Sorry for the long ass post...

So on friday i decided to get a 4 channel amp for my speakers, i got the Alpine MRP-F250. I already have a JBL BP600.1 for my sub, it delivers 600W RMS to the sub. The new alpine amp delivers 40W RMS to each speaker so 160W total. For power, I had an 8 gauge power/ground wire for the JBL amp.

I forgot to get a power kit and wanted to install the amp friday night, so using extra wire (8gauge) I had around, I just split the existing 8 gauge wire to both amps and split the ground wire for both too. So when I was done, it was time to test it out, and the problems begin.

When I put the volume past 12 on most songs, the amp would cut out, it wouldnt shut off completely. If i turned the volume down a little it came back on. However, no matter how high I put the volume the sub amp wouldnt cut out, although I've never had a problem with it. I checked and double checked EVERY connection I made or modified during the installation, everything was good, problem still there.

So saturday I got more 8 gauge wire, I decided to run a seperate power wire for each amp. I also replaced the positive battery terminal, positive wire ring terminals, and ground wire ring terminals. Each amp now has its own 8 gauge power wire and ground wire. I also sanded the grounding point a little more, and replaced the self tapping screw with a nut and bolt for a tighter connection. Time to test it... turn the volume up to 12, doesnt cut off! Then 13, 14, 15... and it cuts off WTF??

So I turned off the sub from the head unit, didnt help, disconnected the remote turn on to the sub amp so it would be off completely, didnt help. Sanded a new grounding point for the alpine amp with a nut and bolt, didnt help.

Ive had the sub amp (600W) with an 8 gauge power wire in there since a week after I got the car, and I've never had any problems with it cutting off, and the new amp is 40W x 4 so its certainly not too much for the car to handle. As far as I know the battery and alternator are fine and operate as they should.

One other thing, when the engine is off, there is no output from the alpine amp no matter what the volume is, even though the amp is on. However the sub amp works fine.

I'm truly stumped, any ideas would help, thanks!

I already posted this in the A/V forum, just thought it might get some extra attention here too.

 

are you running factory hd unit and spkrs?

 

no, its all listed in my sig.. the head unit is Alpine CDA-9847, front speakers are Alpine Type R 6.5" components, rear speakers are Alpine Type R 6x9 coaxials.

 

most likely your system needs more juice
start looking at the battery
do you have a cap?

 

dont have a cap. how could it need more juice when the 600W sub amp runs fine by itself? sub amp still runs fine when both amps are running, and with only the alpine amp on it still shuts off like its not getting enough power. I kind of eliminated the batt/alternator being the problem since its been fine for my JBL amp for almost a year.

 

I have a 760watt. Never had a prob but now I do. Battery going down the shitter. A cap should help with the extra load the second amp is creating. I would still get a cap non the less. Its like a second plate of pasta for the fat boy.

 

well even when im not running the sub amp, the alpine amp cuts off, which is only a 160W load, and if im running only the sub amp its fine. Also I would think while running both amps that the sub amp would cut off before the 4 channel amp since the sub amp uses more power..

 

then you have a problem witht eh amp
it might be defective

 

You might want to do some homework on the Alpine amp as well...it's possible that the Alpine is temporarily shutting down due to voltage drop. Some electrical components are designed to shut off when operating voltage drops too low. Your sub amp most likely doesn't have this which is why it stays on. Alpine used to advertise that their amps took advantage of the ~14 volts generated when the car was running to produce extra power when compared to the ~12 volts generated from the battery without the charging system. I wouldn't be surprised if they built in something that shuts the amp off if the voltage drops. I could be wrong, but check out their website and see what you can find out

 

Get a cap, and a 4 gauge wire kit, you're bottle necking your power.

I run 4 gauge, with 2 caps, and 2 amps

 

the reason ur sub keeps playing is because it has a bigger power demand it starts to hog up the juice from the battery and ur other amp basicly loses the power the bigger guy always wins the only way u can fix it is bigger altenator or a cap on ur sub id say a 1 farad for sub and get a .5 for the speakers but just to let u know i think the stock bose amp puts out 50 watts rms or was that max?? idk o and have u disconnected the bose amp totaly or is it still hooked up cause then thats also draining sum power

 

i run stock. Beat that. lol

 

you could be running too small of a fuse.. you need atleast a 60a fuse.. and get 4guage wire.. itll make all the difference in the world.. and make your ground as short as possible and the same guage as the input wire

 

I = :dog:

And def get a 4 gauge man, like I and wilp said, you're bottlenecking your power.

 

i would use some sort of distributor block for the power, and two seperate grounds for the amps.

 

this could also be a bad ground cuz this is what happened to me in my saturn, everybody is saying check power,i say also check the ground.(good contact)...