Short Wave Binaural AM test SDR Console V 3.0.26

General Discussion
Post Reply
pe1etr
Posts: 2552
Joined: 07 Oct 2014 00:40
Location: Near Lobatse, Botswana

Short Wave Binaural AM test SDR Console V 3.0.26

Post by pe1etr »

Not exactly Pink Floyd in Binaural Stereo, but getting there.
https://youtu.be/fF2mOOiorEA

Peter

pauldbnut
Posts: 29
Joined: 21 Jan 2018 21:29
Location: Dinosaur Country (IoW)

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by pauldbnut »

Hehe, neither is it ever meant to be, Peter.
Thanks for the video. Have you tried on MW yet?
For me, binaural is much more about what you cannot easily resolve with other techniques.
Paul White (Grumpy Old Git)

pe1etr
Posts: 2552
Joined: 07 Oct 2014 00:40
Location: Near Lobatse, Botswana

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by pe1etr »

pauldbnut wrote:
16 Dec 2020 23:01
Hehe, neither is it ever meant to be, Peter.
Thanks for the video. Have you tried on MW yet?
For me, binaural is much more about what you cannot easily resolve with other techniques.
You're welcome.
It is more effective on SW than on MW.

Peter

pe1etr
Posts: 2552
Joined: 07 Oct 2014 00:40
Location: Near Lobatse, Botswana

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by pe1etr »

Another test from a short wave powerhouse.
https://youtu.be/PL3eHFdYeQs

Peter

User avatar
John Faulkner, Skegness
Site Owner
Posts: 7644
Joined: 19 Sep 2014 15:55
Location: Skegness, Lincolnshire. JO03dd
Contact:

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by John Faulkner, Skegness »

I experienced a strange audio effect similar to this while listening to medium wave DX recently where my sound card did something odd, producing a strange and subtle stereo reverb. I found that certain parts of the weak audio I was listening to 'seemed'to be clearer and I was convinced that I could hear more weak speech this way. It's almost certain to be what your brain gets used to though. You can't really improve audio, just alter it. Sometimes these effects can appear to lift something out of the noise, or it could have the opposite effect and destroy the audio.

pauldbnut
Posts: 29
Joined: 21 Jan 2018 21:29
Location: Dinosaur Country (IoW)

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by pauldbnut »

Hello, John.

I agree that "effects" can be a useful way to help the brain "click" - making sense of something almost inaudible. That's why we often play with bandwidth or tone controls, or switch between speaker and headphones, and why "audio processors" are quite popular. It's a way of tricking the brain out of a rut.

But I disagree a little on "improving" audio and surely an audio noise blanker is a case in point? Admittedly, no extra information is added, but noise is reduced - the point being that SNR is what matters.

Now, with a plain AM demodulator you are actually throwing away information by averaging the two sidebands. Demodulating AM as ISB (and presenting to left and right) you at least keep the individual sidebands and let the brain extract the maximum information as best it can.

Binaural is something else entirely. It goes several steps beyond ISB in that:
  • Sideband info is near enough 100% phase coherent, so that the wanted audio is very strongly focused and stable at front centre stage.
  • Other co-channel (and closely on-frequency) signals, although central, may be less prominent and are typically less stable.
  • Adjacent channel bleed-through lies at the extreme left/right.
  • Background noise is completely uncorrelated and is spread more-or-less evenly across the sound stage.
So binaural really does give the brain a much better chance of resolving competing signals, especially the dominant one on a channel. And, unlike "effects" (in my experience, anyway) never "destroys" the audio. Note that CCIR rated binaural as having a 6 dB intelligibility gain over any other detection method (including SAM!).

A much more interesting question is whether non-dominant signal recognition is improved with binaural.

As far as I know, all the publicly available software offering true binaural (UHSDR, TeensySDR, Kiwi and SDRC) use carrier locking (Costas loop or something similar). But you can still get almost all the gains of binaural by allowing fine tuning of the carrier reinsertion.

In a situation where several stations have slight carrier offsets (quite common), fine tuning can sometimes enhance a weaker station enough to make it a "catch" rather than just another "also ran". Close to the sweet spot, it may fade and wander on the sound stage at the "beat" frequency. Tenth of a Hz tuning steps can just about freeze that.
Paul White (Grumpy Old Git)

pauldbnut
Posts: 29
Joined: 21 Jan 2018 21:29
Location: Dinosaur Country (IoW)

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by pauldbnut »

Sorry, with my usual focus on MW, I forgot to mention the deep fading more common on SW.
Listening binaural, the Luxembourg effect is great fun: all the improvement of SAM, plus waltzing around the sound stage. With more than one actor on frequency it can be something of a ballet :).
Paul White (Grumpy Old Git)

User avatar
John Faulkner, Skegness
Site Owner
Posts: 7644
Joined: 19 Sep 2014 15:55
Location: Skegness, Lincolnshire. JO03dd
Contact:

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by John Faulkner, Skegness »

You put that all beautifully and poetically! Far more so than how what I are could done! :lol:

Now to try to follow that (coherently) myself.

Er .... Nope. Can't! Your explanation of binaural, etc. is very welcome. I have great difficulty remembering what is sample rate, bitrate, etc. and recently got them wrapped around my neck in a discussion where I fell flat on my a̶r̶s̶e̶ face and ended up looking like more of a prat then I usually do.

There is obviously a lot of mileage in this kind of audio technology when used to dig out weak or co-channel stations, noisy stations, etc., especially once it has been put into the digital realm. I cannot add anything to this, other than to say that I hope (and pray - if I had a faith) that such technology will be be much simpler to control / implement into our DXing routines one day.

Very interesting reading though and thank you for that.

pe1etr
Posts: 2552
Joined: 07 Oct 2014 00:40
Location: Near Lobatse, Botswana

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by pe1etr »

pe1etr wrote:
06 Jan 2021 06:51
Another test from a short wave powerhouse.
https://youtu.be/PL3eHFdYeQs

Peter
Enhanced version: https://youtu.be/n38E8Z4NFUQ
A studio re-mix of audio from mono SW radio station. Use headphones for full effect.
This video is for entertainment purposes only.
Peter

pauldbnut
Posts: 29
Joined: 21 Jan 2018 21:29
Location: Dinosaur Country (IoW)

Re: Short Wave Binaural AM test SDR Console V 3.0.26

Post by pauldbnut »

pe1etr wrote:
10 Jan 2021 05:13
Enhanced version: https://youtu.be/n38E8Z4NFUQ
A studio re-mix of audio from mono SW radio station. Use headphones for full effect.
Hi, Pieter.

Unvarnished stereo and surround sound (for example) are not "effects", they are audio capture and presentation techniques attempting to portray a kind of realism - in other words, an experience close to live listening.

By contrast, "effects" (or FX) are deliberate manipulation of an original to produce an effect (surprise!) - anything from subtle colouring to gross distortion such as "phaser", mimicking other instruments, and 101 others I have no particular interest in studying.

I'm not dismissing FX. It is now ubiquitous and I find much of it very pleasant indeed.

There is also a grey area between the two. Performance recordings have always been "adjusted" by engineers. Sometimes that is limited to compensating for defects in acoustics or other unwanted distractions. Or, that god-like creature may apply certain "improvements" to the original, for example bringing a soloist more to the foreground. Needless(?) to say, I'm inclined to deplore that as not like a live performance.

Now, with that out of the way...

"Binaural" (in the sense implemented by UHSDR, Teensy Convolution SDR, KiwiSDR and SDR Console only, so far) is not an "effect". It faithfully presents the lower and upper AM sidebands, as received, to left and right ears. It adds nothing to and subtracts nothing from the original (theoretically, anyway). It is a presentation technique. Indeed almost a "demodulation method", but not by a strict definition - maybe more akin to a demodulation variant (as in envelope/synchronous AM).

Listening to binaural, what you might have mistaken for "effects" are mostly propagation-induced distortions. The principle contributor is probably selective fading, perceived as movement left-right on the sound stage and some "phasiness". And, by the way, this is probably responsible for the utterly misguided comments I have read that binaural is "better" for SW than MW - can you see why?

You may be under the illusion that binaural has only entertainment value and is a good candidate for improving upon (I deduce that from your offering a new "faux surround sound" version of the original). Not at all:
  • It often improves intelligibility (even over SAM, assessed by CCIR as a further 6 dB!)
  • It is a window on propagation conditions
  • That tool, in expert hands/ears (not mine), has the potential for even deeper diagnostics
So, I'm sorry if you find me pernickety but:
  • I object to your caption on the first CRI as "... binaural effect", as misleading to those who follow your excellent posts but may not know better
  • I applaud your second CRI "faux surround sound" for its pleasant sound (entertainment value), but hope you would not claim it to be somehow "better" (apples and bananas)
In case you don't think the distinction is important, consider this. Without being told in advance, a casual listener to (real) binaural may have no idea whatsoever of its significance or value. So binaural gets dismissed as just another effect, and maybe a fairly mild one that needs plenty of improvement to sound more interesting. I can see that misunderstanding going on for years - what a waste! I BELIEVE it's worth taking the trouble to explain it properly.

Yeah, one of my heroes was Sanskrit grammarian Panini who is supposed to have said over two millennia ago something like "Calling a thing by its right name is the beginning of wisdom". Note: he wasn't stupid enough to suggest wisdom followed naturally or easily from there.

I shouldn't really care, but honestly I'm a bit sad that you still don't seem to have taken the trouble to read (or at least properly absorb) my earlier explanations and clarification. Were they so obscure or badly written? Or is it that nearly everyone in the age of Social Media now has the attention span of a Twitter post and finds anything of this length too tiresome to be bothered with?

Don't worry, I'll button my lip again. For as long as I can.
Not-A-Troll Paul
Paul White (Grumpy Old Git)

Post Reply

Return to “Short Wave Broadcast Bands”