Trying to diagnose issue with starboard cockpit speakers

[hynespa]

I have a 420 Sundancer which had been upgraded with a Fusion MS-AV750 stereo. My speakers in the cockpit are 160W Panasonic marine speakers (which I believe are original to the boat). The boat also has externally two externally powered amplifiers (one for the cockpit speakers and one for the cabin speakers).

The two cockpit speakers on the port side work fine - as does the subwoofer. The two speakers on the starboard side do not work unless I crank the volume and then there is a brief crackle ... and then they come to life and sound fine. If I turn the volume back down to a normal level they continue to work and sound normal for a while ... and then eventually fall silent again. If I repeat cranking up the volume again ... then they come back to life again ... for a while.

I thought the wiring connectors might be loose on the speakers ... but removing the speakers, sliding off the connectors, spraying with D5 and then putting them back on didn't seem to make a difference one way or another.

My thought is that the issue could be one of three things:

1) Bad speakers. However if the speakers were blown ... why would they come on at all at a higher volume and then sound fine?

2) Bad wiring. Maybe the speaker wires got corroded somehow (I sprayed the terminals with Deoxit D5)?

3) Bad amp. If it was a bad amp however - why would it only affect the starboard speakers and not the port speakers?

My next step in troubleshooting will be to take apart the salon couch (the external amps are located behind the couch) and try to bypass the existing speaker wires to see if that makes a difference. I will also try to reverse the right/left channels coming out of the amp to see if that makes a difference as well.

Anybody else come across this problem or have any other troubleshooting steps to try?

Thanks!!

 

[bahamabreisus]

Try reversing speakers on the amp. That would tell you it's the amp. Other than that, I would say the head unit is the problem.

 

[bobeast]

Your symptoms point to either a defective amp or a loose ground. I'd check for a loose ground wire where the amp gets its power. If that looks clean, swap out the amps to see if the problem follows the suspect amp.

 

[dtfeld]

What amps?? Are they original to the boat or new? I'm thinking bad amp or bad ground/wiring as well. Swap some wires around and see what follow the wire swap.

 

[LG111]

Take the RCA plugs out of the Amp. Clean the contacts and press them back on. I bet that's the issue.

 

[brewster16]

I would certainly start with speaker replacement. Those old weathered Panasonics are likely fried.

 

[blaster]

It seems anytime I blow an amp it starts with the right channel. The way it works with increased power is definitely suspect.

how old are these components?

 

[hynespa]

I really appreciate all these responses!

@brewster16 - was extremely helpful over in the 420 DA threat explaining how to remove the back of the couch to get to the amp.

@brewster16 and @LG111 - also appreciate your comments about potentially being bad speakers or dirty RCA adapters.

@bahamabreisus , @bobeast , @dtfeld and @blaster - you all suggested the amp. It turns out the Amp is original to the boat - it is a 2004 Clarion APX480M amp. When the PO upgraded the stereo to a Fusion before I bought the boat ... it looks like they kept the original Clarion amp.

@bahamabreisus suggested reversing the speakers on the amp. I did that - and sure enough it switched the problem from being with the Starboard speakers to being with the Port speakers. So that suggests a potential failing amp (@blaster even indicated that his external amp problem also started with the right channel).

I am pricing out swapping out the old Clarion external amp for a similar Fusion external amp (the MS-AM504 for $319.99). I have a question into Fusion support because the MS-AM504 instructions show 4 RCA cables coming in from the head unit (LF/RF/LR/RR) but there are three outputs for that zone from the head unit (L/R/SW). So not sure if I am supposed to run an RCA cable from the subwoofer output in the head unit to the external amp ... or just L/R outputs .. and then the subwoofer frequency is handled by the amp?

Thanks again for everybody's help on this!!

 

[Chris-380]

I really appreciate all these responses!

@brewster16 - was extremely helpful over in the 420 DA threat explaining how to remove the back of the couch to get to the amp.

@brewster16 and @LG111 - also appreciate your comments about potentially being bad speakers or dirty RCA adapters.

@bahamabreisus , @bobeast , @dtfeld and @blaster - you all suggested the amp. It turns out the Amp is original to the boat - it is a 2004 Clarion APX480M amp. When the PO upgraded the stereo to a Fusion before I bought the boat ... it looks like they kept the original Clarion amp.

@bahamabreisus suggested reversing the speakers on the amp. I did that - and sure enough it switched the problem from being with the Starboard speakers to being with the Port speakers. So that suggests a potential failing amp (@blaster even indicated that his external amp problem also started with the right channel).

I am pricing out swapping out the old Clarion external amp for a similar Fusion external amp (the MS-AM504 for $319.99). I have a question into Fusion support because the MS-AM504 instructions show 4 RCA cables coming in from the head unit (LF/RF/LR/RR) but there are three outputs for that zone from the head unit (L/R/SW). So not sure if I am supposed to run an RCA cable from the subwoofer output in the head unit to the external amp ... or just L/R outputs .. and then the subwoofer frequency is handled by the amp?

Thanks again for everybody's help on this!!

It’s always better to have a separate subwoofer channel (rca’s) imo. It will give you better control of the sub vs using the signal that is with the front or rear channels

 

[bahamabreisus]

Thanks for sharing the fix, so many come here and ask a question and are never heard from again. Glad it was easy and I was able to help.

 

[hynespa]

So I went ahead and bought Fusion MS-AM504 4-Channel 500w amp to replace the OEM Clarion APX480M amp that I believe to now be on the fritz after troublshooting. I shopped around and found the amp for $214 with free shipping from Hodges Marine.

On the original Clarion amp all the power and speaker connector were connected to the amp with ring terminals. However it appears that the Fusion amp uses thumb screws tightened with an Allen wrench:

- top view of power connection screws
- under view of power connection

Here are my questions:

• I assume I will need to snip off the original ring terminals from the power and speaker wires.
• Do I just strip down to bare wire again and then insert and tighten (the Fusion directions were not clear)?
• Or instead of bare wire do I buy banana plugs or tin the wire first with solder?

Any expert tips are welcome!

 

[Chris-380]

Over the years, I have just stripped, and pushed in/tightened, just make sure no strands get cut.

they do make a “pin terminal” that you could crimp on and clean it up, I just don’t see the need for it.