Venue -Talkback Mic Noise (Pleae try this way)

[Jae Hwan Kim]

It is ok to patch "talkback" on the console surface(not on the screen) through to any channel

However, please try this on the D-Show screen.
1. Unplug your mic from talkback input, if you already are using it.
2. Click Configure mode on the D-show screen.
3. Click the PATCHBAY Tab
4. Click INPUTS Tab.
5. Click CHANNELS & FOH Tabs
6. Patch "Talk" tghrough to One of the input channel(ex. ch 1).
7. You can hear the noise and the see the level on the channel(ch 1).

Thanks
Jae Hwan Kim.
jaehwankim@hanmail.net
Boondang Central Church

[Sheldon Radford]

Hi,

The noise will go away as soon as a microphone is plugged in and terminates the circuit.

Sheldon

[Jae Hwan Kim]

Hi, Sheldon

I already did as your way(pluged in and out the mic), but the noise was still there.
Today, I checked it out with another Venue, but the console has the same noise.

Thanks.
JaeHwan Kim

[Sheldon Radford]

Hi,

To confirm:
Did the noise go away while the mic was plugged in?
Did it at least drop in level while the mic was plugged in?
Was the noise still noticable when the input gain and monitor level were adjusted for a normal listening volume?

We'll likely need more details to troubleshoot this further. I've asked a customer service representative to get in touch with you to find out more.

Sheldon

[Jae Hwan Kim]

Thanks Sheldon.
Until this Friday, I've been attending the 16th Korea International Broadcast, Audio & Lighting Equipment Show.
At the show, I double checked the problem with the Digidesign Dealer.
I think that they will contact to you for this problem soon.
Did you try and check it out as I did?
==================================================
Did the noise go away while the mic was plugged in?
================================================== =
No, the noise was still there.
================================================== =====
Did it at least drop in level while the mic was plugged in?
================================================== ======
No, it didn't at least drop.
================================================== ======
Was the noise still noticable when the input gain and monitor level were adjusted for a normal listening volume?
================================================== =====
Please use a haedphone to listen to.
Of course, it was still noticable.

Thank you.

JaeHwan Kim

[Sheldon Radford]

Hi,

I did check this out using headphones and found the noise went away when a mic was plugged in, as expected.

Is the noise only in the headphones? For example, when the input channel is routed to Left/Right is the noise also present in the main PA or is it gone?

The reason I ask is that there's a feature on D-Show that routes the COM input on the FOH Rack directly to headphones, and sometimes this gets turned on by accident and can add noise to the headphones (but no other output).

Try this:

1) In the Talkback/Osc section of the console press the gray Talkback button so it lights solid
2) Now check the Talkback Level encoder - is the small teardrop shaped LED beneath the encoder lit? If so, the COM input is being routed to the Hepahones. Press the encoder to turn it off. Does the noise go away?

Sheldon

[Jae Hwan Kim]

Most of all, I really thank you.

I did everything what you wanted me to do.
But, the noise was still there.

You have to look at the screen, not the console surface's channel meter.
The noise was not only in the headphones but also in the main PA.
It didn't go away

After I patched a mic through to a channel on the screen and pluged in a mic on the talkback input, the channel gain was changed from (+10dB~+60db) to (-20dB~+18dB).
While the main PA was in volume, the increased gain made the noise increase in volume.
But, the decreased gain (-20dB all the way down) made the noise still there in volume, only little decreased.

I noticed that the talkback button on the console surface didn't work while I patched it through to a channel on the screen, not on the console's surface.
So, I had to push the mute button instead of the talkback on & off function.

I used microphones for the talkback(ex. AudioTechnica AT808G Subcardioid Dynamic Console Microphone and AudioTechnica PRO 41 Cardioid Dynamic Handheld Microphone).

Keep in mind that the Pro41 microphone has a switch on&off.
The noise was still there while the channel gain was -20dB and the mic switch on.
Of course while I increased the gain, the noise was increased also.

However, when I did the Pro41 mic switch off, the noise was gone.

Switch on?? --> Back to the noise again.


I'll checked this out again with hundreds of mics and peace in mind

Thanks agian.
Jae Hwan Kim.
jaehwankim@hanmail.net
Boondang Central Church

[Sheldon Radford]

Hi,


You have to look at the screen, not the console surface's channel meter.



The input channel meters on the console start at - 30 dB, whereas the on screen meters go much lower, to -60 dB, so the noise is at least 30 dB below nominal level if it's not showing on the input channel meters. It can still be an annoyance though, so let's figure this out.




After I patched a mic through to a channel on the screen and pluged in a mic on the talkback input, the channel gain was changed from (+10dB~+60db) to (-20dB~+18dB).



Correct. The gain range changes depending on whether the input is a mic-level stage rack input or a line-level FOH input.


I noticed that the talkback button on the console surface didn't work while I patched it through to a channel on the screen, not on the console's surface.



Also correct. The Talkback button is used to turn Talkback on/off when talkback is routed directly to an output instead of through an input channel.

Here's a clue:


However, when I did the Pro41 mic switch off, the noise was gone.
Switch on?? --> Back to the noise again.




Try these two experiments to determeine if the mic itself is causing the noise:
1) plug the Pro41 into a stage rack input and adjust the input gain to the same listening volume as when it was plugged into the Talkback input. How does the noise level compare?
2) plug a simple dynamic microphone, like a Shure SM58 or SM57 into the Talkback input. Is the noise the same, less than, or worse than the Pro 41?

Sheldon

[Jae Hwan Kim]

Click - My talkback Mic Test (http://jhkstudio.com.ne.kr/pics/TestMic.jpg)

[DigiTechSupt]

Silly question... Is the XLR cable you are using balanced or unbalanced? Have you tried different cables? Different brands and models?

Thanks,
Rich

[Jae Hwan Kim]

Is the XLR cable you are using balanced or unbalanced?

Of course, it was balanced.


Have you tried different cables? Different brands and models?

I've tested with several cables already(3 brands: canare, belden, and unknown cable)

Thanks.

[DigiTechSupt]

JaeHwan,

We were able to redo the tests with the same microphones that you used and we are seeing the same results that you reported. When compared to the Stage Rack inputs it is apparent that the console Talkback is ~10 dB noisier, and while we don't require the Talkback signal to be as pristine as the other inputs, we are looking into ways to quiet it down. Perhaps the FOH Rack COM input can be used instead of the console Talkback for your application?

Thanks for bringing this to our attention.

Rich