Hi!
Is there any available processor that is similar to Jim Bongiorno's Trinaural?
https://www.sst.audio/new-products/trinaural-processor
I will set up 3 speakers but the source of sound is traditional L+R stereo. Mostly, I need Mono sound but also light fill-in of left and right stereo. Advice on how to get this?
thanks!
Is there any available processor that is similar to Jim Bongiorno's Trinaural?
https://www.sst.audio/new-products/trinaural-processor
I will set up 3 speakers but the source of sound is traditional L+R stereo. Mostly, I need Mono sound but also light fill-in of left and right stereo. Advice on how to get this?
thanks!
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The marketing hype says its fully analogue, which means it isn't doing anything too complicated. It does say it's not simply a L+R into the centre but it might not be far off - for example it could be frequency selective. The headphone people have something like this that they call cross-feed, a frequency selective filter for mixing L and R - it's not directly relevant to your question other than an example of a relatively simple analogue filtering.
The idea of a centre speaker for stereo is an old one and I suspect you'll find lots of ideas by googling on that topic.
The idea of a centre speaker for stereo is an old one and I suspect you'll find lots of ideas by googling on that topic.
I think just about anything can do basic trinaural, since that just involves mixing input channels in various combinations into the three output channels. There are some more advanced types of trinaural matrixing that do more than that, but I am not sure what sort of relationships are used in the unit at the link you provided.
FWIW, I am working on (building the speakers for) a trinaural system of my own using software DSP.
There is a thread on one of the forums here that has several useful posts about the various trinaural mixing matrices that can be used. Use the search function and you should find it.
FWIW, I am working on (building the speakers for) a trinaural system of my own using software DSP.
There is a thread on one of the forums here that has several useful posts about the various trinaural mixing matrices that can be used. Use the search function and you should find it.
???
I believe I am looking for the following:
Mono channel will play only the L+R common signal. NOT the sum but what’s in "common".
Left speaker will play the difference in left input and common signal.
Right speaker will play the difference of the right input and common signal.
As a result most of the signal is coming out of the mono speaker and only a little bit of the stereo information is coming out of left and right.
Mono channel will play only the L+R common signal. NOT the sum but what’s in "common".
Left speaker will play the difference in left input and common signal.
Right speaker will play the difference of the right input and common signal.
As a result most of the signal is coming out of the mono speaker and only a little bit of the stereo information is coming out of left and right.
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Sounds simple but you need to define (mathematically) what is meant by ‘in common’. And what is the centre, is it a narrow zone or a wider zone. Personally, I don’t see how a simple-to-implement definition will end up with your centre channel being any different from R + L, except scaled in volume perhaps.
My theory might be wrong but it seems the center channel should only play the information that does not contain any bleed in that I would call “stereo affect”.
Simply Summing L + R would contain everything. But I am trying to keep the center channel containing only information that is in common between L and R. We are left with the difference which is the “stereo information”
I think we should take that stereo information and only let L + R Reproduce that “stereo information”
Is this making any sense?
Simply Summing L + R would contain everything. But I am trying to keep the center channel containing only information that is in common between L and R. We are left with the difference which is the “stereo information”
I think we should take that stereo information and only let L + R Reproduce that “stereo information”
Is this making any sense?
Your idea makes intuitive sense and we've all thought of/about it at some point in our journey. I even asked in a related thread "What if you came upon an awesome speaker but only ONE?", just a few weeks ago and received many replies. As for defining mathematically common(L,R), one might simply try min(L,R) digitally on the envelopes and see/hear what happens. Or FFT then take min at each frequency (but there are issues).
I'm afraid that may not be possible using a simple matrix.
You may try Dolby Pro Logic (or its variants) with channel steering (auto-balance) enabled, as is usually done by professional cinema units.
Have a look at mid/side stereo (coding), it may be useful to create a centre channel w/o the side information.
You can transfer LR-stereo to mid/side stereo and vice-versa.
"Mid/side – sometimes called sum/difference – is a technique whereby a stereo recording is changed from the usual left and right to mid and side. The ‘mid’ or ‘sum’ is the mono portion of the recording (everything the left and right signals have in common) and the side is the stereo portion (everything else)."
e.g.
https://oldcottageaudio.co.uk/the-beginners-guide-to-midside-processing/
Some links in German, did not find it in English, but the math should be clear:
https://de.wikipedia.org/wiki/Mid/Side-Stereofonie
www.sengpielaudio.com/Stereo-Matrix01.pdf
www.sengpielaudio.com/Stereo-Matrix02.pdf
www.sengpielaudio.com/Stereo-Matrix03.pdf
You can transfer LR-stereo to mid/side stereo and vice-versa.
"Mid/side – sometimes called sum/difference – is a technique whereby a stereo recording is changed from the usual left and right to mid and side. The ‘mid’ or ‘sum’ is the mono portion of the recording (everything the left and right signals have in common) and the side is the stereo portion (everything else)."
e.g.
https://oldcottageaudio.co.uk/the-beginners-guide-to-midside-processing/
Some links in German, did not find it in English, but the math should be clear:
https://de.wikipedia.org/wiki/Mid/Side-Stereofonie
www.sengpielaudio.com/Stereo-Matrix01.pdf
www.sengpielaudio.com/Stereo-Matrix02.pdf
www.sengpielaudio.com/Stereo-Matrix03.pdf
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