I was thinking about posting this topic on the Home Theater PC Forum, but I think the people here might be as technically able to solve this problem.
Several months ago, Digital Connection’s Cliff Watson stated at the Home Theater Computer Forum, that he was thinking of building an Active Noise Reduction (ANR) system to quiet our noisy HTPC’s. I believe he never got around to that challenge though.
But my projector (Runco 940) is so relatively noisy, that I cannot hear ANY HTPC noise. I guess I was really spoiled by my previous projector, a Vidikron 40SEL. That FPTV was totally silent. I tend to crank up the volume from every source to drown out the Runco. But there is the fan noise back again on quiet passages.
For those of you unfamiliar with ANR, it electronically generates a tone, 180 degrees out of phase with the offending noise, to vastly reduce that noise. ANR is used quite extensively in aircraft headphones. Companies like David Clark and Bose make some of the best and most expensive units for this application. Some passenger aircraft even use ANR throughout the entire cabin to reduce ambient aircraft noise. The Twin Commander business turbo-prop for example, uses 13 speakers and 24 microphones strategically placed around the cabin to find and reduce aircraft noise using ANR.
So my question is, has anyone ever played with ANR?
Is there any way we can use, say a very small amp, a microphone and speaker at the projector, and our HTPC’s as a controller to vastly reduce fan noise?
Thanks,
------------------
Bob Sliwa
"Like a Midget at a Urinal, I was gonna haf'ta stay on my toes...."
[This message has been edited by Dallas777 (edited 11-28-2000).]
Several months ago, Digital Connection’s Cliff Watson stated at the Home Theater Computer Forum, that he was thinking of building an Active Noise Reduction (ANR) system to quiet our noisy HTPC’s. I believe he never got around to that challenge though.
But my projector (Runco 940) is so relatively noisy, that I cannot hear ANY HTPC noise. I guess I was really spoiled by my previous projector, a Vidikron 40SEL. That FPTV was totally silent. I tend to crank up the volume from every source to drown out the Runco. But there is the fan noise back again on quiet passages.
For those of you unfamiliar with ANR, it electronically generates a tone, 180 degrees out of phase with the offending noise, to vastly reduce that noise. ANR is used quite extensively in aircraft headphones. Companies like David Clark and Bose make some of the best and most expensive units for this application. Some passenger aircraft even use ANR throughout the entire cabin to reduce ambient aircraft noise. The Twin Commander business turbo-prop for example, uses 13 speakers and 24 microphones strategically placed around the cabin to find and reduce aircraft noise using ANR.
So my question is, has anyone ever played with ANR?
Is there any way we can use, say a very small amp, a microphone and speaker at the projector, and our HTPC’s as a controller to vastly reduce fan noise?
Thanks,
------------------
Bob Sliwa
"Like a Midget at a Urinal, I was gonna haf'ta stay on my toes...."
[This message has been edited by Dallas777 (edited 11-28-2000).]