Subwoofer plate amps downunder?

[Stu]

Anyone have any suggestions for a subwoofer plate amp in Australia?

I have a few in mind - Jaycar has a 600W and a 150W unit... I was thinking more along the lines of 300W, but getting the 600W might give me more headroom. One problem - the frequency response is given as 32-250 Hz, 32 Hz being much higher than I want. I don't suppose anyone knows if this can be modified?

The old 350W unit would be good, but those seem pretty hard to find these days...

There's also a Class H unit on eBay here , but the frequency response still isn't great - the roll-off seems to start around 30 Hz again (it says the -3 dB point is 19 Hz, but it also says -6 dB at 22 Hz, so there's an inconsistency there)... seems reasonable value as well.

I've heard good things about the Redgum amps, but they're a bit out of my price range.

Any other suggestions?

[Moondog55]

http://www.audiomarketplace.com.au/

But they appear to be out of stock of the O-Audio plate amp at the moment, give them a phone call and ask
Otherwise

http://oaudio.com/500W_SUBAMP.html

Looks like value for money

[Stu]

Thanks... almost seems worth shipping it straight from the U.S, though.

A$500 vs US$275 (price found at http://www.subwoofer-builder.com/amps-all.htm) -- should save about $150 at current exchange rates.

Actually, the 300W unit seems more what I'm after and that would be cheaper still. Much more expensive than the second hand Shiva I'll be using with it, but I'll take that as an excuse to upgrade later.

[Moondog55]

I'd always go for the bigger amp, not that I have any plate-amps that are not already in el-cheapo boxes.

I believe the higher price at Audio Market Place is because these O-Audio amps are not UL certified; so AM had to pay for all the electrical compliance tests, even so the new shipping cost is very reasonable and if I had the spare cash I'd probably buy a couple, cheaper than repairing my present power amp which is starting to loose output

[Ian Millar]

Some plate amplifiers allow air to chuff through the RCA and XLR sockets and around the attenuator shafts etc, so check carefully if you intend to seal your driver enclosure with one of them. I found out the hard way with a unit purchased from the Netherlands. Also if using passive radiators, I would not mount a plate amplifier on the subwoofer at all due to possible vibration-induced component failure.

[rabbitz]

These are supposed to be very good but I've never used one.

http://darcheraudio.com.au/shop/inde...products_id=82

[Stu]

Thanks, rabbitz... guess there's no reason it has to be a plate amp, and that looks like a really nice unit, but it would be stretching my budget somewhat.

Maybe a stereo amplifier would suffice in the short term (haven't even built the box yet, so I should be able to at least test it with that), though.

If it weren't for 32 Hz cut-off, I'd definitely go with the 600W Jaycar unit, might still go for it anyway and see if I can modify it.

[Moondog55]

Stu are you driving an 8R nominal load or a 4 ohm nominal?

Because Rod Elliot has a little blurb on an easy method to bridge a stereo amp for high power mono although I just use old stereo amps to drive my subs and I've never really needed more than 2 by 200 watts

http://sound.westhost.com/project14.htm

[Stu]

It's a dual 8-ohm driver... if I used a stereo amp, I'd just run one voice coil per channel (triple-checking the polarisation, of course).

[Moondog55]

I like dual 8R drivers, usually wire to 16 and run in pairs or triplets though.
Which driver is it?? What size? details !! I crave details