Adam Schabtach writes:
>>Yup, an excellent technique. You can also synthesize frequency sweeps in the
computer and use those as the test signal. There is a freeware program called
MakeATestTone which generates AIFF files of frequency sweeps of whatever
duration, range, and amplitude you want. Play the test tone out through one
channel of your audio interface and record the output of the device through an
other channel.<<
Yes, that sounds just like a freeware program I tried, but there were so many
problems. Just listening by ear I could tell by the changing timbre and hollow
sound of the swept sinewave that it was generating other harmonics. Can't get a
pure sinewave out of this computer. The input back into the computer was so
weak no matter what I tried, the plot was almost non-existant and kind of
sloppy looking anyway. And it only plotted on a linear scale, not log scale.
That's why I dropped that method and turned my Nord Mod into a sweep generator.
>>I suppose the first thing one should do when employing this technique is to
loop the test tone output straight back into the recording input, so as to
measure the frequency response of your audio interface.<<
And I forgot about this one. When doing that, one should get a straight line,
but I was getting all kinds of bumps and ripples so any plot wasn't accurate
anyway.
-Elhardt