I am looking for someone who has experience with 3rd party microphones in combination with Cisco Telepresence products. In my case is it a SX20 with mini Jack audio input and there I plan to use a XLS to Mini-JACK converter and than either two Cisco CTS-MIC-CLNG= Ceiling Microphone or two 3rd party microphones as alternative. Our customer is not happy with CTS-MIC-CLNG= because of its dimension.
I would need a 3rd party microphone for hanging ceiling supension with 360° opening angle.
I have done this a lot for C20 systems.
You will need a XLR to 4Pin mini Jack converter due to the C20 Pin outs which is the same on the SX20.
If you use a normal 3 pin mini jack you will get voltage across your ground pin from the Control voltage that powers the LED on the original Mic.
So if you user a 4pin minijack to XLR you only connect the Ground, Audio Hot and Audio-Cold.
Great info. I'm curious if you were able to find these XLR to 4 pole 3.5 adapter cables anywhere for sale, or if you are custom making them for your jobs?
Alexandra, in my particular case, I made an adapter using a 3 pole minijack (since I couldn´t find a 4 pole one); but considering pin-out of the minijack and the cannon connector (XLR) it worked fine. I used a C20 with two ceiling mic.
The same thing (regarding dimension) happened. I just took the MIC out of the huge acrylic (cuting the seal) and hunged the tiny MIC from the celing of the room. We have made a lot of tests, wiht and without the acryclic to hear the differences, but there wasn´t any. The room was a reglar reunion room (15 meters by 4 meters and 3 meters high). The ceiling mic with the acrylic is four auditorims, with very tall roof. Hope it helps.
Since the Ceiling MICs don´t have MUTE Control Button, it was not a problem. GND and Microphone Control may be shorted, but they are signals not Voltage, so no QuickSet C20 damage were caused nor MIC was muted due to this. I have two MICs connected con the C20 using this "home made adapter - XLR to miniplug 3-pole" and it is used quite often without any problem.
Can you explane, how you were able to provide the Ceiling MIC with the needed phantom power without using the Mic-Control-Pin?
I´m asking, because I do not get any DC voltage between Mic+ and GND or Mic- and GND.
I only do get about 10-11V between Mic control and GND, which could be used for powering the mic.
This was a while ago, and the "adapter" was made for a client (which I can not longer review the pin out and how it was made, unfortunatelly).
At that time, I found out that I needed an external power, but it happened to happen that worked the way it was built and no problems at all since then. There isn´t any external power. Just used the femate XLR connector and o the other end the 3-pole mini jack.
Maybe, with that small ammount of voltage is enough. The sound is very loud and clear on the other site of the videoconference.
Technical Specification of the Ceiling MIC stats that 12V to 48V is needed, dough:
Transducer: Electret Condenser
Impedance: 240 Ohms
Open-Circuit Sensitivity: 7mV/Pa (-43dB re 1V/Pa)
Power Sensitivity: -43dB re 1mW/Pa
Equivalent Noise Level: 20dB SPL typical (0dB=.0002 dyne/cm2), A weighted
S/N ratio: 74dB minimum at 94dB SPL
Maximum SPL at 3% THD: 150 dB SPL
Operating Voltage: 12 to 48 VDC Phantom power with positive voltage on pins 2 and 3 with
respect to pin 1 of output connector
Current Drain: 1.1mA
Switch: Frequency select switch for flat or rising response
Output Connector: Standard Male 3-pin XLR
Sorry not to be so explicit; but trustme it works fine!
we used also in the past for C20 a 3-pole minijack to XLR adapter to connect old MXP microphones to C20.
This worked great so far, but doesnt seems to work with SX20 at all. When connecting this 3-pole adapter to SX20 Mic Input someting seems to be shorted and this Mic Input gets totally muted until reboot without any plugged adapters.
It really seems there is a difference between C20 and SX20, can somebody confirm?
The adapters were selfmade by a 3rd company, so what is the working solution to build this adapter?
SX20 does not provide phantom power on audio hot/cold. C20 does. So you will need an external phantom power supply. To prevent the unwanted mic mute, I would recommend to use a 4pin 3,5mm connector, because with a 3pin connector, you would shorten 10V on Ring2 against ground.
this is not what i wanted to hear, so 3pin extension cables would also not work in that case.
But I am a bit confused, how gets the SX20 microphone the 12V Power, it is still the same microphone than the C20 one. So i assumed the same plug and powering.
Actualyl i understood as follows:
C20 has phantom power through audio-+.
Sx20 has no phantom power through audio+-, but how the microphone can work then? Its the same microphone. will it gewt the power through R2 for Microphone Control?
I believe there should be any way to connect XLR microphone without need of an exernal phantom power supply, or not?
I suspect, that the original Microphone uses the voltage from R2 even on C20.
Darren was able to build a phantom power supply by using R2:
But I would recommend to get a ready made phantom power supply for around 50 €/$, because they provide 48V, which most microphones work better.
Thanks again for the answer.
This is bad to hear, as we bought also a lot of C20 microphone extension cables with 3pin mini jack plug which worked well for C20 (microphone control is not important because the users are familiar to use remote control), but the cables seem to be useless with SX20 now So another order of 4pin minijack extension cables is needed.
Bad step Cisco, I believe they want to prevent the use of 3rd party microphones and/or extension cables)
Were you able to find 3rd party microphones that'll work with the SX20? Have a customer who would like the ceiling mic for a small conference room, doesn't want the Cisco Ceiling mic.