Sunfire Ultimate A/V Receiver HT Labs Measures
This graph shows that the Ultimate's left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1% distortion at 150.9 watts and 1% distortion at 231.3 watts. Into 4 ohms, the amplifier reaches 0.1% distortion at 265.5 watts and 1% distortion at 398.1 watts. With five channels driving 8-ohm loads, the amplifier reaches 0.1% distortion at 132.6 watts and 1% distortion at 190.7 watts.
The analog frequency response measures +0.15 decibels at 20 hertz and –0.70 dB at 20 kilohertz. Looking at a broader bandwidth, the response measures +0.10 dB at 10 Hz and –2.76 dB at 50 kHz. In modes that involve signal processing, the response is –0.08 dB at 10 Hz, +0.10 dB at 20 Hz, –0.75 dB at 20 kHz, and –49.12 dB at 50 kHz. Response from the multichannel input to the speaker output measures +0.09 dB at 10 Hz, +0.15 dB at 20 Hz, –0.70 dB at 20 kHz, and –2.77 dB at 50 kHz. THD+N from the amplifier was less than 0.079% at 1 kHz when driving 2.83 volts into an 8-ohm load. Crosstalk at 1 kHz driving 2.83 volts into an 8-ohm load was –70.96 dB left to right and –68.97 dB right to left. The signal-to-noise ratio with 2.83 volts driving an 8-ohm load from 10 Hz to 24 kHz with "A" weighting was –83.33 dBrA.
From the Dolby Digital input to the loudspeaker output, the left channel measures +0.15 dB at 20 Hz and –0.76 dB at 20 kHz. The center channel measures +0.20 dB at 20 Hz and –0.15 dB at 20 kHz, and the left surround channel measures –0.02 dB at 20 Hz and –0.49 dB at 20 kHz. From the Dolby Digital input to the line-level output, the LFE channel is +0.53 dB at 20 Hz when referenced to the level at 40 Hz and reaches the upper 3-dB down point at 118 Hz and the upper 6-dB down point at 120 Hz.—AJ