[sdiy] BLEP vs MinBLEP

Richie Burnett rburnett at richieburnett.co.uk
Fri Feb 19 18:17:16 CET 2021


I've uploaded BLEP and equivalent MinBLEP sweeps just for you Brian ;-)

http://www.richieburnett.co.uk/temp/blep/

"BLEP_96k" is the same as the Saw_BLEP16 example I uploaded before but this 
is running at 96kHz.  "MinBLEP_96k" is using the same FIR kernel but with 
minimum phase reconstruction, also at 96kHz.  I uploaded them both at 96kHz 
sample rate so that you can see the difference in the samples around the 
transitions clearly.  The standard linear-phase BLEP has pre-ringing and 
post-ringing around the transitions.  Whereas the MinBLEP has more ringing 
but it is all after the transition.

Incidentally in this example the group-delay or "look-ahead" was 8 samples 
for the 16-point BLEP, and that dropped to 3 samples for the 16-point 
MinBLEP.  So it is clear that it doesn't get rid of the look-ahead 
completely.

I can't hear any audible difference, but the phase of some of the higher 
harmonics are definitely different as is evident by time-aligning and 
subtracting one example from the other.

Also I didn't mess about getting the MinBLEP group-delay to be *precisely* a 
whole number of samples so there is a little bit of DC offset towards the 
end of the MinBLEP sweep! (>.<)

-Richie, 


-- 
This email has been checked for viruses by AVG.
https://www.avg.com




More information about the Synth-diy mailing list