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Charles, Marine Tech
Category: Marine Electronics
Satisfied Customers: 3313
Experience:  US Navy (Ret) I have been installing Marine Electronics for over a decade now.
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Installed a new 400 watt amp and head unit. Had an existing

Customer Question

Installed a new 400 watt amp and head unit. Had an existing 400watt bass cannon. After installing the amp and head unit, I have a hum coming through the speakers. This is when the engine is off. When it is on, it's worse. When the engine is off, I can hear popping through the speakers when I turn on any of the controls (lights, etc..). When I put on the bilge pump, the whine of the pump comes through the speakers. The amp is run directly from the battery (both negative and positive) using a 4AWG wire. The bass cannon has been run the same (but I never had any problems with this).
Submitted: 1 month ago.
Category: Marine Electronics
Customer: replied 1 month ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Charles replied 1 month ago.

Hello, my name is***** will assist you.

Expert:  Charles replied 1 month ago.

Where are you getting power for the head unit?

Customer: replied 1 month ago.
the head unit works fine full power and sound. Again, had an older head unit that I replaced. I had a 400watt bass cannon that I wired direct to the battery. Worked great and not issues. However, when I changed out the head unit for a new Kenwood and then added a 400 watt amp to drive new Infinity speakers, is when the hum sound began.. Again this is with the engine off. Worse when it is on. Popping noise when I activate any power switch on the boat.
Customer: replied 1 month ago.
I am getting power direct from the battery. I have two and I am running off of one of them. The same battery that is driving the bass cannon. The amp and bass cannon are both Pyle
Customer: replied 1 month ago.
I am thinking the head unit has a ground loop. The black is running off of the accessory panel. Maybe why I am hearing popping noises. Also there is a drifting and crackly sound constant through the speakers. Again, this was not the issue before.
Expert:  Charles replied 1 month ago.

Remove the power from the amp, and run just the head unit, see if the noise is still there. If it is, you will need to install a filter on the power line to the head unit. If not, then you need the filter in the power to the amp.

Customer: replied 1 month ago.
How will I drive the speakers to test. They are running from the head unit to the amp and then the amp to the speakers.
Expert:  Charles replied 1 month ago.

You can take one from the amp and hook it to the speaker output from the head unit. Only really need one to test with.

Customer: replied 1 month ago.
Ok, I disconnected all the speakers from the Amp. I then ran just one speaker from the head unit direct. No hum and no popping noise when I activate switches.
Customer: replied 1 month ago.
Are you positive though I will need a filter on the Amp? Why? I don't have a filter on the Pyle Bass Cannon and it's 400 watts. No popping or hum. I took off the main speaker and just played sound through the bass cannon.
Expert:  Charles replied 1 month ago.

You need to filter the Amp power supply. Also make sure that you do not have the gains maxed out, and the input voltage from the init to the amp is set correctly.

Customer: replied 1 month ago.
Gains on the amp are at 3/4. Input voltage is regulated by the input source.
Customer: replied 1 month ago.
What type of filter?
Customer: replied 1 month ago.
Were you able to recommend a filter?

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