Radios with Adaptive IF (aka DSP).

Car Receiver Specifications

ALPINE CDA-7842R CAR CD RECEIVER: 1998Alpine CDA-7842R car receiver

Incorporates Digital Signal Processing into its FM section, a feature that the manufacturer called Max Tune PRO. Included on CDA-7878R, CDA-7876R, CDA-7873R, CDA-9812R, CDA-7944R, CDM-7871R, TDA-7592R & INA-N333RS. Max Tune PRO receivers are no longer available.

Utilizes four conventional ceramic filters for FM IF which are fed into the TDA7461 Car Radio Signal Processor Integrated Circuit. Made in Japan.

Radio Data System
Supports EON, PS, Radio Text,
Alternative Frequency,
Traffic Announcement
Radio Broadcast Data System
Not supported
Usable Sensitivity - at 98.1 MHz
Mono 17.2 dBf (1.98 µV)
-3dB Limiting Sensitivity - at 98.1 MHz 21.2 dBf
PS RDS Sensitivity (radio station name)
36.2 dBf (25 dBµV)
Signal-to-Noise Ratio - at 98.1 MHz
Stereo 55 dB
Alternate Channel selectivity (unmodified) 90 dB
Number of IF Filters - FM
Width of IF Filters - FM section
3 x 180 KHz Group Delay Type
1 x 80 KHz
Capture ratio 2.0 dB
Stereo Separation 20 dB
Image Rejection - at 106.1 MHz
40 dB
IF Rejection - at 90.1 MHz
60 dB
Distortion - at 98.1 MHz
0.7% (input: 60 dBµV)
Channel Spacing steps - FM
Switchable: 50 KHz or 100 KHz
Can manually force mono
Not supported
Longwave tuner - LW band
Audio Power amplification
Ipod or auxiliary input
Remote control

SONY CDX-S2000S CAR CD RECEIVER: 2005 Sony CDX-S2000S SSIR-EXA car receiver

Incorporates Digital Signal Processing into its FM section, a feature that the manufacturer calls SSIR-EXA adaptive reception. According to Sony, this minimizes interference between stations.

Utilizes two (2) conventional ceramic filters for FM IF which are fed into a proprietary Sony Noise Suppressor IC.

Radio Data System or
Radio Broadcast Data System
RDS-EON supported on all European models e.g. CDX-S2000
Usable Sensitivity 9 dBf (0.77 µV)
Signal-to-Noise Ratio Mono 69 dB
Stereo 67 dB
Frequency response 30-15,000 Hz
Alternate Channel Selectivity (400 kHz) 75 dB
IF Filters - FM section 2 x 180 KHz
Harmonic Distortion - at 1 KHz Mono 0.3 %
Stereo 0.5%
Stereo Separation - at 1 KHz 35 dB
Channel spacing steps - FM section Fixed: 50 KHz
Can manually force mono for weak FM station Supported
Longwave tuner - LW band Supported on all European models
Audio power amplification Mosfet
Ipod or auxiliary input Not supported
Remote control Supported


Incorporates Digital Signal Panasonic CQ-C1301Processing into its FM section. Included in all models as a standard feature. Panasonic also manufactured a series of high end car receivers with switchable bandwidth.

Usable sensitivity  
6 dB/µV (S/N 30 dB)*
My calculations indicate this is equivalent to:  2 µV or 17.2 dBf once converted.
Frequency response
30 Hz 15,000 Hz (±3 dB)
Alternate channel selectivity
75 dB
Stereo separation - at 1kHz
35 dB

Image rejection ratio
70 dB
IF rejection ratio
100 dB
Signal-to-noise ratio
62 dB

BLAUPUNKT DIGICEIVER: 1990s Audi Concert A3 2008 aka Blaupunkt Digiceiver & Twinceiver in action

Incorporates Digital Signal Processing into its FM section, a feature the manufacturer calls the Sharx Digiceiver digital adaptive filter. According to Blaunpunkt,  this optimizes channel separation so station signals which are extremely close to one another are separated cleanly. Blaupunkt Audi Concert label

Blaupunkt also manufacture Digiceivers for modern day VW/Audi, Mercedes & BMW cars available in Australia (as pictured from the Audi A3). RDS-EON/PTY support. The Digiceiver is the most selective DSP car receiver tested for 100 kHz & 200 kHz signals, relative to the Alpine, Sony, Panasonic, Pioneer & JVC models.

How it works

American DX performance PDF format. Some are written in German

German DX performance

Technical review A

Technical review B 

American measured specs APDF format. Some are written in German

German measured specs B

Comparative test

Component Tuner Specifications 

SONY XDR-F1HD TUNER: 2008Sony XDR-F1HD tuner set to local station Hot 91

A component tuner but more compact, with the same dimensions of a car receiver. Incorporates Digital Signal Processing into its FM section. Basic RDS support.

Technical review 

Non recordable desktop receiver version (released in 2010)

Portable Radio Specifications

TECSUN PL-300WT RADIO: 2009Tecsun PL-300WT pocket radio

A portable radio that incorporates DSP developed by Silicon Labs into its FM section. Also 'rebadged' as the Grundig G8 in the Americas. 

These radios have been used to receive Summer Es FM reception from over 2,300 kilometres away. What more needs to be said? 

Adjacent Channel Selectivity
Minimum 35 dB
Input IP3 (3rd order intercept point) Minimum 100 dBµV EMF

Typical 50 dB

Typical 105 dBµV EMF
Alternate Channel Selectivity
Minimum 60 dB
AM Suppression Minimum 40 dB

Typical 70 dB

Typical 50 dB
Sensitivity with 50 Ohm Network
1.1 µV EMF (S+N)/N = 26 dB*
Spurious Response Rejection - inband 35 dB
- to - Noise ratio
Mono Minimum 55 dB
Soft Mute characteristics Engages for FM signals with a signal to noise ratio of 4 dB or less.

Mono Typical 63 dB
Attenuation during Soft Mute - FM section Maximum 16 dB

Stereo 58 dB
Coverage Extended FM band (64 to 76 MHz)
Frequency Response at -3 dB 30 Hz - 15,000 Hz

Worldwide FM broadcast band (76 to 108 MHz)
Stereo Separation
25 dB
Channel spacing steps - FM section 10 kHz
Total Harmonic Distortion
Typical 0.1 %

Maximum 0.5%

* denotes a non-standard tuner sensitivity measure. These specifications relate to their unmodified FM section performance. Car receiver measurements have been sourced from the service manuals. Portable radio measurements have been sourced from the data sheets.

The Sony CDX-S2000S has 
been modified slightly. The original FM IF filters have been replaced with narrower 56, 80 or 110 kHz ones. These filter modifications may improve or degrade individual values. 

Even though they are designed for "in car use", the car receivers are used inside the house with 12v DC power using Jaycar regulated power supplies.

© 2009-2011 Ryan Leigh Donaldson. All rights reserved.

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