EH3_SOHC

ok im pretty knowledgable about car audio since ive been doing it for about 4 years, all my connections are tight and all speakers are new, i just recently got rid of my jvc deck and upgraded to an alpine that i got from cash converters, well anyway the problem is when ive got my subs turned to 15 and my radio volume is at about 22+ and im bassing everything cuts off....this is only in acc mode but still why does this happen? it never happend with my jvc...could it just be that the jvc was 50x4 and the alpine is 62x4 and needs more power to run everything, all ive got is an 800 watt mono fosgate amp and a set of eclipse 10's, and cadence components all the way around

Fabrik8

Acc mode? What is that? Engine off and running on acc position?
If it's doing it with the engine off, chances are that your voltage is dipping too low when the bass hits, and you're going below the Alpine's input voltage threshold. This could very likely be different than the JVC because it's a different brand. Your battery may be on it's way out. The difference of power that the Alpine deck draws vs your JVC deck is very small compared to the instantaneous power that the 800W amp draws. Hook a voltmeter to your battery and watch what happens when the bass hits..

EH3_SOHC

yea acc with engine off, and the batterys only like 3 months old so ill check the voltage today

Qwiksillva

Depending on the power of the bass and the continuous power, the speaker wires could be not thick enough or not good enough quality. If the wires are too weak, I have seen the headunits cut off. This is very common in my 2nd gen rx-7 because the speaker wires are thin & cheap from the factory.

Whtehnda93DXSdn

Probably drawing to much after being on ACC for to long and the amp is drawing down to low and the Alpine is cutting off becuase of the power drain more then likely. Just my $.02...

Fabrik8

Why would a thin speaker wire be a problem? An undersized wire would be higher resistance than a properly sized wire for the amount of current going through it, and a higher resistance presents less of a load to the head unit. So I'm not buying that at all. Even the small increase in inductance wouldn't bother the head. The power wires to the head unit are a different story, they could be undersized pretty easily. The voltage drop across a grossly undersized power or ground wire could possibly make the head shut off, sure. With 62x4 w peak, the head could draw upwards of 20A very briefly, which is a bit more than a 20 or 22 gauge (common sizes for stock power wires) would handle without sizeable voltage drop across it.
I don't think the speaker wires/outputs are the issue at all though, they are only 62x4 peak, so their continous (average) power is much lower than that. That's nothing compared to the 800w average rating of the amp.

EH3_SOHC

the voltage meter drops to like 10.3 volts everytime the radio cuts off, then shoots back to 14.1v when it cuts back on....that sounds weird as hell to me

Fabrik8

That's not wierd, that's the reason your head keeps turning off. Your amp is making the voltage do that.

EH3_SOHC

haha i had a feelin, would a cap stop it or would it even make a difference, i had one at one time but my alpine wasnt cutting off in that car