Dorrough 340-A Surround Sound Meter +14dB

The Dorrough 340-A Surround Sound Meter +14dB is a single-channel straight-line display loudness meter with 14dB headroom. It is used for applications where several meters are required, and is ideal for HDTV 5.1 and 7.1 Surround Sound applications. The Model 240-A is designed for vertical mounting and is outfitted for XLR connections.

Actual Energy Display Dorrough Loudness Meters display actual energy content of the program material, regardless of frequency, while still indicating the peak amplitude of the complex audio signal. This feature allows all program material to be adjusted for equal perceived loudness while protecting the peak of the waveform. Peak and Average Level Metering The 340A, like all Dorrough loudness meters, simultaneously displays peak and average. The relative difference, in dB, between these two ballistics is derived from the integration time of the persistence scale. Right and Left In puts for Stereo Mixing With one instrument, the operator can easily see the stereo mix and avoid classic in-phase/out-of-phase problems as well as center channel buildup that can cause a mix to seem louder. This is especially important in preparing stereo program material for broadcast, while still being able to maintain monaural compatibility. Made for Surround Sound Applications This single-channel straight-line loudness meter is ideal for applications where several meters are required, such as Surround Sound. These units are particularly useful for HDTV 5.1 and 7.1.
In the Box
Dorrough 340-A Surround Sound Meter +14dB
  • 2-Year Warranty
Input Impedance 20k Ohm balanced, 10k Ohm single-ended, +/- 2%
Common Mode Rejection Ratio 80 dB at 60 Hz, 60 dB at 20 kHz (balanced mode)
Input Sensitivity -10 dB for full-scale display
Maximum Input Level +24 dB before clipping
Signal Path Bandwidth 10 Hz - 25 kHz, +/- .25 dB
Signal Path Distortion Less than 1% THD at 1 kHz, +24 dB input
Sum Error Less than 0.1 dB at 1 kHz
Difference Error Less than 0.1 dB at 1 kHz
Display Resolution Less than 0.1 dB at 1 kHz
Step Size Error +/- 0.25 dB
Absolute Error Full Scale -39 dBu: +/- 0.25 dB model A,B,C
Drift +/- 0.25 dB
Average Time Constant 600 mS, +/- 6%
Peak Acquisition Period 10 uS, to full-scale, sine input 25kHz
Peak Attack Period Virtually Instantaneous
Peak Decay Period 180 mS, from full-scale to all LEDs off (models A, B, C)
Display Update Rate Approximately 10 mS
Display Duty Cycle Display Time, AVERAGE, PEAK HOLD - 75%

Display Time, PEAK - 100%

Power Supply Input Range 117/237 VAC RMS, -20% to +10%, 50-60 Hz
Calibration Controls None Needed
User Controls Left/Right input sensitivity Option DIP Switch
A) [ON] Auto Peak>
B) Difference Mode [ON/OFF]
C) Over Level Alarm [ENABLE]
D) Under Level Alarm [ENABLE]
E) Auto ARMP
User Port DB-9 Connector
A) Alarm relay closure contacts 1 form C, 1A, 30V AC or DC
B) Mode control switch (user supplied)
C) PEAK function switch (user supplied)
Dimensions (WxDxH) 1.5 x 7.5 x 5.0" (in.) (.6 x 3.0 x 2.0cm)
Weight Not Specified by Manufacturer
Packaging Info
Package Weight 1.45 lb
Box Dimensions (LxWxH) 8.9 x 6.8 x 2.8"
All product and company names are trademarks™ or registered® trademarks of their respective holders. Use of them does not imply any affiliation with or endorsement by them.
Select Size *

Similar products