Amp Problems. Need Help.

[GS70350]

Hey guys. I am trying to run an amplifier to my radio which has some RCA preouts. I didnt have any RCA cable to begin with, so i used some RCA plugs and some coaxial cable and made my own. pluged it in, and then hooked up the amp like ive done in other cars. the only thing that changed was that I didnt use real cable which I tried to make. the cable is like TV cable. when I hook it up to some 6x9s to test it out, it doesnt play at all. it just makes this very very very high pitched squeal that peirces your ears. What could cause this?? I tried it again today and it didnt do anything. no sound, no squeal. no nothing. are these crapy homeade cables the problem?? or is there a problem with the amp? the power light comes on. it seems to work. I also would like to know how if im running it correctly for a sub. I ran the two coax cables from the preouts on the radio to the low input RCA plugs on the amp. I left the high input off because I dont have any wires to go to those and I dont want to try and run treble through my sub. so I thought the low stood for low frequency. am I correct?? and what do I do with the output wires since its a 2 way amp. do I connect them and make it mono? or do I just use one since im only using a single 10 inch sub??
thanks a bunch
sorry if these are stupid questions

[Audiowizard]

Jacob,
before ruling out the cables being bad get a DVM and test for continuity between the + and - of your connections, if you have continuity between the + an - then there is part of your problem. Could be a bad connection, wont know until you test them. You want continuity from each end of cable from + to + and - to -.

I personally would go to Radioshack and get a very cheap set of pre-amp cables already made up, I have never had one from there be bad yet.

Not sure what kind of amp that is and how old it is but of it says low on the input jack then it is to feed the amp with signal so it can play through your subs at a lower crossover point.

If the amp is bridgable make sure that it is stable in 4 or 2 ohm configuration and hook up the subs according to their impedence, very important. If you go below the amps rated stability, you can burn up an amp very quickly.

Dont worry, they are not stupid questions .

[GS70350]

Hey. Its a radio Shack Optimus 100 watt 2 way amp. I guess since you use the radio shack stuff often, you may know if these amps are any good. I checked for the continuity with my DVM and it has continuity(spl.). So the amp is giving off power and stuff to the right wires. there is cont. between the (-)s and the (+)s off the amp. is this what I was supposed to see??
now I guess the only thing left is the homeade wires. I will go buy some radio shack ones next time im at the mall here. thanks for the help