The Quarks - M.O.S.D. Computer Speaker

[djg]

If you make the crossover small enough to fit through the woofer hole, you won't need any access besides that. There's not much going on inside these.

[robca]

If you make the crossover small enough to fit through the woofer hole, you won't need any access besides that. There's not much going on inside these.

Well, one of the inductors is pretty heavy and needs securing (screws, since any glue would not hold on the paper-like MDF), plus I like glueing everything down to avoid rattling crossover components or wires over time. Would be pretty messy to try and do it from the small midwoofer hole, so I prefer to have easier access.

More than anything I'm trying to understand what would the problem be if I were to use the speakers upside down, since that would make my plan (open back) possible

[djg]

I glued all my components to the walls. The coil I screwed to a piece of underlayment then glued that. My Quarks (Pg 11) are sealed, never to be opened again. I have had speakers 15 years old that I disassembled to sell the components. Nothing had moved at all.

You can put the crossover on a piece of thin ply small enough to go through the woofer hole and epoxy that down.

I don't care if you use them upside down, I'm just telling you that you don't need to.

It's DIY, have fun.

[Kootskid]

Hi Chris Roemer,
Could you tell me if the 0.35mH inductor is the correct value for the Dayton #20 coil you reference in the following quote. Thanks for the help,
Myles

If you look at the Quark XO, here's how I'd mod it to use the DS90-8 woofer (same box, and same vent).
The tweeter HP filter changes. Instead of a 2.7uF cap & 0.20mH coil, try a 5uF series cap (Dayton poly) and a 0.30mH shunt (to gnd) coil.
Also, for attenuation, take out the series resistor, and try an L-pad instead: 6n (ohm) series resistor, and 4n parallel.
Use a (Dayton) #20 coil, and 5w resistors would probably be OK w/a relatively low power system.
Positive polarity is indicated, but try the tweeter both ways and go with whatever sounds best to you.

The woofer needs a bit more than just the 1.0mH series coil (due to cone breakup around 8kHz).
I'd add a Zobel across the woofer: 10n resistor and 3.3uF cap.
Also run a "tiny" 0.22uF cap (027-402) across the 1mH coil. This acts like a notch (tank) filter.
You could probably go w/the "buyout" bobbin coil here (269-2124).

Fc around 3kHz, w/not much baffle-step (about +3dB).

[Chris Roemer]

I don't SEE any ref. to a 0.35mH coil in my quote.
Use #257-028 for a 0.30mH #20 coil.
If you've GOT a 0.35, may as well try it. It'll change the shape of the rolloff shoulder though.

[Kootskid]

Thanks Chris. I am unwinding an inductor, so just checking. Would you suggest a 5.6uf or 4.0uf , 100V capacitor inseries with the 0.3mH inductor?