Hi Mark, Interesting! Thank you for the update!
Some time ago I have prepared a branch that emulates the gain change during vinyl scratching: https://github.com/mixxxdj/mixxx/pull/602 I have used a frequency independent gain-by-speed curve picked from a Serato vinyl. https://bugs.launchpad.net/mixxx/+bug/1450665/+attachment/4388671/+files/speed-gain.ods Thinking about this again, I wonder if this does already include the RIAA curve. A double speed for a 1 kHz signal means approx. -2.5 dB in the RIAA curve (ratio 0.75) Actually the measured ratio is approx 1.4 which includes the RIAA negative gain plus a positive gain due to the increased speed. Maybe the non straight curve form of RIAA is negligible or selves- compensating due to the the mechanical effects in a speeding vinyl .. What do you think? Kind regards, Daniel Am 05.11.2016 um 20:50 schrieb Mark Hills: > The timecode decoder is almost totally self-calibrating; adding an RIAA > preamp will have almost no effect on the decoding. > > The only reason I can think to implement one in Mixxx is if you want to > use your software preamp to listen to regular vinyls (not timecode) > > Also keep in mind that when scratch etc. the Serato 1KHz sine wave then > appears at all sorts of frequencies. That would make it technically > incorrect to apply an RIAA equalisation, but in practice I don't see it > making any difference. > > A more interesting side note is: to emulate a more 'correct' vinyl sound > during scratching, the playback software should not just timestretch, but > apply an inverse RIAA curve to the audio file, followed by the necessary > timestretching, followed by the RIAA curve. I have not tested how > noticable this difference would be. > > (When you scratch on a regular vinyl and turntable it shifts lots of > frequences around but the equalisation curve is left in place) > ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi _______________________________________________ Get Mixxx, the #1 Free MP3 DJ Mixing software Today http://mixxx.org Mixxx-devel mailing list Mixxx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mixxx-devel
