Originally Posted by 440HzMusic
Also Jobsworth, a clipped signal can certainly damage speakers. If a signal actually clips at amplifier end, it causes a square wave to be sent to the drivers. This causes the drivers to move back and forth from maximum excursion, which can cause tearing and worse.
It's only a problem if the power amplifiers are being clipped, basically it does not matter how hard he pushes his mixer if he does not clip the power amps he will not blow the speakers...
Assuming that the amplifiers are properly matched to the loudspeakers, if you attenuate the level going to the amps so that the signal level never goes beyond 'green' the DJ could play in red all night and never blow anything.
I've noticed that this problem never seem to come up when purpose built DJ systems are installed in dance clubs
by specialists. It's usually when regular PA guys/companies are asked to install or rent systems for a DJ that these situations come up and this is simply because the PA world does not really understand (and sometimes they also don't respect) the DJ/club world.
Many years ago I got a guided tour to check out the systems of two NYC clubs the Tunnel and Limelight...the Tunnel's main room system had enough EAW KF 850 tops and subs to easily cover 20,000 fans in a normal outdoor concert. I think there were over 30 tops and 30 subs plus additional SB 1000 subs for good measure plus there were smaller boxes covering the bar and various nooks and crannies. I was told the capacity in the main room was either five or seven thousand and when I looked at the wall of amplifiers powering the system at full tilt, all the amplifiers had a single green LED that was lazily blinking...the system was not stressed at all. It was loud to the point of being concussive but it was clean and nobody complained.
I'm not suggesting that every bar or club run out and get a similar system...this just underlines the point that it is
a question of headroom, we can even argue that the DJ's are unreasonable in their expectation of how powerful the system should be, but it really is just a question of headroom...especially low frequency headroom. A system might have 'headroom for days' for a regular rock and roll band and would never satisfy the needs of a band like The Prodigy.
As the technical director (stage, backline, lights, sound and video) of a festival in the south west of france which welcomes more than 90,000 fans, the sound contract for the DJ stage will go to a specialist company. The difference in the proposals I have received from the specialists and the general PA companies is telling, The gear is standard fare for the most part it's just the amount of loudspeakers and amplifiers and the absence of line arrays (from the dance specialists that) make the big difference. I do not condone the willful destruction of property and equipment by anyone (band or DJ), but I also believe that promoters owe it to performers to provide the right equipment and facilities to allow them to do their best job.
If DJ's can't play above a certain level (for whatever reason) maybe that should be stated in the contract.