internal sampling rate

Harry Mudd
Posts: 7
Joined: Wed May 13, 2020 6:29 pm

internal sampling rate

Post by Harry Mudd » Thu Jun 25, 2020 10:22 pm

hi folks
I discovered a slighly audio quality loss when using VM with other sampling rates than 48kHz.
Is there a chance to see an update which will gain constant audio quality at 44k1 cause I record all my stuff in this SR.
The quality loss is not dramatic but with high frequency stuff there is some aliasing audible.

Harry Mudd
Posts: 7
Joined: Wed May 13, 2020 6:29 pm

Re: internal sampling rate

Post by Harry Mudd » Wed Jul 01, 2020 6:26 pm

I have created 2 jpgs in PluginDoctor at 44k1 and 48k to show the difference of the audio quality.
There are no modules inserted I just conneted the input with the output.
Attachments
VM 48k.jpg
VM 48k.jpg (101.58 KiB) Viewed 1490 times
VM 44k1.jpg
VM 44k1.jpg (119.88 KiB) Viewed 1490 times

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cherryaudio Greg
Site Admin
Posts: 216
Joined: Wed Aug 29, 2018 5:06 pm

Re: internal sampling rate

Post by cherryaudio Greg » Fri Jul 03, 2020 10:57 pm

Hi,

Thank you for the suggestion, I'll pass it along to the software devs!

Greg

wavemechanic
Posts: 87
Joined: Thu Sep 12, 2019 5:14 am

Re: internal sampling rate

Post by wavemechanic » Sun Jul 05, 2020 12:17 pm

I work at 96kHz. I don't see a problem with the harmonics analysis at 96kHz, but I do see a serious concern with the imposed filter applied at 96kHz. This seems to significantly harm signal above 10kHz. Cherry, why not use a Nyquist-style filter instead of this super gradual one? I've included a suggested filter based on the iZotope RX SRC.
Attachments
screen 2020-07-05 at 5  8.11.30 AM.jpg
screen 2020-07-05 at 5 8.11.30 AM.jpg (49.27 KiB) Viewed 1366 times
screen 2020-07-05 at 5  8.11.18 AM.jpg
screen 2020-07-05 at 5 8.11.18 AM.jpg (47.03 KiB) Viewed 1366 times
screen 2020-07-05 at 5  8.15.24 AM.jpg
screen 2020-07-05 at 5 8.15.24 AM.jpg (7.1 KiB) Viewed 1367 times

andro
Posts: 124
Joined: Mon Apr 06, 2020 4:45 am

Re: internal sampling rate

Post by andro » Mon Jul 06, 2020 9:41 am

I don't quite understand where the signal you are measuring comes from. Can you explain? You said you connected the input to the output. What is driving this?

Also, Is this Plugin Doctor tool worth having?

Harry Mudd
Posts: 7
Joined: Wed May 13, 2020 6:29 pm

Re: internal sampling rate

Post by Harry Mudd » Mon Jul 06, 2020 10:31 am

@wavemechanic
My main sample rate is 44k1. All audio files are 44k1.
My question is why is the audio quality VM a lot better at 48k?
All my other synths are of good qualty independently of the sample rate.
Why not VM? Why the limitation at 48k?
confusing
H

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Captain
Posts: 86
Joined: Sat Aug 25, 2018 11:12 am

Re: internal sampling rate

Post by Captain » Mon Jul 06, 2020 1:28 pm

VM always works internally at 48 kHz, while many/most synths and effects adjust their sample rate to match the outside world. With VM, if the external sample rate is different from 48 kHz, there's going to be some resampling, which always affects the sound quality. I guess the conversion algorithm could be improved, but since it happens in real time, there are latency- and CPU-related limits.

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cherryaudio Greg
Site Admin
Posts: 216
Joined: Wed Aug 29, 2018 5:06 pm

Re: internal sampling rate

Post by cherryaudio Greg » Tue Jul 07, 2020 12:15 am

Hi,

Thanks for reporting this issue! The next update (2.0.24 or higher), will have improved resampling.

Greg

andro
Posts: 124
Joined: Mon Apr 06, 2020 4:45 am

Re: internal sampling rate

Post by andro » Tue Jul 07, 2020 1:15 am

Hi @Harry Mud, could you help me understand my question above? That would be great.

Harry Mudd
Posts: 7
Joined: Wed May 13, 2020 6:29 pm

Re: internal sampling rate

Post by Harry Mudd » Tue Jul 07, 2020 12:38 pm

hi andro,
Plugin Doctoor is a nice tool to check the audio quality of plugins. If you have the knowledge about audio gear like frequency response and distortion then this tool is for you.
In my special case I loaded VMfx into Plugin Doctor and only connected the inputs with the outputs of VM to show the different audio quality of the VM subsystem with different sample rates.
H

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