Stereo sounds good...until I turn on ignition.

[jimidemo]

I installed a new amp and new sub all to the same wiring that was in place. I belive it is all OEM and it is 8 gauge b+ to battery selector switch and the ground goes to battery #2. It all sounds good until I turn on the ignition. There is static in them at that point and if I activate the Taps or blower vent fan it makes the bass hit. With the engine running over last weekend it had a bad hum in the speakers off the amp. I did have all the wire bundled together and found out that was a no no. I rerouted all the wiring and still having static/bass hitting. I've looked at all the grounds and can't find any issues. Anyone have ideas? Is the 8 ga wiring not sufficient? Thanks.

[chpthril]

Is the 8 ga wiring not sufficient?

Maybe, maybe not. What is the brand/model of the new amp, what loads is it driving and whats the apx distance to the battery and switch? What amp and sub did you remove? Noises like this are rare when its just an amp swap and no new wiring.

[jimidemo]

The new amp is a Lightning Audio L-4600 1200 watt amp. It is connected to (4) 6" 150 watt RMS tower speakers, and a Kicker Comp S 300 watt RMS. I removed an old Kicker comp C 12 that was hooked up to a JL Audio e6450, unknown power. The battery and switch are at the back starboard side of boat probably 13'-15' away.

[chpthril]

With all 4 chnls running at 2 ohm, 8gs seems a little lite for a 13-15 foot run, which really equals 26-30 feet of cable. However, i dont see that being the cause of your noise. Whats the gain levels at? If this was not an issue before, then I would begin to suspect the new amp. I would double check the battery voltage at the amp and then double check the RCA connections. Maybe even get another set of RCA and just jump them from the head-unit to the amp.

[jimidemo]

I tried new RCA cables. I will check power at amp. What about one battery going out. The reason I say that is one is a year old and one is a couple years older. The noise happens with gains at all positions. Channel one and two are at 2 ohms and the bridged channel is at 4 ohms...or is this a problem. Maybe I'll throw the old amp back in and see what's up.

[chpthril]

You've bridged a 4 ohm load across 2 chnls, so in effect, each of those 2 chnls splits the 4 ohm. That comes to 2 ohm on all chnls. What is means is the amp is working at near wide open throttle all the time.

Low battery voltage can make electronics do strange stuff.

[jimidemo]

You've bridged a 4 ohm load across 2 chnls, so in effect, each of those 2 chnls splits the 4 ohm. That comes to 2 ohm on all chnls. What is means is the amp is working at near wide open throttle all the time.

Low battery voltage can make electronics do strange stuff.

Thanks for your help.

[tigetim]

Any progress?
I had a similar situation with the original equipment on mine...static like "feedback" through stereo...turned out one of the RCA input cables had loosened up..on visual inspection it looked good, but when I went through each and every wire attachement at the amp...found slightly loose one...plugged it all the way in, and it soleve that problem.

Tim

[jimidemo]

No progress. Have a 1 volt drop at amp when I activate Taps. Have 12.5v at amp. Have swapped to new RCA wires and no change. Will put old amp back and see...not today though. Maybe Wednesday.

[BlackoutATX]

I have a lot of static in my system as well. I'll be trying to address this soon. Hope you get yours figured out.

[jimidemo]

OK...Couldn't wait. Put old amp back in and all was good. Doing some research the new amp is designed to run at 14.4v and the old amp can run at either 12.5v or 14.4v.

[chpthril]

Are you basing that on one amp listing its wattage output at 14.5 and the other listing the output at both 12.5 anf 14.5? If so, thats not what it means, just simply the supply voltage at which the outputs were measured. Most amps will safely run with a supply of above 16V and most will finally cut off at about 10.5.

If voltage is the root of the noise, then its a problem with your boat, not the amp. Have you tested the voltage at the amp terminals?

[jimidemo]

Yes...12.5 volts at amp. Going to return amp....maybe got a bad one as was suggested earlier.