Capacitor identification?

[Ed Valvo]

I have some Polk 3.5" dash speakers that came with a capacitor on the positive side. I was thinking of trying these in my dash. A buddy gave them to me. Anyone know how I can figure out what low frequency they prevent from going through the speaker? There is some numbers on the cap but I'm not sure what they mean.

 

[mcss383]

if it doesn't say, then you will need a meter that will give capacitance.

As far as the freq of the cutoff, search around on www.partsexpress.com in their catalog they have a chart that shows what value gives what cutoff, I would assume their website would have it too.

 

[TURBOV6]

What color is the cap? Micro farad (uf) is whats read in caps. There is also a voltage ratting. Is the 3.5 a dual cone or coax? I don't recall Polk ever giving a cap with there speakers unless its a coax and its for the tweeter.

 

[Ed Valvo]

The cap didn't come with the speakers. It was added. It was aftermarket, probably from some local shop or Crutchfield. Thanks MCSS. I'll try to see if the numbers make sense. I'll advise!

 

[TURBOV6]

There is company that make bass blockers thats consealed. Normally I use a 50-100 microfard for 3.5".

 

[Ed Valvo]

OK, here is whats on it:

PAC
9.9 MFD 10%
100 WV

NP
85 C
812

In English please?

 

[Rayk]

Originally posted by Ed Valvo
OK, here is whats on it:

PAC
9.9 MFD 10%
100 WV

NP
85 C
812

In English please?

9.9 MFD will give you a crossover frequency of 4000HZ which makes those speakes act like tweeters. That's OK if you have good mid range speakers in the doors and want the dash to only reporduce the real highs. If your Polk speakers are full range and you want to lower the crossover point, you can put in larger caps. For example, 100 MFD caps will give you a crossover point of 400 HZ which will make the Polks full range and still protect them from the real low frequencies. Here's a site you can go to to calculate different values for the frequency you want.

http://www.the12volt.com/caraudio/crosscalc.asp

 

[Rayk]

By the way, here is what the info on the cap means:

PAC This is probably the brand name
9.9 MFD 10% 9.9 Microfarad with a 10% tolerence
100 WV The maximum voltage that can be applied

NP Non Polorized - No positive or negative lead
85 C Maximum temperature for stable operation
812 Don't know what this means

 

[Ed Valvo]

Thanks Ray!