Audio Sprocket's James May has often stated that the best type of mic for training ToneDexter WaveMaps is a small diaphragm condensor mic with a very flat frequency response. I've had such a mic (Slate ML-2) on order from Sweetwater since September, but it hasn't been forthcoming. In the meantime I've tried WaveMap training with my dynamic gigging mics (Audix OM7 and Shure SM57), a very cheap Behringer omni-directional condensor mic and a barely functioning old Sony Electret mic. None of these has been completely satisfying, although I definitely made improvements on the amplified sound of most of my pickups.
I recently got the idea that the dynamic mics might do a better job if I could use EQ to flatten out the frequency response curves somewhat. It turns out that the SM57 is a good candidate for this because it has a flat frequency response between 190 Hz and 3 KHz. All I needed to compensate for was a steep bass rolloff from 190Hz on down (about -8db at 70Hz) and a +6db presence peak around 6 KHz.
Using my old Ashley parametric EQ box, I did a boost of +7db at 70 Hz, using a 2 octave bandwidth. (I tune my guitar a half step low, and often drop the low string to the Db at 69.3 Hz. That's why I chose to boost at 70 Hz.) I also did a -6 db cut at 6 KHz, with a bandwidth of about 2 octaves. I was doing some "guesstimating" for sure, but the resulting WaveMaps are working pretty well. I'm finally feeling like ToneDexter is making a marked improvement on the raw sound of my OTSS USTs. Here's a comparison made with my rosewood/spruce grand auditorium. OTSS UST Dry vs OTSS UST w/ToneDexter
https://soundcloud.com/guitaniac/ots...st-wtonedexter
I must observe that all was not "smooth sailing" with the parametric EQ box between the mic and ToneDexter. For some reason, the training took
much longer than when the mic is connected directly to ToneDexter. I never did get a satisfactoy WaveMap with the Audix OM7. This may have to do with my old EQ box or my novice's approach, or it may be a problem which others might encounter with an EQ device between the mic and ToneDexter. I can't say, but I'm happy to have somehow managed a good outcome on the Shure 57-trained WaveMaps for two rigs.