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#1
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Subwoofer hum: is it my receiver?
Apologies to the group if this has been discussed prior:
When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. My equipment is an Onkyo TX-SR500 receiver and Sony SA-WM20 subwoofer. (I know, not the greatest - but it's what I have.) I tested the subwoofer on a friend's Onkyo, and it worked properly. I swapped subwoofer cables and the hum still occurs. I have disconnected all input/output leads from the receiver other than the subwoofer cable. When the receiver is not plugged in, there is a low hum. When the subwoofer is plugged in, the volume of the hum increases, even with the receiver power off. When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. The system was working properly before I pulled it apart to install a wall unit. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. When I disconnected the system, the subwoofer cable was very difficult to remove from the receiver, In fact, the head came apart in my hand, and I needed to use needlenose pliers to pull the casing off the receiver output jack. I am wondering if I somehow damaged whatever is hooked to the backside of this jack, and whether that might cause the hum. Any advice before I cart the receiver off to a shop is gratefully accepted. Brian |
#2
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Subwoofer hum: is it my receiver?
Any advice before I cart the receiver off to a shop is gratefully
accepted. Try lifting the ground on the subwoofer. Use a cheater or a cheap extension cord. If the hum disappears you have found the culprit. If not, ask and we'll make more suggestions, but this is the first (and simplest) thing to check. Alarm and Home Automation System FAQ http://www.bass-home.com/faq/masterfaq/faq.htm Regards, Robert ============================= Bass Home Electronics 2291 Pine View Circle Sarasota · Florida · 34231 877-722-8900 Sales & Tech Support 941-925-9747 Fax 941-232-0791 Wireless Nextel Private ID - 161*21755*1 http://www.bass-home.com http://www.bassburglaralarms.com ============================= |
#3
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Subwoofer hum: is it my receiver?
Any advice before I cart the receiver off to a shop is gratefully
accepted. Try lifting the ground on the subwoofer. Use a cheater or a cheap extension cord. If the hum disappears you have found the culprit. If not, ask and we'll make more suggestions, but this is the first (and simplest) thing to check. Alarm and Home Automation System FAQ http://www.bass-home.com/faq/masterfaq/faq.htm Regards, Robert ============================= Bass Home Electronics 2291 Pine View Circle Sarasota · Florida · 34231 877-722-8900 Sales & Tech Support 941-925-9747 Fax 941-232-0791 Wireless Nextel Private ID - 161*21755*1 http://www.bass-home.com http://www.bassburglaralarms.com ============================= |
#4
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Subwoofer hum: is it my receiver?
Any advice before I cart the receiver off to a shop is gratefully
accepted. Try lifting the ground on the subwoofer. Use a cheater or a cheap extension cord. If the hum disappears you have found the culprit. If not, ask and we'll make more suggestions, but this is the first (and simplest) thing to check. Alarm and Home Automation System FAQ http://www.bass-home.com/faq/masterfaq/faq.htm Regards, Robert ============================= Bass Home Electronics 2291 Pine View Circle Sarasota · Florida · 34231 877-722-8900 Sales & Tech Support 941-925-9747 Fax 941-232-0791 Wireless Nextel Private ID - 161*21755*1 http://www.bass-home.com http://www.bassburglaralarms.com ============================= |
#5
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Subwoofer hum: is it my receiver?
Any advice before I cart the receiver off to a shop is gratefully
accepted. Try lifting the ground on the subwoofer. Use a cheater or a cheap extension cord. If the hum disappears you have found the culprit. If not, ask and we'll make more suggestions, but this is the first (and simplest) thing to check. Alarm and Home Automation System FAQ http://www.bass-home.com/faq/masterfaq/faq.htm Regards, Robert ============================= Bass Home Electronics 2291 Pine View Circle Sarasota · Florida · 34231 877-722-8900 Sales & Tech Support 941-925-9747 Fax 941-232-0791 Wireless Nextel Private ID - 161*21755*1 http://www.bass-home.com http://www.bassburglaralarms.com ============================= |
#7
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Subwoofer hum: is it my receiver?
In , on 02/17/04
at 07:00 PM, (Brian) said: Apologies to the group if this has been discussed prior: When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. This seems like a ground loop issue to me. (read on) My equipment is an Onkyo TX-SR500 receiver and Sony SA-WM20 subwoofer. (I know, not the greatest - but it's what I have.) I tested the subwoofer on a friend's Onkyo, and it worked properly. I swapped subwoofer cables and the hum still occurs. I have disconnected all input/output leads from the receiver other than the subwoofer cable. When the receiver is not plugged in, there is a low hum. When the subwoofer is plugged in, the volume of the hum increases, even with the receiver power off. When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. There is always a small amount of hum. It's difficult for us to decide if it is normal or not unless we hear it or interpret a measurement that we trust. In a very quiet room, close to the speaker, the hum is usually audible. In most homes, with all the heaters, appliances, computers, etc. that are running, the hum is not significant. The system was working properly before I pulled it apart to install a wall unit. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. When I disconnected the system, the subwoofer cable was very difficult to remove from the receiver, In fact, the head came apart in my hand, and I needed to use needlenose pliers to pull the casing off the receiver output jack. I am wondering if I somehow damaged whatever is hooked to the backside of this jack, and whether that might cause the hum. The plug on the end of the cable fell apart? The jack on the receiver separated? It is possible that you damaged the jack on the receiver. Obviously, replacing the subwoofer cable will cure a damaged cable issue. You can quickly check for a damaged jack by using a screwdriver to short the shield (outside) of the subwoofer cable to the shield on a nearby jack. If the problem cures, the the jack must be replaced. Plugging the subwoofer into another outlet can easily cause ground loops. You can test for this situation by using a power extension cord to temporarily use the same outlet for everything in the system. Also, disconnect the cable TV feed if you have one. ----------------------------------------------------------- spam: wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15 13 (Barry Mann) [sorry about the puzzle, spammers are ruining my mailbox] ----------------------------------------------------------- |
#8
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Subwoofer hum: is it my receiver?
In , on 02/17/04
at 07:00 PM, (Brian) said: Apologies to the group if this has been discussed prior: When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. This seems like a ground loop issue to me. (read on) My equipment is an Onkyo TX-SR500 receiver and Sony SA-WM20 subwoofer. (I know, not the greatest - but it's what I have.) I tested the subwoofer on a friend's Onkyo, and it worked properly. I swapped subwoofer cables and the hum still occurs. I have disconnected all input/output leads from the receiver other than the subwoofer cable. When the receiver is not plugged in, there is a low hum. When the subwoofer is plugged in, the volume of the hum increases, even with the receiver power off. When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. There is always a small amount of hum. It's difficult for us to decide if it is normal or not unless we hear it or interpret a measurement that we trust. In a very quiet room, close to the speaker, the hum is usually audible. In most homes, with all the heaters, appliances, computers, etc. that are running, the hum is not significant. The system was working properly before I pulled it apart to install a wall unit. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. When I disconnected the system, the subwoofer cable was very difficult to remove from the receiver, In fact, the head came apart in my hand, and I needed to use needlenose pliers to pull the casing off the receiver output jack. I am wondering if I somehow damaged whatever is hooked to the backside of this jack, and whether that might cause the hum. The plug on the end of the cable fell apart? The jack on the receiver separated? It is possible that you damaged the jack on the receiver. Obviously, replacing the subwoofer cable will cure a damaged cable issue. You can quickly check for a damaged jack by using a screwdriver to short the shield (outside) of the subwoofer cable to the shield on a nearby jack. If the problem cures, the the jack must be replaced. Plugging the subwoofer into another outlet can easily cause ground loops. You can test for this situation by using a power extension cord to temporarily use the same outlet for everything in the system. Also, disconnect the cable TV feed if you have one. ----------------------------------------------------------- spam: wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15 13 (Barry Mann) [sorry about the puzzle, spammers are ruining my mailbox] ----------------------------------------------------------- |
#9
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Subwoofer hum: is it my receiver?
In , on 02/17/04
at 07:00 PM, (Brian) said: Apologies to the group if this has been discussed prior: When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. This seems like a ground loop issue to me. (read on) My equipment is an Onkyo TX-SR500 receiver and Sony SA-WM20 subwoofer. (I know, not the greatest - but it's what I have.) I tested the subwoofer on a friend's Onkyo, and it worked properly. I swapped subwoofer cables and the hum still occurs. I have disconnected all input/output leads from the receiver other than the subwoofer cable. When the receiver is not plugged in, there is a low hum. When the subwoofer is plugged in, the volume of the hum increases, even with the receiver power off. When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. There is always a small amount of hum. It's difficult for us to decide if it is normal or not unless we hear it or interpret a measurement that we trust. In a very quiet room, close to the speaker, the hum is usually audible. In most homes, with all the heaters, appliances, computers, etc. that are running, the hum is not significant. The system was working properly before I pulled it apart to install a wall unit. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. When I disconnected the system, the subwoofer cable was very difficult to remove from the receiver, In fact, the head came apart in my hand, and I needed to use needlenose pliers to pull the casing off the receiver output jack. I am wondering if I somehow damaged whatever is hooked to the backside of this jack, and whether that might cause the hum. The plug on the end of the cable fell apart? The jack on the receiver separated? It is possible that you damaged the jack on the receiver. Obviously, replacing the subwoofer cable will cure a damaged cable issue. You can quickly check for a damaged jack by using a screwdriver to short the shield (outside) of the subwoofer cable to the shield on a nearby jack. If the problem cures, the the jack must be replaced. Plugging the subwoofer into another outlet can easily cause ground loops. You can test for this situation by using a power extension cord to temporarily use the same outlet for everything in the system. Also, disconnect the cable TV feed if you have one. ----------------------------------------------------------- spam: wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15 13 (Barry Mann) [sorry about the puzzle, spammers are ruining my mailbox] ----------------------------------------------------------- |
#10
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Subwoofer hum: is it my receiver?
When the receiver is
powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. just sticking the 3 light tester into an outlet doesnt mean the GROUNDS are connected correctly. in a perfect world, all the grounds only make contact with the neutral at one point, and that is in the panel OUTSIDE YOUR HOUSE. often electritians connect the neutral to the ground inside the panel, and its also contacting inside the meter box. depending on how far this is and other circumstances this alone can create a hum. and this is just one example of where the tester says yes, but its not quite right. you may not have proper ground rods installed, there may be a water meter that breakes the electrical connection in the plumbing which was being used for the ground. etc... but i would first try this. disconnect any cable tv sources you have and see if it goes away. if that doesnt work, do what robert bass said. either isolate the ground plug, or put em both in the same exact outlet and see what happens. you also didnt say if the different outlets are on the same circuit.. lastly, before taking it back to the shop, take it down to bare bones, and i mean bare. just plug in the sub, and use the radio on the receiver and disconnect everything else. if this fixes it, bring it up one at a time until the hum returns. randy |
#11
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Subwoofer hum: is it my receiver?
When the receiver is
powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. just sticking the 3 light tester into an outlet doesnt mean the GROUNDS are connected correctly. in a perfect world, all the grounds only make contact with the neutral at one point, and that is in the panel OUTSIDE YOUR HOUSE. often electritians connect the neutral to the ground inside the panel, and its also contacting inside the meter box. depending on how far this is and other circumstances this alone can create a hum. and this is just one example of where the tester says yes, but its not quite right. you may not have proper ground rods installed, there may be a water meter that breakes the electrical connection in the plumbing which was being used for the ground. etc... but i would first try this. disconnect any cable tv sources you have and see if it goes away. if that doesnt work, do what robert bass said. either isolate the ground plug, or put em both in the same exact outlet and see what happens. you also didnt say if the different outlets are on the same circuit.. lastly, before taking it back to the shop, take it down to bare bones, and i mean bare. just plug in the sub, and use the radio on the receiver and disconnect everything else. if this fixes it, bring it up one at a time until the hum returns. randy |
#12
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Subwoofer hum: is it my receiver?
When the receiver is
powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. just sticking the 3 light tester into an outlet doesnt mean the GROUNDS are connected correctly. in a perfect world, all the grounds only make contact with the neutral at one point, and that is in the panel OUTSIDE YOUR HOUSE. often electritians connect the neutral to the ground inside the panel, and its also contacting inside the meter box. depending on how far this is and other circumstances this alone can create a hum. and this is just one example of where the tester says yes, but its not quite right. you may not have proper ground rods installed, there may be a water meter that breakes the electrical connection in the plumbing which was being used for the ground. etc... but i would first try this. disconnect any cable tv sources you have and see if it goes away. if that doesnt work, do what robert bass said. either isolate the ground plug, or put em both in the same exact outlet and see what happens. you also didnt say if the different outlets are on the same circuit.. lastly, before taking it back to the shop, take it down to bare bones, and i mean bare. just plug in the sub, and use the radio on the receiver and disconnect everything else. if this fixes it, bring it up one at a time until the hum returns. randy |
#13
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Subwoofer hum: is it my receiver?
When the receiver is
powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. just sticking the 3 light tester into an outlet doesnt mean the GROUNDS are connected correctly. in a perfect world, all the grounds only make contact with the neutral at one point, and that is in the panel OUTSIDE YOUR HOUSE. often electritians connect the neutral to the ground inside the panel, and its also contacting inside the meter box. depending on how far this is and other circumstances this alone can create a hum. and this is just one example of where the tester says yes, but its not quite right. you may not have proper ground rods installed, there may be a water meter that breakes the electrical connection in the plumbing which was being used for the ground. etc... but i would first try this. disconnect any cable tv sources you have and see if it goes away. if that doesnt work, do what robert bass said. either isolate the ground plug, or put em both in the same exact outlet and see what happens. you also didnt say if the different outlets are on the same circuit.. lastly, before taking it back to the shop, take it down to bare bones, and i mean bare. just plug in the sub, and use the radio on the receiver and disconnect everything else. if this fixes it, bring it up one at a time until the hum returns. randy |
#14
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Subwoofer hum: is it my receiver?
"Brian" wrote in message
om Apologies to the group if this has been discussed prior: No problem, if you keep an open mind. Grounding problems with subwoofers are very common, and have been discussed many times. Try searching using words like subwoofer and hum at www.google.com . When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. That makes about as much sense as having a short-term cough and sniffles and not suspecting that you might have a cold. It's probably a ground loop issue or another kind of grounding issue called a "grounding potential difference". Probably, the first thing to do is to eliminate the fact that you have the sub and the receiver grounded at separate points as a potential source of problem. IOW plug the receiver and the subwoofer into the same outlet or plug strip, and see what happens. Also, eliminate the rest of your system as a potential source of problems. Remove all connections from your receiver but power, speakers, and the connection to the subwoofer. Once you get reasonably hum-free operation, add things back one at a time and see if any of them are causing grounding problems. |
#15
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Subwoofer hum: is it my receiver?
"Brian" wrote in message
om Apologies to the group if this has been discussed prior: No problem, if you keep an open mind. Grounding problems with subwoofers are very common, and have been discussed many times. Try searching using words like subwoofer and hum at www.google.com . When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. That makes about as much sense as having a short-term cough and sniffles and not suspecting that you might have a cold. It's probably a ground loop issue or another kind of grounding issue called a "grounding potential difference". Probably, the first thing to do is to eliminate the fact that you have the sub and the receiver grounded at separate points as a potential source of problem. IOW plug the receiver and the subwoofer into the same outlet or plug strip, and see what happens. Also, eliminate the rest of your system as a potential source of problems. Remove all connections from your receiver but power, speakers, and the connection to the subwoofer. Once you get reasonably hum-free operation, add things back one at a time and see if any of them are causing grounding problems. |
#16
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Subwoofer hum: is it my receiver?
"Brian" wrote in message
om Apologies to the group if this has been discussed prior: No problem, if you keep an open mind. Grounding problems with subwoofers are very common, and have been discussed many times. Try searching using words like subwoofer and hum at www.google.com . When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. That makes about as much sense as having a short-term cough and sniffles and not suspecting that you might have a cold. It's probably a ground loop issue or another kind of grounding issue called a "grounding potential difference". Probably, the first thing to do is to eliminate the fact that you have the sub and the receiver grounded at separate points as a potential source of problem. IOW plug the receiver and the subwoofer into the same outlet or plug strip, and see what happens. Also, eliminate the rest of your system as a potential source of problems. Remove all connections from your receiver but power, speakers, and the connection to the subwoofer. Once you get reasonably hum-free operation, add things back one at a time and see if any of them are causing grounding problems. |
#17
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Subwoofer hum: is it my receiver?
"Brian" wrote in message
om Apologies to the group if this has been discussed prior: No problem, if you keep an open mind. Grounding problems with subwoofers are very common, and have been discussed many times. Try searching using words like subwoofer and hum at www.google.com . When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. That makes about as much sense as having a short-term cough and sniffles and not suspecting that you might have a cold. It's probably a ground loop issue or another kind of grounding issue called a "grounding potential difference". Probably, the first thing to do is to eliminate the fact that you have the sub and the receiver grounded at separate points as a potential source of problem. IOW plug the receiver and the subwoofer into the same outlet or plug strip, and see what happens. Also, eliminate the rest of your system as a potential source of problems. Remove all connections from your receiver but power, speakers, and the connection to the subwoofer. Once you get reasonably hum-free operation, add things back one at a time and see if any of them are causing grounding problems. |
#18
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Subwoofer hum: is it my receiver?
(Brian) writes:
When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. You appear to have every symptom of a ground loop problem. If possible, plug the receiver and subwoofer into the same outlet, and I'll betcha a quarter the issue goes away. :-) If plugging them into the same outlet is not feasible, seek out an audio isolation transformer for the line level signal that feeds your subwoofer. This isolates the grounds of the two affected component and often eliminates the hum. Best Regards, -- /"\ ASCII Ribbon Campaign | Todd H \ / | http://www.toddh.net/ X Promoting good netiquette | http://triplethreatband.com/ / \ http://www.toddh.net/netiquette/ | "4 lines suffice." |
#19
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Subwoofer hum: is it my receiver?
(Brian) writes:
When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. You appear to have every symptom of a ground loop problem. If possible, plug the receiver and subwoofer into the same outlet, and I'll betcha a quarter the issue goes away. :-) If plugging them into the same outlet is not feasible, seek out an audio isolation transformer for the line level signal that feeds your subwoofer. This isolates the grounds of the two affected component and often eliminates the hum. Best Regards, -- /"\ ASCII Ribbon Campaign | Todd H \ / | http://www.toddh.net/ X Promoting good netiquette | http://triplethreatband.com/ / \ http://www.toddh.net/netiquette/ | "4 lines suffice." |
#20
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Subwoofer hum: is it my receiver?
(Brian) writes:
When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. You appear to have every symptom of a ground loop problem. If possible, plug the receiver and subwoofer into the same outlet, and I'll betcha a quarter the issue goes away. :-) If plugging them into the same outlet is not feasible, seek out an audio isolation transformer for the line level signal that feeds your subwoofer. This isolates the grounds of the two affected component and often eliminates the hum. Best Regards, -- /"\ ASCII Ribbon Campaign | Todd H \ / | http://www.toddh.net/ X Promoting good netiquette | http://triplethreatband.com/ / \ http://www.toddh.net/netiquette/ | "4 lines suffice." |
#21
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Subwoofer hum: is it my receiver?
(Brian) writes:
When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. You appear to have every symptom of a ground loop problem. If possible, plug the receiver and subwoofer into the same outlet, and I'll betcha a quarter the issue goes away. :-) If plugging them into the same outlet is not feasible, seek out an audio isolation transformer for the line level signal that feeds your subwoofer. This isolates the grounds of the two affected component and often eliminates the hum. Best Regards, -- /"\ ASCII Ribbon Campaign | Todd H \ / | http://www.toddh.net/ X Promoting good netiquette | http://triplethreatband.com/ / \ http://www.toddh.net/netiquette/ | "4 lines suffice." |
#22
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Subwoofer hum: is it my receiver?
A couple other things that can cause hum are cheap cable (or a cable gone
bad),and speaker cables tangled in power cables.Try another cable of high quality and clean up around the back of your system.Have all power cables away from speaker cables.Make sure you are running everything out of one outlet,if needed buy a good power bar. Good Luck Brian wrote in message om... Apologies to the group if this has been discussed prior: When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. My equipment is an Onkyo TX-SR500 receiver and Sony SA-WM20 subwoofer. (I know, not the greatest - but it's what I have.) I tested the subwoofer on a friend's Onkyo, and it worked properly. I swapped subwoofer cables and the hum still occurs. I have disconnected all input/output leads from the receiver other than the subwoofer cable. When the receiver is not plugged in, there is a low hum. When the subwoofer is plugged in, the volume of the hum increases, even with the receiver power off. When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. The system was working properly before I pulled it apart to install a wall unit. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. When I disconnected the system, the subwoofer cable was very difficult to remove from the receiver, In fact, the head came apart in my hand, and I needed to use needlenose pliers to pull the casing off the receiver output jack. I am wondering if I somehow damaged whatever is hooked to the backside of this jack, and whether that might cause the hum. Any advice before I cart the receiver off to a shop is gratefully accepted. Brian |
#23
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Subwoofer hum: is it my receiver?
A couple other things that can cause hum are cheap cable (or a cable gone
bad),and speaker cables tangled in power cables.Try another cable of high quality and clean up around the back of your system.Have all power cables away from speaker cables.Make sure you are running everything out of one outlet,if needed buy a good power bar. Good Luck Brian wrote in message om... Apologies to the group if this has been discussed prior: When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. My equipment is an Onkyo TX-SR500 receiver and Sony SA-WM20 subwoofer. (I know, not the greatest - but it's what I have.) I tested the subwoofer on a friend's Onkyo, and it worked properly. I swapped subwoofer cables and the hum still occurs. I have disconnected all input/output leads from the receiver other than the subwoofer cable. When the receiver is not plugged in, there is a low hum. When the subwoofer is plugged in, the volume of the hum increases, even with the receiver power off. When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. The system was working properly before I pulled it apart to install a wall unit. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. When I disconnected the system, the subwoofer cable was very difficult to remove from the receiver, In fact, the head came apart in my hand, and I needed to use needlenose pliers to pull the casing off the receiver output jack. I am wondering if I somehow damaged whatever is hooked to the backside of this jack, and whether that might cause the hum. Any advice before I cart the receiver off to a shop is gratefully accepted. Brian |
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Subwoofer hum: is it my receiver?
A couple other things that can cause hum are cheap cable (or a cable gone
bad),and speaker cables tangled in power cables.Try another cable of high quality and clean up around the back of your system.Have all power cables away from speaker cables.Make sure you are running everything out of one outlet,if needed buy a good power bar. Good Luck Brian wrote in message om... Apologies to the group if this has been discussed prior: When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. My equipment is an Onkyo TX-SR500 receiver and Sony SA-WM20 subwoofer. (I know, not the greatest - but it's what I have.) I tested the subwoofer on a friend's Onkyo, and it worked properly. I swapped subwoofer cables and the hum still occurs. I have disconnected all input/output leads from the receiver other than the subwoofer cable. When the receiver is not plugged in, there is a low hum. When the subwoofer is plugged in, the volume of the hum increases, even with the receiver power off. When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. The system was working properly before I pulled it apart to install a wall unit. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. When I disconnected the system, the subwoofer cable was very difficult to remove from the receiver, In fact, the head came apart in my hand, and I needed to use needlenose pliers to pull the casing off the receiver output jack. I am wondering if I somehow damaged whatever is hooked to the backside of this jack, and whether that might cause the hum. Any advice before I cart the receiver off to a shop is gratefully accepted. Brian |
#25
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Subwoofer hum: is it my receiver?
A couple other things that can cause hum are cheap cable (or a cable gone
bad),and speaker cables tangled in power cables.Try another cable of high quality and clean up around the back of your system.Have all power cables away from speaker cables.Make sure you are running everything out of one outlet,if needed buy a good power bar. Good Luck Brian wrote in message om... Apologies to the group if this has been discussed prior: When I plug my subwoofer into my receiver and turn on the receiver, I hear a hum. The sound is similar to putting a finger across the subwoofer cable lead. I am trying to understand if there is an obvious cause for this hum, other than a problem with the receiver's subwoofer output jack. I do not believe this is a ground loop issue. My equipment is an Onkyo TX-SR500 receiver and Sony SA-WM20 subwoofer. (I know, not the greatest - but it's what I have.) I tested the subwoofer on a friend's Onkyo, and it worked properly. I swapped subwoofer cables and the hum still occurs. I have disconnected all input/output leads from the receiver other than the subwoofer cable. When the receiver is not plugged in, there is a low hum. When the subwoofer is plugged in, the volume of the hum increases, even with the receiver power off. When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. The system was working properly before I pulled it apart to install a wall unit. Other than upgrading some RCA cables and changing the outlets into which some components plug, no changes were made to the system. When I disconnected the system, the subwoofer cable was very difficult to remove from the receiver, In fact, the head came apart in my hand, and I needed to use needlenose pliers to pull the casing off the receiver output jack. I am wondering if I somehow damaged whatever is hooked to the backside of this jack, and whether that might cause the hum. Any advice before I cart the receiver off to a shop is gratefully accepted. Brian |
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Subwoofer hum: is it my receiver?
"xrongor" wrote in message news:HeDYb.212095$U%5.1223717@attbi_s03...
When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. (snip) but i would first try this. disconnect any cable tv sources you have and see if it goes away. A cable TV connection somewhere in the system (such as connected to your TV or VCR) is often the problem, although other posts in this thread may also be useful. If you have cable TV, try disconnecting the cable from your system. If that solves the problem, then go to www.google.com and search web and newsgroups for fixes. Search terms such as: cable TV hum ground loop subwoofer A few searches will probably lead you to more info and simple fixes. Fixes for this sort of problem are often cheap or free. If the cable TV is the problem, also call cable TV company and ask for advice. If you can't fix the problem, here's another resource: rec.audio.tech But I think your problem should be easy to fix, although it may involve a little trial and error and plugging in your gear a few different ways until you find something that makes the hum go away. if that doesnt work, do what robert bass said. either isolate the ground plug, or put em both in the same exact outlet and see what happens. you also didnt say if the different outlets are on the same circuit.. lastly, before taking it back to the shop, take it down to bare bones, and i mean bare. just plug in the sub, and use the radio on the receiver and disconnect everything else. if this fixes it, bring it up one at a time until the hum returns. randy |
#27
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Subwoofer hum: is it my receiver?
"xrongor" wrote in message news:HeDYb.212095$U%5.1223717@attbi_s03...
When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. (snip) but i would first try this. disconnect any cable tv sources you have and see if it goes away. A cable TV connection somewhere in the system (such as connected to your TV or VCR) is often the problem, although other posts in this thread may also be useful. If you have cable TV, try disconnecting the cable from your system. If that solves the problem, then go to www.google.com and search web and newsgroups for fixes. Search terms such as: cable TV hum ground loop subwoofer A few searches will probably lead you to more info and simple fixes. Fixes for this sort of problem are often cheap or free. If the cable TV is the problem, also call cable TV company and ask for advice. If you can't fix the problem, here's another resource: rec.audio.tech But I think your problem should be easy to fix, although it may involve a little trial and error and plugging in your gear a few different ways until you find something that makes the hum go away. if that doesnt work, do what robert bass said. either isolate the ground plug, or put em both in the same exact outlet and see what happens. you also didnt say if the different outlets are on the same circuit.. lastly, before taking it back to the shop, take it down to bare bones, and i mean bare. just plug in the sub, and use the radio on the receiver and disconnect everything else. if this fixes it, bring it up one at a time until the hum returns. randy |
#28
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Subwoofer hum: is it my receiver?
"xrongor" wrote in message news:HeDYb.212095$U%5.1223717@attbi_s03...
When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. (snip) but i would first try this. disconnect any cable tv sources you have and see if it goes away. A cable TV connection somewhere in the system (such as connected to your TV or VCR) is often the problem, although other posts in this thread may also be useful. If you have cable TV, try disconnecting the cable from your system. If that solves the problem, then go to www.google.com and search web and newsgroups for fixes. Search terms such as: cable TV hum ground loop subwoofer A few searches will probably lead you to more info and simple fixes. Fixes for this sort of problem are often cheap or free. If the cable TV is the problem, also call cable TV company and ask for advice. If you can't fix the problem, here's another resource: rec.audio.tech But I think your problem should be easy to fix, although it may involve a little trial and error and plugging in your gear a few different ways until you find something that makes the hum go away. if that doesnt work, do what robert bass said. either isolate the ground plug, or put em both in the same exact outlet and see what happens. you also didnt say if the different outlets are on the same circuit.. lastly, before taking it back to the shop, take it down to bare bones, and i mean bare. just plug in the sub, and use the radio on the receiver and disconnect everything else. if this fixes it, bring it up one at a time until the hum returns. randy |
#29
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Subwoofer hum: is it my receiver?
"xrongor" wrote in message news:HeDYb.212095$U%5.1223717@attbi_s03...
When the receiver is powered on, the hum's volume increases more. The receiver and the subwoofer are configured to plug into different grounded outlets. Both outlets are properly wired. (snip) but i would first try this. disconnect any cable tv sources you have and see if it goes away. A cable TV connection somewhere in the system (such as connected to your TV or VCR) is often the problem, although other posts in this thread may also be useful. If you have cable TV, try disconnecting the cable from your system. If that solves the problem, then go to www.google.com and search web and newsgroups for fixes. Search terms such as: cable TV hum ground loop subwoofer A few searches will probably lead you to more info and simple fixes. Fixes for this sort of problem are often cheap or free. If the cable TV is the problem, also call cable TV company and ask for advice. If you can't fix the problem, here's another resource: rec.audio.tech But I think your problem should be easy to fix, although it may involve a little trial and error and plugging in your gear a few different ways until you find something that makes the hum go away. if that doesnt work, do what robert bass said. either isolate the ground plug, or put em both in the same exact outlet and see what happens. you also didnt say if the different outlets are on the same circuit.. lastly, before taking it back to the shop, take it down to bare bones, and i mean bare. just plug in the sub, and use the radio on the receiver and disconnect everything else. if this fixes it, bring it up one at a time until the hum returns. randy |
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Subwoofer hum: is it my receiver?
A couple other things that can cause hum are
cheap cable (or a cable gone bad),and speaker cables tangled in power cables... I disagree. You will not get audible hum from defective speaker cables. You also will not get it from wrapping them around power cables. Defective interconnect cables can allow noise to enter the system but the SNR on the speaker cables -- after all of the amplification -- is so great that any induced AC there will not be audible. In all probability this is a ground loop problem. -- Alarm and Home Automation System FAQ http://www.bass-home.com/faq/masterfaq/faq.htm Regards, Robert ============================= Bass Home Electronics 2291 Pine View Circle Sarasota · Florida · 34231 877-722-8900 Sales & Tech Support 941-925-9747 Fax 941-232-0791 Wireless Nextel Private ID - 161*21755*1 http://www.bass-home.com http://www.bassburglaralarms.com ============================= |
#31
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Subwoofer hum: is it my receiver?
A couple other things that can cause hum are
cheap cable (or a cable gone bad),and speaker cables tangled in power cables... I disagree. You will not get audible hum from defective speaker cables. You also will not get it from wrapping them around power cables. Defective interconnect cables can allow noise to enter the system but the SNR on the speaker cables -- after all of the amplification -- is so great that any induced AC there will not be audible. In all probability this is a ground loop problem. -- Alarm and Home Automation System FAQ http://www.bass-home.com/faq/masterfaq/faq.htm Regards, Robert ============================= Bass Home Electronics 2291 Pine View Circle Sarasota · Florida · 34231 877-722-8900 Sales & Tech Support 941-925-9747 Fax 941-232-0791 Wireless Nextel Private ID - 161*21755*1 http://www.bass-home.com http://www.bassburglaralarms.com ============================= |
#32
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Subwoofer hum: is it my receiver?
A couple other things that can cause hum are
cheap cable (or a cable gone bad),and speaker cables tangled in power cables... I disagree. You will not get audible hum from defective speaker cables. You also will not get it from wrapping them around power cables. Defective interconnect cables can allow noise to enter the system but the SNR on the speaker cables -- after all of the amplification -- is so great that any induced AC there will not be audible. In all probability this is a ground loop problem. -- Alarm and Home Automation System FAQ http://www.bass-home.com/faq/masterfaq/faq.htm Regards, Robert ============================= Bass Home Electronics 2291 Pine View Circle Sarasota · Florida · 34231 877-722-8900 Sales & Tech Support 941-925-9747 Fax 941-232-0791 Wireless Nextel Private ID - 161*21755*1 http://www.bass-home.com http://www.bassburglaralarms.com ============================= |
#33
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Subwoofer hum: is it my receiver?
A couple other things that can cause hum are
cheap cable (or a cable gone bad),and speaker cables tangled in power cables... I disagree. You will not get audible hum from defective speaker cables. You also will not get it from wrapping them around power cables. Defective interconnect cables can allow noise to enter the system but the SNR on the speaker cables -- after all of the amplification -- is so great that any induced AC there will not be audible. In all probability this is a ground loop problem. -- Alarm and Home Automation System FAQ http://www.bass-home.com/faq/masterfaq/faq.htm Regards, Robert ============================= Bass Home Electronics 2291 Pine View Circle Sarasota · Florida · 34231 877-722-8900 Sales & Tech Support 941-925-9747 Fax 941-232-0791 Wireless Nextel Private ID - 161*21755*1 http://www.bass-home.com http://www.bassburglaralarms.com ============================= |
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Subwoofer hum: is it my receiver?
"Robert L. Bass" said:
I disagree. You will not get audible hum from defective speaker cables. Depends on the circuit. There's a feedback loop in most amps from output to input, and said input is out of phase with the source signal. Hence, there's no attenuation from feedback for signals intruding in the feedback loop. Because of the high open loop gain in that case, hum and other undesired rubble may well be audible. It can even be demodulated, in case of strong RF signals. I've actually seen amps humming and even oscillating due to interference that came in through the speaker outputs. Some small caps across the outputs and gnd, as well as chokes in the output circuit may well prevent this, shielded speaker cables may help too. -- Sander deWaal Vacuum Audio Consultancy |
#35
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Subwoofer hum: is it my receiver?
"Robert L. Bass" said:
I disagree. You will not get audible hum from defective speaker cables. Depends on the circuit. There's a feedback loop in most amps from output to input, and said input is out of phase with the source signal. Hence, there's no attenuation from feedback for signals intruding in the feedback loop. Because of the high open loop gain in that case, hum and other undesired rubble may well be audible. It can even be demodulated, in case of strong RF signals. I've actually seen amps humming and even oscillating due to interference that came in through the speaker outputs. Some small caps across the outputs and gnd, as well as chokes in the output circuit may well prevent this, shielded speaker cables may help too. -- Sander deWaal Vacuum Audio Consultancy |
#36
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Subwoofer hum: is it my receiver?
"Robert L. Bass" said:
I disagree. You will not get audible hum from defective speaker cables. Depends on the circuit. There's a feedback loop in most amps from output to input, and said input is out of phase with the source signal. Hence, there's no attenuation from feedback for signals intruding in the feedback loop. Because of the high open loop gain in that case, hum and other undesired rubble may well be audible. It can even be demodulated, in case of strong RF signals. I've actually seen amps humming and even oscillating due to interference that came in through the speaker outputs. Some small caps across the outputs and gnd, as well as chokes in the output circuit may well prevent this, shielded speaker cables may help too. -- Sander deWaal Vacuum Audio Consultancy |
#37
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Subwoofer hum: is it my receiver?
"Robert L. Bass" said:
I disagree. You will not get audible hum from defective speaker cables. Depends on the circuit. There's a feedback loop in most amps from output to input, and said input is out of phase with the source signal. Hence, there's no attenuation from feedback for signals intruding in the feedback loop. Because of the high open loop gain in that case, hum and other undesired rubble may well be audible. It can even be demodulated, in case of strong RF signals. I've actually seen amps humming and even oscillating due to interference that came in through the speaker outputs. Some small caps across the outputs and gnd, as well as chokes in the output circuit may well prevent this, shielded speaker cables may help too. -- Sander deWaal Vacuum Audio Consultancy |
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Subwoofer hum: is it my receiver?
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Subwoofer hum: is it my receiver?
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