DIY Subwoofer...easy or forget it?

autoconsortium

I have Polk SDA SRS, and they are in my basement...concrete floor. Even with 800 watts a side, I still don't get the bass I want...likely due to the concrete floor absorbing much of the bass. I have an old Adcom GFA555II amp, 300 or so watts into two channels. I am handy with carpenty skills, and also with electronics, to a point. Is it feasible to make my own subwoofer, using this amp? I was thinking a couple of 10 or 12 inch subs in nice box sitting in the corner, or even making a very large coffee table/sub box. I have an adcom GTP600 pre-amp, and it has a sub RCA out jack. I would need to a way to add a gain/volume knob to this setup. Any ideas?

RuSsMaN

Is that sub out filtered? I hope it isn't, so you'll need a crossover too. Find a Paradigm X-30 for around $100 and you'll be well on your way. Loaded with features, and easy to implement.

Cheers,
Russ

gatemplin

Check out www.acoustic-visions.com Kyle probably has the biggest selection of sub drivers at the moment.

Do some searches, and find a design you like, then copy it. That's my 2 cents.

The Adcom is great for a dual voice coil driver.

And you'll probably want a least dual 12's or 15's in a big basement.

hoosier21

To answer your question, YES. You can use the subwoofer out to connect to your Adcom amp to power your subwoofer.

The Adcom GTP-600 is a surround pre/pro, It has a dedicated subwoofer output connection. The subwoofer output has a switch on the back that you can select the low pass filter IN or OUT, it is set at 100hz. And you can adjust the level of the subwoofer via the remote, and probably in the set up menu.

NOTES:

If you connect the amp/subwoofer up to the sub out and have the filter OUT, you will send a full range signal to the fronts and the subwoofer. NOT good, as you will have voices and such coming from your subwoofer.

If you connect the amp/subwoofer up to the sub out and have the filter IN, you will send only 100hz and ABOVE feq. signal to the fronts, the subwoofer out will send 100hz and below to the subwoofer. Better choice.

hoosier21

autoconsortium wrote:

I have an adcom GTP600 pre-amp, and it has a sub RCA out jack. I would need to a way to add a gain/volume knob to this setup.

Just to be clear, your Adcom will adjust the volume.

unc2701

I would go w/ what russman says- 100 hz is a bit high for my taste. Get an x-30, outlaw ICBM or for $30, you can pick up an f-mod on ebay. That Adcom will do great- it's what I've been using for my f--k around t-line subwoofer projects.

link for the F-mod:
http://cgi.ebay.com/Crossover-2-way-adjustable-NO-POWER-REQUIRED_W0QQitemZ5752581172QQcategoryZ14931QQrdZ1QQcmdZViewItem

goingganzo

ok the floor is not absorbing the bass you are just not getting the floor to shake and the tatitle responce from the sub is not there.

if you want bass i can hook you up for 550 i will hook you up with dual av15 subs a 1000 wat samson amp and a svs bass interface. this setup can hit in exses of 120db @22 hz and above. if i could still use the subs i would use the subs they are amazing sound great great responce. had to get 4 ava 18

scubamike

Hey goingganzo, what size room do you have the 4 18s in. I think 4 18s in my living room and my house would just shake apart. I've been thinking about upgrading my single 12 to an svs plus/2 or ultra/2 if I save up some more but I would still be open to building something that is at least as good. I was a carpenter for many years.

goingganzo

17 by 24 by 7 is the room size. my old setup will edge a svs ultra/2 by 3-5 db easly sound quality is super. sono is easy and so is a box sub.