Reading cdnbum88's post makes me worry that not all HDMI outputs on laptops and PCs are going to offer 8 channel or ASIO support. Eventually jevansoh should make a list of supported audio chipsets and graphics cards with HDMI audio out that are compatible with REW. Maybe make a note in the first few posts of this thread for users having HDMI problems to state what audio chipset, soundcard, or graphics card they are using including make, model, version #? The driver version may also help.
I'm glad this thread exists because I'm going to ask alot of dummy questions. I'm probably going to order the USB mic, but I have some setup questions after looking through the REW documentation. My questions are primarily with calibrating for LFE material for the subwoofer channel, and larger bit depths.
I noticed in the 'Checking Levels' section of of REW Help, it mentions increasing the volume or signal level so SPL meter reads around 75 dB. I though the LFE channel was supposed to be played back 10 dB higher than the main channels? Does the bit depth of a file (ie 16 bit, 24 bit) determine how loud the pink
noise signal should be recorded and measured? In other words, would the process for calibrating a system for DVD (16 bit audio) be any different than that for bluray (24 bit in some cases)? Would a lower playback level for a higher bit depth file actually skew the calibration in a less-desired way? Would setting the output level to 85 dB or 95 dB on the sub channel be better if I'm primarily playing back 24 bit audio? Maybe I'm just getting confused between the theoretical dynamic range limited by the bit depth and suitable playback levels. Regardless, if anyone knows the answers to these questions, please let me know.
Couple of comments:
First, I don't know that publishing a list of supported hardware will be that easy.
Second, I don't understand any of your questions regarding signal levels. REW outputs test tones to your AVR. You control the AVR's output level through the master volume control. Part of the initial setup of REW is the calibration of the output signal. The process is described in detail in the Help file, and it is very important that you learn how to do it. Essentially, it works like this: Open the SPL icon in REW and click the "Calibrate" button, which causes a calibration tone to be sent to the AVR. Using an SPL positioned at the MLP at ear-level, adjust the AVR master volume until the SPL reads 75dB. In the REW calibration screen, adjust the level to also read 75dB, and then click Done. Now REW knows that the reference tone from the AVR is 75dB, and can accurately measure the AVR's output as other measurements are taken.
Now, what are all those other questions you had, and what do they have to do with REW calibration and measurements? I'm confused.