My system is in my sig, but I use AudioQuest Type 2 on the fronts and center. A cheaper wire is used on the surrounds and I use Outlaw interconnects.

Anywho, I have not be able to isolate the hum. True, you have to put your ear up to the speaker to hear it, but the ultimate question is is this hum really hurting the listening experience? I mean, I have no way to test if, but does the hum go up in volume with the music? When the 990 is set to zero volume, the hum is just as loud as it is when the volume is -65!

I would like to explore the idea of XLR's except that I need two splitters since I bi-amp the LSi15's. I have not been able to find anything on the internet that allows me to do this.

thoughs?

I know there are dozens of "hums" thread but and Gonk suggested a $49 solution that may or may not work. We have so many electronics in our home that it is difficult to find the culprit.

If you want to determine whether the Jensen will help or not, try unplugging the cable TV coax from the cable box and see if the hum disappears. If it does, the Jensen's the best bet. If the hum is unrelated to the cable TV service, the Jensen will probably not help at all.

If the hum is the same at any volume position when the source device is not playing anything, then it's unrelated to the volume control. That definitely makes checking for cabling issues a worthwhile exercise - make sure connections are tight and that power cables aren't crowded alongside speaker or interconnect cables.

How close to the tweeter do you have to be to hear the hum when nothing is playing? If we're talking a foot or more, I'd certainly keep searching, but if we're talking about an inch or two I might not get too caught up in the "hum hunt."

I to had an annoying hum. The cable box, having used Gonk's method of isolation, was not the culprit. I ended up going the XLR route using XLR splitters. This removed all the noise except for the noise generated by the wireless dog collar! Gotta keep Chessie around so I put up with it. Jim

you have to put your ear right up to it. In the scenario I pointed out, do you think XLR's would defeat such hums as mine (which I am almost 99.9% sure is related to the cable box)?

where did you get those XLR splitters?

gonk, let me be blunt, does the tiny little hum take away from the response and clarity of my vifa tweeter and Polk mid range drivers?

If you have to get your ear right up to it, then I wouldn't think we're talking about much. Of course, if it is related to the cable box (which can be proven by simply pulling the plug on the cable box), the Jensen should cure it and make it a moot point.

They are just a pair of female XLRs soldered to a male XLR in parallel.

Here's a link
http://www.audiogear.com/Audio-Adapters-Xlr.html
You can also do a search for a XLR Y
Jim

Hey somebody - what kind of hum is it that comes out of tweeters? I thought hum was always 60Hz and its overtones.

the hum coming out of the drivers is playing a 60Hz hum, but the tweeter is going to play all of the overtones based on the 60Hz.

*update*

I went behind the cable box and unplugged the cable cord. This reduces slightly the hiss, but something is still there. So I unplugged the component video cables that went from the cable box to the 990. This alone reduced about 70% of the problem. The cable box remained to be plugged in to the 990 via the optical cable, but removing this did nothing to the hiss.
Next, I went to the outlaw cables and some monster ones. I use Outlaws PCA cables on all speakers except the sub, which uses a thick monster Cable. I have to use a Monster set of y adapters for the bi-amping of the LSi15's and Outlaw doesn't make their own brand of Y-splitter. I discovered that the Monster, like the Outlaw PCA's is designed to be plugged directionally which means arrows indicate the flow of the signal. I discovered that this was put in wrong initially. Just unplugging everything eventually got the noises to stop. It's interesting, even with the fronts PCA's disconnected, the 7500 is still sending some signal, and depending on where you put the PCA's (to lay down) you can get quite a bit of noise. I then plugged everything back in except for the Cable component and the cable into the back of the comcast cable box. The hiss was reduced greatly. So I have linked 70 or 80% to the cable box.

BUT, I got to thinking as I was unplugging the Outlaw PCA's from the back of the 990 (both Outlaw products). You see, the cables are quite heavy and since the are likely to dangle downward, the apply quite a lot of pressure on the output jacks of the 990. Are these output (RCA looking) jacks on the 990 at risk of becoming part of the problem themselves? I say this because even when all of the cable cords were removed from the 990, if you were to use your hand and grip the audio chords exiting the 990, you could hear QUITE a noticeable distortion. Call me paranoid, but thatr doesn't seem right.

thoughts?

I've always heard "noise" from speakers when moving around cables with components turned on - others here with a better EE background could offer a specific explanation, but I've run into it with every component I've ever had. Technically, I suspect the recommendation would be to turn everything off when switching cables around and then turn things back on, although practically you're not likely to hurt anything by moving cables around when things are on.

By the way, have you come across this link ?

hell's bells, I guess Outlaw does make them. But they don't make a PCB version.