the same limitations as digital systems because they can't be put under as much stress before they distort the signal. There's a reason why a professional channel strip still weighs twenty pounds and takes up more space than a basic integrated circuit pre, and that's because the stuff on a chip (like stuff used in behringer/audio interfaces) barely meet specification. When microphones come into the picture, it's even worse.

I know some mixers say "8-bit D/A conversion Digital Mixer" or whatever, but could some modern mixers appear analog but are in fact digital?

Yes, and the digital ones are also cheaper to make so we're going to find a lot of them out there from here on out. In fact, 24 bit has around as much headroom as a decent console has gain, so they about level out now but 16 bit is still all over the place, and it's really tiresome but that's the way it is.

One more important, fundamental question that confuses me till today: I notice on my mixer that there is a specific value of 0 dB then +4, +6, +8 dB above that, and of course -20, -40, -60 dB below it. What is that 0dB refering to?

Just like above, 0 dB is around .775 volts.

I read on this technical, in-depth, somewhat confusing website about sound Decibels (dB) (http://www.phys.unsw.edu.au/jw/dB.html), that the "0 dB" value represents the "reference level".

What is the reference level of "0 dB" on mixers pertaining to? Is it related to what a analog speaker can handle in terms of voltage or power?

It's considered a reference level because it's a set standard that everyone has to at least meet for their equipment to pass a fairly accurate signal. Also 0 dB is usually what many things like signal to noise ratio, etc are measured relative to. Most gear can go higher than that though and for recording, the hotter you can get it without bringing in noise or unwanted artifacts the more you can do with the recording overall when you're mixing. It will generally be different all of the time for different sources like say microphones vs a cd player, and that's what engineers call "gain staging". If everything was blasting at 0 dB all of the time, it wouldn't sound as balanced as things playing at different volumes, or even maybe you want to pick up a certain microphone more than the other, etc.
- - - - - -- -- -- --- - -- - -

Lastly, I heard you talk about "headroom" for the house console (which I assume is the main amp that powers the main powered speakers/monitor speakers), and that it should be in the -3 to -4 dBu.

I like to keep a "headroom" of about -6 to -8 dBu, but for mixing channels (so I don't clip during mixing of 2 tracks). Is that too low?

No, not too low but -4 to -6 would be a better option. You start to get a noisy signal when you drop below around -10 dB. If your tracks are clipping because they are at different volumes, a compressor/limiter would be a wise choice.

Should I just be more careful with mixing tracks of different loudness while *still* keeping it in that golden -3 to -4 dBu pre-amp output range?

That seems to be my biggest challenge for just mixing at home (aka I'm not a real Dj), I usually clip during mixing. Alternatively, I'm afraid of the clip, so it comes out not loud enough.

I'm not sure what exactly you're using so I can't make any recommendations for gear or whatever, but a limiter usually takes care of those issues and they also tend to function as a great set of meters to tell you when you need to turn it down without clipping. It will limit the signal and keep your overall loudness in your set if you do happen to stumble upon a track that's too loud. It also tends to make for a more professional set (which is why most DJs like unmastered tracks/vinyl rather than the CD because the CD is usually squashed all the way to 0 dBfs already.)

TyCast

10-13-2010, 08:37 PM

knobcore

10-14-2010, 07:13 AM

Wow, that is quite the answer knobcore!

That was way more elaborate answer than I was expecting.

Thanks for informing me on all this technical audio stuff!

To recap some of the things I learned....

So volts are easier to measure than watts, which is why "dBu" is used.

"0 dBu" = about 0.78 volts

Thats interesting about the hybrid mixers, being both digital and analog. I guess the only way to really know is to look at the technical specs in the manual, I'm assuming.

And to my understanding from your response, "gain staging" is adjusting the Gain of a source to be equal to the other sources coming into a mixer (i.e. a CD player source and a turntable source), so everything is at the right level.

So you recommend getting a compressor. Is that common for Dj's? And by using a compressor, does it effect the sound quality at all? Or does it just make all the frequencies (low-to-high) louder without clipping?

I found your last line quite interesting...

"It also tends to make for a more professional set (which is why most DJs like unmastered tracks/vinyl rather than the CD because the CD is usually squashed all the way to 0 dBfs already.)"

...and brings me to my last question:

So unmastered tracks/vinyls (and by "unmastered", I assume you mean tracks that have not been compressed across the entire frequency range using a compressor) are better because they have not been "squashed" (which I assume means compressed) and therefore are easier to prevent clipping?

In my personal experience of using some unmastered tracks, it seems like it clips more because certain frequencies are much louder than others and have short-lasting high peaks that my desktop mixer doesn't always pick up, therefore leaving to specific moments of clipping.

Do I have it backwards?

Thanks again for your answers,
- TC

Well, CDs can be hard limited all the way up to -10 dB, and it doesn't sound as good on really bass heavy speakers (or anything really) because there are no dynamics to speak of.. Instead of a "boom boom boom" you'd get a "wahh wahh wahh" or something of the sort because the dynamics are so completely squashed.

Vinyl usually isn't like that as much because of the medium involved. Instead of dealing with the limitations of 0 dBfs, they're dealing with the limitations of what you can put in grooves so they have to be more accurate with the volume itself. In fact, the "modern" mastering process can make vinyls sound quieter because the cutting lathe needs some of the quieter parts to round out the grooves and besides a heavy/busy groove puts so much strain on your lathe and needles.

That's one of the bigger benefits for DJs because you're not over-compressing an over-compressed signal. That way you can just sit the limiter at -3 to -6 dB and leave it. You also have more flexibility if you need it.

Also, gain staging is actually not really about signal equality but about how loud you want your source to be, and also to prevent clipping, noise from preamps, and all sorts of other things. How loud you can turn the gain up before these things happen is different for every console or mixer, and different for every sound source as well. However, in your case at the very basics that use of the term would suffice since you're running decks.

vinyltap

12-13-2010, 02:55 PM

Have we covered signal alignment and proper phasing(or rather the right time to reverse phase)? I've noticed a couple of systems at recent parties that seem to be lacking for these reasons. They are very important to the proper sound, that these systems should be capable of.

I also feel it may be of importance to explain the differences in high frequency drivers, more specifically why piezo's have no place in any quality sound system, and especially not one of Portlands largest systems(and recently, most booked).

Jizosh

12-13-2010, 03:00 PM

Those would both need to be in a different thread. Signal phase is a far more advanced concept than clipping audio signals, and totally unrelated. Likewise for anything about speaker drivers.

vinyltap

12-13-2010, 03:03 PM

Those would both need to be in a different thread. Signal phase is a far more advanced concept than clipping audio signals, and totally unrelated. Likewise for anything about speaker drivers.

Can't we just have an all encompassing Pro Audio facts/tips type thread?

Jizosh

12-13-2010, 03:25 PM

Sure. Start one up.

portlandproduct

07-20-2011, 10:24 AM

FYI it means absolutely nothing when a 600 is in the red. It can be in the red and outputting absolutly nothing, or be in the green and be way beyond clipping. This is due to the attenuator upon the back. There's more to a mixer, and voltage, than red just being bad... although thats exactly what it should mean and unfortunately for some reason the industry standard is that it does not. Also, the clipping everyone here describes, mostly pertains to a digital medium. Many cables (well, balanced cables) can handle +4dbu's before clipping, and can handle high voltage amounts.

What I want to know, is if a low pass filter elimantes clipping to some extent, and just sort of creates silent pauses. A clipped signal is in essence 0hz (DC power). Therefore, does a low pass filter completely remove it?

Yes, I was wondering if anyone would mention this. The trim knob on the back of the pioneer mixers is often wrongly adjusted. It is meant to accommodate a number of different decks, and other input devices. Generally when I am plugging a DJ into my system, or reconfiguring my own system, I adjust the trim knob with one of the mains turned around so that I can listen for distortion, and use a test track that is obscenely loud. I can hit 132 db continuously in the green, so am generally able to run a show at -6db across the board. On other sound systems, your trim knob WILL NOT CHANGE unless you change your input device (I.E decks), you will then turn up or down your master accordingly and staying below 0 - not in the red, not in the yellow.

I don't know the answer to the low pass filter, but I'm going to try it out today! That is a fascinating concept. I suspect that in reality a clipped signal is infinity, rather than 0hz, as zero hertz would manifest itself as a constant voltage with no periodicity. I think a low pass filter is looking for the period only, and cannot see the voltage. If it works, you should be able to plug a multimeter into the back of your driverack or crossover and watch the voltage drop to zero while a clipped signal is being sent in with the low pass filter on. This would avoid risking equipment, amp, drivers, etc.