DeltaWave null-testing audio comparator (beta)

[Jud]

Does it have the ability to play a reference in one stereo channel and the comparison simultaneously in the other channel?  If it doesn't currently have this capability, how difficult would it be to add?

[Jud]

OK. Will see if I can get to them tomorrow.  

[Jud]

Can the comparison be saved to a file or piped to a UPnP/DLNA server, and if so, does anyone have a suggestion for one?  Would like to listen to @esldude's files on my main system if I can, which takes its signal from my Windows desktop in the office through a microRendu in the living/listening room.  If not I'll listen on my desktop system and/or headphones.

 

I see the Save Compare Wave and Save Delta Wave options, but am not certain what they do, and am wary they might display the file differences I'm supposed to be listening for blinded.

[Jud]

OK, before we go further: Tried to play the files through the desktop system and getting no sound. (?)

[Jud]

On 3/12/2019 at 7:32 PM, pkane2001 said:

 

What was selected in the DW driver selector drop-down? Did the progress indicated start updating at the bottom? Did the play buttons turn into pause buttons?

 

Oh, and by the way, did you click on Match button before trying to play? The files are not loaded or processed until you click on Match. Show button will also load the files and display some raw plots, but will not try to match them. You can play (or save) the tracks after you Match them, or just Show them, but not before.

 

It was not clicking the Match button - thank you.

 

I believe that playing Ref & Comp will play the left stereo channel of one piece, and the right stereo channel of the other, correct?  Because that' doesn't work for me as a comparison - of course the two channels will sound different.  What I'm after is combining the stereo channels of each of the ref and comp tracks into mono, and playing those mono tracks as the left and right stereo channels of the comparison between the two.  Then when I play them back if they're audibly identical I should get a fused single image right down the center of the soundstage.  I want to see if I hear differences between left and right, any "fusion" defects, under those conditions.

 

I could do that in Audacity, but I'd see the waveforms and know which was which.  I don't know what would be involved in doing it "automatically."  Is this possible, or too much of a pain?

[Jud]

10 hours ago, pkane2001 said:

 

No. You load only one channel of each track into DeltaWave, not stereo. You specify what channels you want from each file (selector L or R is right next to the file name):

 

Once you press Match, these two mono tracks (both left in the above screen shot) will be adjusted to be as close as possible in phase and level. Then, when you play Ref & Comp, Ref will be played in the left ear and Comp will be played in the right ear. 

 

 

That's exactly what playing Ref & Comp is meant to do 

 

 

What we have here is a failure to communicate.  We're using the same words to mean different things, I think.

 

I'd like the option to mixdown each stereo track into mono, then compare the two resulting mono tracks as the left and right channels in Play Ref & Comp.  

 

So you could select, as input for each comparison channel, the left channels of the respective tracks, the right channels, *or both channels of each track mixed down to mono*. Is this possible, or a pain to do? Or is it already available and I'm being thick?

[Jud]

10 minutes ago, pkane2001 said:

 

I think I understand what you mean. But why would this be a useful test? What does mixing down to mono give you? You are not listening to the original tracks anymore. Instead, it would be some mathematical (i.e., processed) combination of the two channels that normally doesn't occur in nature

 

Mixing down to mono gives you the full artist's intention for the music, just with the stereo effect removed.  I think that listening to two left or two right channels results in something the artist never intended us to hear.

 

Ever see those photographic portraits that use only half the face, one side the original and the other the mirror image?  Neither the "two left sides" nor "two right sides" image looks anything like the person's actual portrait.  That's what Delta Wave is doing now.  I'd rather look at two photographs of a person side by side and compare, which to me is what the intermediate mixdown to mono gets you.

 

I did something very similar when comparing speaker cables recently. (I intend to post about this soon.) I hooked up one manufacturer's cable to the left speaker and the other to the right speaker.  While I started out playing mono material, I quickly realized that since my preamp has a mono switch I could use more recently recorded material and just flip that switch. It mixed down the two stereo channels to mono and sent that mono signal to the amp and speakers, making simultaneous comparison of the two manufacturer's cables simple.

 

Having experienced this and thought it worked nicely, I'd be interested to see if the same sort of thing could be made quick and easy with software.

[Jud]

Just now, pkane2001 said:

 

I don't think a recording made for stereo, mixed down to mono is the way the artist intended for us to hear it, either 

 

Probably not a big deal to implement something like this, but let me think about it.

 

You're right of course, but having done it, I don't think you lose as much as leaving out an entire channel.

 

In any case, thanks for your consideration.

[Jud]

That's got it!  

 

Now I actually thought I could tell slight differences in @esldude's files just on my inexpensive desktop system, but my thinking could very, very easily have been affected by the visual from the file matching run.  So another feature request (I know, here I've hardly begun using the program and I have all these requests): A "test mode" where the match is done, but no visual is shown.  Or have I once again asked for something already in the program?   

[Jud]

6 minutes ago, pkane2001 said:

 

Excellent! If you don't want to see the charts or the results, simply uncheck all of them under settings, and you'll see a blank page, instead:

 

Tried unchecking all the display options, now get the following error when trying to play Ref&Comp:

 

2019-03-14 18:44:05.1812|ERROR|Wave.Program|Unhandled thread exception
   at Wave.WaveForm.GetAll(Control control, Type type) in C:\Users\ypa\documents\visual studio 2015\Projects\Wave\Wave\WaveForm.cs:line 4388
   at Wave.WaveForm.currentWavePlot() in C:\Users\ypa\documents\visual studio 2015\Projects\Wave\Wave\WaveForm.cs:line 4264
   at Wave.WaveForm.playRefCompToolStripMenuItem_Click(Object sender, EventArgs e) in C:\Users\ypa\documents\visual studio 2015\Projects\Wave\Wave\WaveForm.cs:line 5403
   at System.Windows.Forms.ToolStripItem.RaiseEvent(Object key, EventArgs e)
   at System.Windows.Forms.ToolStripMenuItem.OnClick(EventArgs e)
   at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)
   at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)
   at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea)
   at System.Windows.Forms.ToolStripDropDown.OnMouseUp(MouseEventArgs mea)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ToolStrip.WndProc(Message& m)
   at System.Windows.Forms.ToolStripDropDown.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

[Jud]

11 hours ago, esldude said:

 

It is a nice piece of software with some very good uses.  Paul has really done something good for us. 

 

 

Yes, I was actually thinking of some uses regarding a certain format billing itself as "master quality."

[Jud]

Speaking of which -

 

I'm not able to access the computer with DWave on it at the moment, but wanted to ask: If there's a good chance this "master quality" stuff uses minimum phase filters at the ADC end, if I don't want to disturb that I assume there's a setting to toggle if one doesn't want to match phase?

[Jud]

Oh! Also - Is there a standard channel in which the Ref and Comp are each played?  That is, whatever is designated as the Reference is always played back in the left channel and the Comp is always played back in the right channel?  Or is this configurable in Settings or elsewhere?

[Jud]

1 hour ago, pkane2001 said:

I'm getting close to completing all the planned features for v1 of DeltaWave.... but not yet 

Version 1.0.18 is now available, and has the following changes/features:

Two new blind/sighted tests added, in addition to the ABX test that was already available:

 

• Added Stereo XY difference test to the Comparator. This is a pair-wise discrimination test that lets you use stereo perception to detect differences between two similar tracks
• 

  

• Added Preference XY difference test to the Comparator. This test lets you determine if you really like the sound of one track over another. As such, this is a subjective blind preference test
• 
   
• Added file and settings information to the test result window for validation, along with signature and file MD5 hashes

Other changes:

• Changed the behavior of play buttons and menu items, including the comparator to not require a Show or Match button press
• Extended default frequency scale on plots to Nyquist frequency

The two new test formats are experimental. I welcome all input as to whether they work, make sense, or maybe are completely misguided.  
@Jud

 

I like not requiring Show or Match.  Some of the mouseover information in the Stereo Comparator was a little confusing to me in a rushed two minute tryout this evening.  I'll see whether it becomes clearer tomorrow.  

 

What I ultimately want to do is this: Save a file doing a stereo comparison where the reference track is the left channel; and save a file doing a stereo comparison where the reference track is the right channel.  This will enable some MQA vs. hi res comparisons I want to do using DeltaWave with Audirvana+ and/or HQPlayer.

 

 

[Jud]

8 hours ago, pkane2001 said:

 

Don't know if I have the best descriptions in the tooltips, but the website has a bit more information on this (and other) tests:

 

https://deltaw.org/comparator.html

 

Look for the X/Y Stereo Difference Test section for instructions.

 

 

Got it, thanks.  I'm pretty amazed at the pace at which you're making changes in response to requests, and grateful.  

 

What remains in order to do the comparisons I would like, as mentioned in my previous note, is only one thing not currently present in DeltaWave, and that is to enable the mixed down Reference track to be compared and saved in either the right channel or the left.  

 

One reason, as I'm sure you already understand, is to be able to determine whether any preference results from differences between left and right ears, differences in speaker-room interactions between left and right, or is due to differences in the tracks themselves.  If preference switches depending on which channel the reference is played from, it's the track; if it doesn't switch, it's ears or speakers.

 

Saving a file with the comparison, which DeltaWave already has (though not with the Reference file in the right channel as far as I can tell) allows the application of various Audirvana+ and HQPlayer upsampling filters on playback.  For me and many others who use the streaming capabilities of these players, it also allows playback through our main systems.

[Jud]

2 hours ago, pkane2001 said:

 

 

@Jud, please re-download the installation zip file. You may need to uninstall the previous version, first, as I left it as v1.0.18

 

The updated DW has the Save Reference Waveform option under file menu. Sorry I missed it in the last update!

 

 

Thanks Paul! I'll check it out this evening.

[Jud]

Hi Paul.  What does DeltaWave do with the stereo comparison if the tracks are different sample rates?

[Jud]

15 minutes ago, pkane2001 said:

 

Hi Jud.

 

The default is to downsample the higher rate file to match the lower rate of the other file. In settings, you can ask it to upsample, instead. In this case the lower rate file will be upsampled to the higher rate of the other one.

 

 

If it gets hold of an MQA file, I'm assuming it treats it as the "folded" (lower) sample rate?

[Jud]

Well now, it will be interesting to see whether an MQA file in one channel and a non-MQA file in another channel will even play back via Audirvana+ (which does the "first unfold" if set to detect MQA) or an MQA-enabled DAC; or for that matter whether a DAC or Audirvana+ would recognize an MQA stereo file mixed down to mono.

 

[Jud]

24 minutes ago, mansr said:

The MQA encoding uses both channels. If one channel is replaced, it will no longer identify as MQA.

 

OK, confirms what I was wondering about.  This makes good comparisons more difficult but not impossible.

[Jud]

Just now, mansr said:

Yes, you'll have to save the decoded MQA first, then use that for comparisons.

 

Exactly.  Tips on how?  

[Jud]

8 hours ago, pkane2001 said:

 

 

@Jud, please re-download the installation zip file. You may need to uninstall the previous version, first, as I left it as v1.0.18

 

The updated DW has the Save Reference Waveform option under file menu. Sorry I missed it in the last update!

 

 

Hi Paul - 

 

- Would the reference file always play in the left channel, even when swapping reference and compare files?

 

- Can you think of any audible advantages that the reference file might have due to being used essentially as a template for matching the two files (other than phase drift correction, which I'd turn off)?

[Jud]

All I want for Christmas (in April?) is for DeltaWave to allow me to move the Reference to left channel or right channel at will (and save the result of the comparison).   

 

In a left-right comparison, this removes any possible advantage if the room or one's ears favor a particular side.

 

 

[Jud]

5 minutes ago, STC said:

No one can ask for a better support than this.

 

Absolutely agree.

[Jud]

3 hours ago, pkane2001 said:

 

That makes me think I that should compute the error value and thresholds in seconds, rather than in samples. A 1 sample error for 44.1kHz sampling rate is 23μs, which might be audible. A 1 sample error in a 352kHz signal is about 3μs, which is below audibility. Thoughts?

 

Does it make the thing overly complex  if you provide the option? I can think of reasons for both.