Radio shuts off when volume turned up. Help.

So I'm getting everything hooked up, and tried turning up the volume. When it started to get loud, not distorting, the head unit shuts off.
My batteries are charged.
I'm thinking maybe the power wire to the deck in too small?
Could it be something with my set-up?
How big should the remote wire be from the deck to the amps?

Head Unit
JVC KD-PDR80

Speakers running off deck:
Sony XS-R1344 5.25"
Polk Audio MM651 6.5"

Amps:
Sony GTX6040 - Not running any speakers yet. Liquid Audio double cans with Polk Audio speakers are on the way.

Alpine MRP-M500 - Powering two Polk Audio DXi 10" subs.

Sounds like a dead battery, but you said they're charged.

1) Disconnect power from the amp and see if that helps.
2) Start disconnecting speakers to see if one is blown, or shorted

Does it do it almost immediately? If not, maybe the amps or HU are over heating?

Try disconnecting both of the Polk MM speakers. Most BTL source units will not tolerate a load below 4-ohms.
Make sure that the speaker positives and negatives aren't mixed between channels. If so it may still play but only to a point. Start with one speaker only and add a speaker one at a time. Wire to a problematic speaker directly thereby bypassing the boat wiring.
Run a jumper positive and ground temporarily to the battery direct. Disconnect all other non-essential wires like remote turn-on and illumination. Disconnect the RCAs to the amplifier. Just ground, accessory, memory and direct speakers.
If the amplifier has a poor ground and is pulling its ground via the RCA connection to the source unit, this could cause the issue.
Check the voltage with a multimeter at the battery and then at the radio with the meter leads connected to the radio supply and ground while the radio is under load and just before it shuts down.
This can also be caused by the accumulation of water damage. A little tuner wash inside can clean away any mineral residue thats collected on the traces. Things seem to work fine until the current increases.
That's a start and should eliminate most of the possible causes.

David
Earmark Marine

Thanks for the info.
All the speakers are brand new, along with the Alpine amp. The head unit and Sony amp were already in the boat, and the Sony isn't powering anything now.
The Sony and Polk MM speakers off the deck should be all at 4 ohm. Sony's are front left and right, Polk's are connected rear left and right.
The amps are grounded to the batteries, and I think I have 4 gauge wire for their power, and the remote wire is 10 gauge. The remote comes from the deck to amp #1, then I ran a wire from amp #1 to amp #2, kind of like a daisy chain.
I also tried selecting each battery, and both, but it was still shutting off.
I only does it when the volume is up around 14. I know that doesn't mean much, but it's fairly loud, but I can tell it's got lots more to go before it starts to distort, or push excursion levels.

I'll try disconnecting the Polk's and see if I still have the problem, then try hooking them up one at a time.
When I first installed the subs, I gave them a test run, and didn't have any problems, so I think I'm ok there.
Is there a way to test polarity with a multimeter to see if maybe I got the positives and negatives mixed up?

Am I the only one that read David's reply and went "English please?" Awesome reply, but reading that it occurred to me I'm 34 years old and just felt like an idiot reading that!

The Polk MM speakers could be less than 4 ohm per speaker, and if so, that would cause the problem.

Jordan,
Polarity wouldn't be the issue in shutting down...just sound quality. If a speaker was wired with the positive of one channel and the negative of another channel it would still play to a point and then could result in a shutdown as you describe.
The Polk MMs are 2.7 ohm while the Polk MM UMs are 4 ohm.

David
Earmark Marine

not enough current getting to the stereo, run a new wire ground and power, well thats 2 wires

Can you turn off the amp section of the head unit,so the in boat speakers have no power?If so turn the in boats off and try cranking the tower speakers and see if it still cuts out.It sounds like the head unit is cutting out to protect the speakers hooked to it.

Great, just checked the manual. Your right, the Polks are 2.7 ohm.... Who does that....

So what should I do with them? Do you think it would be safe to wire them in series off the rear head unit outputs? Would give me 5.4 ohms. Can't remember if it's left positive and right negative, or vise versa.

I've been reading about adding a resistor in series with each speaker. Sounds like a 2 ohm resistor on each one should do it, but it can also affect sounds quality, and I guess it could create more heat.
What's your thoughts?

Jordan,
Disconnect the Polks first to confirm that is your real problem before taking additional action. Resistors waste precious power so I would avoid that route since a source unit has none to spare. If the Polks are the true issue then the four in-boat speakers deserve an outboard 4-channel amplifier anyway to stay clean and keep pace with the sub(s). Keep in mind that source unit power is rated on an extremely liberal basis and the most moderate external amplifier will be a profound upgrade.

David
Earmark Marine

Thanks for your help David. It certainly was the Polks.
Disconnected them at everything was fine. I tried wiring them in series off the deck, and still no problems, great sound and plenty of volume. Ran them for a while this way and the head unit wasn't getting warm.
I think I'll try them that way and see how it goes.

Originally Posted by brett564

Am I the only one that read David's reply and went "English please?" Awesome reply, but reading that it occurred to me I'm 34 years old and just felt like an idiot reading that!

Wait until you run across a thread discussing the math involved in subwoofer enclosure design...
I made that mistake, and my head is still cocked to one side, and I'm not sure if my eyebrows are stuck like this, or what.

Actually, I have learned a lot reading here, but I now realize that after a point, it is like explaining astrophysics to your dog...I'm just not gonna get it.

Ah yes. Thiele-Small parameters. I think there is a college Phd course on them.