Capacitor Question

[the727kid 10+ year member]

How do I figure out what amount of microfards will give me a 63hz xover point?

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[jdawg 5,000+ posts]

depends on the resistance

 

[mtlhead 10+ year member]

oh wow

we actually have a good question about capacitors!!!

COOKIE FOR YOU!

 

[mtlhead 10+ year member]

i get 631.5 @ 4 ohms @ 6dB per octave

 

[the727kid 10+ year member]

It is an 8 ohm load, and how do you figure this? I appreciate the #, but it does me no good in the future if I don't know how to figure out my self, ya know?

 

[mtlhead 10+ year member]

the formula is:

1,000,000/(6.283 x Impedance x Crossover Frequency)

^ for a 6db/octave slope

for a 12 db multiply that number by .707

for an 18 db slope multiply the first number by 1.33

24 db multiply it by .667

 

[mtlhead 10+ year member]

so for your 8 ohm load

you would need a 315.79293 microfarad capacitor for a 6db/octave slope

12 = 223.2656 mf

18 = 420.0046 mf

 

[mtlhead 10+ year member]

also is this a hpf or a lpf?

im assuming hpf

 

[mtlhead 10+ year member]

keep in mind if you want a 12 or more db slope you'll need coils as well

and if its a hpf the cap will be in series with the speaker and the coil will be parallel

if its a lpf, the coil will be in series and the cap will be in parallel

 

[the727kid 10+ year member]

Appreciate it very much //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[jdawg 5,000+ posts]

here is some reading http://www.carstereo.com/help/Articles.cfm