boxerfan88
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As requested by some members, starting a new thread on this recently released software called VB Matrix.
Setup guide:
Setup guide:
Thank you for your info; this sounds very promising and interest.There is a "master" icon with one of the output devices. It suggests the other devices are adaptively resampled to align to the master. That would be the correct way to handle multiple independent interfaces.
@dualazmak : Every adaptive resampling is a compromise to some extent in terms of time synchronization. Look at https://www.diyaudio.com/community/...-interface-options.395392/page-5#post-7423200 - I cannot find the source post which Henrik referred to but I read it too and AFAIR the time shift between the devices deviated around millisecs
@dualazmak : Every adaptive resampling is a compromise to some extent in terms of time synchronization. Look at https://www.diyaudio.com/community/...-interface-options.395392/page-5#post-7423200 - I cannot find the source post which Henrik referred to but I read it too and AFAIR the time shift between the devices deviated around millisecs
I am tagging @mdsimon2 as he might be the person @HenrikEnquist refers to in that post
I am tagging @mdsimon2 as he might be the person @HenrikEnquist refers to in that post
Maybe, maybe not. I read this post and ensuing discussion -> https://www.diyaudio.com/community/...overs-room-correction-etc.349818/post-6578042 a while ago where someone attempted to use a mac aggregate device with drift correction in a crossover application and was unsatisfied with the result due to drifting stereo image.
I'll install VBmatrix on my PC and see how it works compared to mac. My guess is that it is similar in that it is probably OK for bass crossover applications but there is too much shifting at higher frequencies.
Michael
That's what I was referring to! Specifically this post: https://www.diyaudio.com/community/...om-correction-etc.349818/page-87#post-6579441Maybe, maybe not. I read this post and ensuing discussion
Simple adaptive resampling by sample dropping/adding a linearly-interpolated sample may result in the same capture image (what you see) and still prevent buffer issues (what @boxerfan88 sees). Many audio projects do that as it's simple to implement - e.g. gstreamer, mplayer when syncing incoming network stream to output alsa device, etc... Very likely single dropped samples would not be audible in real-world audio stream (but reliably ruin long-run averaging in REW RTA etc.)Gave this a try with VB Matrix, I see no evidence of adaptive resampling syncing when looking at 15 kHz tone.
Simple adaptive resampling by sample dropping/adding a linearly-interpolated sample may result in the same capture image (what you see) and still prevent buffer issues (what @boxerfan88 sees). Many audio projects do that as it's simple to implement - e.g. gstreamer, mplayer when syncing incoming network stream to output alsa device, etc... Very likely single dropped samples would not be audible in real-world audio stream (but reliably ruin long-run averaging in REW RTA etc.)
@mdsimon2 may I know if the above tests were conducted with one of the DAC as the "master"? Or internal clock as the "master"?
I'm just curious.
IIUC that would fit the hypotheses that VB Matrix uses simple sample dropping/stuffing instead of proper adaptive resampling. After the buffer fill/timeshift exceeds some limit, the corrective action is fired, re-aligning the timing. That would be the reset in delay and hiccup in the RTA FFT.Interesting. I looked at the RTA and it seems pretty stable but has a hiccup every 2-3 minutes.
Another data point is if I run REW sweeps and use loopback as timing reference with the "synchronized" DAC, the reported delay between the two DACs decreases over time until it resets at some point.
1:59:46: 30.7 ms
2:00:06: 29.6 ms
2:00:25: 28.5 ms
2:00:51: 27.1 ms
2:01:06: 26.4 ms
2:01:19: 25.7 ms
2:01:31: 25.0 ms
2:01:49: 24.1 ms
2:02:05: 23.1 ms
2:02:21: 22.3 ms
2:02:44: 21.1 ms
2:03:12: 20.5 ms
2:03:24: 19.0 ms
2:03:41: 18.4 ms
2:03:53: 17.5 ms
2:04:22: 16.1 ms
2:04:39: 25.6 ms
2:05:00: 24.7 ms
2:05:13: 23.9 ms
Does this behavior make sense to you? To me such drifting would indicate poor phase coherence that would make it unsuitable for a crossover application.
Did you route to several independent interfaces (one master, the others slave) at the same time?I tried VB Matrix as well. It looks like it routes audio well with no clicks or popping.
I tried VB Matrix as well. It looks like it routes audio well with no clicks or popping. I always had some clicks/pops on voicemeeter.