Example:
That's my cap of tea in measurements.Or SINAD vs level,helps calculate real world scenarios were attenuation is a necessary evil (no one listen to 0db across all the devices).
That's exactly what I thought you were referring to.
I've always wondered... say you've got 20W 500Hz sine wave (12.65V 8Ω), and on top of that you've got 1W 15kHz sine wave (2.83v 8Ω).
Does the part of the 15kHz sine wave when it's between 2.83V have THD+n of -98dB, with distortion increasing to -78dB (or so) at the crests of the 500Hz sine wave?
I'd really like to set up the software used here to play around with. I've got a decent audio interface with 4 channels in, 4 out, made by RME. The Babyface Pro. When I chose the device, I was focused on mobile recording, so instead of buying the ADI-2 Pro (which, retrospectively would've been the better buy, as I can count on one hand all of the times I couldn't have used the ADI-2 Pro (I since bought a nice 300W sine wave inverter and a collection of differently sized 12V AGM batteries lol))
The Babyface Pro FS was reviewed here. The RME website specs THD+n of its ADC as -108dB, and Amir's measurement of it is -107.83 and -107.81 - IMO identical. The ADI-2 FS was also reviewed here, measured as -115dB THD+n. RME's website specifies -114dB for unbalanced, -116 XLR. So, although I haven't come across any 3rd party measurements of my non-FS version of the Babyface Pro, because RME seem to be accurate and even sometimes generous with the measurements they give of their products, I believe the -104dB THD+n spec given. In the mixer console, the peak meter has the level in dB at the top of each channel, and for the XLR inputs the level given is -105. This is in line with specs given, as, at one point I sent -6dB to the input and it registered properly.
Anyway... you seem to know a bit about the software. Is it free to use for personal use? Free trial? -104dB THD+n is definitely good enough to measure almost anything as long as it isn't [proper] hi-fi or professional equipment. I've got good balanced and RCA cables with excellent ends and can avoid pesky ground loops by running my machine with the 300W sine wave inverter (or laptop). If I get it going I've got a few items I know people here would be interested in knowing the specs of. I also have a couple friends with some similarly interesting items I could borrow