I'm running some measurements with Audyssey on my Denon 4311 with Audyssey Pro, and I noticed something kind of weird.
I have my laptop, with current REW/HDMI, narrow band 90 degree UMM-6 cal file, and ASIO, doing sweeps, with an HDMI cable connecting my laptop to an HDMI input on my Oppo 103, and thence to my Denon via HDMI. I'm testing this configuration because I want to use it when I do my Trinnov/R-972 testing, and I wanted a single "source" for my REW sweep when I compare systems..
Anyway, I'm seeing that I get different results for at least one channel (center+subs) whether I have the Oppo send PCM (my preference, to avoid future bugginess with the Sherwood when I run that way) vs. letting the AVR handle via bitstream.
I have an identical mic position, Audyssey XT32 on, Dynamic EQ and DEQ off, and my Oppo successfully shows up in ASIO as 8-channel, 48 kHz, etc, with a 5.1 configuration for my playback device.
See enclosed chart: do these differences below 200 Hz make any sense to anyone? I have a hard time imagining it's a cable issue, as I see the same thing whether or not I have my UMM-6 mic connected on a single USB cable, vs. using a Redmere extender. Also, my laptop is on battery, and I'm using a new Rocketfish 10' hi-speed HDMI cable between the laptop and the Oppo's HDMI front input.
center test.jpg 201k .jpg file
One other thing: I seem to be getting a lot of static when I measure, whether or not I switch channel sources, particularly on the lower and higher part of the frequency sweep. FYI I'm playing at 75 db, verified when I did an SPL sweep.Edited by sdrucker - 9/21/13 at 4:22pm