Channel 2 Input Selector
The second channel of the MP-200 has multiple inputs. These options
are:
• Mike 1 - Used to feed the same mike 1 signal to both Channel 1
and Channel 2 outputs of the MP-200. This is useful to insure that
both channels of your analyzer are adjusted to the same settings.
• Mike 2 - When used with the optional 2nd CM-10 microphone,
this allows comparison of two acoustic inputs.
• Line - Sends the summed mono signal from the Line Input jacks to
channel 2. A typical application allows use of a live music signal to
calculate the transfer function of system by comparing the electri-
cal input to the acoustical output.
• Pink Noise - Monitors the internal pink noise generator of the
MP-200. Is used similarly to the Line input position.
Using the Pink Noise Generator
Pink noise is a random mix of all frequencies in the audio spectrum. It
is very useful for audio analysis because all bands have equal energy.
This means that if you feed pink noise into an audio analyzer, you will
see a flat frequency response. White noise, commonly used for audio
masking, differs because it has equal amplitude at all frequencies. If
you look at white noise on an audio analyzer, the signal level would
rise with frequency by 3 dB per octave.
By playing pink noise through an audio system and monitoring the
acoustic signal coming back into the room, any variance from “Flat”
indicates the combined frequency response of your speakers and
room. To use the pink noise generator in the MP-200, plug a cable
from the unbalanced ¼" phone Pink Noise Output jack to a line level
input on your audio system. Since the Pink noise output level is
variable, you can connect to a console input or directly into a power
amplifier and control the noise volume with the MP-200.
94 dB SPL Reference
The 94 dB reference LED on the MP-200 allows meaningful mea-
surement of acoustic sound levels. This LED will light when the
acoustic level at the CM-10 mic is 94 dB SPL (unweighted). The
MIKE GAIN switch on the MP-200 does NOT have any effect on
this indicator. The reference LED will always show an accurate
reading regardless of the MIKE GAIN switch setting. To use this
indicator, place the microphone in the measurement location. Now
play pink noise through the speaker system and turn up the volume
until the 94 dB LED illuminates. You can now adjust your analyzer to
read 94 dB.
Important Note: To prolong
battery life, the pink noise
circuitry of the MP-200 only
receives power when a plug
is inserted into the PINK
NOISE OUTPUT jack.
Disconnect the plug from this
jack when not in use.
Using the MP-200
Summary of Contents for MP-200
Page 2: ...MP 200 Operation Manual ...
