View Single Post
Old Jun 29, 2008 | 05:17 PM
  #211 (permalink)  
maxcichon's Avatar
maxcichon
Senior Member
Joined: Sep 2007
Posts: 8,015
Likes: 14
From: MOFN, AL, 70 miles from George
Default Re: Biggest stereo bang for the buck mod

Originally Posted by donschorr
Max,

Thanks for all of your research you have done on the caps....

I guess I didn't ask the question properly- Crutchfield rates their bass blockers at what freqency they block at.

The ones I am thinking about block at 150 MHZ...

here is a link.

http://www.crutchfield.com/App/Produ...B150A2&tp=3216

Thanks again for all of your help, I can't wait to do something to get the bass back to the sub woofers!

Don
Don,
When I did this, I was using an audio test CD and it sounded like the doors were quiet under ~ 180 hZ with 270 uF caps.

Here is another quote from a knowing person (post #25):

"Increasing the capacitance value will lower the cutoff frequency for a highpass filter and allow more bass through.

The formula for calculating the cutoff frequency is...
Fco = 1/(6.283 x R x C)

So for 220 uF capacitor and a 4 ohm speaker (I am guessing about the speaker)...
Fco = 1/(6.283 x 4 x .00022) = 181 Hz.

For a 270uF capacitor, Fco = 147 Hz."

Here's a link...
http://www.qrp.pops.net/filter1.htm

It sounded like 180 hZ . This may say something about the resistance of the speaker/sub in the xFire. Maybe 3.6 ohms under load?

After looking at the crutchfield Bass Blockers, 150's would be your best choice!

Best to you!
Max
 
Reply