What size capacitors should I use for a 150Hz high pass filter for a pair of 4-ohm speakers? I understand the capacitor should fit between the + terminals of the source and speakers. What is the proper orientation of the capacitor? What is the right kind of capacitor to use? Should I buy Bass Blockers and be done with it? Seems like a lot of money for a simple cap.

Thanks,
Sixto
95 S420
87 300SDL

The formula is incredibly simple. I have them for 6db, 12db, 18db and 24db /octave roll-off passive crossovers. I used to build them all the time.

The coils for the 12db + rolloffs are the far bigger challenge than the caps. I just try to use a good quality barrel-style cap 240v is pretty typical.. generally avaialbe for under $1.00 at any Chicken Shack or good electronics supply.

I also wrote a program about 10 years ago that runs on DOS that will calculate it all for you.. just select the rolloff points and slope and viola! Now.. where i have that little floppydisk stashed is anyones guess...

I'll look up the formulas for ya and post back in a bit.

sixto,
what kind of radio do you have, most radios you can set the crossovers to block certain frequencies.
Bob

OK.. found the program.. I don't know where I put my formulas:

APC Network:
============

12db High Pass Crossover
4 ohm Speaker Load,
Selected rolloff at : 150 Hz

Capaciter value `C1' = 132.6 uF
Coil value `L1' = 8.488 mH.

I have a copy of the program I can send that does the 6db and 12db crossover calculations that I can zip up and shoot over to anyone that decided to PM me for it.

Let's see if the diagram will post..

NOPE.. I'll attach a screen shot of it.. hey.. what do you want from a program written in C for DOS that I did in 1993.

Capaciter value `C1' = 132.6 uF
Coil value `L1' = 8.488 mH

Attached Thumbnails

 

http://www.carstereo.com/help/Articles.cfm?id=1

Bob, it's a Sony CDX-MP30. I read the manual and there are no high pass settings.

Everyone, thanks for the info. Is this why I learned math?

Sixto
95 S420
87 300SDL

Who needs math when you have software engineers who write this stuff for fun (and considering how many copies of it I sold since 1993.. FREE! )

Most of this info is actualy from years as a pro audio install tech. I've keep every book and note from every notable install. Binders of the stuff...