Goon Posted May 7, 2002 Share Posted May 7, 2002 I have a problem with my sub humming, and I'm out of ideas on trying to get rid of it. I've done a few things that have minimized it, but its still there. The hum originates from my outside cable tv connection. I have coax going to my cable box, and I connect the RCA audio outs of the cable box to my receiver. If I disconnect the coax at the wall jack in my living room, the hum goes away completely. I have added a grounding block to the coax line, so the line comes in from outside, to the grounding block, then to the jack. Its grounded to some water pipes. This helped quite a bit, but did not completely get rid of the hum. I added another ground wire to the block, but that did not help. I've also added a monster cable HTS850 power center the cable runs through before getting to my receiver. Its more of a surge protector, but I thought I'd try it since I needed a power center anyway. No luck. What else can I do? Do I need to add more grounding blocks? I'm pretty sure there is already one outside that grounds the line where it attaches to the cable box. Its actually getting worse. While I was watching TV today, the hum would get loud for about 30 seconds, then subside. It did it about 20 times. Any help is greatly appreciated. Like I said, I'm out of ideas. ------------------ Klipsch Epic CF-3s Klipsch KLF-C7 Center Klipsch RS-3 II Surrounds Sunfire MKIV True Sub Integra 8.2 Receiver Pioneer DVD player Monster Cable Interconnects and Speaker Cable JVC 32' TV Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted May 7, 2002 Share Posted May 7, 2002 Goon, it sounds like the problem I'm having. We've just discussed this. See my thread here in Mondial General Questions: thread Follow the links on this page to the other discussions as well - it will give you some good info, and some options. I located a Mondial Magic unit on ebay, I'll post to report how it turns out. ------------------ First we Rock, then we Roll! A Beast is Lurking.........To be unleashed May 2002 *** Alpha Testing Complete *** This message has been edited by dndphishin on 05-07-2002 at 11:58 PM Quote Link to comment Share on other sites More sharing options...
boa12 Posted May 7, 2002 Share Posted May 7, 2002 goon, does the sub or any other device have a safety ground on the ac plug (3 prongs instead of just 2)? if so & if u haven't already try those 50 cent cheater plugs from the hardware stores. those 3-2 adapter thingies. solved all my loop noise for $1. ------------------ My Home Systems Page Quote Link to comment Share on other sites More sharing options...
Goon Posted May 8, 2002 Author Share Posted May 8, 2002 Thanks guys, I'm going to get my hands on a Mondial Magic unit. Another question though Boa. My sub manual specifically says never to use a 3:2 adapter, and I'm pretty aprehensive about going against that recommendation. Can you explain what the safety ground you referred to really does, and why it doesn't bother you to remove them with the 3:2 splitters? Guess I don't know enough about electrical circuits.. ------------------ Klipsch Epic CF-3s Klipsch KLF-C7 Center Klipsch RS-3 II Surrounds Sunfire MKIV True Sub Integra 8.2 Receiver Pioneer DVD player Monster Cable Interconnects and Speaker Cable JVC 32' TV Quote Link to comment Share on other sites More sharing options...
eq_shadimar Posted May 8, 2002 Share Posted May 8, 2002 Another option would be to lift the ground between the receiver and the sub (assuming that it is only your sub that is humming). I had to do this with my system. I purchased a line level device from Mars music that elminated the hum coming from my subwoofers. You could also make sure that your subwoofer is plugged into the same circuit as the rest of your equipment. If you want to go the cheap route there are some cheaper solutions than the Mondial units. Laters, ------------------ ...wake up to find out that you are the eyes of the world... My Home Theater Page Quote Link to comment Share on other sites More sharing options...
boa12 Posted May 8, 2002 Share Posted May 8, 2002 goon, they say that for liability reasons. if your sub is the only thing w/ a 3-prong plug i'd definitely do it though have to be careful touching it when plugged in. a cheater does NOT reduce power to the device. it just lifts the safety ground which usually causes a ground loop if another device like the cable tv has a different ground. a lot of SUBS come w/ a 3-2 adapter plug. GL can be real tricky though. you can even get them w/ all safety grounds lifted. try the magic 1st. may work totally if that cable tv is the only source of the GL. wasn't in my case though. just put it right in where the cable tv line comes into the house (before any other splitter or device). ------------------ My Home Systems Page Quote Link to comment Share on other sites More sharing options...
boa12 Posted May 8, 2002 Share Posted May 8, 2002 oh & eq has a good point but like me u probably have more connections between the cable box/tv & receiver, like s-video, analog audio, digital audio. i have like 8 different connections so the cheaters were my only choice to take away ALL the noise. or unless i wanted to buy like 8 quality GL isolators for like $500 to maintain the same quality audio & video. ------------------ My Home Systems Page Quote Link to comment Share on other sites More sharing options...
Goon Posted May 8, 2002 Author Share Posted May 8, 2002 Thanks. I'm 100% sure that my only ground loop problem is with the cable line. I think my receiver is the only other component with the safety ground, and I don't know if the outlet my sub is on and the outlet my other equipment is on are on the same circuit. I'll have to check. I'll probably pick up the magic unit, but just to try it, I'll give the 3:2 a try as well. Thanks guys. ------------------ Klipsch Epic CF-3s Klipsch KLF-C7 Center Klipsch RS-3 II Surrounds Sunfire MKIV True Sub Integra 8.2 Receiver Pioneer DVD player Monster Cable Interconnects and Speaker Cable JVC 32' TV Quote Link to comment Share on other sites More sharing options...
boa12 Posted May 8, 2002 Share Posted May 8, 2002 goon, since your receiver has the 3rd prong safety ground it's probably more coming from there on that end. so yea u'd have to do that 3-2 too. i do it for all but u do have to be careful touching them in case the equip may have some elec problem causing voltage on the case. hopefully that magic will fix it for u w/o having to use any cheaters. ------------------ My Home Systems Page Quote Link to comment Share on other sites More sharing options...
Goon Posted May 8, 2002 Author Share Posted May 8, 2002 Whoa! I can't believe those Mondial Magics are $99! Thats a little pricey for something that may, or may not, solve my problem. Oh well, I'm gettin one anyway. ------------------ Klipsch Epic CF-3s Klipsch KLF-C7 Center Klipsch RS-3 II Surrounds Sunfire MKIV True Sub Integra 8.2 Receiver Pioneer DVD player Monster Cable Interconnects and Speaker Cable JVC 32' TV Quote Link to comment Share on other sites More sharing options...
boa12 Posted May 8, 2002 Share Posted May 8, 2002 most have a pretty liberal return policy. www.audioadvisor.com is real good. ------------------ My Home Systems Page Quote Link to comment Share on other sites More sharing options...
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