The LFE output
The LFE output is derived from a sum of the left and right microphones and is running through a low pass filter at 120 Hz and is attenuated
10 dB conforming with the LFE level standard.
Mixing the signals
The unit is in perfect surround balance and does not need any level off-sets. Simply gain all microphones equally (including the LFE signal).
However, some applications may benefit from minor adjustments to achieve the desired level balance on the 5.1 outputs:
• News gathering/interview: Attenuate all channels but center
• Concert hall with large distance to source: Attenuate rear channels
• Acoustical zoom function: Attenuate all channels but center
Adding time delay to rear channels
To increase the sensation of spaciousness it is a recommendable trick to add time delay to the rear channels by typically 10 – 15 ms (corres-ponds to the rear micro-
phones being placed approximately 3 – 5 m (10 – 16 ft) behind the front microphones). This technique works best when the surround directions are consistent, and
may lack front-to-back localization accuracy when recording moving surround environments from the rear.
Fold-down to stereo or mono
The surround signals from the 5100 can easily be folded down for stereo or mono. Since the three front microphones are time coincident, no comb filtering occurs
when summing L, C and R.
Down-mix algorithms
5100 surround outputs
Stereo fold-down
Mono fold-down
L
R
Mono
Left
0 dB
-
-3 dB
Right
-
0 dB
-3 dB
Center
-3 dB
-3 dB
0 dB
LFE
+7 dB
+7 dB
+10 dB
Left Surround
-6 dB
-
-6 dB
Right Surround
-
-6 dB
-6 dB
Care of microphone
DPA 5100 is designed to be very robust and protective materials are used in the construction, including the extremely strong black fabric. Do not try to clean the
microphone as it may be damaged. Avoid all kinds of spray or fluids containing chemical components to remove static electricity on or close to the microphone as this
could cause permanent damage to the pre-polarized layer in the capsules.
DPA 5100 is very resistant to water and can easily be used outdoors with the OC5100 mounted, but keep it away from unnecessary exposure to water and cleaning
fluids.
Hum issues DPA5100
If low frequency hum issues occur with DPA5100, it is advisable to check for proper ground for the main power supply connection for the microphone preamplifier.
Especially on mobile battery operated equipment, when operated with power supply, it is of great importance to ensure ground for the power supply. Due to the high
current consumption of the six channels in DPA 5100, it is more sensitive to ground current flows than other standard mono channel microphones.
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