mikekay

RM,

That was the best analogy I've ever heard. Perfect thank you for that. Im going to 'exchange' amp today. It never did it when I bought it, and I might have gained it too much messing up this one internals. Im also going to exchange my speakers just to be safe. and that way I know im starting from scratch on everything.

Hopefully the noise will go away with the new amp.

Also another question for you audio buff's is it okay to drill holes into the chassis of my car and mount the amp there. How probable is it that + feed is shorting through the amps outside and back into the ground 18" away. you know what a mean? Not very likely right?

mikekay

I guess what im asking is whats the best mounting procedure of an amp to make sure i dont ground it out. its over a layer of that grey matty trunk stuff so the only thing touch the cassis is 2 screws which are at the mount point provided on the amp.

RomanticMoments

Good question. It will vary, depending on the deck itself (it's capabilities, rather) and the volume you regularly play at. The best way to set gains would be with an ocsilliscope, but it takes knowledge to read, let alone understand, what you're looking at. Gains can be set fairly reliably with a multimeter and a given frequency tone, but even that can be difficult, and it's not 100%. The no-tech way I have done it in the past was by having the user turn the system up to the volume they would normally listen to it to. I'd back off the gains to nothing, turn the volume a bit past what they just showed me (for headroom) and adjust the gains until I get clipping. Obviously I would back the gains off again to avoid clipping any further. It's not what I would recommend, but in a pinch, it worked well and because I had gotten the listener to set the vol, I know what they consider "cranked"

mikekay

How can I tell if my amp is clipping? is there a way to do it with a multimeter? I've done the gain that way in the past. because my amp doesn't have a clip light

RomanticMoments

Heavy clipping can be heard as distortion. You can't tell if an amp is clipping with a multimeter. There was a chart I found somewhere that helps with setting the gains with a multimeter, but I can't remember where I found it. If I do find it, I'll post it

mikekay

Actually I found the equation for it amp output*ohm-age all under a root, then take the DMM and hook it up on the amp output and try and adjust gain until you get that voltage.

Thank you for the help guys, Ill let you know if it goes away when Install my exchanged amp. Im also going to try grounding the deck as it still COULD be a ground loop.

Some people have said that the alpines dont have a very good case ground so im going to try that. Ill pop out the deck and see whats behind there even though I hate doing it because its so bloddy packed.

Tomorrow I will donate to the forum in appriciation of the support I have recieved today, and may as well get rid of 'em ad's too!

mikekay

So Guys!

Just an update...

I went and exchanged the amp I blew all my speakers because someone or me accidentatly went 2 channel mode pumping 150W across two speakers and fried the speakers im going to go exchange those too. :'(

After that if the popping still doesn't reside then its the ground and ill just play with that until I get it 100% right. Because everything else checks out fine.

Also anyone know how to test for a distoring/blown speaker with a dmm? I keep getting mixed opinions on how to test it.