This is not related to our business, but I got one of these and sent it
to Kim Girardin for analysis and calibration file.

I am posting this because I couldn't find any information on it before
buying it, and figured it would be a data point for others searching.
It is normally used as an RTA microphone with the dbx "DriveRack PA"
product. Oddly, they do not advertise/market it alone, yet all the pro
audio distributors advertise, stock and sell it for $100. It is a
normal phantom powered omnidirectional microphone and is intended to be
a measurement microphone. It comes with no documentation.

Here is the frequency and phase response plot for mine:

http://www.audiorail.com/dbx_RTA-M.gif
http://www.audiorail.com/dbx_RTA-M.jpg

Here is the calibration file generated for it:

http://www.audiorail.com/dbx_RTA-M.dat

Here is a picture of it:

http://www.swee****er.com/images/items/RTAM-large.jpg

Here are the only authoritative specs on it that I could find:

Polar Pattern : Omni-directional
Element : Back Electret-Condenser
Frequency : 20 Hz ~ 20,000Hz
Impedance : 250 30% (at 1,000Hz)
Sensitivity : -63 dB 3 dB ( 0 dB=1V/ microbar 1,000 Hz indicated by open
circuit )
Operating Voltage : Phantom power 15V D.C.

"The RTAM can handle 48v with no problems." -Tom Cram, dbx Senior
Technical Support, (801) 568-7530,

[bradp015]

Originally Posted by Garth D. Wiebe

This is not related to our business, but I got one of these and sent it
to Kim Girardin for analysis and calibration file.

I am posting this because I couldn't find any information on it before
buying it, and figured it would be a data point for others searching.
It is normally used as an RTA microphone with the dbx "DriveRack PA"
product. Oddly, they do not advertise/market it alone, yet all the pro
audio distributors advertise, stock and sell it for $100. It is a
normal phantom powered omnidirectional microphone and is intended to be
a measurement microphone. It comes with no documentation.

Here is the frequency and phase response plot for mine:

http://www.audiorail.com/dbx_RTA-M.gif
http://www.audiorail.com/dbx_RTA-M.jpg

Here is the calibration file generated for it:

http://www.audiorail.com/dbx_RTA-M.dat

Here is a picture of it:

http://www.swee****er.com/images/items/RTAM-large.jpg

Here are the only authoritative specs on it that I could find:

Polar Pattern : Omni-directional
Element : Back Electret-Condenser
Frequency : 20 Hz ~ 20,000Hz
Impedance : 250 30% (at 1,000Hz)
Sensitivity : -63 dB 3 dB ( 0 dB=1V/ microbar 1,000 Hz indicated by open
circuit )
Operating Voltage : Phantom power 15V D.C.

"The RTAM can handle 48v with no problems." -Tom Cram, dbx Senior
Technical Support, (801) 568-7530,

hi garth,
are you still using the rta mic from dbx?
have you tried the "room eq wizard" app??
thx