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Salt Lake City Receiver Audio Equalization

Receiver audio frequency response equalization

Saturday, July 9, 2005, the AudioControl C-101 Series Two 10-band audio equalizer shown above was installed between the Salt Lake City Kenwood R-5000 receiver and the Windows Media Encoder that generates the receiver audio stream.

Audio Equalization
Without equalization the Kenwood R-5000 audio response drops 12 dB per octave below 240 Hz, rises 9 dB from 240 Hz to 1.92 kHz, and drops 21 dB per octave above 1.92 kHz in LSB mode. With equalization the frequency response drops 12 db per octave below 120 Hz, is flat within 2 dB from 120 Hz to 1.92 kHz, and drops 12 dB per octave above 1.92 kHz. The red led plot above shows the overall equalized response. The end-effect is better-sounding Salt Lake City receiver audio.

Close-up view of frequency-response plot

This is close-up view of the audio frequency-response plot. Note that because the view is looking down, rather that straight-on, there is about 2 dB of calibration-scale parallax.

Frequency-Response Measurement Method
The overall frequency response was measured by modulating an LSB test generator set to 3750 kHz with white noise (the AudioControl C-101 has a built-in white noise generator), tuning the Kenwood R-5000 receiver to the test-generator frequency in LSB mode, and plotting the frequency response of the equalized audio with the spectrum analyzer that is built-in to the AudioControl C-101.

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