Updating Sound System - Uncovering Problems

DURTY1

Our new to us Express 350 has just over 100 hours on it (it's a 2008). It is in great shape, but the sound system needs an update/upgrade. In doing some of the work, we are uncovering some issues.

The system has the Clarion head unit (model #M455A), JL Audio amp (model #M6600 ), 2 speakers in cabin, 2 speakers in "dash" and 2 more on the arch (all 6.5") as well as a 10" subwoofer.

Our initial complaint is distortion when music is turned loud and then eventual shutting down of the amp. This was without running the generator and having the sound on for hours. We have begun running the generator, but no difference in performance.

Phase 1 - Complete: replace all 8 speakers with new Infinity marine speakers and subwoofer with Kicker marine sub. Sounds is a bit better, but no difference with distortion in upper volume range.

Upon opening up the wiring cabinet and reviewing wiring. A couple of very important discoveries. 

1) The JL audio amp is seeing less than 12 volts when on shorepower. As volume increases voltage dips down continually to under 9 volts!!!!!!!

2) The head unit is powering the 2 cabin speakers. On the bass beat, the head unit display dims and blinks. Eventually when cranking it very high for testing, head unit shuts down (protection from clipping it seems).

3) Amp is connected to the head unit using a y-cable and is running 2 channels for 2 speakers (at 4 ohms), 2 channels for 4 speakers (bridged at 2 ohms) and the last channel in bridged mono (4 ohms) for the sub.

First step is to get more power to the amp, possibly via another cable? Currently it is a 4 gauge power and ground ran through the wiring harness. I was thinking about pulling a 0 gauge cable straight from the battery to the amp.

Second step is to address the dimming head unit. It would be nice to upgrade it adding Bluetooth and hire voltage line level outputs. It would require replacing both remotes though (I don’t want another junk Clarion). The only option may be Kenwood, which I am happy with. I get all parts wholesale so the head unit + 2 remotes would likely be around $200.

Later phases are to add another amp and 2 speakers in cans on the arch.

Thoughts on my analysis?

 

DURTY1

That is an important thing that I want to verify. It is the stock setup, so I do believe that the power is coming from the circuit breaker panel at the aft above deck. I need to double check the routing. 

When I am checking that, is there something I should look at? I never liked circuit breakers for audio as they often cause voltage drop...

DURTY1

Yes, I agree, I would like to test for voltage drop in the system. That will be next step.

The JL Audio amp calls for a 60 amp fuse. The 3 batteries, etc. should be able to power it gracefully assuming it receives ~13 volts?

midweste

The JL M6600 can pull up to 60A of current, so you need at a minimum, 4AWG power and ground wires running directly from the house battery, and a in-line fuse rated for 65A or 70A (ANL, AGU or MAXI fuse). Larger power wire such as 2AWG or /0AWG would ensure you have enough current and the flexibility of adding another amp in the future. If the lights dim on the boat whilst running the stereo hard after the above wiring upgrade, you may want to install a car-audio rated 1 or 2 farad capacitor to supply voltage to the amp in quick bursts. Bass notes in particular draw the most current from the electrical system, and the capacitor will help out quite a bit.  (Try upgrading the new power and ground wires first!!)

Next, I would revisit the amplifiers gain settings. 

I've attached the JL M6600 manual for reference to properly adjust the amplifier gains. 

+1 on a new Bluetooth head unit. I have a Alpine UTE-52BT with RF marine remotes and love it! Kenwood is also a great choice. Look for a head unit that is CEA-2006 rated. 

Good Luck! 

-MW

trickyricky

I agree with midweste, I had to install 0awg positive and negative wires with splitters to 4awg to my two amps.  One for mids and highs (regular 6.5 speakers) and one for my sub amp.  Both my amps recommended 4awg wires to provide the proper power.  Everything sounds great, the only distortion now is things rattling in the boat, not the speakers.