35W into 8ohms w. batteries - ideas?

[krilli]

Hello everybody,

I have a friend who is an electronic musician. I'm going to build a battery-powered sound-system for him, on the cheap.

The speakers I currently have in mind are the Cyburgs Viech:
http://www.jogis-roehrenbude.de/LS-B...cher/Viech.htm

This is an 8-ohm horn speaker, 96dB/W, that's supposed to hit 120dB with ~35W. Seems interesting, especially for 100 euros.

What I'd like to try, then, is to use a simple and easy battery circuit to get around 35W from an Amp4. I don't know much about batteries, but it seems that 12V batteries are common and easily available.

Aiming at low distortion, this formula, taken from the FAQ, seems to give 32-33V as a ballpark figure for 35W out of a 41Hz amp:

0.6 * 0.45 * ((32V)^2 / 8Ohm)

Is it technically possible to use a DC-DC converter to raise 12 volts from a battery to 32-33V? Easy, even?

Is it likely, in your opinion, that a cheap and effective solution can be bought readymade? Could anyone recommend some links or literature?

Thanks!

(Other ideas for a cheap, reasonably portable, battery-powered PA-like system are of course welcome! I'm not exactly an electronics expert, so maybe a lower-impedance speaker would be better, maybe for use with an Amp9 or something, if the voltage conversion could be omitted.)

[Henshouse]

I asked Jan about battery power in the support section, and he recommended two 12v SLA batteries in series to produce 24v.

[krilli]

Thanks for the heads-up.

[bikenomad]

quote:Originally posted by krilli

Is it technically possible to use a DC-DC converter to raise 12 volts from a battery to 32-33V? Easy, even?

Is it likely, in your opinion, that a cheap and effective solution can be bought readymade? Could anyone recommend some links or literature?

I'm using the AMP3 as a battery-powered system for electric bass. I currently use it with a dual-voice-coil speaker. I'm powering it with a laptop "smart battery" which is nominally 11.1V (3.7*3). Some other laptop batteries are nominally 14.8V (3.7*4) or so; these might be better for your use.

Boosting 12V to 33V would give you an additional inefficiency of maybe 20% or so. Instead of this, consider starting with a higher-voltage battery.

Some cheap Li-ion packs can be found here, along with chargers:
http://www.batteryspace.com/index.as...S&Category=878

[krilli]

I heart DIY. Thanks guys! 2x 14.8V sounds very interesting.

I'll post pictures of blown eardrums after the concert