Has anyone tried to use the Jensen SUB-1RR or CI-1RR Audio Isolators instead of a Jensen VRD-1FF CATV Isolator to fix subwoofer hum caused by a ground loop? If so, did it work and which one would be best for my Aperion S-8 sub?

I tried the VRD-1FF CATV Isolator, which took care of the ground loop hum; however, it also screwed up my CATV (lost 3-4 channels, heavy pixelation on a few HD channels, problems with OnDemand).

Instead of blindly upgrading to a 705 or 805, or spending more time chasing down reflections of the video signal in my coax and possibly having to deal with Comcast, I'm thinking of swapping out the VRD-1FF for the SUB-1RR or CI-1RR. I like the idea of leaving the CATV feed alone and taking care of the ground loop problem on the RCA line between the receiver and the sub.

SUB-1RR ($115): *jensen-transformers.com/sub1rr.html
CI-1RR ($115): *jensen-transformers.com/ci1rr.html
VRD-1FF ($60): *jensen-transformers.com/iso_vid.html

*Add "www." here. I'm new to the forum and not yet allowed to post URLs.

Receiver: Onkyo TX-SR605
Speakers: Aperion Intimus 422 Harmony 5.1 system (422-LR front, surrounds; 422-C center, S-8 powered subwoofer)
CATV Box: Motorola DCT3416 I
TV: Sony KDL-46W3000
DVD/CD: Older Panasonic DMR-EH50 DVR/DVD/CD

Coax to Motorola. HDMI from Motorola to 605. Component from Panasonic to 605. HDMI from 605 to TV. 15' Dynex (inexpensive from Best Buy) RCA with Y adapter from 605 to Left and Right inputs on S-8 subwoofer (recommended by Aperion). I am also considering replacing the 15' Dynex with a 6' subwoofer cable from Monoprice (can't find a 6' cable locally).

I have the front, center, and surround speakers set to 100Hz on the 605. I also have the cutoff frequency on the 605's LFE channel's low-pass filter set to 100Hz. I have the crossover on the S-8 set to 100Hz (phase set to 0, level set to 5/10). The sub's power is grounded. All of the above equipment is on the same surge protector.

The hum isn't there when the sub is turned on. It starts as soon as the 605's LFE channel kicks in, regardless of input (CD, Tuner, DVD, or CATV). The behavior is the same with the CATV Box on or off. The hum stops as soon as I unplug the coax from the CATV Box.

Thanks in advance for helping me find the quickest path to no more hum.

cheater plug works for me, and now I use something like below for safety:
http://www.tripplite.com/products/conditioners/transformers.cfm#general_purpose

I just noticed your post. I assume you found an answer long ago, but thought I would reply anyway, if only for the benefit of other forum members.

Full disclosure: My company sells Jensen Transformers products.

I speak from experience when I say that the VRD-1FF is a very good cable TV isolator...arguably the best in the world. I know...consider the source. But even so, just looking at the specs, the insertion loss is very low and I can truthfully say that we almost never hear complaints about losing channels. In the few cases where we have, we found that the connector(s) on the VRD-1FF had been damaged during installation.

Jensen Transformers uses F connectors that are of a very high quality, from an electrical perspective, but that high level of electrical performance comes with a caveat - those electrically elegant connectors are somewhat mechanically fragile. What we have found is that among the handful of VRD-1FF isolators that we have seen returned due to performance problems, all of them had damaged connectors. You can actually shake the device and hear the metal parts rattling around inside.

The problem is caused by misshapen center conductors on the connecting coaxial cables. Jensen Transformers advises this issue in the installation instructions and we actually offer RF cables that have high-quality F connectors with dedicated center pins rather than just using the center conductor of the cable as most cables of this type do.

Needless to say, if the connectors become damaged, performance is likely to be compromised, and that certainly can cause problems, particularly with weaker channels. This is one of the few issues that is not covered by Jensen Transformers' excellent warranty, so my best advice is to pay close attention to the connecting cables. If you don't want to buy new cables, it might save you some frustration and expense to examine your old ones under magnification before sticking them into a VRD-1FF.

On your other idea about isolating the hum from the audio side, that is certainly an option, but unless the ground loop is only manifesting itself in the form of hum in your sub-woofer, it is going to cost more money to fix it that way. I know a lot of audiophiles who are using IsoMax isolators on all of their line-level interconnects. It is a viable approach for a dedicated stereo system, but it can get pretty complicated (and expensive) in a system that needs to handle both audio and video.