X5 - FM/HD Top of the Line


It's Time. Meet X5.

Meet X5, Wheatstone’s new flagship FM and HD audio processor.

Built from the ground up, it's based on several breakthroughs, including an innovative new approach to dynamics control and pre-emphasis management.

In more traditional audio processing designs, pre-emphasis is either managed by specialized limiting or carefully designed clipping that merely tolerated the pre-emphasis curve. Thinking about this problem, and the fact that it’s been over a decade since there has been a major development about dealing with pre-emphasis, Wheatstone set out, through our work with DSP, to come up with the ultimate solution to the problem.

We have seen what the power of DSP can do to restore audio and video over the years. What if we found a way to apply that thinking to FM pre-emphasis and peak control?

Enter LIMITLESS. FM peak control technology that reconstructs the audio after the application of pre-emphasis. No more dull smeary highs or spitty audio. Just clean and clear high end that’s perfectly matched to the texture of your HD audio.

X5 also leads the way with Unified Processing®, which allows the processor to share information between ALL stages. In the X5, the iAGC, Dynamics and Limitless Clipper work together no matter which control a user adjusts. Changes are made automatically, in real time, in ways never envisioned before.

The X5 also includes a totally redesigned limiter. As part of the Unified Processing system, this unique limiter, designed as 31 independent filter banks with no crossovers to colorize the audio, works directly with the X5's Limitless clipper, providing an audio blueprint for how the clipper should behave.

Additionally, X5 offers a full suite of static and dynamic RDS features along with with multi-stream UECP support.

The X5 adds a number of other state of the art features, including LIVE LOGGER which documents everything from remote logins to audio failover to preset changes. Our redesigned bass processor and enhancement controls in the iAGC that allow you to safely equalize your audio for maximum consistency. The days of “maybe it will sound better on the next song” are over. Your audio signature is preserved cut after cut, element after element.

Wheatstone’s popular HD/FM audio alignment makes the jump to the X5 with our FM&HD LIVELOCK. The system works either with third-party HD/FM modulation monitors or by itself, using the FM/HD tuner built in to the X5.

Additionally, you can now keep the processor at the studio and still keep HD and FM audio in perfect alignment to the transmitter with our optional MPX SYNC-LINK receiver. MPX SYNC-LINK manages multiple audio streams to keep them in perfect sync, preventing any possibility of the FM and HD audio getting out of alignment.

AES insert points are also available via PPMport. Users can now insert their ratings encoder into the processing system instead of placing it in front of the processor. This allows the X5’s specialized front end to deliver a steady audio diet to the encoder and increase the instances of watermark embedding. What’s more, the sonic transparency of the LIMITLESS clipper preserves the watermark for more reliable detection at the meter.

X5 also offers built-in watermark encoding for the Kantar Media ratings measurement system.

We’ve spoken a lot about what’s new in X5, but Wheatstone processing users will be happy to know that many of the features we’ve pioneered in previous models have been incorporated and improved on in the X5, including our legendary Multipath Mitigation algorithm, our composite processing system with selectable look ahead limiting or clipping, baseband192 composite AES connectivity, and a full set of analysis displays.

The X5. Processing for the needs of radio TODAY!


X5 Now Includes New Nielsen Audio Software Encoder

Wheatstone worked behind the scenes with Nielsen developers and has gone through the necessary testing to receive the Nielsen certification. The Audio Software Encoder is now integrated in our Aura X5 audio processor, which is available to FM stations.

Wheatstone Processing Videos - X5

At NAB 2019, we introduced the X5 FM/HD audio processor along with our new MPX SyncLink. Here are several videos with Jeff Keith and Mike Erickson taking you through some of the new features. Also, there are several videos of customers who've just heard X5 for the first time...



  • Processor shares information between ALL stages – iAGC, limiters and clipper all share information and changes can be made automatically, in real time, in ways never envisioned before. 

  • Redesigned bass processor and enhancement controls in the iAGC that allow you to safely equalize your audio for maximum consistency.

  • Full RDS capabilities.

  • Works either with third-party HD/FM modulation monitors or by itself, with the new FM/HD tuner built in to the X5.

  • AES insert points (PPMport) are also available for customers who wish to insert their ratings encoder into the processing system instead of placing it in front of the processor.

  • New look and feel, with an intuitive GUI and dual touch screens on the front panel.  

  • Experienced users of Wheatstone processing will be happy to know that many of the popular features in previous models have been incorporated in the AirAura X5, including:

– an improved Multipath Mitigation algorithm
– redesigned composite processing with selectable look ahead limiting or clipping, 
– baseband192 composite AES connectivity
– full set of analysis displays. 



What Makes X5 Different? Cool New Stuff...


MPX SyncLink 


The available MPX SyncLink extends the X5 with HD/FM alignment from your studio to your transmitter site. It carefully keeps the HD and FM packets in sync so time alignment done with the processor at the studio is maintained straight through to the receiver. 

FMHD Livelock

FM & HD LiveLock 


Integrated HD and FM analog signal alignment keeps listeners and people meters tuned in to your station even during extreme HD/FM blending conditions. No external boxes needed and no more “dip and skip” in reception that can cause listeners to tune out and people meters to reset, affecting TSL.

How Does MPX SyncLink Work?

MPX SyncLinkFlowchart

HD and FM composite audio are converted to a single WheatNet stream at the X5 and sent over a data link (min 20 mbps) to the SyncLink decoder. There, the audio is converted back to two (2) analog composite signals, one baseband192 (MPX over AES) signal as well as an AES HD signal.

Because all audio is kept in the same IP stream, they arrive at the destination simultaneously and remain in sync. If packet loss occurs, both signals experience the same duration and time alignment is maintained.


Limitless Clipper 


Perfect peak control without a trace of IM distortion, no matter how much HF energy you put into the X5! 

We re-thought the relationship between peak control and HF pre-emphasis! Limitless Clipper uses proprietary high-frequency distortion cancelling technology to pass the highs, but not the overshoot. No more “spitty” highs or pops from clipping; no IM distortion whatsoever. This clipper will take all the highs you can give it, and never give you back IMD. 

This clipper, along with X5’s Phase Linear dynamics, gives you the most powerful FM processor on earth.


Unified Processing 


Key to the X5's exceptional sound is its ability to have every function in the processing chain be informed by and capable of reacting to every other function simultaneously.

Each X5 function in the processing chain interacts closely with other functions to deliver just the right amount and type of processing needed, letting you create a sound that’s as close to the original as possible while still dominating the dial.


Live Logger


Live Logger keeps track of everything happening on your X5. Preset takes? Remote login? Audio failover? Every event is date and time stamped so you can review it. X5 takes audio to a whole new level and, with Live Logger, gives you absolute and complete peace of mind.

PPM Port2



X5 features an insert loop to interface your ratings encoder AFTER the processing. This delivers a signal with greatly reduced audible artifacts, which ensures you’ll be moving all those meters out there.


Multipath Mitigation


X5’s multipath mitigation delivers your signal to more listeners while PPM Port’s smart AES insertion points ensure each and every one of those PPMs register. Better sound delivered to more radios – sound that cuts through and sounds amazing.

AirAura X5 Display Gallery

Pro Main ScreenX5 Active















X5 REAR 082917 3MpxW

WheatNet-IP Extends AirAura X5's Power

images/NEW_FOR_NAB_IMAGES/NAB_NEW_BLADES.jpgWith WheatNet-IP BLADE-3s, you get a virtual rack room in a 1-rack space box. They handle all the I/O (AES/EBU, SPDIF, AOIP, MADI, SDI and AES 67) and provide full routing capabilities. Each BLADE-3 gives you two 8x2 utility mixers, 12 universal GPI/O ports, 128 software logic ports, silence detection, built-in audio clip player, stereo multi-band audio processing, and much more, assignable anywhere on the network. With it you can create workflows that would require a ton of third-party gear.

Click for X5 Specifications

General Specifications

Analog Line Input

Type: Electronic Differential

Input Impedance: > 10Kohm (bridging)

Optimum Source Impedance: < 1Kohm

A/D Converter: AKM5394, 192kHz, 24-bits

Digital Line Input

Data Standard: AES3 (AES/EBU)

Data Amplitude:

Per AES3-2003 assuming minimum allowable output signal amplitude of 2V and minimum allowable input signal amplitude of 200mV

AES Receiver: CS8416, 192kHz, 24-bits

Type: WheatNet-IP

Data Type: 100 BaseTEthernet Network per IEEE 802.3-2008

Input Gain Adjustment Ranges

Gain Range: +/ -24dB

Gain Adjustment Resolution: 0.5dB

Gain Calibration:

Input Failsafe

A gain control setting of 0.0 aligns an external 0dBFs signal with the X5’s 0dBFs internal reference

Type: Automatic

Analog Fail Cause: Audio level below -24dBu (fixed)

Response Time: 30 seconds (fixed)

Digital Fail Cause 1: Audio level below -48dBFs (fixed)

Response Time: 30 seconds (fixed)

Digital Fail Cause 2: Corrupted or invalid AES data

Response Time: Immediate (fixed)

Failsafe Direction: Digital to Analog/Analog to Digital (no Digital to Digital)

Audio Level Balance

Type: Common to both Analog and Digital Inputs Analog/Digital L/R Balance Range: +/-12dB

Control Resolution: 0.5dB

Voice Symmetry via Phase Rotator

Operating Modes: In/Bypass

Filter Type: 4th Order All-pass

High-Pass Filter

HPF Filter Class: 24dB/octave Butterworth

Frequency range: 20Hz – 300Hz

Parametric Equalizer

Sections: Four

Frequency Range: 20Hz – 20kHz

Bandwidth Range: 0.2 – 3.0 octaves

Boost/Cut Range: +/- 14.0dB

Options: Bypass

Bands 1&4 Shelving

5 Band AGC/Compressor with iAGC

Drive Gain Range: -12.0dB to +6.0dB in 0.5dB steps

AGC/Compressor Thresholds: - 50dBFs to -70dBFs

AGC Attack: 50mS to 3000mS

AGC Release: 1000mS to 7000mS

AGC Band Coupling: 0dB to -6.0dB per band to key band

Compressor Attack: 10mS to 1000mS

Compressor Release: 50mS to 3000mS (3Sec)

Compression Ratio: 2:1 to 20:1

L+R Mixer: Boost/Cut +/-6dB

L-R Mixer: Boost/Cut +/-6dB

Gating Mode: Slow Release/Hold

Gate Threshold Range: -20.0dB to -79.5dB, plus OFF

iAGC Attack/Release Speed: 2 to 7.0 seconds

iAGC Threshold: -60.0dBFs to -40.0dBFs

iAGC Window Size: 0dB to 8.0dB

iAGC Operating Style: Linear or Adaptive

Crossover Frequencies

Band 1/2: 60, 80, 120, 150 Hz

Band 2/3: 250, 364, 530, 700 Hz

Band 3/4: 1.2, 1.59, 1.73 kHz

Band 4/5: 4.49, 6.17, 7.55 kHz

31-Band FM Peak Limiter

31-Band Limiter Drive: 80 – 100%

Clipper Drive: -6.0dB to +6.0dB

31-Band Limiter Knee Shape: Soft/ Hard

Pre-Emphasis: Flat/50µS/75µS

Stereo Encoder

Reference grade Stereo Encoder with embedded Composite Processing, Test Oscillator, SCA digitizer, and balanced and unbalanced composite outputs.

Composite Processor Modes: Oversampled Clipper or Lookahead Limiter MPX Processing Drive Range: +/-6dB

Automatic Multipath Limiter: 10% to 100% in 5% steps, plus Off 19kHz Stereo Pilot Injection: 0-20%, 0.1% steps

19kHz Stereo Pilot Phase: +/- 22.5 degrees referenced to 38kHz

SCA 1 & 2 Input: Analog, 10Kohm input impedance

Maximum SCA Input Level: +24dBu

Gain Control Range: -79.95dB to +10dB; OFF Stereo Encoder Operating Modes:

Analog Left/Right Only: Analog L/R or Analog L/R De-Emphasized

Stereo Multiplex: Unbalanced MPX Output

TX 1 & 2 Output Standard Level: 3.5V P-P (1V RMS)

TX 1 & 2 Maximum Output Level: 8V P-P into 1Kohm (BNC Outputs)

BS.412 Power Control: On/Off (Bypass)

BS.412 Power Control Options: Level/Style/Speed/Calibration/Action


Headroom Level: >20dB

Nominal Operating Level: -20dBFS digital

FM Path Processing Latency: 46mS maximum – all features engaged HD Path Processing Latency: 29mS maximum – all features engaged Total Harmonic Distortion: <0.1%, 20Hz – 20kHz *

Intermodulation Distortion: <0.1% SMTPE *

Signal to Noise Ratio: >80dB * Signal Chain Internal Dynamic Range: >144dB

Stereo Separation: >50dB (FM) 100dB (HD) *

Crosstalk: >50dB, 20Hz – 15kHz (FM) 20Hz – 20kHz (HD) *

Power Requirements: 100-250 VAC (auto sensing)

50/60Hz, 100 VA Max.

Power Connector: EMI suppressed IEC male

Shipping Weight: 37 pounds

Operating Temperature: 0 to 50 degrees C (32 to 122 degrees F)

Overtemp alarm reporting via APP@50 degrees C

* Bypass Preset, unity gains, and 75µS pre and de-emphasis

All specifications subject to improvement or change without notice.

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