Subwoofer help.........

amperex

Member
2005-02-20 1:42 pm
MI
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.
 

amperex

Member
2005-02-20 1:42 pm
MI
$1200 later........

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.
 

amperex

Member
2005-02-20 1:42 pm
MI
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".
 

amperex

Member
2005-02-20 1:42 pm
MI
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.
 
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.
 

amperex

Member
2005-02-20 1:42 pm
MI
Tnx

When the Peerless were blown away in accuracy & speed by the nwer ProAc speakers in the bass registers, I sold the subs. Room positioning at the time was a 'no brainer'.

I just do want to make the same mistake this time around. I believe a strong response to 28hz would be great. I am building 3-way speakers, but have not purchased the 12" speakers yet.

Two types of subwoofer systems exist in my mind. One is the 'thump thump' type that one can feel & the other is a highly accurate system that excels with a live performance type presentation. I prefer the 'live performance' option.