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Captain Howdy Captain Howdy is offline
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Default alpine head unit amp problem

Before running coax speakers, you need to rub the speakers down with coax wax
so that they are not so stiff and overload the amp powering them.


In article , "MOSFET"
wrote:
Did you make any alterations to your system before this started happening?

For instance, did you remove your HU for some reason and then put it back
and THEN the problem started? It's possible your HU is not getting a good
ground anymore, that might cause this problem.

The FIRST thing, however, that ran through my head is that you might have
your speakers bridged (your driving two sets of speakers with one output) so
that your HU is seeing a 2 ohm load. But you seem like the kind of guy who
knows what he's doing so I doubt you've gone and done this.

So, if I were you, the first thing I would check is the input voltage at the
HU. Make sure it is getting AT LEAST 11-12 volts. Your sub amp may be
drawing so much current that perhaps your car voltage is dropping too low.
That would CERTAINLY cause your HU to shut down it's internal amps (or shut
down completely). Check that out first with a voltmeter. If that is fine,
make sure your HU is getting a good ground.

If both of those are fine, it may be a problem with your Alpine, but as you
said, it may not matter when you go with all external amps.

MOSFET
"brianlanning" wrote in message
roups.com...
I have an alpine head unit. It's one of the cheaper ones. It's maybe
3 months old. I have it hooked up to coax speakers in the back through
the amp in the head unit. The sub rcas go to an amp and two 10s in the
trunk. I have two more amps on order to drive the coax speakers. But
I have to tolerate my problem for another week while they get here.

I used to be able to crank the system just like this and get plenty
loud. Now, it's acting like the amp is overheating and shutting down.
With all four speakers going, I can play it at a reasonably loud, but
normal listening level for maybe 5 or 10 minutes. Then it starts to
cut out. Then it goes out completely leaving only the subs going. I
can turn it off for 5 or 10 minutes, then it works again. If I fade
the speakers all the way to the front, it lasts much longer, maybe 45
minutes. But it will eventually shut down.

This is new behavior, only within the last two or three weeks. I
haven't changed anything. It worked for a couple months without ever
shutting down no matter how loud I played it. I can feel the heat sink
in the back of the hu. Sometimes it's really hot when it shuts down.
Other times, just warm. There seems to be enough airflow back there.
The heater's not on so it's not blowing on the back of the hu.

So the question is, did I hurt it somehow? I would think it would just
fail completely if I did. I guess I don't care much because I won't be
using the inboard amp after this weekend. So what's happening?

brian