Dither

[jumpingjackflash5]

Hello,

I sent this question to the technical support, but meanwhile I have decided to buy a license for Acoustica Standard and discovered this forum.


1. I have question about dithering plugin. It seems to be that it cannot do plain TPDF dither with flat noise curve. If I set noise shaping to 0 dB and 0.10-0.30 ms filter length (which has near-to-flat response and nice sound), how will the quality of dithering be affected? Won't such a short filter have impact on precision of dither or quantization error - so can it be used instead of plain TPDF for "neutral" conversion?? By the way, I generally highly appreciate the possibility to customize the dithering curve and the amount of noise shaping.

2. question I installed Acoustica on my desktop computer and use it there. I have also a Windows tablet, if I (theoretically) want to use Acoustica also there must I buy additional licence, or can I use the registration info also on the tablet (used only by me).

Jan

[stian]

Hi Jan,

1. I have question about dithering plugin. It seems to be that it cannot do plain TPDF dither with flat noise curve. If I set noise shaping to 0 dB and 0.10-0.30 ms filter length (which has near-to-flat response and nice sound), how will the quality of dithering be affected? Won't such a short filter have impact on precision of dither or quantization error - so can it be used instead of plain TPDF for "neutral" conversion?? By the way, I generally highly appreciate the possibility to customize the dithering curve and the amount of noise shaping.

Yes, the noise shaping amount limits the maximum gain in the noise shaping filter prior to normalization. That's why there's still some noise shaping even when the maximum is set to zero dB. I guess it would be nice to offer a completely flat dither -- ideally by turning down the noise shaping slider to zero. The noise shaping doesn't affect the quality of the dithering beyond the frequency distribution, though.

2. question I installed Acoustica on my desktop computer and use it there. I have also a Windows tablet, if I (theoretically) want to use Acoustica also there must I buy additional licence, or can I use the registration info also on the tablet (used only by me).

You can use the same license key as long as you're the only person using Acoustica.

Best,
Stian

[jumpingjackflash5]

Thanks for answering. Yes for the future versions it would be great to provide option for flat TPDF dither, with no shaping, no DC offset or low frequency bumps (which fortunately even the current shaping does NOT change - great!) etc., just "flat line".
By the way current curve for dithering is well chosen, so even the current form with possibility to set noise shaping gain at 0 dB works well, and when you have confirmed it does not degrade the quality of dithering, it is already a viable option for mastering audio than requires minimal changes (e.g. is subset to additional processing later).

By the way, I have been long using Audacity which has also good functionality, so my decision for purchasing Acoustica was pretty tough (and I am a home user with no professional application), but you supply a lot of good functions and the UI is really great and intuitive. It seems that the software is pretty "new", so some minor glitches appear, but nothing serious or deal-breaking and editing is pleasant to do. Also Batch Processing is great and better than in Audacity.

[stian]

Thanks for answering. Yes for the future versions it would be great to provide option for flat TPDF dither, with no shaping, no DC offset or low frequency bumps (which fortunately even the current shaping does NOT change - great!) etc., just "flat line".
By the way current curve for dithering is well chosen, so even the current form with possibility to set noise shaping gain at 0 dB works well, and when you have confirmed it does not degrade the quality of dithering, it is already a viable option for mastering audio than requires minimal changes (e.g. is subset to additional processing later).

By the way, I have been long using Audacity which has also good functionality, so my decision for purchasing Acoustica was pretty tough (and I am a home user with no professional application), but you supply a lot of good functions and the UI is really great and intuitive. It seems that the software is pretty "new", so some minor glitches appear, but nothing serious or deal-breaking and editing is pleasant to do. Also Batch Processing is great and better than in Audacity.

Thanks, Jan! If you encounter minor glitches, please report them so that we can try to fix them.

Best,
Stian

[jumpingjackflash5]

If I find something that can be reproduced and makes problem I will report.

By the way, the current noise shaping knob works well in the sense that it sets amplification (gain) of noise. So when set to 0 dB only the basic dither noise (that is necessary to cover the quantization error) is shaped and that is correct and appropriate behavior. Actually it makes possible to do shaping without adding more noise than necessary which is a function that is not available that often (e.g. in SoX there is flat tpdf, sloped tpdf and then various noise shapers but they all do some gain). If flat tpdf is introduced, this current functionality should remain as it is, and there can be extra option/check box for disabling filter shaping overall (and possibly graying/freezing the knobs which are used when tuning noise shaping and needn't be used at flat tpdf). Thank you.

[stian]

Hi Jan,

If I find something that can be reproduced and makes problem I will report.

By the way, the current noise shaping knob works well in the sense that it sets amplification (gain) of noise. So when set to 0 dB only the basic dither noise (that is necessary to cover the quantization error) is shaped and that is correct and appropriate behavior. Actually it makes possible to do shaping without adding more noise than necessary which is a function that is not available that often (e.g. in SoX there is flat tpdf, sloped tpdf and then various noise shapers but they all do some gain). If flat tpdf is introduced, this current functionality should remain as it is, and there can be extra option/check box for disabling filter shaping overall (and possibly graying/freezing the knobs which are used when tuning noise shaping and needn't be used at flat tpdf). Thank you.

Thanks, Jan. Noise shaping will increase the measured RMS level, but the perceived loudness is reduced. The difference is very noticeable. You can try 8 bit target resolution and play with the filter settings. I've added an "Enable noise shaping" toggle button and this will be part of the upcoming version 7.1. It makes sense to offer a completely flat dither as well.

Best,
Stian

[jumpingjackflash5]

Thank you. That would be great, in that case Acoustica can provide three types of dither

1. Pure flat TPDF - new
2. TPDF with noise shaping, but 0 db gain with last knob full left (that is really great option important for "minimal invasive" mastering - available now)
3. TPDF with noise shaping and some noise gain, e.g. higher amplitude (e.g. for 16 bit - available now).

[jumpingjackflash5]

Hello,


thank you very much for Acoustica upgrade, it really includes new, TPDF option!


That is truly great, now the dithering plugin is even more useful than before!


Jan

[stian]

Hi Jan,

Hello,

thank you very much for Acoustica upgrade, it really includes new, TPDF option!

That is truly great, now the dithering plugin is even more useful than before!

I'm glad to hear you like it!

In case you're interested, we have created some audio examples for the mastering plug-ins in Acoustica, including Dither (example 5-8) with different options: https://soundcloud.com/acondigital/sets ... ring-suite

Best,
Stian

[jumpingjackflash5]

Hello, thank your very much for the examples, they're interesting.
It is very nice to see that Acoustica is actively developed and supported.
It is very good tool and now I use it for my home recordings.

[stian]

Hello, thank your very much for the examples, they're interesting.
It is very nice to see that Acoustica is actively developed and supported.
It is very good tool and now I use it for my home recordings.

Thanks, we do our best to develop and keep things updated. I'm glad to hear that you can make good use of Acoustica.

Best,
Stian