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‘True Stereo’ hardware FX used with hardware synths

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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby blinddrew » Thu May 30, 2019 2:18 pm

Hmmm. I might have to take issue with this. M/S isn't an effect, it's just a way of encoding a stereo signal. In itself it's no different to L/R - just different ways of doing the maths.
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Hugh Robjohns » Thu May 30, 2019 2:27 pm

Quite so. Mid-Sides is just an alternative formatting of Left-Right with mathematical equivalence.

Probably, the reason its use as an stereo effect is 'not as pronounced' as some other types of effect is that, by definition, the stereo effect is created only by level differences between the two channels, whereas many stereo effects -- like stereo chorus, for example -- typically involve intentional time differences (as well as level differences) between the two channels.

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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby MOF » Thu May 30, 2019 7:28 pm

Quite so. Mid-Sides is just an alternative formatting of Left-Right with mathematical equivalence.

Thanks Hugh.
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Ben Asaro » Fri May 31, 2019 9:50 pm

Bill, here's my humble attempt at various stereo schemes using the TX7.

I used a total of three effects: two Lexicon Alex units, the TC Electronic Mimiq, and the WORNG LRMSMSLR.

Here's the audio, https://soundcloud.com/asfollowswriting/tx7-stereo-test

Here's a description of what I did:
(1) is the mono output of the TX7; (2) is the mono output from the TX7, multed, and put into each Alex on the same Chorus algorithm but set with slightly different regeneration times; (3) is the multed output into the TC Mimiq set for 1 dub and then into the Lexicons; (4) is the same, but with the Mimiq set to 2 dubs; (5) is the same but with the Mimiq set for 3 dubs; (6) is the TX7 going mono straight into the LRMSMSLR with a single chorus going through the mid-side processing; (7) is the TX7 going mono straight into the LRMSMSLR, but the mid-side is going from the chorus into a hall reverb.

Now, I know people were poo-poo'ing the idea of mid-side processing being an effect; and I agree, it's a process, not really an effect -- but I'll be damned if you can't hear it on these examples; it definitely creates a really interesting sound: it has stereo width but also a really strong center image with lots of low frequency girth. Adding the reverb makes it suuuuuper wide, however.

Anyway, I hope you find this useful.
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby blinddrew » Sat Jun 01, 2019 9:16 am

Just to clarify, i wasn't knocking the benefits of using m/s processing (preserving mono compatibility is one), just saying that the principle itself is just one of maths. :)
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Hugh Robjohns » Sat Jun 01, 2019 11:46 am

Ben Asaro wrote:Now, I know people were poo-poo'ing the idea of mid-side processing being an effect; and I agree, it's a process, not really an effect -- but I'll be damned if you can't hear it on these examples; it definitely creates a really interesting sound: it has stereo width but also a really strong center image with lots of low frequency girth. Adding the reverb makes it suuuuuper wide, however.

Sorry... I'm still at a loss as to exactly what your processing chain is and what's feeding the inputs of the MS decoder...

But MS isn't an 'effect' or a 'process', it's a format conversion, plain and simple. The more you put into the Sides channel, the wider the image gets.

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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby BillB » Sat Jun 01, 2019 3:28 pm

Ben, just to say thanks, I’ll give the demo a good listen.
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Ben Asaro » Sat Jun 01, 2019 4:49 pm

Hugh Robjohns wrote:Sorry... I'm still at a loss as to exactly what your processing chain is and what's feeding the inputs of the MS decoder...
H
Sorry, Hugh -- see a more granular breakdown below:

TX7 MONO OUT > LRMSMSLR LEFT IN
LRMSMSLR SIDE OUT > Lexicon Alex [chorus effect] MONO IN
Lexicon Alex [chorus effect] MONO OUT > LRMSMSLR SIDE IN
LRMSMSLR LEFT OUT > 18i20 INPUT #1
LRMSMSLR RIGHT OUT > 18i20 INPUT #2

^ That's the penultimate round in the loop. On the final loop, it's the same but with a second effects processor added with reverb:

TX7 MONO OUT > LRMSMSLR LEFT IN
LRMSMSLR SIDE OUT > Lexicon Alex MONO IN
Lexicon Alex #1 [chorus effect] MONO OUT > Lexicon Alex #2 [reverb effect] MONO IN
Lexicon Alex #2 [reverb effect] MONO OUT > LRMSMSLR SIDE IN
LRMSMSLR LEFT OUT > 18i20 INPUT #1
LRMSMSLR RIGHT OUT > 18i20 INPUT #2
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby BillB » Sat Jun 01, 2019 5:06 pm

And the Mimiq?
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Ben Asaro » Sat Jun 01, 2019 5:37 pm

BillB wrote:And the Mimiq?
When I used the Mimiq:

TX7 MONO OUT > MULT
MULT Out #1 > Mimiq MONO IN
MULT Out #2 > Mimiq STEREO IN
Mimiq MONO OUT > Lexicon Alex #1 [chorus effect] MONO IN
Mimiq STEREO OUT > Lexicon Alex #2 [chorus effect] MONO IN
Lexicon Alex #1 [chorus effect] MONO OUT > 18i20 INPUT #1
Lexicon Alex #2 [chorus effect] MONO OUT > 18i20 INPUT #2
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Hugh Robjohns » Sat Jun 01, 2019 6:02 pm

Ben Asaro wrote:Sorry, Hugh -- see a more granular breakdown below:

Thanks Ben.

TX7 MONO OUT > LRMSMSLR LEFT IN
LRMSMSLR SIDE OUT


Erm... Wih nothing going into the right side of the MS encoder, the Side out signal will be the same as the left in, but possible with a small level change.

The encoder matrix equations are Mid=Left+Right (which you aren't using), and Side= Left-Right... But, as there is no Right input signal involved here, you just have Side=Left... So no change at all (other than level, possibly -- some MS coders introduce a -3dB level shift downwards to maintain unity gain through a complete LR-MS-LR chain).

...Lexicon Alex [chorus effect] MONO OUT > LRMSMSLR SIDE IN
LRMSMSLR LEFT OUT ...

Again, with no Mid input to the decoder nothing much happens here. The relevant matrix equation is: Left = Mid+Side (and Right=Mid-Side), but as there's no Mid signal you just have Left = Side... So no change once again.

So I'm still quite confused... But maybe this bit is doing something more useful:

> 18i20 INPUT #1
LRMSMSLR RIGHT OUT > 18i20 INPUT #2

Where do input 1 and input 2 figure in the grand scheme of the MS matrix chain?
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Ben Asaro » Sat Jun 01, 2019 7:02 pm

Sorry if this is baffling, I admit I don't know why it works, either! But it definitely does something to the stereo image, as you can hear.

I double-checked my notes to make sure I wasn't running the mult into the mid-side encoder; but, nope, it was going mono into the left input and stereo out to the 18i20, inputs 1 and 2 (as a stereo pair).

So, yeah, it's just as I wrote it -- mono in, side out to chorus, side back into the encoder, stereo out. The actual stereo field is quite narrow if you listen to it, so maybe it's just processing the phase differences caused by the chorus itself; whereas, when I added the reverb, you can clearly hear the wet signal panning from hard left to had right...

*shrug* Dunno!
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Ben Asaro » Sat Jun 01, 2019 7:04 pm

Edit: Though it's entirely possible that I sent the MID out and SIDE back in after the chorus; I didn't take any photos as I didn't anticipate doing such a detailed post mortem. :)

However, based on what I am seeing here, if I am interpreting this correctly, using mid or side out makes no real difference.
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Hugh Robjohns » Sat Jun 01, 2019 7:35 pm

Ben Asaro wrote:So, yeah, it's just as I wrote it -- mono in, side out to chorus, side back into the encoder, stereo out.

Okay. I was being dim, but realise now what you meant about input 1/2...

Lexicon Alex [chorus effect] MONO OUT > LRMSMSLR SIDE IN
LRMSMSLR LEFT OUT > 18i20 INPUT #1
LRMSMSLR RIGHT OUT > 18i20 INPUT #2

So while all the previous MS messing about was doing nothing at all, as I explained, here you have a mono chorus effect feeding only the side input of an MS decoder, so the left and right decoded outs will be identical, but in opposite polarities, and hence sound ultra wide when auditioned in stereo.

Left = Mid+Side, Right = Mid-Side, so in your case Left = chorus and right = polarity-inverted chorus.

But I do wonder if there's any normalling of the sockets on the MSLR chain, as that would make things more interesting...
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Re: ‘True Stereo’ hardware FX used with hardware synths

Postby Ben Asaro » Sat Jun 01, 2019 7:44 pm

Aha! Mystery solved! :D

Hugh Robjohns wrote:But I do wonder if there's any normalling of the sockets on the MSLR chain, as that would make things more interesting...
That could very well be the case; WORNG is not very forthcoming about the actual circuit and most people using it are probably just interested in creating whooshing pads in their modular setup. I've been using it as more of a spacial "de-centraliser". However, with just the chorus, there is still a strong central image (with quite a bit of bass, too), which definitely lends credence to this theory!

But WORNG is making some of the most interesting processors out there right now (in my opinion); when you combine their Vector Space module with the LRMSMSLR, things get very interesting, indeed! (Though the price of entry is a bit high)
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