revs drop periodically when sub/amp on (even when vol. muted), VIDEO

**euromandeluxe** · 20-12-2010 12:51 AM

So I've found that if I have my sub and amp hooked up to my system when it's on the car's electricals (and idle) go whack, every few seconds the revs drop, lights dim, etc for a second, then go back to normal.

This is even with the volume muted so i don't think its because of large current draws causing a voltage drop.

If I disconnect the amp's remote turn-on wire, or if the system is off, everything's fine.

watch the vid closely (revs dip everytime lights dim):

what's going on? the setup was all working fine for 4 months and now this has suddenly happened. grounds are ok, connections clean, new battery, fuses seem to be fine? I don't see any reason for the alternator to be bad, had it tested recently.

ideas? car is totally fine otherwise.

**GaDgeT-CRX** · 20-12-2010 09:38 AM

thats a tricky 1 bro... muting volume wont do anything, the remote on from the HU powers the amp..

Does look like some kinda voltage drop, which can be tested by hookin up a multimeter to the battery, test. Then do the same with the power and earth connections on the amp, to see whether there is any loss between the 2 points.

How many watts is your amp? What gauge wires are you running? Where is your earthing point for the amp (is it too long, is it touching bare metal)?

**euromandeluxe** · 20-12-2010 02:36 PM

Originally Posted by GaDgeT-CRX

thats a tricky 1 bro... muting volume wont do anything, the remote on from the HU powers the amp..

Does look like some kinda voltage drop, which can be tested by hookin up a multimeter to the battery, test. Then do the same with the power and earth connections on the amp, to see whether there is any loss between the 2 points.

How many watts is your amp? What gauge wires are you running? Where is your earthing point for the amp (is it too long, is it touching bare metal)?

thanks for the reply

I mentioned the mute thing because I didn't want to make it look like the voltage was dropping when the bass hit or anything, volume (and I guess current draw) don't make a difference..

the volts do drop across the battery terminals when the lights dim/revs drop, from 14+ to around 12+, but they climb straight back up again. I should mention the lights dim periodically when the amp's on when the engine is off too.

haven't checked voltage between power and ground while amp is on, but with car off it reads normal (same as battery, 12.6V or something).

ground wire is short and goes to bare metal (sanded off the paint). what baffles me is it was working fine for months prior.. any other ideas?

**GaDgeT-CRX** · 20-12-2010 02:47 PM

Only thing I can think of with the info provided, is that the battery is not pushing enough power to the amp (as indicated by dimming lights).. Either caused by battery on the way out, or not having sufficient current draw via power cables to the amp.. How old is current battery? What gauge wires are you running to the amp (and watts being drawn)?

**arverson** · 20-12-2010 05:10 PM

didnt we go thru this already?

http://www.ozhonda.com/forum/showthr...d-system-is-on

**euromandeluxe** · 20-12-2010 06:05 PM

You're right, I had that thread posted a few months ago when the issue first began. Back then I didn't realize the problem was localized to the sub amp/sub - thought perhaps it had to do with the headunit, or the splits and their 2ch amp (180W RMS for the 2ch). Ive reposted as I now know the battery and alternator are definitely fine. I also haven't had time to follow it up.

Battery has been replaced since then (around 2 months ago) with a bigger batt with no resolution.

Wires are at least 8Ga if not 4.

Will check power specs later today.

I've never heard of voltage variation like this before.

**ICACHA** · 20-12-2010 06:28 PM

www.bcae1.com

do yourself a favour and do some reading on how everything works.

**arverson** · 20-12-2010 11:07 PM

if everything you've mentioned is fine then that points the finger at the sub & amp. sounds like a faulty amp. hopefully not but see if you can try with another amp in its place. just to eliminate & see if the amp/s are at fault.

what amp/s have you got? what subs? how are the subs connected to the amp?

otherwise take it to a specialist and they'll be able to troubleshoot it quickly for ya.

**ej20i** · 22-12-2010 06:02 AM

Its your power wire. what brand have u got?
if you got cheapies then thats your problem
go for something like kicker or street wires
solved my problem just by using different power wires

**SRVTIR** · 22-12-2010 07:00 AM

You need a capacitor. This will stock the spikes mate..

**euromandeluxe** · 23-12-2010 06:20 PM

Power wire is just the standard stuff from Jaycar.

I thought a capacitor was needed for when you get dimming etc when bass hits hard (and the amps are drawing peak power).

**euromandeluxe** · 24-12-2010 03:28 PM

Thanks for the helpful replies. Looks like a bad amp.

First I tried re-grounding by sanding a spot of paint/self tapping screw. Same problem. Then I swapped over the power and ground wires from the amp with those from my other amp (which has been working fine). The wire gauges and fuses are identical. Same problem again. This points the finger at the amp, yes? The fuses in the amp itself are fine too.

What can I do about this, is it really time for a new amp? This one's barely 18 months old.