I just got a cheap amp for free. It's an Optimus 400W/4channel (from Radioshack).
When I went over to my local audio shop to have it installed, I was told that I'd need a capacitor ($150). Is this necessary? Any recommendations? Thanks.

 

nope you don't need a cap.

 

not necessary, but depending on the application it could enhance the performance. If you are going to bridge the amp and power subs, a cap would make the amp work less due to a reserve of power. If you are going to run mids/highs off of it, I wouldn't bother with the cap. Subs make an amp pull a lot of current, while coaxials and such do not.

One thing about that amp is that one of two things is true ... either it's power is overrated or it will be sending through a lot of distortion.

Personally i would use it as a sub amp if you don't have one, as the distortion it produces would not be as noticeable through the subs.

 

Thanks for the info! What happened is the shop refused to install it, saying it would be unsafe without a capacitor. I was planning on running 4 Nakamichi speakers and pioneer subs. I don't think its power is overrated, but I can't spend over $200 for installation with a cap or a new amp.

 

Your stock electrical system will handle 400w just fine. Ive found that about 600-700w (atleast on my 96) begins to put strain on the stock electrical system.

 

Refused to install it????

Dumba$$es ... its prob better they didn't do it as it will most likely save you a headache in the future. They were just trying to rip you and make some quick cash other than the install labor. The most that the labor should cost is $75 for the amp.

R U planning on running all those speakers off that amp? Make sure if U do the install yourself you brush up on your wiring techniques. Most likely you'll need to bridge the rear channels for the subs, and a series/paralles wiring for the 4 nak speak's.

Good luck with whatever u do ...