Meetinghouse Webcast - Poor Audio Quality

12 postsstarted by rhusted 4,420 viewsoriginal topic

New Member
#1
We've had two successful webcasts from our Stake Center to outlying buildings. The video is pretty good, but the audio sounds very 'tinny' and has some kind of electronic distortion. When the signal goes into the Webcast Communicator hardware, it sounds great... but by the time it's webcast back to the units, it picks up a distinct distortion - so that people sound a bit like robots (if that makes sense). Is anyone else experiencing this problem and is there a fix for it?

The meetinghouse webcast solution is WONDERFUL and our members have been truly blessed (one unit is about 80 minutes from the Stake Center). We're just hoping to improve the audio quality so that they can hear better at the remote buildings. (The broadband speed doesn't seem to make a difference in regards to the quality of the audio signal.)

Thank you in advance brethren, for any suggestions or assistance that you can provide.
Community Administrator
#2
rhusted wrote:so that people sound a bit like robots (if that makes sense).

Sounds like digital distortion. Possibly too low a bit rate setting for the sound. Someone with more experience with the Webcast Communication can probably point you to the right place to look.
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Senior Member
#3
rhusted wrote:We've had two successful webcasts from our Stake Center to outlying buildings. The video is pretty good, but the audio sounds very 'tinny' and has some kind of electronic distortion. When the signal goes into the Webcast Communicator hardware, it sounds great... but by the time it's webcast back to the units, it picks up a distinct distortion - so that people sound a bit like robots (if that makes sense). Is anyone else experiencing this problem and is there a fix for it?

The meetinghouse webcast solution is WONDERFUL and our members have been truly blessed (one unit is about 80 minutes from the Stake Center). We're just hoping to improve the audio quality so that they can hear better at the remote buildings. (The broadband speed doesn't seem to make a difference in regards to the quality of the audio signal.)

Thank you in advance brethren, for any suggestions or assistance that you can provide.
Initially, we had great difficulty with our audio. We could not find an input level that did not result in some distortion with at least some speaker's voices. I eventually found a setting in the device's set up menu for boosting the input audio level and this had been set towards the high end of the scale. Turning that down to the lower end resolved our audio problems.
Member
#4
The problem comes from an effect known as aliasing. It is the result of a sampling rate below the frequency limits of the sound source.

There are basically two solutions, 1) use a low pass filter on the input to the communicator and 2) use a higher banwidth setting on the communicator. I have had success with both methods.

For method 1, the simple way to do this is to put a small mixer on the input of the communicator and use the equalizer to roll off the audio at about 8 KHz. For method 2, use a custom setting on the communicator and set the bandwith above 400 Kbps.
Church Employee
#5
rhusted wrote:We've had two successful webcasts from our Stake Center to outlying buildings. The video is pretty good, but the audio sounds very 'tinny' and has some kind of electronic distortion. When the signal goes into the Webcast Communicator hardware, it sounds great... but by the time it's webcast back to the units, it picks up a distinct distortion - so that people sound a bit like robots (if that makes sense). Is anyone else experiencing this problem and is there a fix for it?
Thank you in advance brethren, for any suggestions or assistance that you can provide.

There is another possible issue that may be causing your problem (I am assuming that you are using the hardware communicator) and inputting the Audio into the communicator on with a Stereo Mini to RCA break out cable:
On the hardware communicator, the audio input (3.5M audio plug) is not wired in the standard fashion. Because of this the church has made arrangements for an adapter cable, which will make the necessary changes in the wiring so that you can use this RCA to Mini cable to input the audio. You can order the cable directly from Poll Sound in SLC, or I have been told it is available at the LDS online store (not everyone will see it, as this will depend on the LDS accounts privileges)
Unless you are already using this cable at the input location, I would assume that this is the cause of the “tinny” sound

Best of Luck
Steve Poulsen - Meetinghouse Facilities Technology Engineer
Member
#6
StevePoulsen wrote:On the hardware communicator, the audio input (3.5M audio plug) is not wired in the standard fashion. Because of this the church has made arrangements for an adapter cable, which will make the necessary changes in the wiring so that you can use this RCA to Mini cable to input the audio. You can order the cable directly from Poll Sound in SLC, or I have been told it is available at the LDS online store (not everyone will see it, as this will depend on the LDS accounts privileges)
Is this due to a different wiring system than the default one (if so, what is different)? Or is this due to the communicator expecting mic level audio rather than line level audio?

Thanks

Aaron Z
Community Administrator
#7
StevePoulsen wrote:On the hardware communicator, the audio input (3.5M audio plug) is not wired in the standard fashion.

For those of us handy with a soldering iron, how is it wired? Like a laptop mic input? (tip = power, ring=audio, sleeve=ground)?
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Church Employee
#8
RussellHltn wrote:For those of us handy with a soldering iron, how is it wired? Like a laptop mic input? (tip = power, ring=audio, sleeve=ground)?

Sort of: Tip = no connection, Ring = Hot Audio, Sleeve = Ground. This actaully got me thinking that if you use the Left side of the RCA to Mini cable you should be oaky, now I will have to go try it out and see what happens.

Hope this helps
Steve Poulsen - Meetinghouse Facilities Technology Engineer
Senior Member
#9
I noticed this same issue while testing today. I'll try a filter and/or a higher quality setting.

Would a standard mono cable work?
Craig
Saint George, UT
Community Administrator
#10
craiggsmith wrote:Would a standard mono cable work?

No, it wouldn't.
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Senior Member
#11
I thought the lack of RCA inputs on this box was a major deficiency, and now this. Strange though -- in the past I've just used a straight mono cable and I never received any complaints but I never had the opportunity to monitor it closely myself. It would seem like I shouldn't get any audio at all. Facilities recently added RCA audio and video outputs to our satellite cabinet so I'll try a stereo cable with one side disconnected.

But in my experience this type of sound is due to extreme compression, which I assume is the aliasing issue mentioned above. So I'll do some experimenting.

Thanks.
Craig
Saint George, UT
Senior Member
#12
The audio wasn't as bad this afternoon so it was more difficult to test. But rolling off the high end did seem to help, although the impact on the overall sound quality was not desirable. Playing with the cables as suggested didn't have any effect. So I switched to medium quality and the tinniness went away although the overall quality wasn't great. But it appears we have enough bandwidth for it. I meant to try it at the 250k setting but forgot.

Regarding the cables, using either channel of a stereo cable gave the same sound which was also the same as a mono cable, and using both channels of the stereo cable had a noticeable increase in level. To me this means the jack is wired normally, unless I am missing something.
Craig
Saint George, UT