Help!!! (1 Viewer)

[Kha:T]

My home theater is driving me nuts. Please help...

I used to have a cheap (~$50 some 5-6 yrs ago) surge protector/powerstrip made by Archer that I bought at Radio Shack. It had several switched and unswitched outlets, and I plugged all of my equipment (TV, DVD player, powered subwoofer, etc.) to it. It had never given me the kinds of problems I am having now.

About two weeks ago, I decided to replace that Archer unit with a Monster Cable power center (HTS2600), which is plugged into a wall outlet using a ground lift (3-prong-to-2-prong adapter). I still have the very same equipment, but I also added another subwoofer. Before, I hooked up the single subwoofer to the LFE out on my Onkyo receiver (TX-DS797) using a subwoofer cable. Since I now have 2 subwoofers, I run a Y splitter at the LFE out on the receiver and run a subwoofer cable to each respective subwoofer. I also hook up all equipment to the designated outlets on the HTS2600, e.g., receiver plug to "receiver" outlet, cd plug to "cd" outlet, so on so forth. I plug the subwoofer power cables to the "timed" outlets on the power center.

Here are my problems, which had never happened before I got the extra subwoofer and HTS2600. Every time I turn on the receiver, my subwoofers (a Mirage and an Earthquake) make a loud thump. When I press and switch between the source buttons (cd, dvd, video2, video3, etc.) on the receiver, I can hear faint, transient pops coming from the front and/or center speakers. My Mirage sub never emitted a hum so loud when it's on. Actually I never noticed the hum before, but when it's on now, it's so loud that it's becoming annoying. The ground seems to be O.K, as the ground indicator on the power strip to which the power center is connected to reads O.K. The ground indicator on the power center also reads O.K.

Does someone know what's going on? I'm suspecting that there may be a ground loop in my system, but I'm not an electrician and do not know how to check it. Please, someone help me solve this problem.

Thanks in advance for all help and inputs.

 

[Ed Moxley]

If there is a hum, there is probably a ground loop problem. Even though you have the 3 prong grounding plug, it doesn't necessarily mean that you are grounded good. There could be corrosion in the lines or hookups, in the walls. Try plugging the sub's power cord in another outlet in the room. The "Y" adapter you're using may not be shielded good.
Good luck. Maybe someone else will have more suggestions.

 

[Kha:T]

Thanks for your input, Ed.

Here's what I tried. I unplugged the two subwoofers and the receiver from the HTS2600 and plugged them all into another cheapo (~$20) Monster Cable powerstrip/surge protector. I turned the receiver on and there was no thump. The hum was still there, but it's quieter than when those three things were plugged in the HTS2600. So I think I've narrowed it down to the HTS2600.

Another thing. I noticed how the amperage indicator lights on the left side of the HTS2600 momentarily spiked up then just as quick went down when I turned on my TV set or receiver/subs. Is that at all normal? Could that current spike be the culprit that causes the "on" thump from the subs? Does anyone else have a Monster Cable power center and have a sub or two connected to it? Do you have the same problem?

 

[Ed Moxley]

I would guess that to be normal. It always takes more power to boot something up, than to keep it going. That's why a lot of people leave their computers on 24/7. It takes more gas to crank a car, than to let it sit there and run for a couple minutes, when stopped and talking with friends. Same kind of thing. I don't use those kind of power strips, so I haven't had the experience with them.........