Question about noticeable abnormal sub noise...normal??

[brazosdog02]

I have a pair of LV12 subs. When listening to one particular movie, there is a very noticeable 'whirring' noise coming from the subs. Its not a hum or a whine.....its in between and sounds like background wind noise but its not. What in the world is it and how do I stop if its not normal? There is also a 'hum' although very subtle. Im trying to verify if it does it with just this movie or what.


When the movie is PAUSED OR MUTED there is no noise whatsoever. It seems to do it with both BD and Dish sources. What is the deal???

[curtis]

Can you tell us the name of the movie?

[brazosdog02]

The movie is Frozen. I have kids...we watch that thing all the time. I simply attributed the noise to background wind but it seems to do it on quiet scenes that are not outdoors and it does it from my cable box as well. Both sources exhibit it and both have LFE feeds. Not sure how to troubleshoot. I have ALL of my AV equipment on a single 20A circuit, but last night I moved the subs to a separate circuit....I can't tell if that had any effect and Im not sure this is even ground loop noise since it goes away when paused or muted. No idea how to troubleshoot it or if its just normal. Its a strange white noise.

[davef]

The movie is Frozen. I have kids...we watch that thing all the time. I simply attributed the noise to background wind but it seems to do it on quiet scenes that are not outdoors and it does it from my cable box as well. Both sources exhibit it and both have LFE feeds. Not sure how to troubleshoot. I have ALL of my AV equipment on a single 20A circuit, but last night I moved the subs to a separate circuit....I can't tell if that had any effect and Im not sure this is even ground loop noise since it goes away when paused or muted. No idea how to troubleshoot it or if its just normal. Its a strange white noise.

If you are hearing this background noise from Frozen using two different sources (DVD and cable), it is in the soundtrack. Speakers and subwoofers simply reproduce what is being sent to them. If there was something wrong your equipment, you would hear this same noise regardless of what movies was being played and it would be continuous.

If you had a ground loop, you would hear it throughout any source being played and even with no source.

[brazosdog02]

No...thats not what I meant. I mean i get the noise from the BD watching Frozen, but I get it from Cable box too....when watching anything. I mean that the noise is independant of the movie being player. Sorry.

The noise is continuous as long as I do not mute or pause a movie or cable box. When paused or muted...all noise stops...even the white noise sound.

So, the noise coming through the Sub is either normal, or it is resulting from something the AVR is doing. I guess teh AVR could be 'defective' but its new and not cheap. It may have done this all along, but since I have not listened to my system at these levels before, I did not notice it. Perhaps another lead on Audyssey causing it is valid.

[davef]

No...thats not what I meant. I mean i get the noise from the BD watching Frozen, but I get it from Cable box too....when watching anything. I mean that the noise is independant of the movie being player. Sorry.

The noise is continuous as long as I do not mute or pause a movie or cable box. When paused or muted...all noise stops...even the white noise sound.

So, the noise coming through the Sub is either normal, or it is resulting from something the AVR is doing. I guess teh AVR could be 'defective' but its new and not cheap. It may have done this all along, but since I have not listened to my system at these levels before, I did not notice it. Perhaps another lead on Audyssey causing it is valid.

Are you only hearing this while watching Frozen?

[RicardoJoa]

You shouldnt hear any unusual sound at LP. I just cant imagine hearing a hum at LP specialy while playing music or watching movie.
If you hear noise (hum)when your sub vol knob is turned up, turn it down till the noise is lower and adjust at AVR.
As with your wind noise, i think you should isolate whether that has to do while playing music or watching movie. Do you hear that wind noise with everything disconnected except power? With a RCA in? With music Playing?

[brazosdog02]

IM still messing with it. I listened yesterday and at the LP with a good volume, its not discernible unless you really know what you are listening for. Its really hard to isolate because there is a very strict set of parameters to make it happen including volume. It has to be getting a feed from LFE. RCA Cable cannot be unplugged. It cannot be 'paused' or 'muted' or it won't make the noise. It might be perfectly normal....or rather, acceptable. Im going to try one more thing that involvs unplugging ALL audio cables from the back and all HDMI cables aside from the one source I happen to be using. If that doesn't solve it, Ill try killing the breaker to every light in that room to remove the possiblity of dimmers being an issue. The system is on its own circuit so thats an easy thing to test. There is a noticeable hum in the beggining of "Frozen" but its when the singing first starts and I think it goes away. I'm almost 100% positive its in the soundtrack somehow since its starts literally a second or two before the rest of the audio. Its like when the audio track goes 'live'. Very odd. Im probably being way too anal.

[RicardoJoa]

IM still messing with it. I listened yesterday and at the LP with a good volume, its not discernible unless you really know what you are listening for. Its really hard to isolate because there is a very strict set of parameters to make it happen including volume. It has to be getting a feed from LFE. RCA Cable cannot be unplugged. It cannot be 'paused' or 'muted' or it won't make the noise. It might be perfectly normal....or rather, acceptable. Im going to try one more thing that involvs unplugging ALL audio cables from the back and all HDMI cables aside from the one source I happen to be using. If that doesn't solve it, Ill try killing the breaker to every light in that room to remove the possiblity of dimmers being an issue. The system is on its own circuit so thats an easy thing to test. There is a noticeable hum in the beggining of "Frozen" but its when the singing first starts and I think it goes away. I'm almost 100% positive its in the soundtrack somehow since its starts literally a second or two before the rest of the audio. Its like when the audio track goes 'live'. Very odd. Im probably being way too anal.

Ok, if you cant reproduce that while having cable off, paused or mute, then at least it sounds like it only happends when it is playing and not due to cable or electrical.

It sounds like the sound your are hearing is from the LFE.
I remember one time i was using my headphone and i adjusted the bass which in my avr was 50hz because the headphone had weakbass. The next day, when i switched it back to speaker without turning down the bass, i noticed the sound was odd and it seemed like a hum, but slighly different. I then realise that the bass was set 6 db higher. So the extra bass had caused that unusual noise. It may not necessarly be the system, but the room it self. I think it might even be flutter echo at those low frequencies.

[brazosdog02]

Im running my Audyssey hotter than it wants, and you are the second person to mention LFE noise. So...I could be hearing something normal or just an artifact of my settings. You have to remembe that I have never ever ever had a 'system' like this, so im not well versed in normal.