Speaker Distortion after Amplifier Install

[Nitro15]

I have a unique problem related to my amplifier/ speaker setup. With the engine running, the speakers hooked up to my amplifier emit a constant "popping" sound & are heavily distorted no matter the volume. However, with the engine completely off & the electronics running solely off of battery power, the system sounds great. I have the amplifier's power & ground running directly to the battery on separate terminal bars so that they're not in direct contact with the main harnesses.

I've ruled out the RCA's going from the amplifier to the head unit & have tried a ground loop isolator with no luck. The amplifier is brand new & I only recently noticed this issue when I had my boat out for the first time this past week. Has anyone experienced something similar or have any recommendations on where to go from here? Should I re-route my grounding cable to a different location on the boat? I'm open to all suggestions. Thank you!

 

[The Bill Collector]

https://www.crutchfield.com/S-bDmo8...car/noise_suppressors_installation_guide.html

https://www.amazon.com/Isolator-BOS...t=&hvlocphy=9033267&hvtargid=pla-406644644055

 

[Skybolt]

... https://www.amazon.com/Isolator-BOS...t=&hvlocphy=9033267&hvtargid=pla-406644644055

Those work awesome! Period.

 

[Wylie_Tunes]

How was the amp tuned? Improper setting can overdrive a speaker, leading to poor performance and sound quality. There can be a 15-20 % increase in amplifier output between static battery voltage and alternator voltage.

I would look to isolate and resolve the root issue, prior to plugging up any bandaids.

 

[Nitro15]

How was the amp tuned? Improper setting can overdrive a speaker, leading to poor performance and sound quality. There can be a 15-20 % increase in amplifier output between static battery voltage and alternator voltage.

I would look to isolate and resolve the root issue, prior to plugging up any bandaids.

It's a fairly simple 4-channel amp with only gain & high pass filter settings. For the initial tuning, I followed the instructions that came with the amp. Gain settings all the way down & set the stereo to 75% max volume. Slowly increased the gain from there until I was happy with the sound without any distortion.

 

[brewster16]

I had the same problem for a long time. I tried those isolators and band aid fixes and none worked at all. I finally hired a "pro" who tuned my amps and it completely solved the problem. I didn't even know amps needed to be tuned.

 

[dtfeld]

I had a high pitched whine in my system, and I spent a year trying everything mentioned above plus. Turned out the Amp was bad and replacing it solved the problem. I assumed bad capacitors due to age.

 

[Nitro15]

I had the same problem for a long time. I tried those isolators and band aid fixes and none worked at all. I finally hired a "pro" who tuned my amps and it completely solved the problem. I didn't even know amps needed to be tuned.

I can't even imagine the relief/ joy you must've felt after getting it fixed... When you say "tuned", are there additional steps that need to be taken beyond setting the gain/ high pass filters? I'm fairly new to this & would love to learn more.

 

[Nitro15]

I had a high pitched whine in my system, and I spent a year trying everything mentioned above plus. Turned out the Amp was bad and replacing it solved the problem. I assumed bad capacitors due to age.

I hope that's not the case with mine! The amp is literally brand new, I installed it about 2 weeks ago. It works great, just not when the engine is running! Lol... I may have to return it for another one if all else fails to rule it out. I'm glad you were able to fix yours. What brand do you currently have?

 

[dtfeld]

I hope that's not the case with mine! The amp is literally brand new, I installed it about 2 weeks ago. It works great, just not when the engine is running! Lol... I may have to return it for another one if all else fails to rule it out. I'm glad you were able to fix yours. What brand do you currently have?

I bought a JL Audio. Not the cheapest, but I think in this case, you get what you pay for.

 

[Chris-380]

I hope that's not the case with mine! The amp is literally brand new, I installed it about 2 weeks ago. It works great, just not when the engine is running! Lol... I may have to return it for another one if all else fails to rule it out. I'm glad you were able to fix yours. What brand do you currently have?

Any chance your speaker wires or rca (from head unit to amp) are running near any wires associated with the engine that it’s inducing noise.
I have used higher quality ($$$$) rca’s (shielded) to eliminate noise in the past…

 

[brewster16]

Unless you are a glutton for lots of trial and errors and throwing money away on cheap quick attempts to solve your audio problem....call in a marine electronics guy. I know nothing about amp tuning but I watched them resetting things and all the noise was gone when they were done. After that it's been full rich clean sound, including the sub-woofer ever since.

 

[Nitro15]

Any chance your speaker wires or rca (from head unit to amp) are running near any wires associated with the engine that it’s inducing noise.
I have used higher quality ($$$$) rca’s (shielded) to eliminate noise in the past…

Hey Chris, I'm sure they're near some wires associated with the engine. All of the wiring for the amp is behind the dash near the main panel. I did my best to keep everything separate & have played with moving the wires around to minimize contact... I thought it may have been the RCA's too but I unplugged them from both the amp/ stereo & the noise is still present. Right now I'm leaning towards a bad/ improper ground (my grounding cable runs from the amp toward the back of the boat & is grounded on the negative terminal).

 

[mrsrobinson]

Reminds me of the engine whine noise in my cars growing up when I added amps. I recall they had special spark plugs then to get rid of the noise.

 

[Chris-380]

Good deal, I had speaker wires pick up inductive noise, I ended ups sleaving the wires with a piece of liquid tight with metal liner….

Wylie is the guy on stereos imo. So do as he suggested

Hey Chris, I'm sure they're near some wires associated with the engine. All of the wiring for the amp is behind the dash near the main panel. I did my best to keep everything separate & have played with moving the wires around to minimize contact... I thought it may have been the RCA's too but I unplugged them from both the amp/ stereo & the noise is still present. Right now I'm leaning towards a bad/ improper ground (my grounding cable runs from the amp toward the back of the boat & is grounded on the negative terminal).

 

[Nitro15]

Update: I moved the amp ground from the battery to the grounding panel behind the dash. While I was doing so, I noticed some funkiness going on with the stereo wiring harness. Long story short, it was pretty hacked up. Both the main power wire (yellow, 12v) & accessory (red) were spliced together & connected to the main fuse panel for power. I have to believe this was done to avoid running a power wire back to the battery. The ground wire was also spliced together but with a "dead" wire. I cleaned that up & ran a new ground for the stereo as well. I'm in the process of running a new power wire from the battery to the stereo & keeping the acc wire separate (as it should be).

 

[Nitro15]

Update 2: I re-wired the head unit according to the manufacturers' instructions which included a direct power line to the battery & a separate accessory line to the main fuse panel. I also re-grounded both the stereo & amplifier to the grounding panel & did a final check on all connections/ fuses. Doing so has dramatically reduced the distortion that I've been experiencing but has not completely eliminated the problem. I still get some popping/ static in the speakers that makes it impossible to listen to music with the engine running. Does anyone have any additional suggestions on how to resolve this issue? I'm a bit stumped at the moment & not sure where to go from here.

 

[Wylie_Tunes]

Connecting power amplifiers to the helm BUS is a concern for me. In most boats, the gauge of the cable was adequate for just what accessories the boat builder would have connected to the BUS, and audio amps are not one them. 2nd, you run the risk of picking up "dirty" noise from the helm electronics..

So, ground the audio direct to the battery or a short distance away to a suitable main ground bar, is best. For amp's B+, this needs to also come direct from the battery, but through a main battery switch. The amp will draw from the house bank (or cranking bank depending on the setup) while the switch is on, and the battery is isolated from any parasitic draw when the boat is not in use. Proper circuit protection should be used also.

As to media unit............it has to share the same voltage source as the amp(s). So again, the helm BUS is NOT the place to connect the media unit's main B+ and B-. If it has a red switch IGN circuit, thats ok to draw through the key switch or rocker.

 

[ttmott]

Also measure the AC voltage in the DC system. Set your voltmeter to AC and see what the voltage is. It should be zero on the batteries and less than 20 millivolts with the engine running. If your alternator is going south it can put a lot of ripple in the DC system and could affect your sound system performance.

 

[Nitro15]

Connecting power amplifiers to the helm BUS is a concern for me. In most boats, the gauge of the cable was adequate for just what accessories the boat builder would have connected to the BUS, and audio amps are not one them. 2nd, you run the risk of picking up "dirty" noise from the helm electronics..

So, ground the audio direct to the battery or a short distance away to a suitable main ground bar, is best. For amp's B+, this needs to also come direct from the battery, but through a main battery switch. The amp will draw from the house bank (or cranking bank depending on the setup) while the switch is on, and the battery is isolated from any parasitic draw when the boat is not in use. Proper circuit protection should be used also.

As to media unit............it has to share the same voltage source as the amp(s). So again, the helm BUS is NOT the place to connect the media unit's main B+ and B-. If it has a red switch IGN circuit, thats ok to draw through the key switch or rocker.

I have to admit, this is a bit technical for me but I'm following along! Here's how my system is currently configured (please feel free to critique if you think I made a mistake):

Amplifier Power (10 gauge): connected to Battery 1 (starboard battery) w/ inline fuse
Amplifier Ground (10 gauge): connected to ground bar behind dash

Stereo Main Power (16 gauge): connected to Battery 1 on separate terminal bus bar
Stereo Accessory Power (16 gauge): connected to 5amp stereo slot on main fuse panel
Stereo Ground (16 gauge): connected to ground bar behind dash

Amp is a 4-channel Clarion XC2410
Speakers are 6 1/2" Kicker 49KM604W

 

[Nitro15]

Also measure the AC voltage in the DC system. Set your voltmeter to AC and see what the voltage is. It should be zero on the batteries and less than 20 millivolts with the engine running. If your alternator is going south it can put a lot of ripple in the DC system and could affect your sound system performance.

I'll certainly look into that, thank you! I've been meaning to pick up a new multimeter so now is probably the time to do so.

 

[Wylie_Tunes]

I have to admit, this is a bit technical for me but I'm following along! Here's how my system is currently configured (please feel free to critique if you think I made a mistake):

Amplifier Power (10 gauge): connected to Battery 1 (starboard battery) w/ inline fuse
Amplifier Ground (10 gauge): connected to ground bar behind dash

Stereo Main Power (16 gauge): connected to Battery 1 on separate terminal bus bar
Stereo Accessory Power (16 gauge): connected to 5amp stereo slot on main fuse panel
Stereo Ground (16 gauge): connected to ground bar behind dash

Amp is a 4-channel Clarion XC2410
Speakers are 6 1/2" Kicker 49KM604W

Battery 1; it sounds like there are at least 2 banks. If so, and there is a dual bank switch, I prefer to connect the audio to the common output of the switch.

in-line fuse; if this is located in the engine bay, or shares the air space with the engine bay, I suggest this to be ignition protected.

Amp GND to bar behind dash; Direct to a battery ground post or a close main ground BUSS.

Stereo main and gnd; Need to share the same voltage as the amp. In most cases, taking these direct to the amp's power terminals is a shorter distance.