WTB - Plate amp for subwoofer project

DollarDave

Anyone have a plate amp laying around in the 150 - 300 watt range?

Now that I scored an HSU (from schwarc) and "get" the benefits to my HT, I am starting a DIY sub for the kid's tv room. I just grabbed an SVS driver (from dipiazza) in the flea market to get things started.

I would prefer Bash, but I don't know the differences so with a little education I could be persuaded toward another brand...

burdette

For the kids' room? Parts Express carries some well-respected plate amps. I've been using their 250w amp for about 4 years with nary a problem, and I used their 1000w amp for a church-sub project last year.

I see they now have some BASH amps - $130 for 300W....

http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&CATID=43&ObjectGroup_ID=505&CFID=3780220&CFTOKEN=53600210

And, outstanding customer service... and a great forum for DIY questions.

DollarDave

anonymouse wrote:

I have a 100W Jensen amp which you can have for $50 shipped.

I'll strongly consider that, do you think that will be enough to push a 12" SVS ISD? I know that somewhat depends on the box size that I build - I estimate that will be about 18x22x24. That tv room is relatively small like 14 X 15.

DollarDave

I like the sonotube idea and my local Home Depot carries it. The trick was mounting an internal amp. You have a good solution to that problem. I would think that I could go either 16" or 18" sonotube and about 27" - 33" tall. I'll do the math to get at least 6 cu ft of volume. Is the cross-over inherent to the external amp?

tryrrthg

DaveMuell wrote:

I like the sonotube idea and my local Home Depot carries it. The trick was mounting an internal amp. You have a good solution to that problem. I would think that I could go either 16" or 18" sonotube and about 27" - 33" tall. I'll do the math to get at least 6 cu ft of volume. Is the cross-over inherent to the external amp?

If you're building a ported sub don't forget to subtract the volume of the port from the internal volume of the sonosub. I'm pretty sure the entire port is "seen" as a solid cylinder, so subtract all of the ports volume, not just the tube itself.

So you're tube will likely be a lot bigger than 33" to get 6 cubic feet. I made a sonosub (with an old SVS ISD driver) a few years ago with 18" tube and the tube was around 31" tall to get 4 cubic feet or so.

here is a handy little tool:

http://www.quux.net/roo/diy/sonosub/sonocalc.html

DollarDave

Thanks for the help and the link!

What should my target cu ft be? Maybe 6 is over-kill? Is 4 sufficient? I am obviously a novice so any help is greatly appreciated.

tryrrthg

I would just shoot for something in the same size range as SVS uses. Can't go wrong that way. Obviously you'll have to do some math because I don't think they'll give you too much info on enclosure volumes, etc.

If the ISD driver is anything like the one I had, I would shoot for something in the 5 cubic feet range with this single 4" flared port - use the full length port when you get it.

DollarDave

I meant the Jensen external amp - does it have a cross-over built in? Tell me more about the connection options, etc.

Like you said, this may be the way to go to start with.

schwarcw

Dave,

I like the Crown amps. Check Audiogon, eBay or the online retailers. Get a lot of power, at least 500W to make that ISD or 12.1 sing. Like anomouse said "high power, lower distortion"

Of course, for the kids room, this may be overkill. And the bass boom from their Xbox may kill you!

burdette

I built a sonosub - 16" tube, just over 5ft3 internal volume (net the driver, port, etc). I used a plate amp, but it is in a separate outboard box. I just use about 3' of speaker wire from the amp's outputs to the sub.

I doubt a single 4" port will work - if I remember correctly, all the box calculators I used redlined a single 4". I used a single 6" port.

If you can't get the T/S parameters for the driver, then try to duplicate a manufacturer's volume/port as closely as possible. SOME drivers are forgiving on design - some, not so much.

If you want to chit chat about this, let me know. My sub turned out GREAT - flat to around 15Hz, and it was fun to build.

DollarDave

anonymouse wrote:

Yes. Its a regular plate amp. It has a crossover, low and speaker level inputs. Do you want me to unearth it in the cave and take a hard look?

That would be great. Or if you shoot me the model number, I can google it.

DollarDave

Bump. Received my SVS driver, but still need an amp.

DollarDave

One more bump for a BASH before I buy the Jenson...

fireshoes

I have a plate amp of some kind in my basement. I'll check in the morning to see what it is. It's from partsexpress.com.

DollarDave

anonymouse wrote:

So do you want the Jensen?

I haven't ruled it out, I just haven't built my box yet. Still secretly hoping for for one to come up with a little more power.