Amp mounting in helm compartment AR230

[Cory]

So are you saying using the long RCA's isn't a bad idea?

 

[jcyamaharider]

It is not a bad idea, works just fine.

 

[maboat]

I'm not saying its a bad idea, I'm just saying these choices are trade-offs. It may save some money in favor of shorter power cables, but you create a situation that is more susceptible to noise and interference. Do long RCA cables work? Sure it works, but is not ideal.

I'm sure I'm not the only person who has been playing music on the boat when you suddenly hear something like "hummm click click click click click" and then one of the cell phones stored in the glove box starts ringing. The signal cables are picking up interference from the cell phone. The engines and ECU's also generate interference but you may not hear it over the running engines. Longer signal (RCA) cables are like bigger antennas that pick up more interference which then gets amplified. Yes I know they are shielded cables, but that does not make them completely immune. Its definitely worth investing in the best cables you can get for long signal runs. And if you use high-quality (and more costly) RCA cables for long runs, then the cost savings becomes much less.

Again, I'm not saying either way is right or wrong. Its that there are pros and cons each way. I just wanted to point out some of the drawbacks that aren't necessarily obvious. Its not a free tradeoff. If you have a choice in mounting locations, then its good to know all the facts to make that choice. Both ways "work" with different pros and cons.

 

[drjames1107]

I agree with @maboat . I used 1 6m RCS because I had to not because I wanted to. The other 2 I used were 1 meter long. The interference from an extended run can be annoying, and some experience it and some don't. I was lucky and my long ruin has caused no interference so far.

 

[maboat]

Actually the better amplifiers will have a buffered pass-thru so the RCA 'out' is driven by its own OP amp. It's easy enough to verify with a multimeter.

This true in many home audio systems that do not have input gain control. But do you know of a specific brand or model that has it AND ALSO is suitable for marine audio applications?

 

[Cory]

Cost isn't really the issue for me, I just like the idea of having the amps in the back, as we store all the ropes and fenders in the helm compartment and I don't want everything getting wet in there.

 

[maboat]

Cost isn't really the issue for me, I just like the idea of having the amps in the back, as we store all the ropes and fenders in the helm compartment and I don't want everything getting wet in there.

Totally understand that. My situation is the opposite, ropes and fenders and other wet thing in the back. My helm is the driest area on the boat so it gets the towels, chips, and most of the electronics.

You will be fine. Just keep your RCA runs away from the cupholders (common storage place for cell phones ) and the engines. Actually, now that I think of it. I suspect the RGB LED wiring may generate noise too so I'd avoid parallel runs with RGB cables if possible. That could be more annoying than the cell phones.

 

[Cory]

The battery compartment is my dry compartment, opposite side is the cooler, fenders and ropes in the helm and all the life jackets, towels and food goes in the head compartment.

 

[cozilla]

Might be a dumb question but is everyone running new speaker wire from the amps to the speakers or tapping into the stock wiring near the headunit?

 

[Julian]

I ran new wire from my amps, and use the existing wires from my head unit. I have 4 pairs of speakers in the boat-Bow and stern run off the HU, cabin off the 4 channel amp. I too ran RCAs to the amp in back by the batteries. My HU is by the passenger (port side) so easy to run and I've never heard any interference...and I'm anal.

 

[maboat]

I do both, depending on speaker location

 

[Cory]

I'm planning on running new speaker wires, as it will all terminate at the amps instead of the head unit now.

 

[drjames1107]

I ran ALL New Wire to each Speaker.

 

[jcyamaharider]

All the more reason why I put my amp behind the helm, I didn't have to run new speaker wire and like @maboat this is my dry area in the boat.

 

[David Analog]

This true in many home audio systems that do not have input gain control. But do you know of a specific brand or model that has it AND ALSO is suitable for marine audio applications?

Yes, a good example would be the JL Audio HD and Slash series of amplifiers. These have buffered pass-thru outputs. The output voltage will be preamp level regardless of whether you are using high level on the input. Also, the buffered outputs resist noise. If the RCA inputs and outputs are merely split internally then you have open output RCAs (when unused) that are capable of picking up radiated noise. And without a buffered pass-thru, you cannot short the unused outputs to reduce noise contamination without also shorting the inputs.

As for RF or magnetic field noise induced into the RCA cable, in decades I have rarely seen this on a correctly installed system with decent RCA cables. Generally the cause is voltage being transmitted down the RCA above ground shield as a result of a voltage potential difference between audio components. When the long RCA was shorted at the input end the noise was the same as when the RCA was eliminated, replaced, upgraded, or re-routed. So generally this is a case of misdiagnosis or poor gain setting (running wide open as if the amplifier input gains are a volume control). Now if you do stupid things like protracted side-by-side and bundled power and RCA runs or coil up excess RCA cable into a quasi antenna right next to a known source of radiated noise then you are daring noise. But it's no different than with a speaker crossover inductor or other components.

 

[woodard1983]

A little late in my response here and I don't have pics, but I mounted my amps in that same helm compartment. I mounted them to the back of the seat so that they would be further off the floor.

I just removed that seat, made an amp board that fit and marked off the holes where the seat bolts went through...mounted the amps and used the bolts from the seat to hold the amp rack in place...it's only happened a couple times, but I have gotten water in that compartment (sub moves & a heavy rain storm) so I wanted to make sure and have them off the floor as much as possible

 

[Cory]

Related question, my head unit has a single RCA plug for subwoofer, where as my sub amp has both a red and white. Do I only hook up to the white, or do I put in a "Y" and hook to both?

And if a "Y" which end do I put it on? "Y" at the head unit and run a double RCA wire, or run a single wire and "Y" at the amp?

 

[wakeformer]

Here is my AR230 amp install pic

 

[woodard1983]

reference the manual on your amp...it is possible that it will accept a mono RCA input, but if not you will need to use a splitter "y cable"

 

[David Analog]

Related question, my head unit has a single RCA plug for subwoofer, where as my sub amp has both a red and white. Do I only hook up to the white, or do I put in a "Y" and hook to both?

And if a "Y" which end do I put it on? "Y" at the head unit and run a double RCA wire, or run a single wire and "Y" at the amp?

Use a 'Y' splitter at the amplifier end. For noise rejection I like occupying both inputs, although the LP filter would probably knock it out anyway. There may also be a very slight positive difference in gain if you occupy both inputs.