How fix high pitch through the tower speakers?

First off I have an '07 Outback with a dual battery setup and perko switch. I have listened to all the speakers in the boat and do not hear the high pitch noise threw them.

For tower speakers I have a set of Infinity's with the Infinity amp. These are the speakers I can hear the high pitch noise through. It goes away when the key is off, but soon as its on the noise starts. It gets annoying when just cruising around the lake.

I looked for a previous post for this but couldn't find it, any ideas to fix this?

I see your not new to the site but welcome to posting realm LOL.

The pitch could be a few things. Since your only hearing it in the towers its a lot easier then you think to narrow it down.

Its one of these things.

Ground line.
RCA wire
Amp
Speaker

If the amp is grounded right to the battery like it should just make sure the connection is good and solid. Not lose or any sort of bad connection.

Are the RCA for the Tower amp running along the power lines of the amps? If so move them away.

Amp- switch the tower speaker wires to your other amp and give it a listen. You can hook your infinity amp to the cabins. Does this solve the problem in the towers? Does this move the noise to the cabins?

Speakers- if the sound is there even when moved to another amp then your speakers are most likely bad.

If you sound goes away when you plug the towers into another amp then the amp is the culprit check all connections and RCAs

If you checked the above and still have noise, plug cabins into the amp and the noise moves to the cabins then the Amp is suspected of a the problem.

Those are where id start and let us know how it works out for you.

09operator,

Several questions to narrow it down:

• Verified your batteries are resting at over 12 volts with no alternator?
• Veified grounds are tight?
• Tower amplifier powered off Perko common versus battery-direct?
• Adjusted tower amplifier input gains down?
• Does noise pitch vary with engine RPM?
• Does noise level vary with volume changes or remain consistent?
• Without the tower amplifier on, have you put your ear directly to the other in-boat speakers listening for the noise?
• Is the noise there only with the engine running or without the engine running and the key powering the engine management electronics?
• Is the noise in both tower spekaers?

David
Earmark Marine