Tower speaker frequency buzz issues

This summer I put a set of XM7s on my tower and I absolutely love them, sound great and amazingly loud. Nothing was wrong with them until randomly they will get a buzz coming out of them no matter what the volume is set at. The loudness/frequency of the noise seems to be determined by the amount of throttle using. Sometimes it will be there, sometimes not. All I have to do is switch off the sound system entirely and then switch it on and it will be gone. After that it might come back at the end of a song or it won't at all. I'm pretty sure they aren't blown out, the buzz only seems to come from the left speaker so i switched them over and it was still just the left.

What could be wrong? is it a powering issue or cabling issue somewhere? I have the ws-420. If i plug my zune directly into the aux on that the buzz seems to happen less often than when I plug into the aux spot provided on the boat.

If you need any more information to potentially help debug it let me know.

Thanks

Brit - sorry to hear of your troubles with the buzzing. The fact that the buzzes with the throttle indicates you have a ground loop gremlin in your system. The xm7's are a very efficient speaker , so any noise issues in a given setup will be heard on then first.

There are several things to take a look at as We isolate different areas to pinpoint what's going on and from there make some changes. First thing I'd like you to do is bypass the 420 and plug your iPod directly in to your amplifier.

After you do that, give me a call and I'll walk you thru the 12 or so other checks that may be needed. Whatever the case , I'll get to the bottom if it for you.

Brian
Exile Audio
971-645-3145
I can be reached over the weekend if need be.

Thanks a lot! I'm probably not going to be in a position to be out there until monday but I'll definitly give you a call then. Once again, I love the speakers I'm just pretty sure the boat was wired poorly to start with!

Are the head-unit and Ws-420 both sharing the same ground as the amp(s)?

Somewhere a ground has probably been compromised. This frequently happens especially with the shock and vibration in a towboat. The sudden appearance of the noise can also be traced to corrosion, a loose RCA shield, water damage to electronics or something that has changed in the factory harness or molex where the radio is grounded. It can be as simple as a loose ground or crimp at the battery where an amplifier is now seeking a ground through a connection with another audio component creating voltage to flow in the signal path (not a good scenerio). Certainly one of the first steps should be to eliminate the factory ground for the source unit and tie this in to a reference point with the largest system amplifier (as Mike indicated). Do visual and vibration checks to verify that all grounds are tight including RCAs. Then circumvent each electronic component one at a time as part of a process of elimination. You can even go as far as to temporarily wire the source unit directly to the speakers. Confirm that you have 12.5 volts at rest in that you can't begin meaningful diagnosis with low voltage. Place your ear close to the in-boat coaxials with nothing else playing to determine if you have the same noise but at a reduced level as this can reveal how far up the signal path the issue is. Some types of shorts at the speaker or wire transition into the tower can cause the amplifier to generate noise and once induced may show up in the alternate channel. Re-check all of the input levels to make sure its not a simple case of being over-gained. Again, this is going to be resolved by isolating and/or eliminating each component in the signal path one by one. Once you have checked the basic connections and before you begin the more involved checks make sure you have some bypass wire, RCA barrel connectors, a few RCA jumpers and a multi-meter. If you find that a single electronic component is causing the noise and you suspect water damage then I can tell you how to possibly salvage it.

David
Earmark Marine