nickrolando

I installed a subwoofer/amp in my friends car last week.

He has a a single 12" JBL GTO1204D (Dual 4-ohm) and a Alpine MRP-M500 Amplifier.

The subwoofer is wired to a final impedance of 2-ohm.

The headunit is a Kenwood.

The problem that is happening is if the radio is turned up past like 32 volume after the subwoofer hits a few music notes, it turns itself off but the AMP DOES NOT TURN OFF, IT STAYS ON

If the volume is not turned up past 32 everything in his car is extremely low in general but putting past 32 is blasting it, just making it decently loud enough.

Wire is 8ga, which in my experience is definitely enough for the alpine amp.

The only way to get the sub to come back on is by turning the car off and then back on.

Any ideas would be greatly appreciated.

Please let me know.

-Nick

JustaBuustedD17

Ok, What exactly are you referring to as it? The stereo turns off?

My thoughts are that there are wires that are touching...They could be speaker wires...I know mine goes into a "protect mode" if speaker wires ever touch. The volume thing is a little odd...make sure you don't have the RC wires crossed up. Make sure it is white to white and red to red

....The amp staying on could be your "remote" wire for your amp...If it is any other wire as a remote wire the amp will stay on as long as the remote wire is powered...I chose the ignition wire off the back of the stereo as mine...or you can use the one for the Cigarette lighter...


Let me know if this helps...

MDB...

civic0427

Turn the gains down on the amp and see if that helps. Sounds like your either over heating it or drawing too much power. I bet that will work. Also make sure your power and ground are the same gauge wire. Hope this helps.

TiggerDX

iTrader: (1)

Sounds like a short in the sub or the wiring to the sub. The amp will not overheat that quickly. Rewire the sub to an 8 ohm load and see if the amp will still shut down.

As an FYI, the sub cannot shut itself off. (Unless you have some type of electronic sub) Subs are passive devices that require an external device to drive them.
Although the amp is powered on, it sounds like it is going into protect mode. There are only a few reasons that it would do that, that quickly. Power wire too small. 8 ga should be OK. Not ideal. (Sub amps should always have at least 4 ga.)
Wire to sub too small. Short in wiring to sub or in the sub. Short in the amp.

If you are saying there is a massive volume difference between 31 and 32, there is a problem there. Your volume control should provide a fairly continuous increase in volume as you turn it up.
Are the speakers powered by the head unit or an amp?

nickrolando

It seems that sub woofer was bad. Replaced it with the same model sub woofer and it seems to be working fine now!

JustaBuustedD17

Wierd!!!

nickrolando

The thing is the Alpine Amplifier blue light stayed lit up and it did'nt get hot at all before sub shut off

TiggerDX

iTrader: (1)

When an amp goes into protect mode, it is not shutting off power to itself, it is shutting off power to the sub. So the light will stay on. And as I said, it takes a few minutes for an amp to get hot enough to go into protect mode. In this case, when you pushed the power, the wires moved in the sub causing a short. The amp saw the spike in resistance and shut down power output to protect itself.

Kennykid2002

iTrader: (1)

Well, if the amp goes into protect mode, usually there would be a light change on the amp.
This happens on my Sony Xplod amp I used to have, green light would turn red.

It could be that the sub had a damaged voice coil.

Just make sure to tune the amp correctly
https://www.civicforums.com/forums/3...-tutorial.html

mike98

Tigger, i have the same exact problem except that i am already running a single 8 ohm sub with the alpine mrp m500. Do you think that a damaged 8 ohm sub could cause this to happen?

Thanks,
Mike

GolNat

iTrader: (7)

It's either what tigger said, bad sub, or wiring. It could also be that you are over driving the sub and it is clipping but probably not with that amp and an 8ohm sub.

TiggerDX

iTrader: (1)

If your amp is shutting off power to the sub but still on, it is either a bad sub, bad wiring or you are over driving the sub. Rarely will it ever be the amp (but it does happen)
See if you can find someone with a sub you can borrow. See if you have the same problem. That is the fastest way to isolate the problem.

steady

I'm going to use this to see if anybody has a clue for my part because i have the same problem in my truck.its a 10 konaki hooked up to what I believe is a mono 450 watt amp.it didn't start until about a week ago.at different times at different volumes the sub cuts out and plays and cuts out every second at various levels.before, I could play it as loud as I wanted and now it's doing this.the first thing I did was check the amp while it was doing it to see if the amp was cutting off.it wasnt.then I checked the speaker wires to the amp, the box, and in side the box to the sub.wiggled things around to see if it made a difference and nothing.to check and see if it was the sub itself I hooked up a 12 to it and played it and it did it for a the first 20-30 seconds and then I didn't have any problems even at loud volumes.what makes me unsure is that sometimes the 10 will play at decent levels like the 12 did with no problem but not very often.the only thing I haven't looked at is the connections in the back of the radio because that's troubleshooting that will take the most work and time.

TiggerDX

iTrader: (1)

If it did it with the second sub, then you have a signal issue. That could be anywhere from the head unit to the sub.
You need to find the situations where you can readily duplicate the issue. Is it a certain frequency? Are you driving or stopped?
Start with the simple things. Check the connectors at the sub. RCAs do go bad, or become loose. Replace the wire to the sub with heavier gauge.
Put a volt meter on the output side of the amp and see if voltage to the sub is being cut when it happens (eliminates the sub as the cause) then keep working backwards. Make sure power and signal wires aren't being pinched somewhere. Work your way to the head unit.