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Title: What parts of a digitial mixer are digital?
Post by: Jim Layton on October 09, 2018, 09:09:43 AM
I have searched but think I can get a more concise answer right here. I've been using digital mixers for years. I enjoy not hauling around a rack of compressors and other outboard gear.

So what "sections" of a digital mixer are digital? Example. Is the mic preamp A or D? If D, does that mean it is run by a processor and built to "sound like" an A preamp? Same for PEQ, GEQ, FX, compression? Plug-ins excluded in the question. I'm asking about an X32 or Si Expression-level board.

Was the digital mixer invented primarily to send "material" to computers for recording and mixing or was it to cut down on physical gear?

So in general, a basic digital mixer accepts A signals, converts the mix to D then converts to A for output to the PA?

I drilled down into A/D in medical equipment and see that there is lots of "magic" related to sampling, filtering, etc, etc. It looks fairly complicated to make things work (sound?) well.
Title: Re: What parts of a digitial mixer are digital?
Post by: David Allred on October 09, 2018, 10:11:29 AM
I have searched but think I can get a more concise answer right here. I've been using digital mixers for years. I enjoy not hauling around a rack of compressors and other outboard gear.

So what "sections" of a digital mixer are digital? Example. Is the mic preamp A or D? If D, does that mean it is run by a processor and built to "sound like" an A preamp? Same for PEG, GEQ, FX, compression? Plug-ins excluded in the question. I'm asking about an X32 or Si Expression-level board.

Was the digital mixer invented primarily to send "material" to computers for recording and mixing or was it to cut down on physical gear?

So in general, a basic digital mixer accepts A signals, converts the mix to D then converts to A for output to the PA?

I drilled down into A/D in medical equipment and see that there is lots of "magic" related to sampling, filtering, etc, etc. It looks fairly complicated to make things work (sound?) well.

The power switch.  (Sorry.  That's about all I can contribute.)  ???
Title: Re: What parts of a digitial mixer are digital?
Post by: John Roberts {JR} on October 09, 2018, 10:18:01 AM
Depending on how finely you want to drill down, and how you define digital, there is a lot of analog content in the glue circuitry peripheral to a digital mixer (like power supplies, etc).

In broad strokes the mic preamp is generally analog, but there are modern mic preamp chip sets with digital gain control, so hybrid or mixed technology.

Headphone outputs and analog outputs will have analog buffer circuitry.

The "mixing" is performed inside the digital domain after audio stems have been converted to digital streams.

Digital mixers have been around for decades but generally too expensive for anything but high end studio use. Only recently has the technology dropped enough to become cost competitive with analog mixers for live PA use.

JR

[edit- if you think about it a power switch is on/off so kind of digital   ;D   [/edit]
Title: Re: What parts of a digitial mixer are digital?
Post by: TJ (Tom) Cornish on October 09, 2018, 11:19:04 AM
I have searched but think I can get a more concise answer right here. I've been using digital mixers for years. I enjoy not hauling around a rack of compressors and other outboard gear.

So what "sections" of a digital mixer are digital? Example. Is the mic preamp A or D? If D, does that mean it is run by a processor and built to "sound like" an A preamp? Same for PEG, GEQ, FX, compression? Plug-ins excluded in the question. I'm asking about an X32 or Si Expression-level board.

Was the digital mixer invented primarily to send "material" to computers for recording and mixing or was it to cut down on physical gear?

So in general, a basic digital mixer accepts A signals, converts the mix to D then converts to A for output to the PA?

I drilled down into A/D in medical equipment and see that there is lots of "magic" related to sampling, filtering, etc, etc. It looks fairly complicated to make things work (sound?) well.
Jim, the vast majority of a digital mixer's function is done in the digital domain.  The input preamp is analog (probably with digital gain control), and this goes directly to an A/D converter.  All processing - EQ, dynamics, plug-ins, delay, etc., are done in the digital domain and only become analog again at the D/A converter feeding the output driver and analog out.

There are several reasons for this - fewer components in the device (you pay for software development once; you pay for hardware in every unit), A->D->A conversion takes time and multiple rounds would make the desk unusably slow, and the extra functionality you can get in digital, e.g. virtually infinite summing headroom, fancy phase manipulation, modelling, etc.

The nuances of A/D conversion are beyond my expertise, and sampling theory is complicated.  In the early days it was done for functionality - either better quality (CDs vs. cassettes/vinyl (yes I know some people prefer vinyl  ::) ), or some other function that was difficult to do in analog hardware.  These days it's done for cost reasons, and you get the extra features as gravy on top.
Title: Re: What parts of a digitial mixer are digital?
Post by: Dave Garoutte on October 09, 2018, 11:51:04 AM
Plus a lot of effort has been done to keep it digital as far along the stream as possible to the last device (stage boxes, Dante, etc), which needs to be analog, the speaker. 

Darn, JR beat me to it on the power switch being binary. :(
Title: Re: What parts of a digitial mixer are digital?
Post by: David Allred on October 09, 2018, 03:25:20 PM


Darn, JR beat me to it on the power switch being binary. :(

HEY! HEY! HEY!   :'( :'( :'(  Am I invisible here?   :(   
Title: Re: What parts of a digitial mixer are digital?
Post by: Dave Garoutte on October 09, 2018, 03:56:47 PM
HEY! HEY! HEY!   :'( :'( :'(  Am I invisible here?   :(

What..who said that???   Is someone there?? :o
Title: Re: What parts of a digitial mixer are digital?
Post by: Tim McCulloch on October 09, 2018, 04:13:15 PM
HEY! HEY! HEY!   :'( :'( :'(  Am I invisible here?   :(
What..who said that???   Is someone there?? :o

The Dave's are out of polarity,  canceling out each other. 🔇
Title: Re: What parts of a digitial mixer are digital?
Post by: Rick Powell on October 09, 2018, 06:58:45 PM
Well, there's also the analog Littlelite jack for mixers so equipped, but some of them have digital dimming control.
Title: Re: What parts of a digitial mixer are digital?
Post by: Tim McCulloch on October 09, 2018, 08:01:35 PM
Q: What parts are digital?

A: The parts that run on ones and zeros.
Title: Re: What parts of a digitial mixer are digital?
Post by: Scott Bolt on October 09, 2018, 08:52:51 PM
Good question.

As mentioned above, the beginning of the input, and the end of the output.  Everything in between .... digital.

Also of note here is that circuits and amplifiers for preamps and output drivers are industry standard these days and vary very little from mixer to mixer IMHO.

The differentiation is in the digital processing algorithms.

While I frequently argue that preamps are not golden in a mixer (most are created basically equal these days), processing algorithms really are.

Can you hear the difference between a 3K digital console and a 60K digital console?  You bet.  Is it in the preamps?  I don't think so.
Title: Re: What parts of a digitial mixer are digital?
Post by: Stephen Kirby on October 10, 2018, 12:47:40 AM
Since the power switch is operated by pressing with a finger, it's definitely digital.    ;D
Title: Re: What parts of a digitial mixer are digital?
Post by: Erik Jerde on October 10, 2018, 12:58:59 AM
Well, there's also the analog Littlelite jack for mixers so equipped, but some of them have digital dimming control.

Oh you mean those fancy desks that do both sound AND lights.  Big spender there!
Title: Re: What parts of a digitial mixer are digital?
Post by: Steve M Smith on October 10, 2018, 03:11:03 AM
The bit in the middle.

The input preamps are analogue, then ADC converters digitises the signals.  Some digital magic happens inside, then some DACs convert it back to analogue again at the outputs.

Can you hear the difference between a 3K digital console and a 60K digital console?  You
bet.  Is it in the preamps?  I don't think so.

I try to point out the same thing when people argue about the differences between X32 and M32 preamps. Preamp design isn't rocket science, people have been making good preamps for decades.  If there is a difference, it's not the preamps.


Steve.
Title: Re: What parts of a digitial mixer are digital?
Post by: Peter Morris on October 10, 2018, 03:55:16 AM
Good question.

As mentioned above, the beginning of the input, and the end of the output.  Everything in between .... digital.

Also of note here is that circuits and amplifiers for preamps and output drivers are industry standard these days and vary very little from mixer to mixer IMHO.

The differentiation is in the digital processing algorithms.

While I frequently argue that preamps are not golden in a mixer (most are created basically equal these days), processing algorithms really are.

Can you hear the difference between a 3K digital console and a 60K digital console?  You bet.  Is it in the preamps?  I don't think so.

Exactly ....  :)
Title: Re: What parts of a digitial mixer are digital?
Post by: Robert Lofgren on October 10, 2018, 07:38:57 AM
Isn’t the power switch a synth due to the contact bounces that act as an ocillator?

Technically the power switch could be considered tri-state since it is neither on nor off when stopped in the middle, ending up in a third undefined state.

Since the power switch is operated by pressing with a finger, it's definitely digital.    ;D
Title: Re: What parts of a digitial mixer are digital?
Post by: David Allred on October 10, 2018, 10:25:00 AM
The bit in the middle.

The input preamps are analogue, then ADC converters digitises the signals.  Some digital magic happens inside, then some DACs convert it back to analogue again at the outputs.

I try to point out the same thing when people argue about the differences between X32 and M32 preamps. Preamp design isn't rocket science, people have been making good preamps for decades.  If there is a difference, it's not the preamps.


Steve.

So all preamps are equal and don't matter?  That doesn't sound right.
Title: Re: What parts of a digitial mixer are digital?
Post by: Steve M Smith on October 10, 2018, 11:21:22 AM
So all preamps are equal and don't matter?  That doesn't sound right.

No.  But just about all of them are more than good enough.


Steve.
Title: Re: What parts of a digitial mixer are digital?
Post by: Peter Morris on October 10, 2018, 11:28:18 AM
No.  But just about all of them are more than good enough.


Steve.

... and the preamp alone is not responsible for the sound of the whole desk ...

FWIW http://www.audiomasterclass.com/newsletter/the-famous-5-preamp-everything-you-need-to-know#article_2
Title: Re: What parts of a digitial mixer are digital?
Post by: John Roberts {JR} on October 10, 2018, 11:38:41 AM
So all preamps are equal and don't matter?  That doesn't sound right.
yeah, they must "sound" different to justify higher cost...   ::)

I have discussed this before. One digital console preamp has incorporated a soft limiter into the digitally controlled mic preamp. So it will sound different (better?) if driven into clipping than a preamp without a limiter. Below clipping it will still sound the same as other preamps.

There are always major differences in human factors engineering. Things like look, feel, control laws, EQ shape, etc, etc etc... Higher price points involve more attention to such design details. 

Just being digital does not eliminate human factors design, while audio path quality on a bench test may measure similarly.

JR 

 
Title: Re: What parts of a digitial mixer are digital?
Post by: Jon Brunskill on October 10, 2018, 07:42:29 PM
... and the preamp alone is not responsible for the sound of the whole desk ...

FWIW http://www.audiomasterclass.com/newsletter/the-famous-5-preamp-everything-you-need-to-know#article_2

agreed completely. Maybe 10% of the sound, processing and summing and output drive and A/D and D/A are also huge parts of the puzzle. I roll my eyes when people tell me they bought the M32 for the A-MAY-ZING Midas preamps.
Title: Re: What parts of a digitial mixer are digital?
Post by: Steve Loewenthal on October 10, 2018, 08:55:31 PM
So what "sections" of a digital mixer are digital?
The power switch.  (Sorry.  That's about all I can contribute.)  ???
A: The parts that run on ones and zeros.

First I want to give visibility to David Allred. The original question was what parts are digital, not what parts are analog.
He contributed a correct answer. It just took a little longer for others to realize it was an actual contribution.

As to the ones and zeros, while potentially correct, it is still only a partial contribution as not all digital is in ones and zeroes.
The early computers contained many relay switches, which is either on or off. It was only the paper analog representation that showed this as ones and zeroes.
Core memory was always on, but the polarity is what mattered. It was basically an iron dougnut with a couple wires strung through it.
Most modern processors are basically millions of very small transistors that either allow the circuit to continue or not.

I may even be convinced that digital does not run on ones and zeroes, but instead run on the digital entities that can be represented by an analog string of a 2 character alphabet.

With all that said, please forgive me for not actually contributing anything meaningful to the original question.
Title: Re: What parts of a digitial mixer are digital?
Post by: David Allred on October 10, 2018, 10:56:00 PM
agreed completely. Maybe 10% of the sound, processing and summing and output drive and A/D and D/A are also huge parts of the puzzle. I roll my eyes when people tell me they bought the M32 for the A-MAY-ZING Midas preamps.
Odd how when ever someone mentions that the Mida pres are worth the extra money, no one ever spoke up to the contrary.  Why so?
Title: Re: What parts of a digitial mixer are digital?
Post by: Scott Holtzman on October 10, 2018, 11:20:49 PM
First I want to give visibility to David Allred. The original question was what parts are digital, not what parts are analog.
He contributed a correct answer. It just took a little longer for others to realize it was an actual contribution.

As to the ones and zeros, while potentially correct, it is still only a partial contribution as not all digital is in ones and zeroes.
The early computers contained many relay switches, which is either on or off. It was only the paper analog representation that showed this as ones and zeroes.
Core memory was always on, but the polarity is what mattered. It was basically an iron dougnut with a couple wires strung through it.
Most modern processors are basically millions of very small transistors that either allow the circuit to continue or not.

I may even be convinced that digital does not run on ones and zeroes, but instead run on the digital entities that can be represented by an analog string of a 2 character alphabet.

With all that said, please forgive me for not actually contributing anything meaningful to the original question.
Hexadecimal notation is just a simple way to represent 8 binary states.  Most processors in 70's were 8 bit but the data and address bus were 16 bit so those we're 4 digit hex FFFF would be high on all 16 lines on the bus.

Sent from my VS996 using Tapatalk

Title: Re: What parts of a digitial mixer are digital?
Post by: Tim McCulloch on October 11, 2018, 12:01:36 AM
Odd how when ever someone mentions that the Mida pres are worth the extra money, no one ever spoke up to the contrary.  Why so?

Some of us don't wish to begin the extended pissing contest over preamps... okay, I'm lying.  I LOVE to argue about the utter BS that 99% of preamp drivel is.  But I'm not taking the bait.
Title: Re: What parts of a digitial mixer are digital?
Post by: Roland Clarke on October 11, 2018, 01:18:44 AM
Some of us don't wish to begin the extended pissing contest over preamps... okay, I'm lying.  I LOVE to argue about the utter BS that 99% of preamp drivel is.  But I'm not taking the bait.

I love the fact that a certain pre/eq/compressor combination used to be so popular as a money channel even with the advent of digital desks I used to see them in foh racks all the time.  The joke was that studio engineers used to consider them pretty rubbish.
Title: Re: What parts of a digitial mixer are digital?
Post by: Robert Lofgren on October 11, 2018, 01:47:41 AM
I can tell that if I connect a sm7b to an xr18 and a mr18 with a +60dB of preamp gain that the mr18 has less preamp noise.  8)

Odd how when ever someone mentions that the Mida pres are worth the extra money, no one ever spoke up to the contrary.  Why so?
Title: Re: What parts of a digitial mixer are digital?
Post by: Uwe Riemer2 on October 11, 2018, 03:03:20 AM
Odd how when ever someone mentions that the Mida pres are worth the extra money, no one ever spoke up to the contrary.  Why so?
You called?

To me the DL16/X32 signal path sounds better than the X32.
To me and others the DL251 signal path sounds better than the DL16.
To me a soft clipping circuit on the preamp is a useful tool.
Do these compensate lack of art or bad mixing decisions? No

Does quality of the processing algorythms matter? The best sounding concert I heard was Tobi Hof mixing Deep Purple on the Pro2C, no outboard gear.
Does feature set, look and feel matter? The reason I would not buy a S21.
Does the mixing app matter? A&H should really hire David Giga

Ups I got carried away

Title: Re: What parts of a digitial mixer are digital?
Post by: Steve M Smith on October 11, 2018, 03:09:19 AM
I can tell that if I connect a sm7b to an xr18 and a mr18 with a +60dB of preamp gain that the mr18 has less preamp noise.

I'm sure you can in a critical listening situation, but can you tell with live music?  I have an XR mixer and preamp noise has never been an issue.


Steve.
Title: Re: What parts of a digitial mixer are digital?
Post by: Robert Lofgren on October 11, 2018, 04:53:59 AM
No, it is only an issue with voiceovers or similar low level applications using the sm7b and you really need to crank the gain. It becomes highly obvious if you gate the voice.

The sm7b is notorious for its very low output and many mixers struggle with the sm7b unless you use a cloudlifter in between. Please note that I’m not talking about highlevel sources like brass or guitar amps.

As soon as you lower the gain I’m hard pressed to hear any big diff. A slightly more high-end on the mr18, but I tend to lowpass the highend anyway as I in general don’t like any highend buildup when using many channels. Just like any lowend buildup.

I'm sure you can in a critical listening situation, but can you tell with live music?  I have an XR mixer and preamp noise has never been an issue.


Steve.
Title: Re: What parts of a digitial mixer are digital?
Post by: Jean-Pierre Coetzee on October 11, 2018, 11:04:26 AM
I would say it depends.

With modern Dante/Ravenna/AES networks I would say that the actual console is 100% digital. You don't need to control the pre from the console and in some situations it isn't controlled from the console and likewise you don't need to convert to analogue from the console you could very well be sending a digital stream somewhere else and the converts to analogue.

Pre-amps are digital but a RIO is really not part of the CL5 console, it will operate without a CL5 no problem so it is a dedicated stage box, the CL5 is the console and save for the omni in/out there are no analogue ports on there. Going back to the RIO once again it isn't part of the console.
Title: Re: What parts of a digitial mixer are digital?
Post by: Daniel Rugotzke on October 13, 2018, 03:27:01 AM
Technically, the encoders (faders, knobs, and possibly buttons) on most digital mixer control surfaces are analog.  These encoders are converted to digital values that then control manipulation of the audio data.  All the audio processing is digital.
Title: Re: What parts of a digitial mixer are digital?
Post by: Mac Kerr on October 13, 2018, 11:38:05 AM
Technically, the encoders (faders, knobs, and possibly buttons) on most digital mixer control surfaces are analog.  These encoders are converted to digital values that then control manipulation of the audio data.  All the audio processing is digital.

Is my understanding of encoders mistaken? I think the only thing analog about them is that they have a linear sliding knob. Instead of a constantly variable resistance they create a string of pulses, a digital output.

Mac
Title: Re: What parts of a digitial mixer are digital?
Post by: John Roberts {JR} on October 13, 2018, 11:46:40 AM
Is my understanding of encoders mistaken? I think the only thing analog about them is that they have a linear sliding knob. Instead of a constantly variable resistance they create a string of pulses, a digital output.

Mac
This pedantic inspection of minutiae related to the glue components and circuitry around a digital mixer is not very informative (IMO).

Indeed digital encoders deliver a digital code output (duh) that digital processors can accept directly. Analog pots and faders used to control digital consoles generate a varying analog voltage, that gets digitized by A/D convertors for use controlling the digital signal inside the digital domain.

JR

 
Title: Re: What parts of a digitial mixer are digital?
Post by: Don Boomer on October 13, 2018, 12:01:22 PM
if you think about it a power switch is on/off so kind of digital   ;D   

So you are making a big assumnption that the power switch is an on/off switch. It might not actually be so.

Just poking at you bro  ;)
Title: Re: What parts of a digitial mixer are digital?
Post by: John Roberts {JR} on October 13, 2018, 02:11:46 PM
So you are making a big assumnption that the power switch is an on/off switch. It might not actually be so.

Just poking at you bro  ;)

Power switches are generally two state... either on or off... the definition of binary (digital).

I have designed on/off switches in battery powered products that both provide analog voltage to boot up the processor, and a digital switch input for the processor to use alternately depending on previous state. When it's time to turn off this digital input tells the processor to stop holding the power supply on.

This is the way most web discussions go, too much info only vaguely related to the OP's question.  ::)

JR
Title: Re: What parts of a digitial mixer are digital?
Post by: David Allred on October 13, 2018, 03:50:15 PM
This pedantic inspection

JR
Very George Costanza of you. ;D
https://youtu.be/-cYpEsY_WGY
Title: Re: What parts of a digitial mixer are digital?
Post by: Jay Barracato on October 13, 2018, 06:40:26 PM
Very George Costanza of you. ;D
https://youtu.be/-cYpEsY_WGY
How's this for pedantic:

Devices aren't analog or digital, signals are.

Using electricity to transfer a signal is different from using electricity as a power source.

Is my bedroom light analog or digital?

When noise is superimposed on a digital signal, does the circuit suddenly become analog?

If my m32 takes in an analog signal and outputs a predictable analog signal, can I consider it an analog device? ( From the standpoint of system design, yes).

Sent from my Moto Z (2) using Tapatalk

Title: Re: What parts of a digitial mixer are digital?
Post by: Steve Loewenthal on October 13, 2018, 07:24:44 PM
This pedantic inspection of minutiae related to the glue components and circuitry around a digital mixer is not very informative (IMO)...

IMO, the OP was an invitation for pedantic inspection of minutiae. Something this forum is often very good at. While some parts of this discussion may or may not be informative, it has certainly provided enjoyment for myself and hopefully others. Please continue with the inspection of minutiae.


Devices aren't analog or digital, signals are.

Yes

Power switches are generally two state... either on or off... the definition of binary (digital).

Just because something is binary does not make it digital. The British measurement of volume and weight is basically binary (OK Base 2 for some) (2 teaspoons to a tablespoon (ignoring some history) 2 table spoons to an ounce, a couple of forgotten antiquated intermediate measurements, 2 cups to a pint, then quart, another forgotten intermediate, gallon)
Title: Re: What parts of a digitial mixer are digital?
Post by: John Roberts {JR} on October 13, 2018, 08:41:53 PM
IMO, the OP was an invitation for pedantic inspection of minutiae. Something this forum is often very good at. While some parts of this discussion may or may not be informative, it has certainly provided enjoyment for myself and hopefully others. Please continue with the inspection of minutiae.
you asked for it...
Quote

Yes
this is an old conceit, but yes individual circuitry inside digital ICs are linear analog*** components configured to perform digital functions.
Quote
Just because something is binary does not make it digital.
I stand corrected... just messing...

on/off switches are "bi-state".  Digital math is binary, or hex, or octal, or...
Quote
The British measurement of volume and weight is basically binary (OK Base 2 for some) (2 teaspoons to a tablespoon (ignoring some history) 2 table spoons to an ounce, a couple of forgotten antiquated intermediate measurements, 2 cups to a pint, then quart, another forgotten intermediate, gallon)
huh...  maybe?

JR

*** if we drill down to individual electrons and holes it becomes almost digital again, but we don't get down that small, yet.
 
Title: Re: What parts of a digitial mixer are digital?
Post by: Robert Lofgren on October 14, 2018, 02:27:44 AM
*** if we drill down to individual electrons and holes it becomes almost digital again, but we don't get down that small, yet.
You got me thinking of quarks...
Title: Re: What parts of a digitial mixer are digital?
Post by: Steve Loewenthal on October 14, 2018, 05:21:01 PM
you asked for it...

I did. Thanks for the reply. :)
Title: Re: What parts of a digitial mixer are digital?
Post by: Wes Garland on October 14, 2018, 10:32:32 PM
Binary?  Aw crap. I thought "digital" meant you operated it with your fingers!