Kokopelli

Having problems with my amp cutting out when the volume starts to go up. Amp is 4 x 40 watts rms hooked up to 2 6 1/2's and 2 6x9's, its wired with 10 gauge monster cable (about 17' run) with a 30 amp inline fuse to a known good battery, grounded to the common ground behind my dash but only used 12 gauge as ran out of 10. The speakers connected to my head unit (4x18 watts rms) will continue to play when the amp cuts out. If I install a 1 farad stiffening capacitor by the amp will it help? Amp also cuts out when opening engine hatch. Don't understand what is going on here, friends boats have much larger amps with no trouble. Any ideas?

HyperBaja

I have the same problem, except when the sub/smp hits, i can watch the lights on the head unit cut out.

Through everyone Ive talked to, we dont have the power to support it. A cap will bandaid the problem, and not actually fix it. Need a second battery.

I plan on getting an Optima yellow top next time I go to the boat store.

Tommy

mcollinstn

Do not use a shared ground. Run a dedicated ground for your amp.

My first thought was overtemp due to low impedance, but if your amp is a 4x40 then each amp section should be loaded properly with your current setup.

(just for kicks, check to make sure you aren't running the amp "strapped" into a 2x80 mode or something).

Anyhow, you can use a multitester to watch the voltage at the amp all the way up until it kicks out. Shouldn't drop below 12 "ish".

Back the the overtemp, make sure your amp is located where it can receive ample cooling airflow. Also make sure it is mounted where air can flow properly into one end of the unit and out the top. Heat is usually what kicks out an amp and lack of airflow, drop in voltage, low impedance load, and running into heavy clipping (waveform distortion) are what create heat in an amp.

zahndok

For 17 Ft. you probably ought to be running more like # 4 wire for power imho.
Too much voltage drop over that distance under a load. Usually two good batts.

born2burn

You need to shorten up the distance between your amp and batt with a designated batt for the stereo system with isolator. A cap will help store energy for when the bass hits on peaks, it will also let your system play longer before you have to start the engine to recharge. You need a better ground as well.

Audiofn

Run your ground back to your battery, forget about the cap as it will not help in a system of your size, 10 ga wire is boarderline for that kind of power and length of run so if you are going to replace the ground you may as well go and get 8 ga for the ground and maybe even upgrad your power to 8 ga. You ground should always be as large if not larger then your power.

Jon

Kokopelli

Thanks for the replys. Heat is not my problem as the amp is located on a bulkhead in the cabin with good circulation and will cut out immediatly before there has been any chance to build up heat. I do have 2 good batteries and I've tried running the power off of just one and off of both (at the batt. selector switch) and it makes no difference. Running a larger ground back to the battery sounds like the best idea but will be a *****, I installed the power before I had a new interior installed while the boat was stripped down...Oh well live and learn. I know the cap is a band-aid but wouldn't it help with my dancing volt meter and dimming nav & dash lights?

ChrisK

The ground sounds like it is your problem as john stated. I would also make sure it is larger than you think you need. 2 8ga. runs sounds like what you need. If the lights are dimming and the volt meter dancin, it may also be due to the size of your power and ground wires. I would first upgrade them, then see what happens... You may find that the other issues go away also.

Audiofn

I highly doubt that a cap is going to help with any of your problems.

Jon

HyperBaja

Today on mine.... Moved the amp from under the pass side of dash to right by the engine compartment. About 7 feet of wire instead of 12. Helped a lot. Before, 15 was about the cutoff point, and that was with the engine on and above 1200. 19 in the driveway, with the engine off, then it started to rain, will be interesting to see tomorrow on the water.

Also ran a ground strait to the amp same 8 gauge wire.

So in my experience, equal size power/ground, ground for just the amp, and then moving the amp closer to the battery helped.