If the effect you are looking for is 'Dancing Lights' the SSR is not a good choice.
If you just need full on at loud passages, you need a storage device, large capacitor etc, or something like Bertus posted.
Max.

Yeah, i'll try first the envelope detector posted by Bertus. I'll post the result, Thanks Max

 

i'm figuring out the values of my R and C for the envelope detector. I'm using the subwoofer output so i'm inputting @ 150 Hz more or less or a period of 0.067 sec. Since i'm using halfwave rectifier to get my pulsating DC, my input signal will go back to zero in half that period. If my input is 12 volts max @ 150 Hz, what are the best possible combinations of R and C to keep my signal above 3 vdc so as not to repeatedly turn on and off the SSR output undesirably.

 

Hello,

You likely only need a capacitor.
The SSR load will be enough to discharge the capacitor.

Bertus

 

Hello,

You likely only need a capacitor.
The SSR load will be enough to discharge the capacitor.

Bertus

would a 22 or 47 uf capacitor suffice?

 

Hello,

You could try the capacitors and see the effect on the light.
As the SSR has an input voltage range of 3 to 32 Volts, there is likely a constant current source in the SSR.
The drawn current from the capacitor will be the current determined by this current source.

Bertus

 

Way back, Bertus did suggest that, essentially just adding an RC tom your rectifier circuit, and calling it an envelope detector, correct but confusing. Then I suggested it again in #16, not calling it an envelope detector . So please do try it and let us know, before others lead this thread into much more distant wandering. AND, sometimes the simple solutions do work quite well. And just adding the capacitor is about as simple as it gets.