Pioneer Elite VSX-74TXVi THX Select2 AV Receiver Measurements
All measurements were taken on the left channel. The Pioneer VSX-74TXVi's frequency response from its analog CD input to the speaker out, in Pure Direct mode, measured –0.43dB at 10Hz, -0.15dB at 20Hz, -0.15dB at 20kHz, and -0.91dB at 50kHz.
The response from the multichannel analog bypass input to the speaker output measured –0.42dB at 10Hz, -0.16dB at 20Hz, -0.15dB at 20kHz, and -0.91dB at 50kHz.
The Dolby Digital frequency response (optical input to speaker output) measured -0.35dB at 20Hz and -0.29dB at 20kHz in the left channel, and -0.06dB at 20Hz and -0.26dB at 20kHz in the center. With the left-surround channel set to "small" and the crossover frequency set to 80Hz, the high-pass filter response was –6dB at 62Hz, –3dB at 81Hz, and –0.22dB at 20kHz. The line output of the LFE subwoofer channel, normalized to the response at 40Hz, was -0.17dB at 20Hz, -3dB at 111Hz, and –6dB at 118Hz.
The S/N (A-weighted, 2.83V into 8Ω) measured –102.9dB. Gain measured 28.6dB, CD in to speaker out, with an 8Ω load and the level control set to "+2.0."
THD+noise in two-channel operation at 2.83V into 8Ω measured 0.007% at 20Hz and 1kHz, and 0.006% at 20kHz.
THD+noise in two-channel operation at 2.83V into 4Ω measured 0.058% at 20Hz, 0.039% and 1kHz, and 0.006% at 20kHz.
With only two channels operating at 1kHz, the Pioneer clipped (1% THD+noise) at 211Wpc into 8Ω and 334Wpc into 4Ω.
Driving all seven channels into 8Ω, the Pioneer delivered 63Wpc at 20Hz and 136Wpc at 1kHz (to the nearest watt) before clipping (1% THD+noise). This test was repeated several times with approximately the same result, and the unit went into protection on each run after a reading was obtained. But it recovered after a few seconds when the input signal was removed. The limited power at 20Hz with all channels operating did not affect the listening tests (using full range left and right speakers). This was likely due both to LEU's relatively small room and the fact that multichannel film sound rarely stresses all channels simultaneously with a very low frequency signal.
Into 4Ω, with all seven channels operating, the Pioneer delivered 188Wpc at 1kHz. But an internal mains fuse blew on the 20Hz test before a reading could be obtained. AC receivers are not generally rated down to 4Ω, but our standard procedure is to test receivers and amps into that impedance since many speakers on the market provide a load that low, or lower, at some frequencies.—TJN