Dirac 3 a lot faster than the Dirac in Wavelab 6?

Wavelab was recently updated to use v.3 of the Dirac time-stretching algorithm (Wavelab 7 originally came with v.2 of Dirac). According to the Dirac website, Dirac 3 offers “vastly improved processing speeds” over the previous version.

I have Wavelab 6, which uses a much older version of Dirac – can anyone let me know roughly how much faster v.3 is than the version of Dirac used in Wavelab 6?

It recently took me about 100 minutes to slightly time-stretch (using the highest Dirac quality) a 6-minute 32-bit stereo wav (I have a quad-core Q6600 PC), so if Dirac 3 is a lot faster than the older versions then that’s reason alone for me to upgrade to Wavelab 7.

This depends on the algorytm and quality setting, this also depends on the platform. Note that envelppe time stretch is also possible now.
What is your typical use case?

Typical use is a slight speeding-up of a whole 32-bit stereo wav, using the highest Dirac quality (on XP SP3 – I know Wavelab 7 doesn’t directly support XP, but many people find it works fine on XP).

But using with DIRAC method? Preview? Frequency localization? Time localization?..

I mainly use the Frequency Localization ++ method for a whole mix (as recommended by the drop-down menu). And Preserve Pitch.

I did a few quick benchmarks, using a 10 second file (44 kHz), and with a stretch factor of 105%.

Mode Frequency Localization++ and Best quality:
WaveLab 6: 381 sec
WaveLab 7.1.1 (Win): 54 sec (7 x faster than WaveLab 6)
WaveLab 7.1.1 (Mac): 28 sec (1.9 x faster than under Windows)

Mode High Quality and Average Time/Freq
WaveLab 6: 19.7 sec
WaveLab 7.1.1 (Win): 9 sec (2.18 x faster than WaveLab 6)
WaveLab 7.1.1 (Mac): 4.8 sec (1.9 x faster than under Windows)

Mode Quick and Auto/Preview
WaveLab 6: 1.37 sec
WaveLab 7.1.1 (Win): 0.4 sec (3.4 x faster than WaveLab 6)
WaveLab 7.1.1 (Mac): 0.2 sec (2 x faster than under Windows)

In conclusion, you can see sometimes a very large performance gain. You can also see a better speed on the Mac (DIRAC uses here some Mac core DSP component as helpers).


  • The Mac and windows machines are not exactly the same, but should give similar results.
  • Windows is Windows 7 - 64, but that should make no difference eg. with XP.
  • WaveLab 6.1.1 uses DIRAC 1.2.9
  • WaveLab 7.1.1 uses DIRAC 3.2.5

Thanks Philippe, that’s some very useful comparisons.