Subwoofer Hum
jcircus
Posts: 3
Hello,
I recently purchased the RM6750 home theater speaker kit. The sound is awsome, however the subwoofer has a constant hum even when everything (exept power) is disconnected. I have tried different outlets around the house, and purchased a good APC power strip. I dont think this is normal, but I could be wrong. any help is appriciated.
I recently purchased the RM6750 home theater speaker kit. The sound is awsome, however the subwoofer has a constant hum even when everything (exept power) is disconnected. I have tried different outlets around the house, and purchased a good APC power strip. I dont think this is normal, but I could be wrong. any help is appriciated.
Post edited by jcircus on
Comments
-
is your sub cable grounded/shielded? if not, I've been pleased with the inexpensive one I purchased from blue jeans cable. No more hum once I installed it.
-
is your sub cable grounded/shielded? if not, I've been pleased with the inexpensive one I purchased from blue jeans cable. No more hum once I installed it.
Yes, I am using a Belkin Pure AV subwofer (double shielded) cable. but that doesnt matter. Even with the audio cable disconcted from the sub, the hum is still there. -
hmmm...I wonder if there is a loose connection in the sub somewhere?
-
Might be a ground loop hum. Try a cheater plug and see if it goes away...
-
ken brydson wrote: »Might be a ground loop hum. Try a cheater plug and see if it goes away...
Sorry to be ignorant, but what is a cheater plug?
Also, I went throught the tests on this site regarding "ground loop hum" - http://oreilly.com/pub/h/4241 to remove the subwoofer hum. Like I said before... removing the RCA cable between the subwoofer and receiver does not get rid of the hum. just being plugged into any power outlet in the house, creates the hum.
Does Polk support folks reply to this forum, or do i need to contact them directly?
Thanks for your suggestions. -
A cheater plug is an adaptor that is 3 prongs on one end 2 on the other, or vice versa. Use whichever one you need (I forget if polks subs are 2 or 3 prong plugs)"....not everything that can be counted counts, and not everything that counts can be counted." William Bruce Cameron, Informal Sociology: A Casual Introduction to Sociological Thinking (1963)
-
is your sub cable grounded/shielded?
-
I have the same issue, I recently purchased a RM705 speaker system and it has a continuous hum. With the power switch off and the inputs disconnected the unit still makes a buzzing sound continuously. This is not related to the ground feedback issue as it is only a 2 prong plug and there are no inputs connected. I don't even have a receiver to connect it to yet.
-
I've had the RM6750 for a little over a year then all of the sudden the other night it started making a constant humming noise. I disconnected the audio cable and it still does it. I also moved the plug to a different outlet on another breaker - no change. What should I do? please help.
-
I hate to say it but my hum has returned. I used a cheater and plugged it into the wall. The sub cable has grounds and is shielded(audioquest). The hum seems to vary in loudness as I move closer and away from the sub-Carver true signature. Anything I'm overlooking?
-
Try the cheater plug on the receiver.HT SYSTEM-
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's -
Try the cheater plug on the receiver.
thanks! That seems to have solved the hum issue. -
Your welcome. Usually these small ground loop problems occur when adding things to your system. Cables are also a grounding device and the more you have connected to the main source....receiver or pre amp, the more likely an annoying ground loop will occur from having too many grounds at one point.
Of course that's not always the case, and ground loops can be caused by a variety of things, but it's one of the first to check and the easiest.
HT SYSTEM-
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's -
Do you have cable TV? If so, this can cause the hum issues. You can buy a ground loop isolator that connects inline with your coax cable to resolve the issue. Of course if you're OK with the cheater plug on your receiver, that works as well but removes a layer of protection that the receiver was designed to have.____________________________________________________________
polkaudio Fully Modded SDA SRS 1.2TLs + Dreadnaught, LSiM706c, 4 X Polk Surrounds + 4 X ATMOS, SVS PB13 Ultra X 2, Pass Labs X1, Marantz 7704, Bob Carver Crimson Beauty 350 Tube Mono Blocks, Carver Sunfire Signature Cinema Grande 400x5, ADCOM GFA 7807, Panasonic UB420, Moon 380D DAC, EPSON Pro Cinema 6050 -
Of course if you're OK with the cheater plug on your receiver, that works as well but removes a layer of protection that the receiver was designed to have.
True in theory, if your going directly into a wall outlet. If your going into a Power conditioner though, you still have a layer of protection against surges and spikes. Of course if you had a good power conditioner, you may not need the cheater plug either.
Back in the day, we used to run a simple wire from a case screw to another piece to get rid of some hum issues. I used to use a cheater plug for over 5 years, with no ill effects. Yes, it's a temporary fix, but it will give you some time to save coin for a decent power conditioner. Better cabling and Hospital grade wall outlets will help also.
Post edited by tonyb onHT SYSTEM-
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's -
Seems like I see Monster HTS 3500's on CL all the time for under $100. Cheap insurance.____________________________________________________________
polkaudio Fully Modded SDA SRS 1.2TLs + Dreadnaught, LSiM706c, 4 X Polk Surrounds + 4 X ATMOS, SVS PB13 Ultra X 2, Pass Labs X1, Marantz 7704, Bob Carver Crimson Beauty 350 Tube Mono Blocks, Carver Sunfire Signature Cinema Grande 400x5, ADCOM GFA 7807, Panasonic UB420, Moon 380D DAC, EPSON Pro Cinema 6050 -
Thanks for all the comments. I have an Acme hospital grade outlet and just installed a APC LE1200 Line-R 1200VA Automatic Voltage Regulator. I noticed a little hum but when I moved the Fios cable it disappeared. I may need to install a ground loop isolator. Any advice on where to purchase it?
-
-
