PA power; sound system 'K'
If you went to buy a sports car, you would be looking for qualities like speed, handling and comfort, and wouldn't just go and buy the one with the highest fuel consumption, no?
So it should be with sound systems that you choose the one that is devastatingly loud, controlled and pleasing to listen to, whatever the style of music.
I am constantly being asked "great rig, how many "K" is it?" 'K' being an incorrect term for a Kw, which is a unit of electrical power consumption.
1000w electric heater uses 1 Kw of electricity. A 1000w power amplifier would allegedly use 1Kw, if it was amplifying a constant sound into the lowest impedance (maximum no. of speakers) at full volume, which never happens in the real world. Almost all amplifiers that tried, would overheat and either shut down, or explode within about 3 - 5 mins. Opus amps don't.
Then there's the power rating on speaker drivers, which (supposedly) tell you how much power a speaker can handle, not how loud it is, and certainly not how good it is at reproducing the required frquencies. And anyway, a clipped (distorted) signal being generated by any one of the electronic devices (mixers, graphic equalisers, electronic crossover amplifiers etc) will damage a speaker driver far more than 'volume'. More speakers are damaged by amplifiers that are too small than too big.
Now for a true story!
Some time ago, at an event in London, we got called in to do a small system for an upstairs "chill out" room, which we did with 4 stacks run through an ambisonic surround sound system. At the front was 1 x opus double 18" sub a side with a multi purpose opus monitor on top and the same at the rear, but with single 18" subs. Downstairs was a '20K' Electro voice system. I'll try not to slate it too much, but it wasn't very nice.
In the morning, the main rig had to leave, so we were asked if we would take our system downstairs, so the party could continue, which we did. We set up whilst the other system was still running. A bit of re-configuration put the single 18" subs on top of the double 18", to give the correct height for the monitor/top boxes , and left the other 2 monitors free for dj monitors. Total system was 6 x 400w bass cones and 2 x 500w mid/tops - less than 4'K'. The system was still warm and ready from upstairs, so we visually communicated with the guy from the other system (who was waiting to pack up), who turned his off, and we turned ours on. I'll never forget his face as his jaw hit the deck, because our sound system, a fraction of the size and half the cost of his, was CONSIDERABLY louder and in a completely different league with regards to quality.
So how come ours was louder?
Lots of reasons. Lets start at the beginning.
- His DJ mixer was being over driven (most dj's do), probably because the big system wasn't very loud, and/or his monitors weren't very loud. Opus mixers cannot be over driven, because we reconfigure the gain structure so it can't.
- His system had compressors and limiters to stop too much signal getting to the system - result = clipped (over driven) signal being compressed (squashed) and limited.
We didn't need any. - His had graphic equalisers to try and sort out the mess from the dj, and to correct any anomalies from the speakers.
We didn't need any. - His system controller (crossover) delivered a digital copy of the real thing. Our controller was pure analogue.
- His amplifiers, although all reputable brands, were made in china by companies that are now run by accountants, not engineers, who only want to know how cheap can it be built for, and how much can it be sold for.
Opus build all their own system controllers, amplifiers and speakers with NO COMPROMISE on sound quality.
The speaker cones were probably similar in efficiency, if not quality, and although he had many more of them the 'music' was now in such a state that the cones didn't quite know what to do.
Believe it or not, this is the standard way to set up large systems, everybody does it. Some have digital system controllers that have graphic equalisers and limiters built into them, some run the sound through band mixers, regularly small budget ones, to give them 'more control'. Yet more stuff to degrade the signal.
In the world of ultimate hi-fi, any tone controls, graphics etc are regularly bypassed, and the best sound is achieved by using the best sounding signal (cd player/vinyll & stylus etc) through the best sounding cables, through the best sounding amp, to the best sounding speakers. If the speakers give a flat frequency response (every note at the same volume) and a good phase response (bit more complex!) then no equalisation should be necessary. Why not do the same with sound systems???
