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Issues with 0dBFS+ Levels On Digital Audio Playback Systems - page 3

By Chris Tham — October 23, 2004

Panasonic DVD-RP82, analog outputs, no upsampling

The Panasonic didn't do too badly, and was able to reproduce 0dBFS+ levels up to +1.1 dB FS:

*Frequency (sine wave)*	*Phase*	*Analog peak level (theoretical)*	*Observed level*	*Relative level*
997.0 Hz	0°	0.00 dB FS	-7.5 dB FS	0.0 dB FS
5,512.5 Hz	67°	+0.69 dB FS	-6.9 dB FS	+0.6 dB FS
7,350.0 Hz	90°	+1.25 dB FS	-6.6 dB FS	+1.1 dB FS
11,025.0 Hz	45°	+3.00 dB FS	-6.6 dB FS	+1.1 dB FS

At levels higher than +1.1dB FS, the player started clipping, as can be seen for the waveform of the Sine wave @ 11,025 Hz 45° phase:

Panasonic DVD-RP82, analog outputs, upsampling using Remaster 1 algorithm

The Panasonic behaved far worse when the internal upsampling algorithm is engaged (I tried Remaster 1, but the other two algorithms were just as bad). The internal upsampler converts 44.1/16 to 88.2/24. It was only able to handle up to +0.1 to +0.3 dB FS:

*Frequency (sine wave)*	*Phase*	*Analog peak level (theoretical)*	*Observed level*	*Relative level*
997.0 Hz	0°	0.00 dB FS	-7.5 dB FS	0.0 dB FS
5,512.5 Hz	67°	+0.69 dB FS	-7.4 dB FS	+0.1 dB FS
7,350.0 Hz	90°	+1.25 dB FS	-7.4 dB FS	+0.1 dB FS
11,025.0 Hz	45°	+3.00 dB FS	-7.2 dB FS	+0.3 dB FS

Here's how the player handled the waveform of the Sine wave @ 11,025 Hz 45° phase:

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