Author Topic: DISTRIBUTED AUDIO POWER AMP SYSTEM VS. SINGLE VERY LARGE AUDIO POWER AMP SYSTEM (Read 1936 times)

TinTopHack · « **on:** August 06, 2009, 11:00:26 AM »

Nowadays, there many who offer and there are many who buy high power amps with power capabilities of 1000W or more. While these things may look and sound impressive, they cost a lot because they are using a lot of customized components especially in the power supply section.

Personally I prefer the distributed approach to an audio power amp system where in smaller relatively low power amps (say 400W to 500W each) are working together to create a high power system. I see several advantages with the distributed approach over the single large power amp system:
1. In a large power amp system, a failure will put you in a zero situation unless you have a spare. While in a distributed system a failure in one will not stop your operation completely.
2. In a large power amp system, a spare will be very costly. In a distributed power amp system a spare will not cost so much and it is easier to create redundant systems.
3. In a large power amp system the stress is concentrated on that one big system while in a distributed system the stress is spread out so the overall system reliability is higher.
4. In a distributed system you have the flexibility to control the sound level in each area of coverage. In a large power amp system this is not possible.

The idea of distributed systems is not new. It is already used in power supply systems of large power hungry installations. For example, a Cray super computer is using distributed power supply system so that a failure in one section will not shut the whole thing down. In telecom installations it is the same setup. You can see a lot of hot-pluggable power supplies working together to supply a building full of telecom hardware.

What do you guys think?

Philippine Electronics Forum · « **on:** August 06, 2009, 11:00:26 AM »

Woots29 · « **Reply #1 on:** August 06, 2009, 12:19:03 PM »

i prefer distributed

i had previous setups with that technique

even the amplifer is not high power, it gives balanced

sound levels to the crowd

Philippine Electronics Forum · « **Reply #1 on:** August 06, 2009, 12:19:03 PM »

audiomachines · « **Reply #2 on:** August 06, 2009, 03:33:07 PM »

headroom is one reason why we use "kiloamps" especially in a live sound situation, we usually triamp ,typical setup would be 300watts for the compression drivers, 600watts to 1kw on the midbass and 1kw or more on the subwoofer system. Clipping a low power amp do more damage on the driver/speakers even if the speaker is rated more than 3 times than the amplifier.

Philippine Electronics Forum · « **Reply #2 on:** August 06, 2009, 03:33:07 PM »

TinTopHack · « **Reply #3 on:** August 06, 2009, 04:13:49 PM »

Tri-amping is actually a form of distributed system.
I agree about head room. But the question is - why can we not avoid clipping a low power amp?
Is this just a matter of discipline? Can we say that if you can avoid clipping a 1000W amp, you can also avoid clipping 2 units of 500W amps or 4 units of 250W amps?

Philippine Electronics Forum · « **Reply #3 on:** August 06, 2009, 04:13:49 PM »

audiomachines · « **Reply #4 on:** August 06, 2009, 09:19:01 PM »

Well how would i put it ba, take this for example ever try playing a Blue Man Group cds on your tiny BOSE speakers? see if it would do justice to the record, We have to cope up with the "artistic expression" of the artist. A thunder should sound thunderous. The artist want you to be a part of the "experience". And that is also the reason why we have those THX certified cinemas to cope up wiith the demand of modern soundtracks of the movies.

Art pushes the technology beyond its known boundaries.

Philippine Electronics Forum · « **Reply #4 on:** August 06, 2009, 09:19:01 PM »

TinTopHack · « **Reply #5 on:** August 07, 2009, 01:52:18 AM »

Ok I think what you are trying to explain is the need for headroom so that when a loud portion of the music comes, like thunder, it comes out very loud like thunder.

Let us say, you are using a 1000W amp and you are playing this music where a certain part has a sound of the thunder. Its volume is set so that without that sound of thunder the music is only demanding 500 Watts
from the amp. So you still have a reserve of 500watts waiting to be used for the thunder sound part. Then comes the thunder sound and it so happens it only demanded an additional 400watts from the amp so that at the time when that thunder was reproduced, the amp was delivering 900 watts without clipping.

For comparison, let us say we have two 500W amps playing the same music. Their volume control is set so that without the sound of the thunder the music is demanding 250 watts from each amp. So with 250 watts from each amp, the total power delivered is 500 watts with each amp having a reserve of 250 watts waiting to be used for the thunder sound part.
Then comes the thunder sound part demanding an additonal 200 watts from each amp or 400 watts total so that at the time each amp was delivering 450 watts without clipping. Just like the first setup the 2 amps are delivering 900 watts without clipping.

Under the 2 conditions - could we say we get the same effect? (ignoring the effects of the speakers).

For me everything - headroom, clipping and power output requirements are all relative. Pushing a 1000 watt amp to clipping is as easy as pushing a 500W amp to clipping. It is just a matter of how you set level of the input signal which consequently determines the headroom you give to the amp in relation to the kind of music you are playing.

The same applies to THX certified cinemas. As we all know the dynamic range of a movie soundtrack is so wide. for example in a war movie you need to hear the whispers of two soldiers when they are crawling towards an enemy position. Since the movie theater is such a large area, you need to set the volume of the system so that even the whispers of the soldiers can be heard by the movie goers. BUT the sound of gunshots or bombs which are very loud sounds must also be reproduced without distortion or clipping. Let us say you need 300W to reproduce the whispers so that the movie goers can hear them clearly. For the gunshots and bombs let us say you need 1400W to reproduce them realistically.

This means you need a system capable of delivering at least 1500W. At this point the designer of the THX system has 2 choices - to use one big 1500W amp or to use 2 or more smaller amps working together as long as the total power delivered is at least 1500W. Whether he choose the big one or the distributed system the movie goers will never know as long as the power needed to reproduce a whisper or a gunshot or sound of a bomb is there.

I think there are a few reasons why distributed audio amps are not being pushed by the manufacturers-
1. They do not earn much from it or at least that is what their marketing people think.
2. Many customers are not aware of the advantages of distributed amps.
3. Manufacturers are caught in the competition loop where to be number one you need to have a model with the highest power output.
4. The distributed system requires more speaker boxes than the single large audio solution.
5. You need a special preamp to drive several power amps at the same time. (This can be easily made)

audiomachines · « **Reply #6 on:** August 08, 2009, 08:28:24 AM »

^ kung mobile or touring ang application ng mga amplifiers mo extra expense sa logistics, cabling and rigging pra lng mka achieve ng desired spl.Kalimitan pa nman sa mga venue open air wla kng benefit ng room gain, just the air itself.

TinTopHack · « **Reply #7 on:** August 10, 2009, 10:04:58 AM »

Agree - extra cabling and logistics. Kaya lang karamihan sa setup kawawa ang audience sa harap ng speakers dahil sobrang lakas (imagine standing 3 to 5 meters in front of a speaker box pushinh out 1000 watts of music) while yung sa side or yung malayo OK lang. While the equipment should reproduce art according to the artist's vision, it should also take into account the audience. Kaya lang dito sa atin the audience will not normally complainn - most of them do not realize the problem anyway. Or if they do their complaints do not reach the right persons to handle it.

audiomachines · « **Reply #8 on:** August 10, 2009, 01:49:58 PM »

yap kya sir pagnag stack ng speaker (usually horn loaded mids pra controlled ang dispersion) sa mga scafolding above the head na pra wag maka hurt ng audience, den my maliit na sidefill speakers para dun sa audience na malapit sa stage. Then magandang EQing ng mga speaker para di maka fatigue ng mga listener, my clarity pero non fatiguing ung sound. You cannot compensate sa lack of clarity by shear volume lng he he he I would prefer ng mga setup na around 80-90dB sa audience area then peak na mga 120 max ok na skin un tipid pa sa maintenance ng speakers at amplifiers.

TinTopHack · « **Reply #9 on:** August 10, 2009, 11:10:36 PM »

OK. Thanks for the inputs.

But I think this setup can be used with distributed amps??
Like the side fill speakers - they could be driven by a separate group of amps?
The speaker stack - same?

Siguro intial cost mahal but long term may be more cost effective? and more reliable?
More importantly an amp failure will not shut you down completely?

sicnarf_frot · « **Reply #10 on:** March 20, 2010, 01:41:24 PM »

Sir TinTopHack at audiomachines pwde makahingi sa nu nga full set up para sa sasakyan na ung labas ay parang binubogbog ka sa low bass..bigyan niyo naman ako..recommendend na amp for CAR at ung speaker diameter at wattage at kung my pre amp at crossover..kung pwde ung pinaka ganda na makatipid ako..bago pa ako dito sa electronicslab hope u will help

malamig · « **Reply #11 on:** May 30, 2010, 09:20:30 AM »

Maganda itong topic na to, sana madagdagan pa ng shares ng ibang masters....

Rene · « **Reply #12 on:** May 31, 2010, 01:43:27 AM »

Mgandang topic nga ito! Manood n lng tyo at matuto.

Philippine Electronics Forum · « **Reply #12 on:** May 31, 2010, 01:43:27 AM »

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