Upsampling causes nasty audio effects

[Barak]

I have a bunch of lectures recorded as .wav PCM 8Khz, 16 bit, mono files. When I try to use dBpowerAMP to upsample them (for example, to 11025Hz, 16 bit, mono), the resulting file has a nasty "tinny" (not to be confused with tiny ) quality to it. I can understand losing quality with downsampling, but I would think I could upsample without reducing sound quality. How can I safely upsample?

[Spoon]

Download Release 9 - and on the Configuration page enable 'Professional Frequency Conversion'

[Unregistered]

what goes on in Professional Frequency Conversion?

Out of interest - I am converting a number of stereo wav files from 32000 to 44100 (to be burned to cd) - what goes on when Professional Frequency Conversion is selected converting wav to wav? Is there some algorithmn that calculates the missing samples - some kind of interpolation?

[Spoon]

Yes that sort of thing, but it does it much better than the standard windows one.