Hello
Here’s the problem, according to a Sound & Vision review and lab tests the receiver just does not have the power output into 7 channels.
DOLBY DIGITAL PERFORMANCE
All data were obtained using various test DVDs with 16-bit dithered test signals, which set limits on measured distortion and noise performance. Reference input level is -20 dBFS, and reference output is 1 watt into 8 ohms. Volume setting for reference level was 60. All level trims at zero, and except for subwoofer-related tests, all speakers were set to "large," subwoofer on. All are worst-case figures where applicable.
Output at clipping (1 kHz into 8/4 ohms)
1 channel driven: 84/138 watts (19.2/21.4 dBW)
5 channels driven (8 ohms): 30 watts (14.8 dBW)*
Distortion at 1 watt (THD+N, 1 kHz, 8 or 4 ohms): 0.02%
Noise level (A-weighted): -75.1 dB
Excess noise (with sine tone)
16-bit (EN16): 1.2 dB
Frequency response: 20 Hz to 20 kHz +0, -0.1 dB
*Multichannel tests, regardless of source signal (digital or analog, stereo or multichannel) or decoding modes, caused the STR-DG910 to limit output to about 30 watts or less per channel; see accompanying lab notes. Since the receiver lacks analog multichannel or preamp inputs, direct testing of power-amp channels was not possible.
http://www.soundandvisionmag.com/receivers/2354/test-bench-sony-str-dg910-av-receiver.htmlChannel Power Rating : 7.1 Channel Power Rating: 100W x 7 Amp Power (700W) (8 ohms, THD 1.0%)
This last specification is from the Sony website and the power rating is not up to FTC snuff.
There's still the high level to low level converter option.
