also in espeakedit (not ng) the resampling quality seemed to be so-so (maybe not sox's fault, maybe command-line-settings) but resampling from a low-quality source-wav file isn't the same as starting from one of higher quality

default currently is 22050 HZ 16-bits maybe increase to 32kHz+ and 32-bit-float compile option to do down-sample

and if using sox use best-quality sinc option, max percision