OH NO Buzzing for me TOO!!!

[zx_toth]

Last night I accidentally left my whole system on .... leaving it on for a good 8 hours straight. I woke up this morning horrified by this and quickly turned the whole setup off. No problem I thought.

I brought home the projector from work today as I did a presentation today and thought Id fiddle around with it. I plugged it in using simple composite video cord as thats all I had laying around and turned my rig on ....

immediately I got a terrible buzzing sound from my right speaker. Perhaps from the mid/woofer as it is a mid frequency not really high frequency ... I can get rid of the buzzing by disconnecting the positive (red) binding post on my Rotel Amp. This defeats the purpose of course as I need that connected to hear sound.

At least I know its my right speaker and the woofer or possible the tweeter (not really sure how either would sound if they buzzed) and I know that it stops I disconnect the positive speaker wire connection.

Any suggestions? The only things that happened that is different from yesterday is that I had left the system on all night and second I connected an extra electronic into my Monster Power Center while swapping a few cords (took out a component video cord and swapped it for a composite video).

Appreciate your guys advice ... I keep doing some more process of elimination stuff ...

Zsolt

[zx_toth]

As I disconnected more and more electronics from my Monster Power Center the buzzing has decreased. But as soon as I plug even more than my reciever in the buzzing returns to the speakers. This wasnt so yesterday :( Not sure what to do now....

[bigaudiofanatic]

Try a different outlet in a different room and see what that does you are creating a ground loop somewere in the circuitry.

[zx_toth]

Ill go try a different outlet now and see what happens ....

Since I know nothing about ground loops I did a search of the definition/explaination

A ground loop is created when two elements in a circuit or two different machines connected together receive their ground reference signal from different places. A different ground potential (voltage) creates this loop, interfering with the signal. Special ground-isolation devices are needed to cure the problem. Ground loops are also a problem in audio, where their most disturbing effect is a low frequency oscillation known as "hum" or "motorcycling". Some audio related ground loop problems can be cured by properly reconnecting the ground leading cables to a single point, usually at the most sensitive input area, or at the power supply. Such problems mainly emerge when high amplification is needed, such as when microphones or other sensitive pick-ups are connected to the system.

What are these "Special isolation devices"? I dont have cable cord or satelite setup hooked in (from my searching the forum, this seems to be one of the most common suggestions).

Zsolt

[woofiepaws]

Right side, left side or both?

[bigaudiofanatic]

Correct

[zx_toth]

Just the right speaker, not both.

On the back of my Monster Power Center there is a copper binding post labelled ground. Not sure if I can somehow use this to solve my problem. Im still trying to understand what a ground loop is and why I all of the sudden am plagued by it considering yesterday everything was "peachy:.

[zx_toth]

I plugged in my Power Center to a different outlet and that did nothing as there was still buzzing coming from the speaker.

Im thinking BigAudioFanatic that you meant to seperate my components out of the Power Center and try to put them into seperate outlets ...?

Anyhow I took a few quick pictures of the situation ...

A pic with the alternatate outlet used on an adjacent wall. A picture of the back wall behind the rig showing the two outlets, I use the one closest to the picture to plug in the Power Center. My signature links to usual pics of my rig for further reference. The pic of the back of the Power Center shows the power cords plugged in and on the bottom left hand corner of the Power Cnter is hat "ground" binding post.

Hope that gives some more info to work with ... hoping to resolve this, this weekend.

Thanks .... Zsolt

[McLoki]

Does the problem go away when you remove the projector from your setup? Get a 3 prong to 2 prong adapter (so you can plug a 3 prong appliance into a 2 pong outlet) and use that on your amp - does the problem go away?

If not, try it on each 3 prong thing in your audio setup until the buzz goes away. (it should eventually)

let us know what you find out.

Michael

[zx_toth]

Ok, so the volume of the hum does NOT change when I turn th volume knob up or down on my preamp so my understanding is that culprit happens after the processor/preamp ... the only two things after that are my amplifier and the right Lsi25 speaker.

Let me go back downstairs and play with it a bit more ...

This little article is nice, though again its not the cable box for me as I dont have cable ... as suggested in the article as the probably source

http://www.audioholics.com/tweaks/co...m-hum-and-buzz

[zx_toth]

Does the problem go away when you remove the projector from your setup? Get a 3 prong to 2 prong adapter (so you can plug a 3 prong appliance into a 2 pong outlet) and use that on your amp - does the problem go away?

If not, try it on each 3 prong thing in your audio setup until the buzz goes away. (it should eventually)

let us know what you find out.

Michael

Thanks Michael, Im going to go into our version of the RatShack (The Source) tommorow and pick one of those 3 prong to 2 prong adapters up and test it out ...

Reviewing my system I have 3X 3 prong power cords

1) Monster Power Center
2) Denon Reciever
3) Rotel Amp

When I shut everything off except the amp (plugging it directly into the wall) the humming continued albiet at a lower level.

A few questions for those up to the task late at night:

1) From this can I assume that it is the amp causing this situation? (Ill find out tommorow for sure)
2) Any thoughts on why this didnt happen prior to yesterday, Ive been enjoying te setup since Oct 18th without problems.
3) Are there any disadvantages to using a 2 prong adapter (losing the hum probably outweighs any disadvatages no doubt)?

Zsolt

[McLoki]

You should be able to get them anywhere. You can used them for any 3 prong electrical appliance - here you can get them at wal-mart type stores, dollar stores, drug stores, etc. Total cost should be under $2.00.

It looks kind of like this...

[McLoki]

When I shut everything off except the amp (plugging it directly into the wall) the humming continued albiet at a lower level.

A few questions for those up to the task late at night:

1) From this can I assume that it is the amp causing this situation? (Ill find out tommorow for sure)
2) Any thoughts on why this didnt happen prior to yesterday, Ive been enjoying te setup since Oct 18th without problems.
3) Are there any disadvantages to using a 2 prong adapter (losing the hum probably outweighs any disadvatages no doubt)?

Zsolt

I would guess the amp as well. (I am surprised it happens if the amp is the only thing plugged into that bank on your power center) As you said - you will find out for sure tomorrow.

It usually starts when something new is plugged in somewhere in your house. (not neccesarily to your audio system and usually something 2 prong that is pluged in) what is new that is plugged in today that was not 2 days ago?

The amp will no longer be grounded. Once you find out what is causing the problem, you may be able to ground the chasis of that device to another device with a 3 prong outlet. - you should be ok just running with the 2 prong adapter though.

Is your amp usually plugged into your power center? are there other things plugged into that filter bank?

[zx_toth]

I would guess the amp as well. (I am surprised it happens if the amp is the only thing plugged into that bank on your power center) As you said - you will find out for sure tomorrow.

It usually starts when something new is plugged in somewhere in your house. (not neccesarily to your audio system and usually something 2 prong that is pluged in) what is new that is plugged in today that was not 2 days ago?

Is your amp usually plugged into your power center? are there other things plugged into that filter bank?

The right speaker hummed when the amp was plugged directly into the wall, not into the Power Center. The reciever another 3 pronged device was plugged into the Power Center and than into the wall, while I tested the amp directly into the wall.

New two plugged items? Well just the projector that I plugged in for 10 minutes than unplugged once I heard the hum. Nothing new that has stayed in the walls.

Yes I have usually plugged the amp into the power center/filter bank ... The TV, Reciever, powered LSi25 subwoofer amps, dvd player, nintendo wii, amp are all plugged into the power center ... I was wondering a couple of days ago actually whether I had exceeded some sort of current consumption reccomendation on the Power Center as a few of those things are power hungry and all being drawn through one power cord ...

Unfortunately, I did what the article I posted above said not to do "Flail around, connecting and disconnecting and losing track of what youve done". When I first came across the problem thats exactly what I did and lst track exactly of what was plugged in at the time of the intial start of the humming ... very unfortunate. Note to self for future ... relax, take an inventory, than proceed methodically.

Zsolt

[WilliamM2]

If it is only happening in one speaker, I would suspect a fault with the amp.

[zx_toth]

If it is only happening in one speaker, I would suspect a fault with the amp.

Hmm, Ill be back in the city I purchased the amp from in two weeks, if this problem persists I think I will take it in to get looked at. I called the store and told them of my problem, they were just about to send out a technician without hesitation (great service) until I informed them I was about 200 kms away ... which I knew would be the deal breaker :(

McLoki: I went to The Source today requesting the 3 to 2 prong adapter and was told that they are "Illegal" in Ontario. The customer service rep that answered the phone at the AV Store I purchased the amp from told me to break off the 3rd prong off of my Monster Power Center, I said I think not. He admitted that it probably would be better than to get a regular 3 prong two or 3 way adapter and plug the Power Center into there and break off that prong off the adapter.

Ill try some two prong trial before I take the amp in ..... but William2 that is a good point, why is it only one speaker? it would make sense that both should be doing it if it was the amp being not properly grounded ... or so my amateur brain would lead me to believe.

[McLoki]

PM me your address. I will send you one. :)

[zx_toth]

PM me your address. I will send you one. :)

I appreciate the offer but I wouldnt want to do anything illegal :D Actually, Im just going to snip off the third prong from a small square surge protector tommorow and give it a try. I had to put aside this problem at about 3:30pm today as I have a assignment for school due so I had to work on that for the past 6 hours. Back at the humming speaker tommorow though!

Zsolt

[zx_toth]

I wrote down the options availble to me ... and tried the ones that I had immediate access to an none of them worked ..

1) Simply switch the outlet in the back of the Monster Power Center and see what happens

result: Buzz remains in right LSi speaker

2) Guy at The Source who pushes Monster products, said that I should make sure the 3 pronged electronics are on different rows of outlets. Thus have the reciever on the top row and Rotel amp on bottom row.

Result: Buzz remains in right speaker

3) Use an extension cord (3 prong) to plug in the Rotel amp to a distant outlet

Result: I tried 3 other outlets in the room. In the far back wall and another one side wall. Buzzing remains.

4) Chop off 3rd prong on an adapter and than plug in the Rotel amp to an outlet.

Result: I dont have anything to cut the copper prong with at this point, as I am very unhandy and dont own any decent tools .... Ill borrow something tommorow.

5) Try and ground the Rotel amp by attaching a cable from the ground connection on the Monster Power Reference Center to the chasis of the amp.

Result: Didnt really know what to attach the cable to on the Rotel amp as there isnt a ground connection. Just kind of placed it on a number of sites on the chasis and didnt get a change in the Buzz. Buzz remained in the Right Speaker.

6) I disconnected the right LSi 25 and hooked up my RM 7302 center speaker to the Rotel amp to see whether the buzzing would only occur with the LSi speaker and suggest something wrong with the LSI speaker.

Result: The exact same buzz started to come out of the RM7302 when the Rotel amp was turned on leading me to believe that the source is the amp for sure and nothing to do with the speaker itself.

Is anyone getting the suspicion that William2 is correct that something is not OK with my Rotel amp? Ive only had the thing since Oct 18th, most manufactuers defects would probably present themselves pretty soon I imagine?

Besides the 2 prong thing I dont know what else to try besides taking it back to the store to get them to check out the amp. But I certainly would feel like a moron if it still was something to do with my electrical setup.

Please continue to advise me. Much appreciated.

Zsolt

[McLoki]

When you say you are trying all this with the amp - do you mean the amp in your LSi25 or your main amp? If you mean main amp - try the amp in your LSi as well. (plugging in with extension cord, the extension with the ground plug removed, etc....)

Michael

[zx_toth]

When you say you are trying all this with the amp - do you mean the amp in your LSi25 or your main amp? If you mean main amp - try the amp in your LSi as well. (plugging in with extension cord, the extension with the ground plug removed, etc....)

Michael

Actually, I mean the seperate amp, not the one in the LSi. The internal amp in the LSi has given me no problems ... that I am aware of

I edited my previous post and renamed amp to Rotel amp just to clarify. Thanks for the comment about vagueness.

[McLoki]

Try the tests with the amp in your LSi. Considering most hum is at 60hz - it would be in the bass section of the speaker. (and would explain why it only happens in that speaker.)

let us know what you find out.

Michael

[zx_toth]

Try the tests with the amp in your LSi. Considering most hum is at 60hz - it would be in the bass section of the speaker. (and would explain why it only happens in that speaker.)

let us know what you find out.

Michael

One of the basic things I did before getting to indepth with the LSi internal amps was to. Run the setup with the LSi amp volume totally turned down and the buzz still remains in the right speaker.

Further than that I unplugged the LSi 25 amps on both speaker and than turned on my Rotel Amp and continued to hear the buzzing from the right speaker. Since the LSi 25 amps are not powered at that point Im assuming that there isnt a problem with them.

I hoping that tommorow, Monday, Polk customer service can review our posts and possibly suggest something as well. I will also call the store I bought the amp from and let them know what Ive been up and see if they can arrange to test the amp in two weeks time if I can find no solutions.

Tommorow Ill take the amp and one speaker to a totally seperate room in the house and hook it up and see what happens. This came to me because even if my preamp is off and I only turn the amp on and NOTHING else the buzz still happens (though at a lower volume than when my preamp is also on). So if I move the amp and speaker (hook it up to the right side) to a totally seperate electrical outlet not associated in anyway to the electronics in the living room .... there will either be a buzz (its the amp) or there will be no buzz (it has to do with the ground loop all those electronics being in that room hooked up in that way). That will be an after work project ... I wish I could call in sick tommorow to work for this, "My amp is sick" :)

I will never take a smoothly running system for granted again :)

Zsolt

[Dennis Gardner]

Forget the call to Polk, you've got a bad right channel. I would check the following:

1. Unhook the amp from that channel and power the LSI with the Denon's right channel speaker post. This takes the Rotel & interconnect out of the equation.

2.Swap the interconnects going from the Denon to the Rotel.

3. Change out the speaker cable.

This should tell you where the issue lands.

It isn't a power/ground loop issue since it is in only one channel.

Check cables closely, they can cause hums while still passing signals.

[zx_toth]

What a beautiful sound, no sound can be .... once you get rid of a BUZZING OR HUMMING that is plaguing you for nearly a week now all I want to do is turn on my reciever, turn on my amp and listen to the silence that comes out of them .... wow ... so quiet, so beautiful .....

I thank everyone for there suggestions and not giving up on my situation.

The mystery got solved when I took Dennis's advice and stopped concentrating on the electronic equipment, power cords (3 prong or 2 prong), and speakers and look at what is connecting these things together ..... THE INTERCONNECTS.

I pulled out the cabinet. Changed the speaker wire ... no change in the buzz. I replaced the interconnect ...... BOOOOOOM ... slience (silence does not go boom but my mind when boom when it heard nothing) .... INTERCONNECT ..... My thought immediately turned to "Oh man now I need to replace my expensive silver resolution interconnect, I wonder if Frank has a replacement program ..... just to make sure I undid this quiet interconnect and put back the 'faulty' one ...... BOOOOOM silence .... the word 'IDIOT' immediately entered my mind ... a bit of self talk "YOU FREAKING IDIOT YOU PROBABLY LOOSENED THE INTERCONNECT WHEN YOU PULLED OUT THE CABINET TO PLUG IN THE PROJECTOR FROM WORK". Despite the fact that I am near 80% sure I had thought I retightened the connections before my initial frenzy of connecting and unconnecting I guess I either didnt or I didnt do it forcefully enough ...

So again thanks for all your help and dont be an "idiot" like me and check the interconnects and cables before you start moving equipment and unpluggin and plugging extension cords/switching outlets/ and becoming almost ready to hire a electrician to put in a dedicated outlet .....

Good Night

Zsolt

EDIT: Seems like after all I may need to replace the interconnect because as I sat there longer and longer the buzzing slowly appeared again. I moved the connection around the buzzing stoppped. Later it came back again. I gently pushed down on the interconnects neck and the buzzing got worse ... I gently pushed up on the buzzing got better .... AH HA .... loose connector head .... seems like after all Ill haveto talk to Frank from Signal. With a life time warranty I have no doubts about great service.

Z

[Dennis Gardner]

It was a ground loop issue of sorts, just not of the power variety, but the signal variety.

Glad you found it!! I'm sure Frank will treat you right............

[McLoki]

Glad you got it..... . Those annoying buzz problems can be a nightmare to track down. Excellent deduction work by Dennis.

Congrats - now just enjoy before you start changing more stuff... :D

Michael