Hi all,
I'm about to embark on this massive learning experience in using the SPL meter and REW.
After reading the first few sections of the help files, I see that I need to start by calibrating my sound card, which is a Hercules Fortissimo III 7.1 (which was around $AU110.. not exactly a cheapie).
I've already made up a 25m cable to run from the SPL meter to my PC, and as yet haven't tested it (I'm not sure if it's going to supply it's signal to left or right channel, but that shouldn't be a problem either way). I dug out my shortest twin-RCA to 3.5mm phono jack splitter lead and an RCA adaptor to use for the sound card feedback loop test. I connected them from the sound card's FRONT SPEAKER output, to the LINE IN input, and selected LINE IN as the recording source in the Fortissimo's control panel.
Looking at the meters within REW it seems that the signal is being read on the LEFT channel. Again, I don't expect this is a problem.
What IS an issue is the graph I'm getting from the calibration test. It's really nothing like any of the graphs on the "calsoundcard.html" page of the help files. For the past 2 hours I've been sitting here reading through every post I can find in this section regarding folks calibrating various brands and makes of sound cards, but there is no mention of the Hercules Fortissimo III. There's also many references to this so-called "monitoring" setting, but I cannot find this to disable it either in the Fortissimo Control Panel, or the "Sound & Audio Devices" section of the WinXP Control Panel. (I have seen an option for "monitoring" in SoundForgeXP 4 WAV creation/editing software before, but I expect that's part of that software and not part of the sound card's control panel.)
Seems I've well and truly fallen flat on my face at the first hurdle...
All this begs me to ask the question tho - since there are downloadable files for calibration of SPL meters, is it not suitable to have downloadable calibration files for individual makes/models of sound cards as well ?
