Axiom Home Page Forums General Discussion Home Theater Subwoofer and receiver both humming

So either I'm going crazy and it's been humming all along, or it just started to him full time this evening.

I'm second guessing myself now, but earlier today I must have tried powering it on and off at least 5 times and I was confident the humming was gone when powered back on and I also tried adjusting the sub volume once and turning the knob made no difference.

Just now I checked it and it's basically humming at all times. I turned the volume up and the humming gets worse, when my volume is up past 50% it starts to make a rumbling sound accompanied by a static/white noise type of sound. A sound similar to being tuned into a radio station that you aren't receiving the signal for. When the volume is below 50% the white noise sound goes away and it's not a rumbling sound, just a steady hum.

What do you make of this?

Before cutting open any devices or cables, does the sub power cord have a ground pin? If so, can you find an extension cord with only a 2 blade electrical plug, meaning one without a ground pin?

I have had humming issues with all 3 Axiom subs I have owned, and the ground screw fix did not work with any. All were fixed by the above.

Your mileage may vary, but it is easier and safer than some of the above suggestions.

The sub power cord does not have a ground pin, it's a 2 blade plug.

Try a few more things:

1. Remove the RCA cable, turn the volume down and listen to the tone of the hum. Now raise the volume and put your finger on the RCA jack. Does the tone decrease in frequency (sound lower in pitch)?

2. Reverse the plug if not polarized. Does hum disappear?

3. Move the sub to another circuit. No need to plug RCA in. Does the hum disappear?

I don't notice any difference in the sound when I put my finger on it.

The plug is polarized so I cannot reverse it.

Tried the sub in three other outlets in different rooms and the sub acts the same everywhere.

The humming doesn't start until the volume knob is in the 40-60% range. Below that, it doesnot appear to be humming

Sounds like a sub amp problem to me. If you really want to try a repair, remove the amp and closely examine the power supply filter capacitors for bulging or leaking. You may also have a leaky transistor in the pre-amp section of the sub amp. None of this is for the uninitiated. Trade it in when you can.

Thanks for all of you help, I really appreciate it.

I'll try to get it apart this weekend at some point amd see what I can find.

I attempted going through the trade up part of the website but my serial number isn't recognized, I'm guessing because it's so old and there doesn't appear to be a model number anywhere on it. I sent a message to axiom yesterday hoping to see what I can get for my sub if anything.

As much as I would like a new sub i don't think the discount will be significant enough to convince my wife I need a new sub.

Does it sound like the driver is ok? I could always replace the plate amp I'm assuming at a cost effective price point.

How long would you estimate a typical sub will last?

I have a similar issue. When I plug in the trigger on both or one EP500 I get a hum, once triggers are removed hum goes away tried removing ground screws did not make a difference.

RJ

You may get 120 bucks on trade-in.

I doubt very much Axiom can provide you with a new amp. They're not building them any longer and parts are likely obsolete.

If the driver plays without warbling, it's likely OK.

There is no "typical" subwoofer. I've known folks whose amps failed within a month. I've had my cheap Sony for almost twenty years. It depends on a lot of factors but mostly on whether the engineer selected parts appropriate for the design. A well-designed sub ought to last at least 15 years.

RJ, I recommended in the past to get rid of extraneous cables. A trigger cable is extraneous. I shut all my subs off when not in use.