WTB - Plate amp for subwoofer project

[DaveMuell]

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.

[anonymouse]

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

[DaveMuell]

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.

[anonymouse]

I have no idea what the rated power of that driver is. As always, more power means lower distortion.

There are a couple approaches you can take here. You can go with an externally mounted amp which will give you future flexibility to change it, or you can rely on a thin plate of aluminium to seal off your inch think MDF on the back and have less flexibility down the road.

If you choose the external option, this little jobber can allow you to get started at a very small outlay, and upgrade later if you want to drive it harder.

Or build a sonosub, which probably means an external amp anyways, unless you are real good with woodowork.

[DaveMuell]

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]

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

[DaveMuell]

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 (http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=268-352) - use the full length port when you get it.

[anonymouse]

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?

The plate amp has a crossover. Its a regular subwoofer amp. You would just build a small standalone box for it.

[DaveMuell]

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.

[anonymouse]

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.


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? :)

[DaveMuell]

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.

[DaveMuell]

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

[anonymouse]

Hey sorry I did not get back to you. The amp has low and speaker level inputs, and a variable crossover from 50-200 I believe.

[DaveMuell]

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

[anonymouse]

So do you want the Jensen?

[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.

[DaveMuell]

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.