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STXtreme technical specifications

Analog inputs

Quantity: 2 stereo (XLR)
Level: +15 dBu
Impedance: 15 kOhm
Signal to noise: 113 dB(A) at -60 dbFS
Frequency range: 5 Hz to 96 kHz
THD+N: -105 dB
Sample rate: 32 - 192 kHz, 24 bits
Crosstalk: < -90 dB

Analog outputs

Quantity: 2 stereo (XLR)
Level: +15 dBu
Impedance: 75 Ohm
Signal to noise: 116 dB(A) at -60 dbFS
Frequency range: 20 Hz to 60 kHz, usable for MPX or normal audio.
THD+N: -104.5 dB
Crosstalk: < -90 dB

Digital inputs

Quantity: 4 stereo (XLR)
Standard: AES3
Sample rate: 32 - 192 kHz, 24 bits

Digital outputs

Quantity: 4 stereo (XLR)
Standard: AES3
Sample rate: 44.1, 48, 176.4, 192 kHz, 24 bits.

The system runs at either 44.1 or 48 kHz as the base frequency. Each digital output can be separate switched to run at 44.1/48 or at 176.4/192 kHz, the latter for digital MPX output.

SCA/RDS input

Quantity: 1 mono (BNC), can be used in multiple ways.

 

MPX outputs

Quantity: 2 (BNC)

All analog or digital outputs can also be used as MPX outputs.

Audio over IP

AES67: Limited support, input only for now.

 

Streaming outputs

MicroMPX: Up to 100 streams to different target decoders, or through different paths for redundancy.

Processing cores

One STXtreme unit can run 2 FM/HD processors or 1 FM/HD processor plus 2 HD-only processors (contact us if you need more).
Having more than 1 instance costs more.

Remote control

Remote control: HTML5-based, compatible with nearly all modern browsers and devices.

Input to output delays

Between 4.7 and 120 ms, depending on presets and settings.
Different outputs can have different delays, so a low latency studio monitoring output can be used alongside a high latency, higher quality MPX or HD output.

Power up

Boot time: Around 23 seconds.
Firmware update off-air time: Usually around 24 seconds, certain updates may take longer.

Size and weight

Dimensions: 485 x < 505 x 88 mm (19", 2 RU)
Weight: Below 11 kg
Shippng weight: 11.1 kg

 

Power supply

Voltage: 100 - 240 V
Frequency: 50 - 60 Hz

 

Networking

2 network connectors, usable for remote control, streaming, AoIP.

 

USB

USB connectors on the front (2x) and the back (1x), for performing software updates or connecting external devices. 

STXtreme firmware features

New features may be added in the future.

Audio processing features

Dehummer cleans up problematic constant tones.
Declipper repairs clipped (too loud) audio.
Dequantizer adds extra bit depth (about 2.5 bits).
Delossifier improves the sound of low bitrate MPEG2/MP3 files.
DeReverb removes microphone reverb.
Noise gate removes background noise.
FM hiss removes FM stereo hiss from the input signal.
Azimuth correction corrects phase issues caused by analog tape recordings.
Single instrument phase errors fixes single instruments in music that are in anti-phase.
Phase inversion detects phase inversions of one channel and corrects it.
Speech detection detects when speech is transmited and dynamics changes the processing settings.
Bandpass sets a lowpass and highpass frequency.
Equalizer can be used as a graphics equalizer in multiple places in the processing chain.
Auto EQ adjusts the spectrum without using compression, which reduces pumping and breathing.
Phase rotation protects the clipper against asymmetrical waveforms.
Phase delay can be used to change the sound, for example to stretch bass sounds and make them more boomy.
Stereo Boost is a multband stereo enhancer.
Stereo Image can control stereo phase and width separately, and can be used to make mono-compatible audio.
Stereo Phase adds a phase difference between left and right, wihch spreads 1-channel audio over both channels and makes it sound more natural.
Stereo Delay adds a delayed stereo signal, with levels adjusted based on the stereo strength.
Stereo Reverb adds reverb to existing stereo sound, thus adding stereo without adding reverb to vocals.
AGC slowly controls the level, and can also be used in matrix mode to make the stereo more consistent.
Natural Dynamics boosts the level of percussion instruments in the mix.
Low Level Boost raises the level of quiet sections in classical music.
Multband Compressor 1 and 2 with configurable 2 up to 9 bands each, which dynamically adjust their behavior based on the audio content.
Wideband compressor can be used to make the output more pumping, if required.
Bass EQ controls the bass frequency content in the same way that Auto EQ does for the whole spectrum.
Immersive Bass and Bass Exciter add higher bass harmonics, which adds warmth and makes the bass more audible on small speakers.
True Bass adds lower bass harmonics, only if they have been filtered out from the recording.
Highs Exciter and Absolute Highs add higher frequency audio if that's missing from (usually older) recordings.
Bass Clipper controls the bass level, but also can be used to exactly shape the bass sound to be much warmer and punchier.

FM specific features

Stereo coder with more than 90 dB pilot protection
RDS encoder with UECP and ASCII-mode remote control support, including features like TMC, EON etc.
Composite clipper adds about 2 dB of extra loudness to the received audio while sounding cleaner and more dynamic.
RF bandwidth limiter with built-in FM exciter and spectrum analyzer precisely controls the RF bandwidth after modulation on FM, reducing interference and multipath reception issues.

Due to this combination of features, some stations experienced an up to 30 km (20 miles) larger stereo reception area from their transmitter when replacing their old FM processor with this ours.

Other features

Nielsen PPM audio watermarking
Kantar and Intrasonics audio watermarking are supported by the firmware but need to be certified; contact us if you need it.
Password protected, partially skinnable web interface.
Scriptable JSON/HTTP remote control for all settings is possible.