i think my amp is blown

[matinm90 10+ year member]

okay so right now i have two kicker (4 ohms) cvrs 12 inch subs, they are each wired in a two ohm configuration, i have a sound stream pca2-360 amp, so for i just reconfigured their load resistance a few days ago, and i know that based on reading the manual for my amp that it is designed to handle two subs rated at 2 ohms connected to the amp, but for some reason, even if there is no sound coming through the receiver, the subs just make a boom boom boom sound, i have tested the subs resistance, and they check out perfectly, end when i gently press down on them they are normal, no weird noise or anything. whats really weird, is that if i manually turn off the subwoofer output from my receiver, the subs just keep going, but if i completely disconnect the rca cables from the amp, the noise stops, im thinking its the amp, any thoughts?

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[Spooney 10+ year member]

Sounds like a bad rca shield ground somewhere along the line. If you plug the rcas into the amp and gently wiggle them does the sound change? If not do you have a multimeter?

 

[matinm90 10+ year member]

ill try that, but keep in mind that the subs just keep constantly outputting the same beat, boom boom boom, and it never stops, until i turn off the stereo which of course turns off the amp. and yes i have a multimeter. thanks for ur help in advance btw.

 

[Spooney 10+ year member]

Is the amp hooked up 2 ohms per channel or do you have the 2 subs wired at 2 ohms each hooked up to the bridged channel? I need you to be a bit more specific about the wiring of your subs.

 

[matinm90 10+ year member]

oh right sorry, so each amp is designed to be 4 ohms, but the voice coils are wired in parallel, so each sub is 2 ohms, and so, each channel on the amp receives 2 ohms from each sub. it is not bridged.

 

[Spooney 10+ year member]

Take your multimeter and set it to continuity check(amp and radio off for this test is fine) . Is there continuity between the rca shield ground(the outer ring of the rca plug) on the rca cables and the ground wire for your amp. Better yet if you can easily get to the back of your radio is there continuity between the chassis of the radio/radios ground wire and the rca shields of the radio ? In almost every head unit the rca shields and the chassis of the radio/ground wire should be connected usually through a small internal fuse. sometimes this fuse blows and causes the issue you are experiencing.

 

[matinm90 10+ year member]

okay when u say the ground wire, do u mean the main ground wire for the receiver? or the amp?

 

[05trailblazer 10+ year member]

amp/hu

 

[matinm90 10+ year member]

okay but what u were saying before that is check the ground wire for the amp and ground wire for the rca cable right? and what do u mean by continuity?

 

[05trailblazer 10+ year member]

to see if there still current going thru will the hu/amp is still on or off

 

[smgreen20 10+ year member]

In other words, a completed circuit.

 

[matinm90 10+ year member]

okay I'll try that. But do you think it would help if I connected an RCA cable from my iPhone to my amp directly to see if it's the amp or not?

 

[subzero 5,000+ posts]

go to a shop before you break something else.

 

[matinm90 10+ year member]

okay, if it is my amp, eh, oh well. cuz i was thinking about getting a new one anyway, but thanks for all the help.

 

[Spooney 10+ year member]

It would help rule out the amp. If it still does it with an Ipod connected directly to it then there is an internal problem in the amp. As far as continuity I mean you are looking for 0 ohms of resistance between the test point. I asked you to perform two test. First test take one lead of your multimeter and put it on your amps ground terminal or ground wire and take the other lead and touch the outer ring of the rca cable going into the amp. How many ohms are you getting? Second test you ate going to touch one lead to the chassis of the headunit or its main ground wire for the head unit and the other test lead will need to be touched to the outer ring of the rca outputs on the head unit. Again we are looking for 0 ohms of resistance between these points.