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Sub kicking off my RF P600.4 powering cabin speakers when moving


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I am noticing a lot of fluctuation in voltage when the sub hits (which is to be expected) but it is only when we are moving that it will kick the RF P600.4 off momentarily (literally for 1-2 seconds). I can have the boat running while we are sitting still and I have no problems... it isn't affecting my JL amp for the sub or Syn4 that I have running the Rev10s just the RF for the cabin speakers. Do I need to add a capacitor, add batteries, or wiring??? It is only happening when the volume is way up so it hasn't been too big of a problem, but on the occasion that we want it loud I don't want my cabin speakers cutting out every third or fourth bass note.

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That's understandable since the turn 'On'/Off' voltage threshold for all amplifiers is not the same. Bottom line is that the voltage is sagging when the bass transients draw down the voltage. So there is a weak link in either the voltage supply or the voltage delivery.

Forget the stiffening capacitor. It's not a solution for the duration of the problem and it definitely should be avoided on any vehicle/craft that is not a daily driver, as it can easily become a charging system liability rather than an asset.

So the suspect areas might include:

Bad connections or terminations. The voltage level may measure fine under static conditions of minimal draw until there is a considerable draw. CCA wire. Cheap terminals. Bad crimps. Corrosion. Inadequate gauge of supply wire.

Grounds. At battery(s). At engine block.

Aged battery(s). The stereo can create a load test of sorts that the battery(s) are failing. Batteries that are run too long past their useful lifespan are an excessive strain on the alternator.

Batteries that require AC shore charging because usage is beyond what the alternator can maintain. An improper charging routine can result in a noticeable performance change in your batteries in just a single season.

Alternator issue. Lose belt. You should see a marked increase in voltage level once the engine is running. The boat operations are likely to draw another 25 amps minimum.

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Ok I checked all the connections and everything looks good and tight. But I am questioning the wiring... It is 2awg wiring to a 3-out distribution box that splits to 6awg. This obviously is a pretty easy upgrade, but would I be better off running 0/1 gauge wire to a 3-out distribution box with 4awg, or just running a separate power and ground feed to the sub amp and keeping the existing wiring for the other two amps???

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Knowing that it's a new boat probably eliminates a few of the suspected causes.

Certainly the 1 into 4-gauge distribution is right for the amount of current being drawn. 2 into 6 is light even in consideration of the very short distance runs. This alone may be the solution.

If the RF amplifier is driving eight in-boat speakers, that is a big load. Running all four channels at a 2-ohm load, or lower, can challenge the amplifier's single power supply. So as a test, try temporarily eliminating half of the eight speakers on the RF amplifier, whether at the input or output, and see if the amplifier behavior changes. If the RF amplifier no longer shuts down, the cable upgrade may be the remedy, or the amplifier may have an internal issue, or you can re-connect all speaker and eliminate one output at a time, then one speaker at a time, looking for a single problematic speaker. You can also measure the DCR of each speaker looking for one that is considerably lower than the others.

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I did two things and the problem is solved. I upgraded the wiring which was really easy since even the RF splitters they have are already setup for 1awg to 4awg and added a deep cycle battery. I didn't realize until looking that my setup had two starter batteries so I went ahead and added a deep cycle battery on the #1 battery bank and everything is working great, and now we have been able to run the stereo hours at a time without draining the batteries too low to start.

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