When connected to Denon 2808ci receiver i get humming noise.Since there is no ground wire to connect,how do get rid of the hum?

The number-one cause of subwoofer/speaker hum is the coaxial cable connecting your cable or satellite receiver to your provider (either through an inground run to a cable box or through a satellite dish). Here is how you test for this:

1. Turn your system on and get it to produce the hum by watching a movie. Pause your DVD or videotape so that the hum is all you hear.
   

   TIPDon't use a normal cable or satellite program for this; you're about to disconnect the cable that provides the audio and video for your cable/satellite feed.
   

2. Find the coaxial cable running from your cable or satellite receiver to your service provider, and while listening to the hum, unscrew the connector and disconnect the cable.
   

Did the hum stop or reduce by a large amount? If so, the cable you disconnected is the source of the noise. If this is the problem, you have several ways to fix the issue permanently (if not, jump ahead to the next section):

1. Call your cable or satellite company and ask for a service call. Sometimes you get a smart cable guy, and if you demonstrate the problem he can do something upstream to ground the coaxial cable and remove or reduce the hum.
   
2. Buy a power strip that has F connectors as part of its surge protection. Plug the strip into the AC outlet and feed your main coaxial signal through these connectors. This ties the shielding of the coax (the source of the noise) to your AC ground and sometimes can solve the problem.
   

   WARNINGOddly enough, this solution (surge protection) can sometimes increase the humming.
   

3. Go to your local RadioShack store and buy three inexpensive items: a Matching Transformer (part #15-1253), an Indoor/Outdoor Matching Transformer (#15-1140), and a Cable Coupler (#278-304). Connect your coaxial cable to the cable coupler, and then to the first matching transformer. The output is two screws for the old two-wire antenna wire. Your indoor/outdoor matching transformer has two connectors for the screws, and the other end is a coaxial connector. Hook your cable or satellite receiver into this connector and see if the hum goes away.
   

Here is why this trick works: the first transformer converts your 75-ohm coax into a 300-ohm antenna connector. The second transformer converts the 300-ohm back to a 75-ohm connector. The humming, which usually is at around 60 Hz, can't pass through these conversions.

Ground Loop Hum

The second cause of hum is called a ground loop, and it almost always shows up right after you bring home a brand-new, self-powered subwoofer, or perhaps an external amplifier.
Take a look at all the plugs on the power cords on your home theater equipment. In most systems, the receiver (or amplifier) has a three-prong power plug, but most of your other devices have only two-prong plugs. This is not by accident; the device with the three-prong power plug is grounded. This means that device "owns" the ground. As long as no other power device has a three-prong plug, everything works well.
When you bring home a self-powered subwoofer and plug it in, though, you might notice it has a three-prong plug; this is for safety reasons. However, when you connect an RCA cable from your receiver to your subwoofer and turn everything on, you suddenly notice a loud hum.
The external amplifier in your subwoofer is now fighting with the amplifier in your receiver for possession of the ground. Both devices want to define 0.00 volts. But because the wiring in the two amplifiers to your household AC ground is different, one device is really using 0.001 volt and the other device uses something closer to 0.003 volts. The subwoofer cable connects the two, and the fighting begins.
You have to stop these two devices from trying to own the ground, or get them to not "see" each other. First, make your system produce the humming noise. Disconnect the single RCA cable between your receiver and subwoofer. Did the noise stop? If so, you have a ground loop issue.
The proper, safest way to solve this problem is to buy a special subwoofer cable with little arrows on the wire to show the signal direction (see ).
[img src="http://oreilly.com/images/hacks/htheaterhks/figs/htheaterhks_0601.jpg">
Figure 1. Subwoofer cable with directional arrowUnfortunately, many people have been ridiculed when asking about these sorts of cables at their local electronics store: "But cables don't really have a direction. My expert friend at work laughed at me when I asked about this!" Yes, your friend is right. Cables don't have a direction, but these little arrows indicate that this cable will prevent or solve your ground loop problem.
Remember when I said the hum started when you connected the RCA cable? That RCA cable really contains two wires: the center wire and something called the shield. The center wire carries the audio signal, but the shield tries to define 0.00 volts. The shield is the wire that lets the two different components (the receiver or amplifier, and the subwoofer) see each other's ground, and causes the fight. What if you took your subwoofer cable and disconnected the shielding from just one end? Wouldn't that solve the problem? Yes, it would. This is exactly what a subwoofer cable with little arrows does. The shield is not connected at both ends. The shield has to be connected at one end, for connecting to your receiver or amp, so you should run the cable so that the arrows show the flow from the receiver to the subwoofer.

WARNINGIt is unsafe to use a two-prong to three-prong "cheater" plug on the subwoofer power cord to solve the hum problem. Even if the subwoofer came with a cheater plug in the box, it's REALLY not safe to do. Don't do it.

Hi,
you may have a bad Earth power 110 V AC cable connection which makes such hum / buzz even nothing connected..
Check the connections between components and make sure they are secure before proceeding to the next Step. Sometimes, loose connections can cause a hum.

Separate the audio cables from the power cables; electromagnetic interference from the power cables can cause stereo hum. Use cable ties to secure the audio cables away from the power cables.

Plug in a surge protector to the outlet, and then plug all the components into that surge protector

Connect a ground plug to the surge protector and then plug the ground plug into the main outlet. A ground plug is available at any hardware store, and turns a three prong connection into a two prong. Ground plugs help eliminate 60 cycle hum.

5 Connect the ground wire from your turntable to the ground wire connection on the receiver. If this doesn't work, looking on the back there should be a grounding point,

Unplug your receiver.. Split a wire and attach one of the splits to the receiver where you will see the text, "ground" or something similar. Attach the other end to something metal such as a pipe that goes into the ground. Secure with electrical tape. Plug in.
connect the ground wire to a screw on the electrical outlet.

Read more: How to Fix a Hum on a Stereo Receiver ' eHow.com http://www.ehow.com/how_5183193_fix-hum-stereo-receiver.html#ixzz1PpFHs1Mv

Take care and please remember to rate me"AS THUMBS UP" Thanks

Hi,
you may have a bad Earth power 110 V AC cable connection which makes such hum / buzz even nothing connected..
Check the connections between components and make sure they are secure before proceeding to the next Step. Sometimes, loose connections can cause a hum.

Separate the audio cables from the power cables; electromagnetic interference from the power cables can cause stereo hum. Use cable ties to secure the audio cables away from the power cables.

Plug in a surge protector to the outlet, and then plug all the components into that surge protector

Connect a ground plug to the surge protector and then plug the ground plug into the main outlet. A ground plug is available at any hardware store, and turns a three prong connection into a two prong. Ground plugs help eliminate 60 cycle hum.

5 Connect the ground wire from your turntable to the ground wire connection on the receiver. If this doesn't work, looking on the back there should be a grounding point,

Unplug your receiver.. Split a wire and attach one of the splits to the receiver where you will see the text, "ground" or something similar. Attach the other end to something metal such as a pipe that goes into the ground. Secure with electrical tape. Plug in.
connect the ground wire to a screw on the electrical outlet.

Read more: How to Fix a Hum on a Stereo Receiver ' eHow.com http://www.ehow.com/how_5183193_fix-hum-stereo-receiver.html#ixzz1PpFHs1Mv


Take care and please remember to rate "AS THUMBS UP" Thanks

Hi,
you may have a bad Earth power 110 V AC cable connection which makes such hum / buzz even nothing connected..
Check the connections between components and make sure they are secure before proceeding to the next Step. Sometimes, loose connections can cause a hum.

Separate the audio cables from the power cables; electromagnetic interference from the power cables can cause stereo hum. Use cable ties to secure the audio cables away from the power cables.

Plug in a surge protector to the outlet, and then plug all the components into that surge protector

Connect a ground plug to the surge protector and then plug the ground plug into the main outlet. A ground plug is available at any hardware store, and turns a three prong connection into a two prong. Ground plugs help eliminate 60 cycle hum.

5 Connect the ground wire from your turntable to the ground wire connection on the receiver. If this doesn't work, looking on the back there should be a grounding point,

Unplug your receiver.. Split a wire and attach one of the splits to the receiver where you will see the text, "ground" or something similar. Attach the other end to something metal such as a pipe that goes into the ground. Secure with electrical tape. Plug in.
connect the ground wire to a screw on the electrical outlet.

Read more: How to Fix a Hum on a Stereo Receiver ' eHow.com http://www.ehow.com/how_5183193_fix-hum-stereo-receiver.html#ixzz1PpFHs1Mv


Take care and please remember to rate "AS THUMBS UP" Thanks

Make sure ALL of the interconnected equipment is powered from the SAME receptacle to avoid ground loops due to the safety ground. DO NOT Use two wire power or use ground lifting plug adapters. Make sure you use balanced lines, either XLR or TRS cables. Do NOT use TS cables.

What amplifier is this? Humming noise is normally caused by video cables in audio ports, high voltage wires too close to audio wires, or ground loops.

You can go buy a audioquest SUB-X subwoofer cable with a additional ground wire on it an connect the ground cable to the ground slot of the receiver an the other end to a screw on the sub or into one of the high output terminals on the woofer if it has them an this will take that humming sound right away but the cable is around $90

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.

-Chris

I switched out of the audio-out cables from the cable box to the audio in at the Denon receiver and went with a coaxial cable connection. That switch got rid of the hum. I don't understand why the initial connection produced the hum, but the unit is working fine now.

Check capacitors in power supply......also check for over-heated
resistors..all 1 ohm.....replace if cooked...................T.