Blown or Fried Crossover

knownalien

How would you know if you had one? Does the speaker hum?

F1nut

Can you provide more info on what is going on and with which speaker?

knownalien

well, I thought that I had a typical ground loop at 60 Hz. Don't ask me how I know it's 60 Hz, I just do. Anywho, I bought a Jensen transformer for $50 which supposedly could fix it, because MUCH of the problem seemed to come from the cable box (has hardrive in it DVR). In other words, if I unplugged the cable coaxial and the problem went away mostly, so the Jensen seemed like a no-brainer. the Outlaw 7500 I use powers all the fronts and bi-amps the LSi15's (the 7500 is a 5 channel 300 watt 4 ohms).I have an outlaw 2200 mono amp that powered the LSi9 rears. The rears never had the hum. Swtiching power sources of the amps never changed anything. The symptom was that when DVD (for example) was selected but no source played, you could put your ear next to the drivers (tweeter too) of all of the fronts and hear the hum. I tried everything I could think of including help from the Outlaw forum:

http://ubb.outlawaudio.com/ubb/ultimatebb.php?/ubb/get_topic/f/34/t/000987.html

In the end, I simply used the 2200 mono blocks to power the LSi15's (obviously no bi-amping) and not the only thing you hear out of the LSi15's is a hiss from the tweeter . . . different from a hum. the 7500 is still assigned to the LSiC and the LSi9 rears (where the hum has now emerged).

The hum is a low level hum which does not increase in volume. My concern is that the "hum" takes away from the accuracy of the music if it is also trying to play this "hum."

knownalien

But I feel like the culprit is REALLY the cable box. If I unplugg its power cord completly, the sound still exists, but it I unplugg the cloaxial the problem DOES go away. This is why #1 I am baffled the Jensen doesn't work and #2 that somehow the 2200's are doing a better job of "shielding" the channels.

wirebill

Hello,
Is your cable connection on the outside of your house grounded to your electrical service? If not, it should be. Just a thought.
Bill

knownalien

wirebill wrote:

Hello,
Is your cable connection on the outside of your house grounded to your electrical service? If not, it should be. Just a thought.
Bill

I don't believe it is, but it is unclear how this would be. Do you mean the metal rod in my basement should somehow be connected to one of the ground screws on the splitters?

wirebill

The metal rod that you are talking about is most likely the ground rod.The cable system should be grounded to your electric service. you can run a wire from the cable spliter and connect it to the ground rod clamp.The cable spliter should have a ground screw on it. I don't know that it will solve your hum problem but there is a good chance that it will.
Good luck,
Bill

knownalien

^^ I have tried this before, but I admit the connection wasn't very good. I will try this now.

knownalien

ok. I used the ground wire of cable used for 20 amp sockets. The connections are secure. the hum remains.

VXR8

Hi,

Out of left field but maybe trying something like a Belkin Pure AV product to "filter" out the nasties may help too? Just a suggestion.

knownalien

I already own and use the Monster Ht2000 MKII.

wirebill

"I already own and use the Monster Ht2000 MKII."

You may want to try connecting the cable directly into the cable box without going through the monster filter. I have heard of them sometimes creating noise.
Bill

Serendipity

wirebill wrote:

"I already own and use the Monster Ht2000 MKII."

You may want to try connecting the cable directly into the cable box without going through the monster filter. I have heard of them sometimes creating noise.
Bill

Sometimes these things create problems in the signal. Not saying that power conditioners are useless, they have a purpose, but sometimes they can create problems (first hand experience).

knownalien

wirebill wrote:

"I already own and use the Monster Ht2000 MKII."

You may want to try connecting the cable directly into the cable box without going through the monster filter. I have heard of them sometimes creating noise.
Bill

it was already set up that way (bypassing the conditioner). in fact, since the run from the monster to the cable box was a short one I decided I wouldn't skimp out on that one and use a Comcast cable (when it originally went through the Monster). So, I went to Tweeter and bought a very expensive one. Would you believe it caused more noise than the Comcast one??!!!! I think I may have a bad cable. Ok, but what gets me is why the mono blocks (2200) seem to be able to handle that better than the 7500 made by the same company (see my sig)???

wirebill

I think at this point I would try calling the cable company and see if they can help, but I wouldn't count on it.
I'm running out of ideas.
Bill

adam2434

Have you tried a 3-prong to 2-prong adapter (cheater plug) for your amps? This approach lifts the earth ground, so do so at your own risk. However, it can reduce ground loop hum significantly though, and is a cheap experiment.

A combination of this and a cable isolation transformer eliminated 90% of my hum (barely audible).

knownalien

adam2434 wrote:

Have you tried a 3-prong to 2-prong adapter (cheater plug) for your amps? This approach lifts the earth ground, so do so at your own risk. However, it can reduce ground loop hum significantly though, and is a cheap experiment.

A combination of this and a cable isolation transformer eliminated 90% of my hum (barely audible).

that might be an idea. But I just know that Comcast ain't gonna lift a finger to kill a hum. But, I may be able to get them to give me better cable cut to length, because much of the cable I have is too long and therefore wound up, which may aggravating the problem. the 3 to 2 prong apprach may be a last case scenario thing, but I never heard of it before.