High Power, Low Weight

[RevMen]

I am an acoustical engineer and I occasionally do field NR/NIC/STC tests that require producing broadband noise at a very high volume. Our current rig is a generic Peavey bass head and cab that work fine but weigh so much. I hate lugging them around to do these tests.

Yesterday, as I was loading this equipment into my car again, I resolved to investigate building my own noise source. Most of my amplifier knowledge concerns tube amps, which are absolutely the wrong choice for this application. So I have ventured into the Solid State forum seeking help.

I am hoping my solid state friends can help me identify how best to build an amplifier with the most power for the least weight. It does not need to have high fidelity, as it will only be used to blast pink noise at 105+ dBA.

I will only need a single channel if I use crossovers, but it might make sense to individually amplify the woofer with one channel and the tweeter or tweeter+mid with another. If I do use multiple amplification channels, there's no reason that I can see that they need to be the same.

Any thoughts on how best to do this?

[qusp]

well since sound quality isnt a concern, perhaps you should look into class D amps

actually i'm serious but thats pretty funny anyway in a pocket protector kind of way.
class D requires less by way of heatsinking, is generally more efficient and thus compact. you dont find so many fully diy projects though, as there are regulations for the EMI and most designs are pretty much completely SMD

[sgrossklass]

Yeah, Class D with SMPS, doesn't get much lighter than that.

Example: Peavey IPR-1600, 2x 530 W / 4 ohms, 3.3 kg. No typo. Of course the case is flimsy as hell, but it shows what's doable. Doesn't cost an arm and a leg either.

As mentioned, this is not very DIY-friendly territory though. It's fairly demanding stuff for all kinds of reasons, best bought in the form of populated boards.

[thaumaturge]

Modified class D or T class. Tripath. Old stock still available. How about 800Wx2 ?
Tripath TA0105A 800Wx2 Super Class-T Audio Amplifier - Boards | Kits | Components | Modules | Tools
Add a big lightweight SMPS and a case.
Or.... just buy something like this: (22.3lbs 2x2000W) Behringer EUROPOWER EPX4000 Power Amp: Shop Pro Audio & Other Musical Instruments | Musician's Friend

Doc

[Speedskater]

Just buy a used budget pro audio power amp with a SMPS. You can't build anything lighter. The cost of parts for a DIY amp will be more than cost of the pro amp and then there is your time and what about reliability?

[RevMen]

Originally Posted by Speedskater

Just buy a used budget pro audio power amp with a SMPS. You can't build anything lighter. The cost of parts for a DIY amp will be more than cost of the pro amp and then there is your time and what about reliability?

Makes a lot of sense.

[djk]

http://www.ebay.com/itm/BEHRINGER-IN...item2eb8aff472

Under 7 lbs, 300W/4Ω x2, $180 (delivered).

BEHRINGER INUKE NU1000 ULTRA LIGHT WEIGHT HIGH DENSITY AMPLIFIER

[null object]

Peavy actually makes super light weight amps. 1500w 7pounds.


Some models also have a built in cross over at 100hz. You could high pass one channel and low pass the other to make a two way mono amp. All in one. No other electronics needed. I think this is your best bet.


If you can tolerate Tools in suits then watch this. Anyone in a suit makes me nervous.
Peavey IPR Power Amp Series - Sweetwater - YouTube

[djk]

He only needs 105dB, so the $180 Behringer should do (1KW in bridge), it's about $100 less than the lowest priced Peavey. They both have active crossovers built in.