Re: Microphone wiring

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Mon, 26 Feb 2007 11:31:59 -0500, Marc_F_Hult
<MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote in message
<q406u2pia1euogu6lsr42udo46dkbvh0i5@xxxxxxx>:

>On Mon, 26 Feb 2007 01:48:30 GMT, Reg <reg@xxxxxxxxxx> wrote in message
><O%qEh.1049$LF6.369@xxxxxxxxxxxxxxxxxxxxxxxxxx>:
>
>
>>
>>I have one mic so far, currently direct connected to a
>>PC:
>>
>>Acoustic Magic Voice Tracker
>>http://www.acousticmagic.com/products/
>>
>>I've read they work well for VR so I expect
>>to add 3 Crown pressure zone mics:
>>
>>Crown PZM Series microphones
>>http://www.crownaudio.com/mic_web/pzm.htm
>>
>>As far as mixers, my first choice would be:
>>
>>ClearOne XAP 800
>><http://www.clearone.com/products/product.php?cat=1&prod=1>
>>
>>Otherwise, I expect to use:
>>
>>Shure SCM810 Eight Channel Microphone Mixer
>>http://www.shure.com/ProAudio/Products/MixersAndDSP/us_pro_SCM810_content
>>
>>4 mics total. One or two might possibly be added in
>>the future, but no more than that. Longest run from
>>mic to mixer would be about 40-50 ft.
>>
>>The application is voice recognition using Homeseer 2.2
>>with some custom vb.net code.
>>
>>I appreciate the help.
>
>
>Hi Reg,
>
>I have Crown PZM-11LLWR, PZM-11, PZM-6FS, PZM-6D and PCC-130SW mics and
>HomeSeer but use IVIE automixers, not Shure or ClearOne.
>
>If you haven't already, do try out HomeSeer's Voice Recognition (VR)
software
>and satisfy yourself that it works adequately for your purposes with a
single
>near-field, optimal microphone placement. The expensive mic and mixers you
>propose serve to reduce the severity of distribution problems and
>multiple-input problems but will do nothing to help the situation if a
>simple, local, minimal background-noise, one-mic setup does not perform
>adequately.
>
>If you do proceed, avoid mics without built-in active electronics for
>line-level distribution. The PZM-11LL (Line Level) and PZM-11LLWR (Weather
>Resistant) have line-level output amps that can be powered from 12-24vdc.
use
>one twisted pair of the CAT-5 for signal and another for power.
>
>Be sure to provide current limiting of the DC power over CAT-5.  Phantom
>power from the mixer will handle that automatically, but will require
>modification or special order of the PZM-l1LL.
>
>If you should pick up too much noise, you can add baluns if and where needed
>but if your CAT-5 is well installed, noise typically isn't an obstacle for
>VR. The biggest single problem I've had with audio noise in recent years has
>been minor buzzing picked up from flaky X-10 dimmers (now resolved).
>
>HTH ... Marc
>Marc_F_Hult
>www.ECOntrol.org


Lest I be misunderstood or misconstrued, note that by "audio noise" in the
paragraph above I meant "electronic noise" . Extraneous noises picked up by
mics are a severe problem even with the best of installations. In general,
folks seem to have much greater expectations of multi-mic VR than the physics
permit.

http://www.shure.com/ProAudio/Products/us_pro_ea_myth
http://www.shure.com/ProAudio/Products/us_pro_ea_predicting

One partial solution is to restrict the installation to phone-based equipment
with good fidelity.

... Marc
Marc_F_Hult
www.ECOntrol.org