[gregfisk]

The woofer's themselves won't contribute to the group loop likely unless maybe if the subwoofer amplifier was some estranged balanced output device or CSS driven without a ground/virtual ground... etc. But disconnecting the amplifier for the subwoofers as I suggested would in fact tell us just thus! Perhaps that's what you mean Greg, but I just wanted to make sure because not having speakers connected with a powered amplifier isn't advisable.

Yes, that is what I was saying. If the sub amps are connected to the bypass and are plugged into a different outlet it could be causing a ground loop. What's puzzling to me is the crackle sound Mike is hearing?

[mlundy57]

I've put the filter back in. Touching the body and the barrels did not make a difference, nor did unplugging the interconnect to the sub plate amps.

For clarity, the speaker system is the open baffle Wedgies on top driven by a NAD C372 power amp, and 3x8" servos in an H-Frame on the bottom driven by Rythmik HX300 plate amps. All of the components in the chain are plugged into a Panamax power conditioner which is plugged into a single wall outlet.

Also, the sound I am talking about is not a low frequency hum coming from the woofers but rather a higher frequency hiss/crackle coming from the tweeters. The best way I can think of to describe it is that it sounds like static, like the sound you hear from a radio that is not tuned into a station, only muted. It is in both speakers. It is louder on the back side of the tweeter than the front. It is not loud enough to hear over music playing at a normal volume unless I put my ear right up to the tweeter.  However, when the music is playing very softly or everything is on but no music is playing the sound can be heard from the listening position.

[Danny Richie]

Okay, that doesn't sound like a ground loop now.

[Folsom]

Could it be a broken interconnect? A broken interconnect can radiate RF into both channels potentially. You could check by swapping the extra set used with the filter, with another for the subs or such.

I would move to a metal box and ground it to the jacks incoming. Then wire in star pattern to them, instead of series like now.

[Captainhemo]

If the  extra set of IC's youi've added  checks out ok, I'd actually get he iron out and just  try  setting it up as a straight filter, run the ground direct to the outputs of the filter and skip the  bypass for now.  I know , it shouldn't  make a difference but   it's a place to start.
If that happens to  make  the difference, I'd then try re-doing the bypass but without the series ground like Folsom said , even if you don't replace the box right away.

jay

[mlundy57]

I'll check out the possibility of a bad interconnect after while. Now it is time for some more wetsanding, this time to 800 grit, on the Wedgies I'm building and shoot another coat of poly. Then I get to sand to 1,200 ...

Mike

[corndog71]

I would also check for loose speaker connections, loose servo connections, etc.

[Peter J]

Mike, perhaps you've done it before, but most polyurethanes don't "burn in" like solvent finishes (they typicallly coalesce) which means they are particularly difficult to cut and buff. If you happen to sand through the top layer you get a halo where top coat meets one below. Disregard if you're using catalyzed urethane automotive finishes.

[Folsom]

I would also check for loose speaker connections, loose servo connections, etc.

That cannot be true with what has already been stated.

[Folsom]

Any luck Mike?

[mlundy57]

As a matter of fact, I am totally flummoxed. After extensive swapping of every component, the noise turns out to be intermittent and unrelated to any of the components, interconnects or speaker cables.  It is not even related to a particular file on the computer because sometimes a particular track will have noise and other times that same track will not have the noise even with no change in equipment. The same goes when I play the same track directly from the CD rather than from the computer.

I have tried both solid state and tube components with the same result, sometimes the noise is there, other times it is not.  This is why I hate electrical problems.

The only thing I can think of I haven't tried is something that is on the drawing board but not feasible at this time. That is, when I remodel this room I am going to pull a dedicated 20 amp circuit from the panel box just for the AV equipment. That's about a year away though.

[Danny Richie]

Something in the house is on and generating RFI. Go around the house and turn off or shut everything down until it's gone.

My daughter installed a booster for her modem once and it put a ton of noise on my system.

[Captainhemo]

Something in the house is on and generating RFI. Go around the house and turn off or shut everything down until it's gone.

My daughter installed a booster for her modem once and it put a ton of noise on my system.

Or get Dave to send you an Uber    I recently  had the opportunity to compare the uber to my Minibuss, I was  shocked at the difference as the other fellow i had over to  audition the  two pieces.

I'd bet it is a fredge or a freezer comprssor   cycling on and off  once in a while. If not,  like Danny says, you could try shutting down various circuits to  try and narrow  the search

jay

[mlundy57]

Something in the house is on and generating RFI. Go around the house and turn off or shut everything down until it's gone.

My daughter installed a booster for her modem once and it put a ton of noise on my system.

Now that you mention it, I have recently installed a WiFi booster in the hallway outside my listening room to try and keep the wifi tablet I use to control JRiver from dropping out. Next time I hear the noise I'll unplug it and see if that helps.

Jay,

Something like that may end up being necessary because shutting the house down so I can listen to music will fly about as well as a lead balloon. 

Mike

[Danny Richie]

Now that you mention it, I have recently installed a WiFi booster in the hallway outside my listening room to try and keep the wifi tablet I use to control JRiver from dropping out. Next time I hear the noise I'll unplug it and see if that helps.

Jay,

Something like that may end up being necessary because shutting the house down so I can listen to music will fly about as well as a lead balloon. 

Mike

Just shut stuff down one at a time until you find it.

I'd be willing to bet money on the WiFi booster. Those are really bad. Some of them actually send a signal down your electrical wiring and use it as an antenna. And here we are trying to do everything we can to get all that noise off the line. 

[mlundy57]

Just shut stuff down one at a time until you find it.

I'd be willing to bet money on the WiFi booster. Those are really bad. Some of them actually send a signal down your electrical wiring and use it as an antenna. And here we are trying to do everything we can to get all that noise off the line. 

Danny,

You just brought up another potential issue.  I have set up a wired home network throughout the house but since I couldn't run ethernet cable to every room without tearing up all the walls, my network is based on powerline taps which plug into the outlets in every room and distribute the internet signal over the house electrical wiring.

It looks like I'm going to have to hard wire ethernet cable to each room after all resulting in a bigger remodeling job than I originally planned.

[Folsom]

Could a power conditioner be cheaper?

[Danny Richie]

Danny,

You just brought up another potential issue.  I have set up a wired home network throughout the house but since I couldn't run ethernet cable to every room without tearing up all the walls, my network is based on powerline taps which plug into the outlets in every room and distribute the internet signal over the house electrical wiring.

It looks like I'm going to have to hard wire ethernet cable to each room after all resulting in a bigger remodeling job than I originally planned.

Yep, those are supreme noise makers.

[mlundy57]

Would running a dedicated 20 amp circuit to my listening room clean things up?

The dedicated circuit would come from a second breaker box which is in the garage and separate from the main breaker box (in the master bedroom) that is currently feeding power to the lights and outlets in the listening room. The lights and regular outlets would still be powered from the main box.  Only the AV equipment would be powered from the new circuit.

[Danny Richie]

RFI is radio frequency interference. It picks it up through the air.