Hauptwerk V6 Audio! Wow!

Would there be a benefit if the sets would be released at 96kHz ?

It's good to hear these positive responses to an audio improvement using HW 6. I have upgraded but am in an unusual situation as I have yet to hear HW 6 with the familiar speakers. Because my PC and my Scarlet 18i20 interface are in use out in the garage with the Allen ADC-8000 project I've been listening with a pair of AKG 712s which sound great of course but it's not easy to make a comparison to the HW 5 sounds that were always via the speakers.

I did figure out that it's easy to challenge a strong i9 PC at 96kHz when playing a large registration. I've been able to run my PC as configured for the internet without turning off any services except SysMain and without disconnecting a pair of cloud services. That is no longer the case, but that's OK. I will work on tweaking Win 10 and change the output buffers to 1024 bytes instead of 512.

Thanks to Martin for the great work!

[mdyde]

Thanks, John. Excellent.

Would there be a benefit if the sets would be released at 96kHz ?

For Hauptwerk v6+, basically, no.

In more detail:

- Although 96 kHz could theoretically reduce interpolation distortion a little further, with Hauptwerk v6's new 'higher definition' pitch shifting option selected (which uses extremely high-quality interpolation), interpolation distortion should be well below the threshold that human hearing could detect anyway, even with very larger numbers of pipes sounding.

- Hence there would be no audible reduction in interpolation distortion compared to just using the 'higher definition' pitch shifting option with 48 kHz samples. (The interpolation used by the 'higher definition' pitch shifting setting was specifically designed to make further reductions in interpolation distortion so small as to be inaudible/unnecessary.)

- Also, using 96 kHz samples would roughly double RAM requirements, and would massively increase CPU demand further (probably more so than just using the 'higher definition' pitch shifting option).

- If the sample set producer were to use 96 kHz samples but *didn't* apply an anti-aliasing filter low enough (e.g. at around 24 kHz) within the sample files themselves, then you would effectively be re-introducing aliasing distortion for upward pitch-shifts. I.e. you would be undoing at least some of the main benefit of running the audio engine at 96 kHz.

- On the other hand, if the sample set producer were to use 96 kHz samples but *did* apply a high-quality off-line anti-aliasing filter low enough (e.g. at around 24 kHz) then you might as well just use 48 kHz samples instead (which could comfortably retain all frequencies within the human hearing range, and high-quality off-line anti-aliasing filters can be very good indeed and zero-phase, avoiding adverse effects on nearby frequencies within the human hearing range).

Hence, in summary, using high-quality 48 kHz samples (which have a had a high-quality anti-aliasing filter applied by their producer), together with the Hauptwerk 'higher definition' pitch shifting option and the Hauptwerk 96 kHz audio engine/output option should effectively give you all of the audible advantages, with none of the disadvantages of using 96 kHz samples (2x RAM, even more CPU demands, possible risk of re-introducing aliasing distortion).

Hope that helps!

[Edit: P.S. For Hauptwerk v2-v5, using 96 kHz samples could indeed have made an audible difference to perceived clarity due to the resulting, albeit fairly small, reduction likely in interpolation distortion. But for v6+, the new 'higher definition' pitch shifting option gives a massively greater reduction in distortion than using 96 kHz samples would, and all for about the same CPU overhead trade-off, and without the 2x RAM disadvantage.]

If one is using an organ in its original pitch/temperament and with sampled tremulants, is there any audible benefit provided by the 96 kHz settings? Martin, you said "...thus avoiding aliasing distortion when pipes' pitches rise by more than a certain amount." So presumably if one is using a circumstance where the pitch isn't rising beyond the recorded samples (because of not using simulated tremulants or not using any pitch/temperament shifts), there really isn't a meaningful benefit provided?

If that's true, it seems strange to me that, given what would appear to be the small relevant case, that some people are reporting a massive change in sonic experience from the past. Unless of course they were always pitch shifting their organ dramatically for some reason. Or is there something else?

[mdyde]

Hello Carson,

If one is using an organ in its original pitch/temperament and with sampled tremulants, is there any audible benefit provided by the 96 kHz settings? Martin, you said "...thus avoiding aliasing distortion when pipes' pitches rise by more than a certain amount." So presumably if one is using a circumstance where the pitch isn't rising beyond the recorded samples (because of not using simulated tremulants or not using any pitch/temperament shifts), there really isn't a meaningful benefit provided?

That's correct -- if not raising pipes' pitches by any significant amount, and as long as the sample set producer has applied an anti-aliasing filter in the samples at an appropriate frequency (a few semitones below the Nyquist frequency, as we recommend in the sample set producers' documentation, so as to allow for small upward pitch-shifts, e.g. due to modelled wind fluctuations), then the 96 kHz option is unlikely to give much of a noticeable benefit.

Unless specifically raising any pitches significantly, the 'higher definition' pitch-shifting option is likely to have a much more significant/audible benefit than selecting 96 kHz. I.e. of the two, 'higher definition' pitch-shifting option is the most beneficial in most cases, if you only have enough spare CPU power to use one of the two options.

I wanted to share another use-case where the new audio system is breath-taking.

I previously posted about my adventures in multi-channel reverb. I learned today that Sounus Paradisi commercial reverb files include a 96kHz component which is now being activated. I tried out my previous crazy setup and the results is remarkable.

Short version: take an older, or dry stereo set, split out the divisions using HW perspectives, apply different IR files to each. Recombine, magic!

Have a listen to the Scots' Rieger in Caen:
https://youtu.be/uvdmFKtHz74

Martin - you are a genius!!! Stunning...

PS - yes the CPU overhead for this is ridiculous - I have what was until last week top-of-the-line mac mini, and it was chugging along at almost 50% CPU utilization during the soft chorale

[mdyde]

Fantastic -- thanks! If you have plenty of spare CPU power you might as well take advantage of it!

Yes, the sound improvement is also very noticeable in headphones (AKG K712), even for my ears that are really a bit older ...
Great job, Martin, thank you very much!

[mdyde]

Excellent. Thanks.

I haven't upgraded so i can't judge yet.

I wonder if it is mandatory to load the sets in 24 bit instead of 20 bit to take advantage of these sonically 96khz improvements.
Many people load their sets standard in 20 bit as (favorite bitdepth of Jiri as mentioned on the SP website).
So they may have to reload in 24 bit???

Jan

[mdyde]

Hello Jan,

I don't think it would make a significant/audible difference.

Good evenin, Martin,

thanks a lot for this upgrade.
I succesfully upgraded yesterday, after your advice (it only took 10 mins or so with correct .exe file) and difference is clearly audible, especially if you play mixtures. THe sound is much cleaner (less muddy).
I also checked the CPU usage with and without 96 khz. WIthout it the CPU usage while playing fugue Es dur, 5 voices, was 10%, and with 96 khz ON it was 14 %. (I have an 5 years old I7 4 core 4820k, 3.7 GHZ)

[mdyde]

Thanks very much, Vladimir. Splendid!

Hello,

I am considering to upgrade to HWK6, especialy for the audio improvement. My computer processor is an i5 3750K.
I don't use very big instruments (Steinkirchen, Trost, Velesovo, Caen, Reinhardsgrimma).
Is my computer strong enought to have the benefits of the new HWK6 audio performance?

Thanks for support!

Regards.

[mdyde]

Hello Dom,

Thanks very much for the interest in v6.

You can enable/disable the 'higher definition pitch shifting' option (which is the option that gives the most obvious sonic benefit in most cases) on a per-organ basis. Hence you could potentially enable it for the organs that don't currently stress your CPU much, but disable it it for the very CPU-intensive organs. Or enable it for those with which you feel it gives the most noticeable benefit.

Very roughly the option doubles the CPU demands, and they're roughly doubled again (i.e. x4 in total) if you also enable the 96 kHz audio engine option.

Hence, very, very roughly speaking, if on your PC the 'audio CPU' meter on Hauptwerk's Audio, MIDI and Performance' large control panel doesn't normally go above about half way up the green bars when playing any given organ with the largest registrations that you'd normally use in v5, then you could probably afford to enable the 'higher definition pitch shifting' option in v6 without too much risk of CPU overload (audio glitches).