My face when the experienced DJ's levels are in the RED

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Originally Posted by kooper1980

I agree with Jester, so long as the master is all good.

Correct me if I'm wrong but the sound engineer will protect the sound system. Not saying its right cos it isn't but the speakers won't be in danger because all good venues employ a sound guy to make sure idiot DJ's don't ruin the system with their blazing hot outputs.

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I'd like to correct you ;)

If the mixer is clipping there is not much even the best soundguy can do...

All he can do is lower the volume, either at a later gain stage or by employing a limiter. Which both won't help to save the speaker from the clipped signal...

The thing is: there are two ways to destroy a speaker - physical and electric.

Physical destruction of a speaker happens when you feed a speaker with a signal that is too loud, i.e. the membrane of the speaker can't take the amplitude of the signal as it is too big. This is what can be prevented by a soundguy by lowering the volume of the signal after the mixer.


Electric destruction happens when you feed a speaker with a clipped signal. Speakers are not designed to deal with clipped signals, so they will eventually get destroyed. In fact, the danger of electric destruction is much higher than the danger of electric destruction, which is also why you always chose an amp that has more power than the speakers can nominally take (about 25% more power usually), simply because it is way more dangerous for the speakers if the amp is clipping compared to if the amp is sending out a signal that is slightly too loud for the speakers.


Btw.: the same should be true for clipping channel meters... if there is actual clipping happening in an individual channel, the signal will be compromised - you just can't 'unclip' a signal.

The argument that clipping is "ok" on induvidual channels is only true for DAWs, that (due to oversampling) have almost unlimited internal headroom so in the end you're fine as long as you don't clip the master (which still doesn't mean you sould clip your channels in your DAW.. ;)).


There is only one feasible solution here: avoid clipping at all points in the signal chain. Once you clip, you'll never be able to fix that at a later point.

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Originally Posted by TCMuc

I'd like to correct you ;)

If the mixer is clipping there is not much even the best soundguy can do...

All he can do is lower the volume, either at a later gain stage or by employing a limiter. Which both won't help to save the speaker from the clipped signal...

The thing is: there are two ways to destroy a speaker - physical and electric.

Physical destruction of a speaker happens when you feed a speaker with a signal that is too loud, i.e. the membrane of the speaker can't take the amplitude of the signal as it is too big. This is what can be prevented by a soundguy by lowering the volume of the signal after the mixer.


Electric destruction happens when you feed a speaker with a clipped signal. Speakers are not designed to deal with clipped signals, so they will eventually get destroyed. In fact, the danger of electric destruction is much higher than the danger of electric destruction, which is also why you always chose an amp that has more power than the speakers can nominally take (about 25% more power usually), simply because it is way more dangerous for the speakers if the amp is clipping compared to if the amp is sending out a signal that is slightly too loud for the speakers.


Btw.: the same should be true for clipping channel meters... if there is actual clipping happening in an individual channel, the signal will be compromised - you just can't 'unclip' a signal.

The argument that clipping is "ok" on induvidual channels is only true for DAWs, that (due to oversampling) have almost unlimited internal headroom so in the end you're fine as long as you don't clip the master (which still doesn't mean you sould clip your channels in your DAW.. ;)).


There is only one feasible solution here: avoid clipping at all points in the signal chain. Once you clip, you'll never be able to fix that at a later point.

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+1000000

In all the processors I've encountered (DBX, BSS, etc), I have never encountered a magical "un-clip" setting. <over simplified explanation > A square wave is a square wave, whether it happens at the amplifier or earlier in the chain, the speaker will (if you ignore inertia in the cone mass) essentially stop moving for a moment in time leading to an increase in thermal build up and eventually failure.<end over simplified explanation)

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Originally Posted by tekki

Hahahahahaha!

Can't even find a picture that would do justice! :)

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http://www.youtube.com/watch?v=1lHEC9d1lpA

Activating any filter on the DJM900NXS will put the levels to Red. Just want to point this out.

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Originally Posted by hrtbrkd

Activating any filter on the DJM900NXS will put the levels to Red. Just want to point this out.

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I've noticed this also with my (somewhat mid-level) Korg Zero 4. Each time I activate the high or low pass filter on an individual channel, it gets louder temporarily until it gets about half-way through the wet/dry. If the channels are at mid-gain and only hitting orange it will immediately get to the reds on the channel meter. It's annoying. I usually will end up killing a bit of the bass pre-effect to make sure it doesn't clip at all.

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Originally Posted by hrtbrkd

Activating any filter on the DJM900NXS will put the levels to Red. Just want to point this out.

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No, actually, it won't. It might flicker them to the first red if you're mainlining the last yellow, but that's just how filters work obviously.

I notice a lot of people don't fundamentally understand the gain staging on DJMs (the same types of people who use the DJM-600 as their reference for "Pioneer sound quality").

There are 3 levels of "red" on a DJM: 10, "over" and "lit up." 10 is the first red. And is a perfectly acceptable place to hold the sound, as long as you pay attention to volume fluctuations and understand your input (best to keep it on the last yellow though). "Over" is the second red, you don't want it to hit this, but the newer DJMs have more than enough headroom to allow small adventures into it without problems, just reach for your gain knob when you've got the chance. "Lit up" is the classic solid double reds, don't do this, even though you could probably get away with it if you were really careful.

/cue purists denouncing running the meters over 0 to preserve their precious .wavs over the hissing and decades old monoed club system.

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Originally Posted by rgtb

1.) square waves don't kill speakers. excess power kills speakers. a properly configured management system will prevent excess power.
2.) besides, moderate amounts of clipping do not lead to square waves anyway.
3.) nobody ITT claimed that DSP can un-do clipping. but things like expanders can mitigate the effects of it.


your aggressive tone is inappropriate. if you want to criticize what i wrote, please be specific and stay on-topic.


i suppose most people here--myself included--will agree that one should try to avoid clipping in the first place. unfortunately, clipping sometimes happens. even if a capable sound engineer is present in the venue. i've seen it happen even in good, established venues that care a lot about sound. today's technology can prevent that an amp clips. but i've yet to see the technology that makes 100% sure that a DJ mixer never clips.

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Just go to your corner, and leave your false information out of this thread. Is that aggressive enough for you?

Square wave may have been an over simplification (it's almost as if I should have somehow referenced that is was a simplified explaination :rolleyes:), a symmetrically clipped signal will cause the RMS (average) power delivered by the amplifier to the speaker to increase, therefore heat generated by the individual components is going to increase. The more you clip that signal the higher the average power delivered to the speakers, the more heat has to be dissipated by the components.

If you are smart enough to over spec the system for that particular job, you can usually depend on a good limiter (preferably per pass band) to keep that RMS voltage in a range that is safe for your system to operate. If you are one of the majority, and you decided to save a few bucks and spec out just enough or even not enough rig for the job, in this case it's not uncommon to push the system to the limit even with a perfectly devised gain structure and the margin for error becomes unsettlingly small. In bass heavy music, it's usually the subs that will go first, it just becomes a question of whether they fail thermally (voice coil over heating and either deforming so that it rubs against the rest of the motor assemble, or simply burning until it becomes an open circuit) or physically (voice coil leaving the magnetic gap and doesn't go back in, or basket separates from cone, im sure there are other ways it can happen these are just two that I've watched happen).

Did you know that the adhesive they use on speakers is flammable? I learned that while watching a DJ, we were running a VZ5000 into 4 JBL 2x18 subs in a 300 cap bar, so the rig was definitely not under spec'ed, he just kept driving the signal so hard that the subs couldn't dissipate the heat being generated. One of the drivers was recently reconed and the glue actually ignited a fire.

Tone it down peeps.

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Originally Posted by rotebass

Just go to your corner, and leave your false information out of this thread. Is that aggressive enough for you?

Square wave may have been an over simplification (it's almost as if I should have somehow referenced that is was a simplified explaination :rolleyes:), a symmetrically clipped signal will cause the RMS (average) power delivered by the amplifier to the speaker to increase, therefore heat generated by the individual components is going to increase. The more you clip that signal the higher the average power delivered to the speakers, the more heat has to be dissipated by the components.

If you are smart enough to over spec the system for that particular job, you can usually depend on a good limiter (preferably per pass band) to keep that RMS voltage in a range that is safe for your system to operate. If you are one of the majority, and you decided to save a few bucks and spec out just enough or even not enough rig for the job, in this case it's not uncommon to push the system to the limit even with a perfectly devised gain structure and the margin for error becomes unsettlingly small. In bass heavy music, it's usually the subs that will go first, it just becomes a question of whether they fail thermally (voice coil over heating and either deforming so that it rubs against the rest of the motor assemble, or simply burning until it becomes an open circuit) or physically (voice coil leaving the magnetic gap and doesn't go back in, or basket separates from cone, im sure there are other ways it can happen these are just two that I've watched happen).

Did you know that the adhesive they use on speakers is flammable? I learned that while watching a DJ, we were running a VZ5000 into 4 JBL 2x18 subs in a 300 cap bar, so the rig was definitely not under spec'ed, he just kept driving the signal so hard that the subs couldn't dissipate the heat being generated. One of the drivers was recently reconed and the glue actually ignited a fire.

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You're telling me that there wasn't a brick wall limiter in front of the amps, and that absolutely nobody was paying attention long enough for the subs to catch fire? You know how you solve your amps running too high? Turn the input gain way the Hell down. Clipping may be bad, but it alone can't turn a properly managed system into a fireball.

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Originally Posted by Shishdisma

You're telling me that there wasn't a brick wall limiter in front of the amps, and that absolutely nobody was paying attention long enough for the subs to catch fire? You know how you solve your amps running too high? Turn the input gain way the Hell down. Clipping may be bad, but it alone can't turn a properly managed system into a fireball.

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Thank the bar owner who made the decision against all recommendations that a simple stereo two way cross-over was "good enough". As far as baby sitting a rig that's not mine, I don't much care, he blew up his VZ3600 and called to rent our 5000. I just happened to stick around for a few beers and got treated to some pyrotechnics ;)