• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Comparing different convolution solutions

ppataki

Major Contributor
Joined
Aug 7, 2019
Messages
1,219
Likes
1,360
Location
Budapest
While experimenting with various filtering methodologies, for example this:


I started using convolution, concretely Jriver's Convolution engine

I have noticed that it introduces quite a lot of delay that can cause audio/video to get out of sync; especially when using external sources like Youtube, etc.

So I started looking for alternatives - please see below some comparison between them

  • Jriver's Convolution
  • Convology XT
  • SIR3
  • Hofa IQ-Reverb 2

Frequency response using the same wav filter file:

1660594444631.png


As you can see there is a difference in the level but there is zero difference between the frequency response curves

I could not see any difference in any of the other curves either - please see the measurement file attached for reference; should you notice anything please let me know

Now about the latency, let's play a Youtube video and check delay:

Jriver:
1660594746697.png



Above 100ms, around 110-120ms

Convology XT:

1660594822923.png



Around 40-50ms

SIR3:

1660594887760.png


Very similar, around 40-50ms


HOFA:

1660594976840.png


This was the lowest, rarely exceeding 40ms

So all in all my conclusion is that I could not find any difference in terms of measurements but there are quite significant differences in terms of delay (especially between Jriver and others)
I add that I also tried ASIO vs WASAPI, the latter resulted in significantly lower latency (using Windows 11 and Topping DM7 DAC)

I hope this helps, please let me know in case of any comments/questions
 

Attachments

  • 20220811 REW inverter convolution solutions.zip
    2.8 MB · Views: 97

ernestcarl

Major Contributor
Joined
Sep 4, 2019
Messages
3,106
Likes
2,313
Location
Canada
While experimenting with various filtering methodologies, for example this:


I started using convolution, concretely Jriver's Convolution engine

I have noticed that it introduces quite a lot of delay that can cause audio/video to get out of sync; especially when using external sources like Youtube, etc.

So I started looking for alternatives - please see below some comparison between them

  • Jriver's Convolution
  • Convology XT
  • SIR3
  • Hofa IQ-Reverb 2

Frequency response using the same wav filter file:

View attachment 224377

As you can see there is a difference in the level but there is zero difference between the frequency response curves

I could not see any difference in any of the other curves either - please see the measurement file attached for reference; should you notice anything please let me know

Now about the latency, let's play a Youtube video and check delay:

Jriver:
View attachment 224384


Above 100ms, around 110-120ms

Convology XT:

View attachment 224386


Around 40-50ms

SIR3:

View attachment 224387

Very similar, around 40-50ms


HOFA:

View attachment 224388

This was the lowest, rarely exceeding 40ms

So all in all my conclusion is that I could not find any difference in terms of measurements but there are quite significant differences in terms of delay (especially between Jriver and others)
I add that I also tried ASIO vs WASAPI, the latter resulted in significantly lower latency (using Windows 11 and Topping DM7 DAC)

I hope this helps, please let me know in case of any comments/questions

115 ms from JRiver's built-in convolution engine should still be imperceptible with any streaming Youtube AV sync test (after allowing the values to stabilize and/or after a DSP reset). For the DSP and MCH audio interface chain I use, ~200 ms (as shown as the second delay value in 'Audio Path') is my perceptual threshold limit. Only beyond that (e.g. 300+ ms), do I start noticing lip-sync issues.

Convology XT seems not to cost anything at all so I'll try it later.
 
OP
P

ppataki

Major Contributor
Joined
Aug 7, 2019
Messages
1,219
Likes
1,360
Location
Budapest
For me 115ms already presents a totally visible lipsync issue with Youtube (even with 50ms I can see a very little)
So I ditched Jriver's Convolution and using ConvologyXT now (as you also said; it is free of charge + its Normalization feature actually works, unlike Jriver's which is just cutting 6dB)
 

ernestcarl

Major Contributor
Joined
Sep 4, 2019
Messages
3,106
Likes
2,313
Location
Canada
For me 115ms already presents a totally visible lipsync issue with Youtube (even with 50ms I can see a very little)
So I ditched Jriver's Convolution and using ConvologyXT now (as you also said; it is free of charge + its Normalization feature actually works, unlike Jriver's which is just cutting 6dB)

Hmmn... something in the software-hardware chain is causing the different results we are seeing. If I were to completely turn off any extra DSP and go back to native 2.0/5.1/7.1 mode, I still see ~110 ms delay -- it cannot go any lower than that number. It's the same result after switching from a multichannel DAC to a plain stereo DAC. There is, of course, no delay noticed with zero additional processing or convolution DSP running in background. Could be my video output is also delayed a bit... Not really sure of the exact cause, but if were true that video is also delayed on my end (I'm no gamer, BTW), I guess that would make it an advantage? :)
 
Top Bottom