JP Rizal Posted August 11, 2012 Share Posted August 11, 2012 My TV has an audio out L/R connection. I connected via RCA to the C4 Audio Matrix Switch. It works... BUT because of the low quality audio and humming it is unuseable. Any ideas on how to fix it?Grounding?, Settings on the matrix switch? If I can reduce or get rid of the humming completely will be awesome.I'm using a good quality RCA connectors I've also tried replacing the RCA cable with the same result. Any ideas will be helpful. Thanks Link to comment Share on other sites More sharing options...
TexasBill Posted August 11, 2012 Share Posted August 11, 2012 My TV has an audio out L/R connection. I connected via RCA to the C4 Audio Matrix Switch. It works... BUT because of the low quality audio and humming it is unuseable. Any ideas on how to fix it?Grounding?, Settings on the matrix switch? If I can reduce or get rid of the humming completely will be awesome.I'm using a good quality RCA connectors I've also tried replacing the RCA cable with the same result. Any ideas will be helpful. ThanksEVERY TIME I have had "humming" is has been related to a bad ground. That would be my guess. Bill Link to comment Share on other sites More sharing options...
JP Rizal Posted August 11, 2012 Author Share Posted August 11, 2012 EVERY TIME I have had "humming" is has been related to a bad ground. That would be my guess. BillYeah mine too. But I just don't know how/where to fix it. What do I ground? How do I ground? Might be simplistic but I do not know what and how I guess more specifically. :-) Link to comment Share on other sites More sharing options...
AceOfSpades Posted August 11, 2012 Share Posted August 11, 2012 Possibly consider changing the outlet location to see if that fix the issue. Also consider replacing the Power cable also. Link to comment Share on other sites More sharing options...
CFUG Posted August 11, 2012 Share Posted August 11, 2012 My TV has an audio out L/R connection. I connected via RCA to the C4 Audio Matrix Switch. It works... BUT because of the low quality audio and humming it is unuseable. Any ideas on how to fix it?Grounding?, Settings on the matrix switch? If I can reduce or get rid of the humming completely will be awesome.I'm using a good quality RCA connectors I've also tried replacing the RCA cable with the same result. Any ideas will be helpful. ThanksAre electrical outlets even grounded there in the Philippines? Link to comment Share on other sites More sharing options...
JP Rizal Posted August 11, 2012 Author Share Posted August 11, 2012 Possibly consider changing the outlet location to see if that fix the issue. Also consider replacing the Power cable also.I see. We'll the TV is plugged to a Monster Power Cleaner Surge protection (HT-350 something) I think those has internal grounded outlets. I could try to change where that is plugged but not sure if that would help. The C4 Audio Matrix Switch is plugged to the rack that plugged to an APC Back-UPS. Again my options are kind of limited in where to re-plug the APC but I could try.Are electrical outlets even grounded there in the Philippines?Yep, The whole house is earthed to the ground by copper wire. So is the electrical panel. Would this be something my electrician can check or improve on. Link to comment Share on other sites More sharing options...
LSDave Posted August 11, 2012 Share Posted August 11, 2012 This sometimes happens if the TV and the amp are on different circuits. The way i narrowed it down to a ground issue was to buy one of those ground lift adapters for a 3 prong plug. I plugged the TV into that(essentially removing the ground on the tv) and the problem went away. So i know i had a difference in ground on the power circuits that fed my C4 amp and my TV. Another band aid type solution, but will work well is a ground loop isolator. These are used commonly in car audio environments. They are cheap and go inline with the existing RCA cable.The only reason my solutions mentioned would not work is if the hum was being induced into the RCAs from a nearby powercable...... which is unlikely. Link to comment Share on other sites More sharing options...
CFUG Posted August 11, 2012 Share Posted August 11, 2012 I had to do that on a cheap mixer- totally got rid of the hum. The other thing to check is that the RCA cable is not parallel to the mains line and one last thing, does your TV have optical-out? Link to comment Share on other sites More sharing options...
JP Rizal Posted August 11, 2012 Author Share Posted August 11, 2012 I had to do that on a cheap mixer- totally got rid of the hum. The other thing to check is that the RCA cable is not parallel to the mains line and one last thing, does your TV have optical-out?Nope, no optical out. And no the RCA's were way far from any electical wires not to mention properly shielded Link to comment Share on other sites More sharing options...
CFUG Posted August 12, 2012 Share Posted August 12, 2012 Then try a cheater plug on one or the other. Your not going to get rid of the TV or the switch and you already changed-out audio connects... Link to comment Share on other sites More sharing options...
TexasBill Posted August 12, 2012 Share Posted August 12, 2012 JP - Note - if "lifting the ground" works (the cheater plug) you should not (in my opinion) leave that fix in place - it is diagnostic only - making the amp and the TV (or what ever component is on a different line) work off the same ground/plug or grounding it better is necessary. Grounds are there for a reason, as many a guitarist/soloist has found out much to their dismay when their sound guy lifts the ground to solve a hum problem and they grab the mike stand while plugged in.Bill Link to comment Share on other sites More sharing options...
CFUG Posted August 12, 2012 Share Posted August 12, 2012 He's not running cut-rate band instruments here- he's running the same equipment we are. Induced noise is very common and shorts to the case are not so. Link to comment Share on other sites More sharing options...
TexasBill Posted August 13, 2012 Share Posted August 13, 2012 He's not running cut-rate band instruments here- he's running the same equipment we are. Induced noise is very common and shorts to the case are not so.JP - please ignore anything that I said - Control 4 user guy knows way more than I do on this subject, grounds obviously are simply not necessary. Bill Link to comment Share on other sites More sharing options...
LSDave Posted August 13, 2012 Share Posted August 13, 2012 IF you do not want to mess around with power circuits.... get one of these...http://www.thesource.ca/estore/product.aspx?language=en-ca&catalog=online&category=Stereo%20Cables&product=2700054 Link to comment Share on other sites More sharing options...
CFUG Posted August 13, 2012 Share Posted August 13, 2012 He's not running cut-rate band instruments here- he's running the same equipment we are. Induced noise is very common and shorts to the case are not so.JP - please ignore anything that I said - Control 4 user guy knows way more than I do on this subject' date=' grounds obviously are simply not necessary. Bill[/quote']?? Didn't I just say that I had an instance where a cheater plug worked? It was on a piece of cheap band gear... Link to comment Share on other sites More sharing options...
CFUG Posted August 13, 2012 Share Posted August 13, 2012 At any rate, it's easy to measure the differential V between true-earth and case to see if if I'm right Link to comment Share on other sites More sharing options...
JP Rizal Posted August 15, 2012 Author Share Posted August 15, 2012 IF you do not want to mess around with power circuits.... get one of these...http://www.thesource.ca/estore/product.aspx?language=en-ca&catalog=online&category=Stereo%20Cables&product=2700054Thank you all for your responses.LSDave, I was reading about the product. Is this suppose to replace the current (offending) RCA audio cable. Link to comment Share on other sites More sharing options...
CFUG Posted August 15, 2012 Share Posted August 15, 2012 ^I would avoid this product and obtain a few different sized ferrite chokes. All the IW TSs come with chokes so maybe you can use those. Wrap your audio and the power cables for both TV and switcher. Much cheaper than a snake-oil cable product... Link to comment Share on other sites More sharing options...
LSDave Posted August 15, 2012 Share Posted August 15, 2012 ^I would avoid this product and obtain a few different sized ferrite chokes. All the IW TSs come with chokes so maybe you can use those. Wrap your audio and the power cables for both TV and switcher. Much cheaper than a snake-oil cable product...You obviously do not understand how a ground loop isolator works. No "snake oil" sales here. Ferrite chokes will most likely not work as they are typically for filtering out higher frequencies(often in the MHz)..... not the 60hz hum that he is hearing.Basically it has 2 1:1 isolation transformers, which eliminate the electrical connection from the input to the output while letting the signal pass through. And for the original poster.... you don't get rid of the existing cable, it just goes in line at one end. Typically the ground loop isolator is 8-12 inches long Link to comment Share on other sites More sharing options...
CFUG Posted August 16, 2012 Share Posted August 16, 2012 Well then, I guess OP should spend the $20 huh? Link to comment Share on other sites More sharing options...
berazafi Posted August 16, 2012 Share Posted August 16, 2012 Use RCA baluns over a Cat5 cable, this should isolate the ground loop you are having Link to comment Share on other sites More sharing options...
CFUG Posted August 16, 2012 Share Posted August 16, 2012 Did the cheater plug work or did it not? Link to comment Share on other sites More sharing options...
JP Rizal Posted August 16, 2012 Author Share Posted August 16, 2012 Did the cheater plug work or did it not?I have yet to go to RadioShack to pick up a couple. I will post it as soon as I get to try it. Thanks for everyone's input. Link to comment Share on other sites More sharing options...
CFUG Posted August 16, 2012 Share Posted August 16, 2012 Is this a power-related hum (60Hz) or something higher-pitched? I still find it hard to believe that equipment today could be so faulty as to lay-down induced or direct A/C on the chassis and RCA outers. You said that the RCAs were not close to the mains but are they of reasonable quality? My guy makes ALL his own RCAs and digital coax assy. so they are good to go no matter where they are placed. Link to comment Share on other sites More sharing options...
LSDave Posted August 16, 2012 Share Posted August 16, 2012 My guy makes ALL his own RCAs and digital coax assy. so they are good to go no matter where they are placed.If he is indeed hearing a 60hz hum.... which it sounds like that is his problem, I am almost willing to bet his cables ARE NOT the issue. You can get that hum where there is a a difference in ground potential between the 2 devices that are being connected by the RCA cables. In some houses, if the RCA is run a long length, the mains circuits that the 2 devices are plugged into might have a difference in ground(this can happen for a number of reasons). When you plug the RCAs between them, it essentially becomes a ground wire for the device with a higher ground. And since our power in north america is 60 Hz, thats why it becomes audible.The original poster seems confident that its not an induced hum into the cable. That is why i think he has a ground loop.The RCA over CAT5 baluns will most likely work as well, because they convert the standard RCA to a balanced single then back at the other end. I have seen instances where ground loops can still occur over balanced cables, but its not as likely. They still use DI boxes(ground loop isolators for pro audio) in some night clubs. Link to comment Share on other sites More sharing options...
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