Wehan Posted September 25, 2015 Author Report Share Posted September 25, 2015 Swap the head units over, no difference same noise. Link to comment Share on other sites More sharing options...
Deeznutz Posted September 25, 2015 Report Share Posted September 25, 2015 Than its your amp! -Frank Link to comment Share on other sites More sharing options...
Wehan Posted September 25, 2015 Author Report Share Posted September 25, 2015 Swapped in an old mtx amp and I get the same noise. Link to comment Share on other sites More sharing options...
Wehan Posted September 26, 2015 Author Report Share Posted September 26, 2015 If it makes any difference I did hot swap the rca cables at the amp but I was using different cables. Could this have damaged the amp? I'm going to grab some female to female rca adapters and hook my ipod up to the rca cables at the dash and see what happens. I can't imagine the noise is penetrating these rca cables as I have seen guys literally zip tie lesser cables directly to their power cables and have no issues. Also I have a y cable that will let me hook some headphones directly to my head unit outputs and take a listen for noise (read about this technique somewhere). Link to comment Share on other sites More sharing options...
Deeznutz Posted September 26, 2015 Report Share Posted September 26, 2015 It's odd that it only does it on the cresendo and not.the JL amp. Disconnect the speakers as mentioned before. Bring.a speaker directly.up.the crescendo and connect and see it there is a whine. If 2 amps do it, than it had to be speaker wire interference because speaker wire isn't shielded. -Frank Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted September 26, 2015 Report Share Posted September 26, 2015 Car is a 2007 Chevy Cobalt coupe. Setup Head unit: Sony DSX-S300BTX, Grounded with my amps and power from same power distro as amps. Mids/highs: Crescendo C1100.4, Polk components front, polk 6x9's rear. Lows: JL 1000/1v1, 2x Alpine Type s 12's Electrical: (+) Stock 115a alternator 5' run of 1/0 from battery (+) to distro block splitting to a 3' run of 4ga to the JL and a 6" run of 4ga to the Crescendo, 12' run of 12ga too head unit. Electrical (-) 2' run of 4ga for both amps to one bolt all paint scraped/wire wheeled off to bare shiny steel, 12' run of 12ga for head unit. 5' run of 1/0 from amp grounds to battery (-), 1' run 1/0 from alternator bracket to strut tower. All power/ground wire is Kunkonceptz OFC Rca cables: Soundrive HF 17' to crescendo and Knukonceptz Karma SS 6m to JL. What size is the charge lead going from alt positive to battery positive? I would want at least 4ga ofc for that run if I was you. I see that you scraped the metal for your amp grounds, but what metal are you speaking of? A strut tower bolt in the rear is ideal. Same side of the vehicle as your alternator ground. Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
Wehan Posted September 26, 2015 Author Report Share Posted September 26, 2015 Car is a 2007 Chevy Cobalt coupe. Setup Head unit: Sony DSX-S300BTX, Grounded with my amps and power from same power distro as amps. Mids/highs: Crescendo C1100.4, Polk components front, polk 6x9's rear. Lows: JL 1000/1v1, 2x Alpine Type s 12's Electrical: (+) Stock 115a alternator 5' run of 1/0 from battery (+) to distro block splitting to a 3' run of 4ga to the JL and a 6" run of 4ga to the Crescendo, 12' run of 12ga too head unit. Electrical (-) 2' run of 4ga for both amps to one bolt all paint scraped/wire wheeled off to bare shiny steel, 12' run of 12ga for head unit. 5' run of 1/0 from amp grounds to battery (-), 1' run 1/0 from alternator bracket to strut tower. All power/ground wire is Kunkonceptz OFC Rca cables: Soundrive HF 17' to crescendo and Knukonceptz Karma SS 6m to JL. What size is the charge lead going from alt positive to battery positive? I would want at least 4ga ofc for that run if I was you. I see that you scraped the metal for your amp grounds, but what metal are you speaking of? A strut tower bolt in the rear is ideal. Same side of the vehicle as your alternator ground. Charge lead is a stock 2ga copper wire from alternator to battery (+) The ground is at a large bolt meant for child seat restraint. Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted September 26, 2015 Report Share Posted September 26, 2015 Car is a 2007 Chevy Cobalt coupe. Setup Head unit: Sony DSX-S300BTX, Grounded with my amps and power from same power distro as amps. Mids/highs: Crescendo C1100.4, Polk components front, polk 6x9's rear. Lows: JL 1000/1v1, 2x Alpine Type s 12's Electrical: (+) Stock 115a alternator 5' run of 1/0 from battery (+) to distro block splitting to a 3' run of 4ga to the JL and a 6" run of 4ga to the Crescendo, 12' run of 12ga too head unit. Electrical (-) 2' run of 4ga for both amps to one bolt all paint scraped/wire wheeled off to bare shiny steel, 12' run of 12ga for head unit. 5' run of 1/0 from amp grounds to battery (-), 1' run 1/0 from alternator bracket to strut tower. All power/ground wire is Kunkonceptz OFC Rca cables: Soundrive HF 17' to crescendo and Knukonceptz Karma SS 6m to JL. What size is the charge lead going from alt positive to battery positive? I would want at least 4ga ofc for that run if I was you. I see that you scraped the metal for your amp grounds, but what metal are you speaking of? A strut tower bolt in the rear is ideal. Same side of the vehicle as your alternator ground. Charge lead is a stock 2ga copper wire from alternator to battery (+) The ground is at a large bolt meant for child seat restraint. If it were me, I would most likely move the ground although it's hard to tell without looking at it. And although it probably has nothing to do with your alt noise, I believe that 2ga wire is only good for about 95A at 140 degrees. Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
412Mark Posted September 26, 2015 Report Share Posted September 26, 2015 You asked me about this since I have the same car. I have no whine at all. The big thing I see different in our systems are the way you powered the radio. I don't think it is that good to have the ground for the head unit that long. Just try grounding it up by where the radio is mounted I have always heard try to keep the grounds as short as possible. I also bought the adapter that plugs into the factory harness to run an aftermarket radio so I had 12v at the radio Link to comment Share on other sites More sharing options...
412Mark Posted September 26, 2015 Report Share Posted September 26, 2015 Doubled it Link to comment Share on other sites More sharing options...
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