Sx20 and integration with third party audio issues

[afattouh2006]

Dears,

I've SX20 (version 7.3.6) integrated with crestron DMPS300-AEC presentation switcher , it's integrated with it for video and audio sending receiving. I've a serious problem in the audio integration; microphones are connected directly to the DMPS switcher, line out from the DMPS is connected to the presentation audio in of the SX20, and speaker out from the SX20 is connected to the DMPS-line in...the audio is looping inside the codec with up-normal habit, creating a noisy looping sound inside the room whenever there's a call established. I've noticed that the local mics are going to the codec through the line-in and then displayed to the speakers (which isn't the requirement) although that i've disabled the sending of the mics to the speakers on the DMPS switcher configuration!! , It's required only to transfer the mic output to the far end ! (normally)!

Can you advise on this?

[Patrick Sparkman]

You've created an audio loop with the way you've routed the audio between the codec and DMPS, the line inputs on the codec are designed to send audio to the far-end as well as speakers in the room, the end result is you're sending audio from the DMPS to the codec, and the codec is sending it back to the DMPS.  Whenever we integrate our codecs with audio DSPs, the microphone and presentation audio are connected to the audio DSP, from there it's sent out as line audio to the codec's microphone input, which is configured as line audio.  Another solution is to connect the microphones directly to the codec instead of the DMPS and let the codec handle all the echo cancellation, AEC, etc.

[afattouh2006]

Thanks Patrick for your reply, actually talking about the SX20, i connected the output coming from the DMPS to its mic input but there's no option inside it to convert this input to line! it's only to enable the input mic mode (on/off), that's why i was bounded to connect it to the only available slot (line in- presentation in). thus i believe the only solution is to connect the mics diectly to the codec?! but what if i have 4 mics, which is my case now??

[Nick Halbert-Lillyman]

I'm not 100% sure I understand your setup so forgive me if you've already tried this, but could you connect the presentation audio directly to the SX20's presentation audio port, while leaving the microphones going via the switcher, but into the microphone port?

[afattouh2006]

Hi Nick, as i understand, this is what i'm currently doing, out from dmps, in to presentation input of sx20, all mics are in to dmps.

[Wayne DeNardi]

We have many installations here with multiple microphones connected to external DSP, then this connects to the SX20 Mic input.  This still leaves the presentation input free for presentation content.  I've attached a cut down/simplified version of our wiring diagram as an example.

Wayne
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[afattouh2006]

I've tried connecting the output from the DMPS to the mic input of the SX20 (both mic inputs i've tried) , the sound looks like distorted, as i believe because this is a mic input and it's sending the phantom power by default on this port. I faced this issue before when using the c-series codecs, when connecting to the mic ports, but there was an option to turn the mic to line

[harikeshan]

Hi All,

I have the same issue, we are using a Crestron DMPS3-300C and terminating 4 Shure Ceiling Mics due to the the U Shaped Table. However, when we tried to send the mic signal via the line output to the Cisco SX20 Mic Input there is no sound detected. Has anybody been able to find a workaround.

Appreciate any advise and help.