| # Speaker Project # Subwoofer Listening Tests and Summary

> > > I had a few more steps before calling the subwoofer finished.

> > > 1) I filled the interior of the speaker with AcoustaStuff. I had a bunch lying around from the last speaker project and I really like it. It doesn't settle like Dacron and it works perhaps better. If you don't want to spend the money for it, just use Dacron fill or something similar (long fiber wool is excellent but it does settle and bugs can get in it if the speaker is not sealed (i.e. a ported design).

> > > 2) I used duct tape to tape over the female screw-keepers used to screw the driver and amp to the enclosure. This helps with the air-seal and stops the keepers from jumping out if you push the screw too hard when unscrewing.

> > > 3) I used duct tape to tape some cheesecloth over the amp (to help with air flow in case the stuffing shifts during movement of the speaker) and to keep some distance between the subwoofer driver and the stuffing - again in case of shifting during movement.

> > > I then retested the speaker acoustic response and verified a slight improvement due to the larger volume.

> > > That's it. After that I hooked the subwoofer up to my main stereo in the living room (which I rarely listen to). I spent about 45 minutes tuning the subwoofer crossover frequency and level and then I listened to some test CD's. It was truly amazing. I have an excellent stereo (Adcom high-end preamp, Acurus 200 WPC amp, Pioneer 65 CD player) hooked up to the subwoofer and my old computer speakers (2 vifa drivers per speaker). If you read Speaker Builder these speakers are pretty much the ones I wrote up as Computer Speakers a couple of years ago - except I have an external crossover rather than internal.

> > > Anyway, I recently went speaker listening with my customer and we listened to a number of mid-high-end speakers (about $1000-$2500 each) and these little computer speakers (at about $50/each) and the subwoofer together just blew the speakers away! I started laughing as I listened to one of our test CDs - with my eyes closed the sound was excellent - and noticeably better than anything we heard on our listening trip.

> > > Finally, I would prefer a lower Q sonically, but the requisite volume for a .7 Q was way out of line both from a wood-building standpoint and from a "room to put it" standpoint. Otherwise the sound is great.

> > > That's it....

> > > On to the main speakers.

> > > On to the next page.

> > > last updated September 03, 2000