Yamaha RX-Z9 AV receiver Measurements


Only the main 7.1 channels were measured (not the front "effects" channels). The stereo analog frequency responses, from the CD input to the speaker output in Stereo Direct mode, were –2.72dB at 10Hz, –0.88dB at 20Hz, –0.09dB at 20kHz, and –0.47dB at 50kHz. The response from the multichannel input to the speaker output differed from the latter results by less than 0.1dB, maximum, at any of the four frequencies.

The Dolby Digital response (optical input to speaker output, left channel) measured –0.57dB at 20Hz and –0.34dB at 20kHz, left channel (–0.36dB at 20Hz and –0.28dB at 20kHz, center channel). With the left surround channel set to Small and the crossover frequency set to 120Hz, the highpass filter response was –3dB at 200Hz and –6dB at 154Hz—both a little high for that setting. With the left surround channel set to Small and the crossover frequency set to 40Hz, the highpass filter response was –3dB at 41Hz and –6dB at 31Hz.

The signal/noise (A-weighted, 2.83V into 8ohms) measured –92.4dB. Gain measured 28.7dB, CD in to speaker out, with the Level control set to "+2." The THD+noise in stereo at 2.83V into 8ohms measured 0.017% at 20Hz, 0.015% at 1kHz, and 0.014% at 20kHz. At 2.83V into 4ohms, the corresponding results were 0.017%, 0.015%, and 0.015%. Driving all seven channels into 8ohms, the RX-Z9 delivered 168Wpc at 20Hz and 165Wpc at 1kHz (to the nearest watt) before clipping (1% THD+noise). Into 4ohms, all seven channels operating, it delivered 221Wpc at 20Hz and 207Wpc at 1kHz. With only two channels operating, at 1kHz, the Yamaha clipped at 224Wpc into 8ohms and 382Wpc into 4ohms .

FM experienced problems with loss of image quality when passing HD signals through the Yamaha's component switcher. But when I ran a 720p resolution pattern through it and observed the result on an 80-inch wide screen using the BenQ HE8700+ projector, the image looked the same as the direct feed. I saw no loss of resolution. The only glitch was that the Yamaha would not pass two of the test patterns from our Leader HD generator: a letters pattern (with alphanumerics of varying sizes on the screen) and a multiple circle pattern. I have no explanation for this. But as to FM's problem, I can only speculate on some sort of incompatibility between his display and the video output of the Yamaha.
Thomas J. Norton

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