Ran into this problem myself in two different homes. Went to A/V store where they install high end equipment, they explained its a problem with the way the AMP for the **** kicker and the amp in my subwoofer, and a/v processor are all plugged into the same electrical circuit in the house. They tried to sell me a $35 ground loop eliminator kit. Didn't go for the kit after looking at it, I came up with a solution that cost me $.39 cents. Thats right 39 cents. Go to Home Depot, Lowes, Ace Hardware and ask for a plug adaptor (they usually come in grey but you can shop around to find other colors). They are sold for older homes that dont have ground fault plugs only the two prong outlets. Plug your Subwoofer or your AMP into the adaptor then plug it in. All the humming and feedback noise will be a distant memory.
An expert who has written 20 answers of more than 400 characters.
An expert who has answered 20 questions.
Re: home theater ground loop problem
Boy you must have a mess. We will start process of elimination. Make sure power cords are out of the wall at first. First plug the preamp into the duplex then plug the amplifier into the wall. Connect the speakers then connect the wires between the preamp and amplifier. All should be well. If buzzing countinues, you need to find a ground adapter. This is a small device that on the female side has 3 prongs and the male said 2 female redeptor. If your using a AC strip plug put the adapter on and then plug in wall...
Well pick it up in the next chapter if nothing works here...
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Hum is a constant low-frequency buzz, usually at about 60 Hz or 120 Hz, which results from voltage differences between true "ground" (what you'd get shoving a copper pipe into the ground) and the electrical "ground" of your receiver's chassis When this voltage differential exists, it's called a "ground loop," and the hum it produces is darned annoying. You'll hear the hum mainly from the subwoofer because it's a low-frequency noise, you will need a ground loop insulator they are about $20 at any electronic store
jd40, Sounds like a grounding issue. The first two places to look into is the powered subwoofer and antenna. During your last test, did you leave the FM antenna and subwoofer connected? Many times the hum is directly related to the antenna and/or the subwoofer and to how they are grounded; creating a ground loop through the receivers ground on the outlet. If the antenna is grounded to the dwellings wiring, hum is inevitable and sometime you can get a ground loop hum from how or how & where the subwoofer is grounded. Try taking them completely out of the loop.
Also try taking it further back to the basics, start with the receiver plugged into a known good grounded outlet with no surge or line conditioner in the loop and nothing connected to the receiver, nothing. Use one speaker and different wire to test each speaker output while in tuner and any other mode but phono. With no signal, you will either get nothing (no hum or static) or just static in the tuner mode. No hum is a good sign. Some systems will mute the speakers if no signal is connected to eliminate the static from being produced through the speakers but a ground loop hum will most likely still be produced even in mute. If you get a hum when nothing is connected to the receiver, try looking into getting a better grounded outlet, even maybe to a different dwelling.
This is the bane of all home theater installations and its called the "60 Hertz Hum" Most likely coming from your cable company.. Simple test... Disconnect any Coax cables from the outside going into your cable box or tv. Hum disappears. Most likely this is caused by a "ground loop" problem.
The solutions are far and varied. Google "ground loop hum" to find different things to try
Sounds like we have reached that point where progressive crossover in technologies means that the usual cautions of earth continuity for the tone arm when using a phono preamp has gone the same way as phono preamps on home theatre.
Have you tried switching to the line level and set the mixer up for that level also. That may reduce any gain induced hum. However it sounds like an earth loop problem, where both decks will need to be earthed in the mixer. Check also that all the gear is running of the same power point. Different mains phases are sometimes available near each other, having any gear (power amps also) on a different phase will cause an earth loop problem.
Is the hum all the time independent of the volume levels, or change with levels adjustments and not at all when turned right down. Let me if changing to line levels helps. We can try some more things, like connecting a temp hookup wire earth to the RCA earth to mixer chassis. Cheers