Trinaural decoding equations for 3 speaker stereo matrix ?

[dewardh]

Originally Posted by Elias

See posts #59 and #60 for a simple how-to.

OK, here's from #59

Originally Posted by Elias

You can wire three speakers Trinaurally in a very simple way to form a matrix (abandon the input resistors in this case)

Ls = L - 0.5*R
Rs = R - 0.5*L
Cs = 0.5*L + 0.5*R

Why would I want to put .5R in the left channel? How is that going to help anything?

[markus76]

Originally Posted by SEdwards

@marcus

Are those FRS8s in the cardboard at the wall? Where is the nearfield bass crossed in?

I have also wanted to try 3"s in 45cm x 45cm carpet squares that I have lying around, and curve the square a little to terminate well in the corners, but I'm very pressed for time at the moment.

Yes, those are FRS8's but I got it to "work" with Behringer P2031A's and B200's too. Very different speaker concepts. They simply differed in tonality but not in spatial properties. The important part is level, timing and spectrum of the reflections.

The near field subs are crossed in at 150Hz for the FRS8's.

[Pano]

Originally Posted by Elias

I think it is an additional advantage to cross feed negative signals to opposite side channels, too.

I agree, but then it's no longer simple, easy to set up, and works well for everything.

[Elias]

Originally Posted by dewardh

OK, here's from #59

Why would I want to put .5R in the left channel? How is that going to help anything?

There are two important benefits in doing so. First it maximises the signal separation between speaker feeds. Secondly it adds MS stereo side signal to side speakers.

It may help if you rewrite the speaker signals with help of MS stereo notations.


- Elias

[Elias]

Originally Posted by Pano

I agree, but then it's no longer simple, easy to set up, and works well for everything.

Well, but have you forget your own post #60 ? What can be simpler ?

It is simpler to wire the matrix of 0.5 than get summed center only


- Elias

[dewardh]

Originally Posted by Pano

but then it's no longer simple, easy to set up, and works well for everything.

Bingoit

[dewardh]

Originally Posted by Elias

It may help if you rewrite the speaker signals with help of MS stereo notations.

As it happens I actually own a Fostex M20RP MS stereo microphone . . . and even for recordings made with it things just. don't. work. that. way. Matrixing that works at the coincident microphone doesn't work with speakers 2 Meters apart. You really need to get past the simplistic "notations" and think about what really happens. If you can figure out how to make a "one speaker stereo" with driver spacing no greater than the microphone capsule spacing you might have something . . .

With more typical microphones and mixing it only gets worse . . .

[Pano]

Originally Posted by Elias

Well, but have you forget your own post #60 ?

Yes. I blame it on old age.

[markus76]

Originally Posted by dewardh

If you can figure out how to make a "one speaker stereo" with driver spacing no greater than the microphone capsule spacing you might have something . . .

I don't think so. Care to elaborate?

[dewardh]

Originally Posted by markus76

I don't think so. Care to elaborate?

No . . . the comment was more sarcastic than serious. MS matrixing only works when capsule/"driver" spacing is a fraction of a wavelength.