Mid-side decoding issue - Total silence from the two side tracks

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That's a great idea - look forward to it. Maybe we could do the reverse and post an m/s pair of files for you to try on your system?
 
How to you get the files from your R16 to your DAW? I always just pull the SD card from my R24 and copy the files directly to the computer. I have never bothered with using the USB connection, but it shouldn't make a difference.

I might try doing an M/S with my R24 later. I can't see any reason it wouldn't work. They are just mono WAV files, the same as if you recorded into a DAW.
 
I might try doing an M/S with my R24 later. I can't see any reason it wouldn't work. They are just mono WAV files, the same as if you recorded into a DAW.
It'll work just fine. Never been an issue on the Roland or Tascam standalones.
 
Hi Folks:

The files below are a very simple spoken audio test with me moving back and forth across the stereo field. I tried uploading the WAV files directly in this post, but HR only permits MP3 audio files. Instead of rendering the files as MP3s -- which risks me modifying them in some unknown way and ruining our experiment -- I have uploaded them unchanged to DropBox. They should be available to anyone using the links below. Please let me know if there are any issues accessing and downloading the files :-)

M-S Test - Side-Mic-CAD - Figure-Eight

M-S Test - Mid-Mic-Spark Blue - Cardioid
 
How to you get the files from your R16 to your DAW? I always just pull the SD card from my R24 and copy the files directly to the computer. I have never bothered with using the USB connection, but it shouldn't make a difference.

I might try doing an M/S with my R24 later. I can't see any reason it wouldn't work. They are just mono WAV files, the same as if you recorded into a DAW.
Hi TalismanRich:

In the past, I used to do the exact same thing you are describing. I would remove the SD card, copy the WAV files directly to my laptop, and then open the files in my DAW.

For many years now, however, I have only been using the R16 as an interface via the USB connection. In this case, nothing gets saved to the SD card. All files created by the interface are saved directly by Reaper to the appropriate project folder.

P.S. It would be great if you could create a small M-S project with your R16 and post the files here. That way I can listen to them and test to see if the stereo field is audible to me :-)
 
Hi Folks:

The files below are a very simple spoken audio test with me moving back and forth across the stereo field. I tried uploading the WAV files directly in this post, but HR only permits MP3 audio files. Instead of rendering the files as MP3s -- which risks me modifying them in some unknown way and ruining our experiment -- I have uploaded them unchanged to DropBox. They should be available to anyone using the links below. Please let me know if there are any issues accessing and downloading the files :-)

M-S Test - Side-Mic-CAD - Figure-Eight

M-S Test - Mid-Mic-Spark Blue - Cardioid
To everyone: These are 44.1khz/24-bit
 
That's a great idea - look forward to it. Maybe we could do the reverse and post an m/s pair of files for you to try on your system?
Yes, thanks Rob. It would be very helpful to have someone else's raw M-S files to see how they sound when I decode them (y)
 
Here is an mp3 of those files - recorded on my Tascam DP-32SD - and with the channels set for mid-side "stereo" technique.

I get a good stereo type image when you're in the middle - and the left and right tests of your voice work as expected. I of course did check each file in it's raw form before recording the mid-side setting (mid mic up the middle - and two-track hard pan with one side phase-reversed for the figure 8 mic).

(I did remove a little of the lowest of low end before converting wav to mp3)
 
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Porterhouse, it was definitely stereo. I used my headphones and your voice moved from side to side.
I took the same files and put them in Reaper and got the same result. Here's my mix, and the setting in Reaper. I inverted the file by going to Track Properties, and phase invert. This suggests that it's not a problem with the recording, but something in the mix. BTW, I grouped the two side channels so that they move as one for volume to adjust the image.



MS Test in Reaper.webp
 

Attachments

Here is an mp3 of those files - recorded on my Tascam DP-32SD - and with the channels set for mid-side "stereo" technique.

I get a good stereo type image when your in the middle - and the left and right tests of your voice work as expected. I of course did check each file in it's raw form before recording the mid-side setting (mid mic up the middle - and two-track hard pan with one side phase-reversed for the figure 8 mic).
View attachment 149734
Hi Porterhouse and TalismanRich:

Yep, I hear the stereo separation perfectly in both of your decoded mixes (y) Which means that:

(1) My signal capture methodology and the resulting files are correct, and;
(2) There is nothing wrong with my headphone amp or the interface output (since your stereo mixes are not mysteriously being summed to mono).

So....there is obviously a problem with the way I am decoding, or perhaps a setting within Reaper that I am not aware of. Thank you very much for helping me out on this, and providing the additional info. I guess it's back to the drawing board for me :cautious: I will, of course, continue to post my progress here :-)
 
Porterhouse, it was definitely stereo. I used my headphones and your voice moved from side to side.
I took the same files and put them in Reaper and got the same result. Here's my mix, and the setting in Reaper. I inverted the file by going to Track Properties, and phase invert. This suggests that it's not a problem with the recording, but something in the mix. BTW, I grouped the two side channels so that they move as one for volume to adjust the image.

View attachment 149737

View attachment 149736
Hi TalismanRich:

Thanks again for you efforts :-) You mention "Track Properties". I have looked everywhere in my version of Reaper, and I do not see track properties. Are you referring to the "Invert Phase" checkbox in the Item Properties? (see attached) Or do you actually have a "Track Properties" option? If so, how do you access it? Please let me know. Thanks!
 

Attachments

  • Item Properties (with comments).webp
    Item Properties (with comments).webp
    43.6 KB · Views: 8
Something strange is happening. I put my in ears in and the track porterhouse posted above gives me a central image but sounds a little odd, then as he moves left, I hear a shift which quickly goes back to centre-ish. Then, as he goes right, i get a movement but that too resolves back to middle, but with a tonal shift. A bit more low end? The attached file in rich’s post resolves perfectly, a move to the left, then centre, then right. I think maybe porterhouse’s has some kind of phase swap, so what I have in my left ear and right ear are opposite polarity? This explains why the centre image appears really wide maybe. It will be really useful to find out what is causing it. I have never had this before.

I dont know if this is useful, but in this old clip i had a U87 in mono on a piano, and then added a side channel from a ribbon. Mics in totally different positions to convention, but I also ran a stereoscope so you can see the spread. I thought it worked very well. The clip should take you to the correct place.
 
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Hi TalismanRich:

Thanks again for you efforts :-) You mention "Track Properties". I have looked everywhere in my version of Reaper, and I do not see track properties. Are you referring to the "Invert Phase" checkbox in the Item Properties? (see attached) Or do you actually have a "Track Properties" option? If so, how do you access it? Please let me know. Thanks!
Sorry, that's where it is. That way I could confirm that the waveform was inverted, which shows in the picture. I shouldn't try to do things by memory! :unsure:

Rob, I think the difference is in the mix between the M and S channels. The S channels by themselves are quite hollow sounding. I played with the relative levels of the M and S blend to get the stable image. It might have been harder to do in the DP24 than in Reaper. As I mentioned, I grouped tracks 2 and 3 so that I could adjust the volume of both at the same time. The S channels are slightly lower than the M.
 
I had the side channels a little higher than the mid. I'm not in a position to listen closely. But I assume that is probably the difference between the two.
 
Hmmm. With my eyes closed, iems in, my brain told me there was left to right movement, but it settled almost central. I have never heard this before. Its really interesting.
 
Hi,
I tested out your wav files and everything works as it should.
I do notice that when you're at the left hand side (face of the Cad mic) you're nowhere near as strong sounding as when you're at the right/back.
That could just be that you were closer to the mic when you did your right movement, I suppose, but I thought I'd point it out.
You're louder in the centre mic too, when you move right, so that's probably it.


Regardless, the recorded files are working in terms of M/S stereo image.

"The problem that has cropped up is that Tracks #2 and #3 together are producing complete silence!"

Sounds like that's the key part of the problem.
Probably telling you what you know but they should sum to silence when neither is panned or, rather, when their panning is the same.
Once you pan them apart (muting the centre mic for now) you should be able to hear them but it'll sound strange, hollow, slightly disorienting.

Then when you bring up the fader on the centre mic things that brings 'sense' to the sound.
The higher the fader on the centre mic, the less pronounced the stereo image will be.

In short, if muting the centre track (listening to #2 and #3) results in silence, then your left/right panning isn't working for some reason.

That's pretty easy to prove.
Solo track #2 - You should hear your voice in the left only.
Solo track #3 - You should hear your voice in the right only.

Solo them both - You should hear the 'strange hollow' I described before. Not stereo, but not quite right. (it is right)
 
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I think maybe porterhouse’s has some kind of phase swap, so what I have in my left ear and right ear are opposite polarity?
That's what it is. That's the foundation of mid-side.

The lower your centre mic (or higher the sides) the less natural it will sound.
If the centre mic is brought right down to the point where it's barely contributing, you're literally just hearing opposite polarity signals in each ear.
 
Porterhouse, it was definitely stereo. I used my headphones and your voice moved from side to side.
I took the same files and put them in Reaper and got the same result. Here's my mix, and the setting in Reaper. I inverted the file by going to Track Properties, and phase invert. This suggests that it's not a problem with the recording, but something in the mix. BTW, I grouped the two side channels so that they move as one for volume to adjust the image.

View attachment 149737

View attachment 149736
I don’t understand - the CAD file is Mono - how did you get a stereo track out of the mono file?
 
That's the trick with M/S. The CAD is in figure 8 mode, and you copy the file to a second channel and invert it. Look at the picture of the Reaper setup I put above. You can see the two "side channel" tracks are inverted. Those are both the same file.

If you talk into the right side, the "left" side signal is effectively cancelled out by the inverted "left" side of the other track. The "right" side predominates. By itself, it sounds really hollow in the middle, though, so you had a cardioid mic to provide the center. You actually end up with a stereo image.
 
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