Axiom Home Page Forums General Discussion Technical Questions EP500 radio interference

Every time I turn on my EP500 while listening to the radio from my Yamaha RXV2400, the sub changes the sound of the radio signal with mosquito noise. How can this be possible?? Is it because the sub is not shielded? It is about 9 feet from the RXV2400. When I turn it off, the interference goes away.

Any suggestions?
jj

have you tried removing the ground screw on the back? this does not sound like a 60hz hum, unless that is what mosquito's sound like in your area.

JJ, I assume that by the "mosquito noise" that you're referring to a high-pitched whine or buzz. I'd think that the sub itself is far enough away from the receiver, but you may have it plugged in at the same spot. Try, using an extension cord, to plug the EP500 in some distance away, to see if this helps with the interference. No, this wouldn't be a ground loop.

The EP500 is connected on another outlet, different from my receiver. I have had the ground screw off since I first got the sub. Both the receiver and sub are connected with a Monster Cable power conditioner and the Monster power-sub conditioner. What I mean by mosquito noise is the sound of the radio receception being weak. It sounds sssshhhhh, as when you are trying to search for a radio station off the air. The sshhh sound goes away when the sub is off and the radio station sounds clear.

jj

did you take the ground screw out because you had a loop problem?

If not, I would reccomend putting the screw back in.

ditto

JJ, I'm a bit surprised that Randy didn't comment that Iowa mosquitos don't go "ssshhhh"! Didn't follow the various "power conditioner" connections, but although I'm not enthusiastic, they certainly aren't the basic cause of the problem. Something(is there an FM antenna?)is apparently too close to either the sub amp or its power cord and is picking up interference which the tuner reproduces.

You might contact Axiom directly and ask about their experience with possible tuner interference and report back if they have any suggestions.

While not directly associated with JJ's issue but on another note regarding ground loops...

Saturday I noticed the dreaded ground loop noise coming from the main speakers (good and loud), pulled the coax cable from the cable box and the noise immediately quit, I then went outside to check the ground wire from the house cable distribution box to the main house grounding rod and sure enough the machine threaded screw holding the cable grounding wire to the rod was loose ... I tightened it up, re-connected the inside cable box and the issue was resolved.

Just something to look for if some of you have a ground loop issue.

I'll try to add the screw back on to see if it makes any difference. I'll keep you posted.

Not related to sound quality at all (although it can cause a hum) but speaking of grounds....

If you are a homeowner, check and see if your phone line has a ground line from the protector/NID/(the box where the outside wire meets your inside wire).

It's a legislated (in Canada anyways) safety feature that can save your butt in a lightning storm or surge situation (Actually just DON'T TALK ON THE PHONE DURING LIGHTNING STORMS...) but it is often neglected by lazy installers if they can't find a "proper" place to ground to. They should actually drive a ground rod into the earth beside your house if all else fails. It's that serious.

Sorry, I know I am sounding like one of those fake, scare tactic, spam emails but it's just a personal irk of mine. Our company does pretty good with this because it's beaten into the techs brains but when I travel, I notice some totally unprotected houses.

That same little box also has 'protection' circuitry in it to help prevent a surge from entering your home. That is it's job. However, a nice big path to ground is added protection on the account that electricity is lazy and takes the past of least resistance. Beats taking it in the ear......

Rant over
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