[sdiy] semi ot: loud speaker for synths

[Czech Martin]

well, this is really on topic, because you finally need
a loudspeaker in order to hear your synth.
Ok, you can use headphones, but not all the time.

You can use these cheap "hifi" boxes from the mall, but you will notice
that the synth bass attack will cause serious problems, or even
break the speaker. The tweeters can suffer, too, but this is a question
of bandwidth and filter steepness.
Synths can make sinoidal waves with full blast, which are very dangerous
for speaker chassis. Mechanical instruments tend to make a lot
of harmonics , with some exceptions like church organ...

I have still 8 12" woofers in the cellar. Now I made the
Thiele/Small measurments: 

Fs=25Hz
Qts=0.42
VAS=180 dm^3 (!!!)

uuuppps, I did not expect them to be that "soft".
Well, a closed box turns out to have a 43Hz corner, and 94 liters
volume, that is a cube of (45 cm)^3. 
A vented box will have about double that volume 190 litres!!!
I planed to have 4 of them
in parallel, in order to have low distortion sub bass...
The spouse acceptance criteria seems not to be met...


mmmmmucho disappointment after all this measurment work...

During my experiments I learned that only 5mm piston movement
is allowed , because otherwise the action becomes non linear
and noisy. So, displacement limits are very soon hit with
very little amp power. Power efficiency is no problem.

Could I deliberately design a "wrong" enclosure, much too
small and repair the resonance and missing low end via
electronic means?


m.c.