Subwoofer help.........

[amperex]

I am building a 40-watt DIY amp & speakers for my son. I am using Ribbon tweeters, Peerless 6" HDS series midranges that plays to 80 Hz.

The issue is a good 12" subwoofer that sounds clear to 80Hz. I tried Peerless 12" XLS, vintage JBL D-120, vintage Tru-Sonics '150's & a few cheap Cerwin Vega speakers

All the above are muddy sounding in proper designed cabinets. On the other hand, my 7" Scan Speak speakers that perform well to about 32 Hz are ultra clear, fast & precise in the bass registers. My DIY amps only have 12-watts output & a 40-watt amp would be bad news with a small 7" speaker.

Any advice is wholeheartly welcomed.

[richie00boy]

I'm surprised you had problems with the sound of the XLS12. I'd suggest that you may have an implementation problem, with your filter and EQ settings, etc. What amp/how much power were you using to drive the sub?

There may also be a positioning issue.

Also, what do you think is a proper designed box? Please give details

[amperex]

correctly sized enclosure of 1" thick MDF & Peerless tuned passive radiator. 250 watt Class A plate amps. I assembled a pair of these from a kit that used theil small parameters.

In the accuracy department, the 7" Scan-Speaks ate these Peerless for lunch tone wise. Of course, the bass is at moderate volumes with the SS, the Peerless could rattle the windows.

The difference is I can hear fingers rub on bass strings, pipe organs vs electronic organs, etc.

The Peerless just push air, the SS delicately controls that air.

BTW- Speakers are modified Pro Ac 2.5 Response with best quality crossovers & these x-overs have a ladder type crossover for a new Seas tweeter. The SS D8513s are not as good as many state. Additionally, the SS midrange has that small peak at 850hz addressed as well. After this tuning, the stock 2.5s are not pleasing any longer.

[chainenoble]

check this one out.very nice tight bass-i'm very pleased with mine.
vifa MA26WR09-04 10"


.http://www.madisound.com/cgi-bin/ind....9126&pid=1808

[richie00boy]

We still need to know more details about the enclosure and filters etc before we can really help you

[amperex]

I can't remember all the design details. The plate amps has variable crossover & variable phase shift. The non-vented nclosures were about 2-1/2 square feet volume with a center brace & lined with 1" sound absorbing material. I believe the passive radiator had 650 grams weight for tuning.

BTW- too bad that Vifa 10" was not available in a 12".

[richie00boy]

Thanks, that's enough to go on. Do you mean 2.5 cu ft volume or the sub was approx 2.5 x 2.5 x 2.5 ft?

[amperex]

Yes. I believe a ultra light cone 12" speaker is fast with accuracy. Again, I wish Vifa made a 12" version. I find the high-end Focal bass speakers at $350 to $400 too expensive. Perhaps Focal has a 4-ohm automobile type speaker that is less expensive. I should have stated the tweeter & mid are 4-ohm.

[chainenoble]

how low do you want to go? maybe a quality 12 woofer in a sealed box, rather than a sub will suit you better

[richie00boy]

You may simply be finding that now you have very deep bass it seems to slow the sound down. This is often an integration issue. I'm sure you can get great sound with the stuff you already have.

Try moving the sub around and see if that helps. Also play with the crossover frequency, level and phase controls. Also, please give us details of the partnering speaker you have built, they may well be the cause of what you are experiencing.