It is impossible to characterize the listening quality of even the simplest limiter or compressor based on specifications, because such specifications cannot adequately describe the crucial dynamic processes that occur under program conditions. Therefore, the only way to evaluate the sound of an audio processor meaningfully is by subjective listening tests. Certain specifications are presented here to assure the engineer that they are reasonable, to help plan the installation, and make certain comparisons with other processing equipment.

Except as noted, specifications apply for measurements from the analog left/right input to the analog left/right output.


Frequency Response (Bypass Mode; Analog Processing Chain): 
±0.2 dB, 50 Hz-9.5 kHz, or as determined by user-settable high-pass and low-pass filters.

Frequency Response (Bypass Mode; Digital Processing Chain): 
±0.2 dB, 5 Hz - 15 kHz, or as determined by user-settable low-pass filter.

Output noise floor will depend upon how much gain the processor is set for ( Limit Drive, AGC Drive, Two-Band Drive, and/or Multiband Drive), gating level, equalization, noise reduction, etc. The dynamic range of the A/D Converter, which has a specified overload-to-noise ratio of 110 dB, primarily governs it. The dynamic range of the digital signal processing is 144 dB.

Total System Distortion (de-emphasized, 100% modulation): 
<0.01% THD, 20 Hz-1 kHz, rising to <0.05% at 9.5 kHz. <0.02% SMPTE IM Distortion.

Total System L/R Channel Separation: 
>50 dB, 20 Hz - 9.5 kHz; 60 dB typical.

Polarity (Bypass Mode and Digital-Channel Processing): 
Absolute polarity maintained. Positive-going signal on input will result in positive-going signal on output. The analog-channel processing employs phase rotation to maximize loudness so the polarity on this channel will be frequency-dependent.

Processing Sample Rate: 
The 9400 is a “multirate” system, using internal rates from 32 kHz to 256 kHz as appropriate for the processing being performed. Audio clippers operate at 256 kHz.

Processing Resolution: 
Internal processing has 24 bit (fixed point) or higher resolution; uses Motorola DSP56362 DSP chips.

Low-Pass Filter (processing for analog modulation): 
4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, or 9.5 (NRSC) kHz as set by user. Unit can be set up to comply easily with ITU-R and NRSC spectrum masks. Filter can be set to be -0.1 dB, -3.0, or -6.0 dB down at the edge of the passband, trading off ringing against brightness.

Low-Pass Filter (processing for digital modulation): 
15 kHz.

High-Pass Filter (processing for analog modulation): 
Constrained by user settable fifth-order "quasi-elliptical" highpass filter to 50, 60, 70, 80, 90, or 100 Hz. All filters have equal-ripple (Chebychev-like) passbands, and 25 and 35 Hz notches for transmitter protection.

High-Pass Filter (processing for digital modulation): 
1 Hz, not user-adjustable. 

Processing Topology: 
The stereo enhancer and two-band AGC are common to the analog and digital processing chains. The processing path splits after the AGC. The analog path receives equalization, five-band compression, distortion-controlled and -canceled clipping, overshoot compensation, and transmitter equalization. The digital path receives equalization, five-band compression, and look-ahead limiting. The parameters of the equalizers, five-band compressors, and peak limiters in the two paths are separately and independently adjustable. 

Processing Delay (processing for analog modulation):
Approximately 17 ms.

Processing Delay (processing for digital modulation): 
Approximately 15 ms. Monitor output with 5 ms. delay emits the digitally-processed signal before the look-ahead limiter.

Analog Audio Input


>10kΩ load impedance, electronically balanced.

Nominal Input Level: 
Software adjustable from –9.0 to +13.0 dBu (VU).

Maximum Input Level:
+27 dBu.

Two XLR-type, female, EMI-suppressed. Pin 1 chassis ground, Pins 2 (+) and 3 electronically balanced, floating and symmetrical.

A/D Conversion: 
24 bit 128x oversampled delta sigma converter with linear-phase anti-aliasing filter. Converter outputs 64 kHz sample rate, which the 9400 then decimates to 32 kHz in DSP using an ultra-high-quality image-free synchronous sample rate converter.

RFI filtered, with high-pass filter at 0.15 Hz (-3 dB).

Analog Audio Output

Two stereo pairs, capable to driving two transmitters.

Source Impedance: 
50Ω, electronically balanced and floating.

Load Impedance: 
600Ω or greater, balanced or unbalanced. Termination not required or recommended.

Output Level (100% peak modulation): 
Adjustable from -6 dBu to +24 dBu peak, into 600 W or greater load, software-adjustable.

>= 90 dB unweighted (Bypass mode, de-emphasized, 20 Hz-9.5 kHz bandwidth, referenced to 100% modulation).

L/R Crosstalk: 
<= -70 dB, 20 Hz-9.5 kHz.

<= 0.01% THD (Bypass mode, de-emphasized) 20 Hz-9.5 kHz bandwidth.

Four XLR-type, male, EMI-suppressed. Pin 1 chassis ground, Pins 2 (+) and 3 electronically balanced, floating and symmetrical.

D/A Conversion: 
24 bit 128x oversampled.

RFI filtered.

Digital Audio Input

Stereo per AES3 standard, 24 bit resolution, software selection of stereo, mono from left, mono from right or mono from sum.

Sampling Rate: 
32, 44.1, 48, 88.2, or 96 kHz, automatically selected.

XLR-type, female, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 transformer balanced and floating, 110Ω impedance.

Input Reference Level: 
Variable within the range of -30 dBFS to -10 dBFS.

J.17 De-emphasis: 

RFI filtered.

Digital Audio Outputs

Stereo per AES3 standard. 

Sample Rate: 
Internal free running at 32, 44.1, 48, 88.2 or 96 kHz, selected in software. Can also be synced to the AES3 digital input at 32, 44.1, 48, 88.2 or 96 kHz, as configured in software.

Word Length: 
Software selected for 24, 20, 18, 16 or 14-bit resolution. First-order highpass noise-shaped dither can be optionally added. Dither level automatically adjusted appropriately for the word length.

Both outputs can be switched independently to emit either the signal processed for analog modulation, the signal processed for digital modulation, or the low-delay monitor signal.

Two XLR-type, male, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 transformer balanced and floating, 110Ω impedance.

Output Level (100% peak modulation): 
-20.0 to 0.0 dBFS software controlled.

RFI filtered.

Remote Computer Interface

TCP/IP protocol via direct cable connect, modem, or Ethernet interface. Suitable null modem cable for direct connect is supplied. Modem is not supplied. 

Serial Port: 
115 kbps RS-232 port dB-9 male, EMI-suppressed. 

Ethernet Port: 
100 Mbit/sec on RJ45 female connector. Compatible to 10, 100, and 1000 Mbit/sec networks.

Remote Control ( GPI) Interface

Eight (8) inputs, opto-isolated and floating. 

6-15V AC or DC, momentary or continuous. 9 VDC provided to facilitate use with contact closure.

DB-25 male, EMI-suppressed.

User-programmable for any eight of user presets, factory presets, bypass, test tone, stereo or mono modes, analog input, digital input.

RFI filtered.


100-132 VAC or 200-264 VAC, switch-selected on the rear panel, 50-60 Hz, 40 VA.

IEC, EMI-suppressed. Detachable 3-wire power cord supplied.

Circuit ground is independent of chassis ground, and can be isolated or connected with a rear panel switch.

Safety Standards: 
ETL listed to UL standards, CE marked.


Operating Temperature: 
32 ° to 122 ° F / 0 ° to 50 ° C for all operating voltage ranges.

0-95% RH, non-condensing.

Dimensions (W x H x D): 
19" x 3.5" x 14.25" / 48.3 cm x 8.9 cm x 36.2 cm. Two rack units high.

0-95% RH, non-condensing.

Tested according to Cenelec procedures. FCC Part 15 Class A device.

Shipping Weight & Dimensions:
25lbs / 10.89kg - 24" x 24" x 9"


Five Years, Parts and Service:
Subject to the limitations set forth in Orban's Standard Warranty Agreement.

Because engineering improvements are ongoing, specifications are subject to change without notice.