Harman Kardon AVR 7300 AV Receiver Measurements
All measurements were taken on the left front channel output, except as noted. The frequency response of the AVR 7300, from the CD input to the speaker output in Surround Off mode, was -0.43dB at 10Hz, -0.10dB at 20kHz, and -0.59dB at 50kHz. The response from the multichannel input was approximately the same. The gain, from the CD input to the speaker output into an 8 ohm load, with the level control set to -4, measured 28.7dB. The S/N ratio (A-weighted, 2.83V into 8 ohms) was 93dB.
The Dolby Digital response from the optical input to the speaker output was -0.18dB at 20Hz and -0.50dB at 20kHz (-0.54dB at 20kHz for the center channel). The output of the surround channel, with the surround high pass filter set to 80Hz, was -3dB at 82Hz and -6dB at 61Hz. The output of the LFE channel was -0.59dB at 20Hz, -3dB at 118Hz, and -6dB at 123Hz, all relative to the output at 40Hz.
The Harman Kardon's low-level harmonic distortion (2.83V out) measured 0.023% at 20Hz and 0.022% at 20kHz into 8 ohms (and virtually the same into 4 ohms).
With all 7-channels driven, the output (1% THD+noise) was 154 Wpc at 20Hz and 152 Wpc at 1kHz into 8 ohms (197Wpc and 214 Wpc, at 20Hz and 1kHz, respectively, into 4 ohms).
Driving the left and right channels only, the 1%THD+noise level was reached at 191 Wpc into 8 ohms and 315 Wpc into 4 ohms. –Thomas J. Norton