Summing Engine

[interlagos]

Hi,
I was wondering if the summing engine of Mixbus is a true emulation of a vintage console.
Or maybe this is just marketing from Harrison.
That's true Mixbus sounds good and I'm a old user of it.
But I saw some video where summing engine are compared and every Daw, included Audacity and Ardour, give the same result.
What about Mixbus ?
Are there the EQ, compressors and drive that gives this special sound ?
Thanks for reading.
Have a good day,
Charles.

[jeff_sloan]

Hi,
I was wondering if the summing engine of Mixbus is a true emulation of a vintage console.
Or maybe this is just marketing from Harrison.
That's true Mixbus sounds good and I'm a old user of it.
But I saw some video where summing engine are compared and every Daw, included Audacity and Ardour, give the same result.
What about Mixbus ?
Are there the EQ, compressors and drive that gives this special sound ?
Thanks for reading.
Have a good day,
Charles.

From the product page:
https://harrisonconsoles.com/product/mixbus-32c/


[font="Open Sans", sans-serif]"Each Mixbus32C channel strip incorporates an exact emulation of the original Harrison 32C parametric four-band sweepable EQ with a separately switchable filter section including second order high-pass and low-pass filters. Every resistor, capacitor, and transistor was modeled. It was impossible to run this complex DSP on every channel strip just 5 years ago."[/font]

[font="Open Sans", sans-serif]And[/font]

[font="Open Sans", sans-serif]"[/font]

• Precise emulation based on Harrison's famous analog console circuit designs
  
  
• Precision algorithms for EQ, Filter, Compression, Analog Tape Saturation, and Summing
  
  
• The Mixbus engine is internally dithered, ramped, and gain staged so that sound quality is preserved as close to analog as possible
  "

If that helps...

[Lars]

Maybe this thread and explanations of Ben Loftis help:

What is "True Analog" ?
https://forum.harrisonconsoles.com/threa...61042.html

[johndev]

A topic that I'm a bit fuzzy on too. My take from the link in the previous post is that it doesn't change the sound, if you didn't use any of its EQ, compressors or saturation drives, other than some avoiding of programming 'errors' that would otherwise make it sound more digital. If my take is right, the Harrison console has no particular sound, it's "clean", so Mixbus is not so much emulating a particular analog sound, as emulating something that has no sound.

"Unless it is explicitly stated in the product manual, Harrison does not add distortion or noise to our digital signal processing products. We don't add hidden eq or level changes. There is no arbitrary "color" or other non-linear artifacts added to the digital signal processing models."

Although it's unclear to me whether this part of the post is still talking about Mixbus.

[PBuryk]

Hello, All -

There's an interesting discussion on this topic (not particularly regarding Harrison Mixbus, but for DAWS in general) over at:
[ https://www.logicprohelp.com/forums/topi...e-for-all/ ]

Cheers!
Patrick

[jeff_sloan]

A topic that I'm a bit fuzzy on too. My take from the link in the previous post is that it doesn't change the sound, if you didn't use any of its EQ, compressors or saturation drives, other than some avoiding of programming 'errors' that would otherwise make it sound more digital. If my take is right, the Harrison console has no particular sound, it's "clean", so Mixbus is not so much emulating a particular analog sound, as emulating something that has no sound.

"Unless it is explicitly stated in the product manual, Harrison does not add distortion or noise to our digital signal processing products. We don't add hidden eq or level changes. There is no arbitrary "color" or other non-linear artifacts added to the digital signal processing models."

Although it's unclear to me whether this part of the post is still talking about Mixbus.

If they say that they model every resistor, capacitor, etc., and have their "precision algorithms" for among other things, summing, then even if you have everything set flat, you are still getting the "sound" of their analog board, as each of those components are going to affect the signal. Nothing is infinitely transparent, except for nothing itself.

When they say add, they mean extra.
They ARE adding noise and distortion by the simple fact that they are emulating their electronic components of their analog boards.

But they are NOT adding noise for noise sake to make it sound like something that it isn't, as they are inferring others do.

That is my take on it.

[johndev]

They ARE adding noise and distortion by the simple fact that they are emulating their electronic components of their analog boards.

Yeah, that's what I thought too but that linked post says that the circuitry of the consoles "minimize distortion and noise down to theoretical limits. In other words, they are true to the signal." Not sure what "theoretical" means exactly here but I'm interpreting it as so low you'd never hear it. Hence the "true to the signal" or, as I put it, "clean" / "no sound".

The circuitry emulation only comes into it with the EQ and compressor, that they behave and therefore sound the same as those on the console. So if all EQs and compressors (and saturation drives) are turned off then Mixbus does not colour the sound at all. But it does avoid some pitfalls that would otherwise make it sound more digital. So Mixbus is 'less digital' sounding than some other DAWs which by definition means 'more analog', I guess, but really it's not "digital" or "analog" sounding, it's neither, it's clean. Which is a good thing.

Again, this only my take on what is being said in that post. I'm not claiming to be holding any facts here.

[jeff_sloan]

I don't think this is the case, remember, they said this:

Precision algorithms for EQ, Filter, Compression, Analog Tape Saturation, and Summing
Summing is done whether or not there is any eq applied. 

[PBuryk]

I would tend to look at it this way:

EQs, Compression, Tape Saturation are all coloration processors by definition.

Summing, on the other hand is, also by definition, a non-colorization process.
That is, the result of summing any number of signals should simply be the addition of those signals levels towards a whole.
So, regardless of the basis - pure analog or digital, the "summing" of those signals should result in identical results.
That, of course, is total theoretical. Because...
1) Summing in analog is subject to the performance of every analog component in the summing circuit.
    Any variation in tolerances or overall linearity, due to their individual electrical attributes or running environment (heat, cold, moisture, etc.) affects the results.
    So, in actuality, no two analog summing devices are totally identical. Whereas,
2) Summing in digital bypasses the tolerance and linearity issues - the summing algorithm is either correct or not correct; there is no in-between ,
     but this introduces errors of its own because of
    1) Stairs-stepping due to bit-level resolution. Dithering helps to minimize this but, let's be honest, it is just a "hack".
    2) Estimation of actual signal level that is not available between samples.
        This error varies depending on same rate so, also in theory, lessens as the sample rate is increased.

My whole point is that neither analog nor digital summing is perfect but, given the choice,
I would opt for digital summing as its results are the same, every time.
Moreover, those results can then be further processed ("colored") to what ever extent is necessary to please the client.

Cheers!
Patrick

[johndev]

Precision algorithms for EQ, Filter, Compression, Analog Tape Saturation, and Summing

There lies the crux of the matter. What does "precision algorthims for summing" mean exactly? I don't know. It's not saying emulation, only precision. Taken together, these two...

Precise emulation based on Harrison's famous 32 series analog console circuit designs
Precision algorithms for EQ, Filter, Compression, Analog Tape Saturation, and Summing

...could be interpreted as: the precision algorithms are what provide the precise emulation, and therefore Mixbus has a precise emulation of analog console summing. I don't think it is saying that.

Summing, on the other hand is, also by definition, a non-colorization process.

Presumably a DAW could add colourisation at this stage if it wanted to.

I haven't seen an official clear-cut answer to the question: does the Mixbus summing engine colour the sound? A Mixbus vs Ardour null test involving summing (multiple tracks) would be interesting.