# Using A Computer As A Mixer



## GrantHughes

Although there are some videos on the internet, none of them seem to quite accomplish this task.

Here's what I'm thinking. I would like to not use a mixer of any form (no USB mixers). I would like to have several channels going into my computer in a way that allows my computer to recognize them as seperate. I would, then, like to use Logic as the mixer. Then I would like to use an XLR for output into the House Speakers.

If there is anything out of this that I'm willing to sacrifice, it would be, in order:

I am willing to use a USB mixer if it doesn't somehow conflict with my overall goal.
I am partially accepting of not having seperated sound input. (If it all just melted together as one sound input)
I will not sacrifice using Logic (because the whole point is to use my computer)
I will not sacrifice using XLR output to House (because, once again, that's the whole point)
So, is this possible, then?


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## Footer

All the AVID consoles are is a big piece of hardware running pro-tools, granted, it is very specialized hardware and not your average pro-tools install. I'm not a logic guy, so I could not tell you if the software can do what you want to do. 

However, your biggest issue is getting the sound in and out without a huge amount of latency... something that can kill you in a live environment. Beyond that, you are going to have to by USB pre-amps and those are not cheap. 

What are you really trying to do here?


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## Morte615

You will probably have to build a custom computer. You can find USB interfaces that will do what you want to do but at that point you are looking pretty much at a USB mixer.

Here is a card that offers multi-in and multi-out: Buy.com - M-Audio Delta 1010LT Sound Card It has RCA and XLR connectors.

You can add this card into a computer then you can use Audacity for the audio. Or I am sure the card will come with software also.


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## Clifford

My question is not so much "what are you trying to accomplish?", but why do you want to do this? Presumably the school theatre already has a mixer. This mixer is designed for the very thing you're trying to do, is already in place, and you won't have to pay for it (assuming you don't already own Logic); and will either not have latency issues (analog) or will have minimized latency issues thanks to the engineers at one of the companies that make digital consoles. Not to mention the fact that computers are generally more volatile than simpler, purpose-built devices.


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## GrantHughes

This is mostly due to our sound board's lack of digitization. With a computer, obviously, any kind of short comings of a sound board, in terms of effects and controls, can be simply downloaded. With the board we have, I find myself limited in some areas. Seeing as how we are unlikely to get a new board of any better quality any time soon, it seems reasonable that I investigate the possibilities in other mediums. For example, if somehow I could have set up a bunch of my sound cues for Hairspray on my computer, I could've worried more about the wireless mic frequencies and less about turning everyone's mic on and off.

So, for clarity, I would have preferred to do our most recent performance using my computer (or an actual digital board). I had thought of how I might have 11 wireless mics set up on my computer. I realized that there is one way, but I would only have one sound input for 11 mics (which is kind of pointless). 

Also, I would not necessarily be looking at a USB mixer, seeing as how I would be using the computer to mix. If I wanted to use a physical mixer, then there'd be no point in plugging it into my computer since I already have a board that is far better than a USB mixer. However, the board does not necessarily beat the theoretical capability of a computer.

Also, I do already own Logic.

And could you please expand on the pre-amp?


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## Clifford

I understand wanting to run cues from a computer, but if that's what you're going for, why not run something like QLab? Why does the entire mix have to run through the computer? If the answer is effects, there are any number of external effects processors out there you can buy or rent for relatively little money. Also, not having onboard effects is not a shortcoming of your analog board, it's something that wasn't usually part of a sound board until digital mixers appeared.

I applaud the fact that you're exploring other solutions, and ultimately we will all be dependent on digital mixers. I don't want to sound like a Luddite who wants everyone to stick with analog forever; however, it seems to me that you're completely reinventing the wheel when adding a couple components to your system will do what you want to do. The world got by on analog systems for a long time, and decent equipment to set up the system you're envisioning may cost more than a used effect processor. Again, it's good to explore other solutions, but when it comes to implementation you have to be practical. Who is paying for this project? Is it you? Is it the school? Who gets to the keep the equipment if you pay for it? If it's you, you're potentially inviting liability and creating dependencies that will leave the school in a difficult position when you graudate. If it's the school, money and approval may be hard to come by.


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## GrantHughes

QLab, however, does not turn on/off microphones, or do any other on-board cues. On a computer, I can have a compressor, an automatic mixer, and a larger base for control. The only (yet to be resolved) problem is how I would go about doing it. And, although I agree that the analog board that I have been using is not only practical but also the most cost-efficient, I also see that it does not necessarily provide for the most productivity in show. That being said, I am just wondering how I can go about accomplishing this, if I were to decide that I ever want to do it. I'm not even saying that I would do this. I would, at minimum, just like to know how. I think it's stupid for me to invest my time is sound design without ever getting into all of the different methods I can go about things. For example, if some method of operation were to fail, I feel that I should know multiple fail-safes and backups. 

I want to continue to do sound further through my career, but I have had no teacher of any sort. I know literally no one more educated about sound than myself. Thus, I have little understand/ability. Although I have been quite successful this far, I am wanting to find out the other ways that I can do things so that I'm not locked into one way that I actually understand.


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## damjamkato

So basically you want something like S.A.C.?


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## GrantHughes

I've already considered SAC. I decided no, most explicitly because I don't have a PC. However, yes, similar programs.


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## Chris15

Every technician is an individual and thus will find different ways of doing things work better for them.
But I personally would hate to be trying to run wireless and especially 11 channels of it without physical faders...

From a technical standpoint, I think that once you have enough preamps to get your audio into the PC you'll have ended up dropping a chunk of change.
Latency is likely to become an issue when dealing with a number of channels on a non dedicated machine.
A dedicated machine will be an additional expense.

From a personal point of view, I prefer never to use a computer what there is dedicated hardware available to do at similar cost, stand alone hardware just wins every time on stability and reliability...


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## museav

GrantHughes said:


> This is mostly due to our sound board's lack of digitization. With a computer, obviously, any kind of short comings of a sound board, in terms of effects and controls, can be simply downloaded.




GrantHughes said:


> On a computer, I can have a compressor, an automatic mixer, and a larger base for control. The only (yet to be resolved) problem is how I would go about doing it.


I think you may be overly generous in your assessment of what you can do with a computer and software in regards to live sound. As others have mentioned, latency is one issue, both in A/D and D/A conversion and in the processing itself. And that is potentially not just overall latency but also differential latency between different paths. You might also be surprised to find how bad some plug-ins are in terms of latency, affecting phase and so on. Some of these issues may not matter that much when doing production work or for some processing but they can matter when you are working with both natural and reinforced sound.


GrantHughes said:


> I've already considered SAC. I decided no, most explicitly because I don't have a PC. However, yes, similar programs.


As already noted, most digital mixers are essentially a dedicated computer, but that is a significant point in that the hardware, firmware and software are all designed specifically for that pupose and to work together. In terms of software and a regular computer, SAC is the only 'virtual mixer' program I know of that is specifically intended for live sound applications. And even that requires what is pretty much a dedicated computer configured specifically for that use.


I once had a university administrator remind an instructor that it was not their classroom, it was simply the room they were assigned for that semester, and I think that general concept of having to differentiate what best serves an indivdual from what best serves the 'big picture' can often affect aspects such as computer based mixing systems. One thing I have noted with both experience and other discussions regarding using computers in general or SAC in particular for mixing is that some aspects that are not problems for personal use, and may actually be seen as advantages, may be have a different persepctive in institutional use. For example:


Who purchases and owns any plug-ins? Not all plug-ins are free, many require registration and some may even require a dongle, so how do you deal with the procurement, licensing and controlling what is loaded?

What do you do if something does not work? You can't take it to the dealer or the manufacturer since you have a multitude of different hardware and software involved. And related to that, how does an audio system Contractor or other contracted provider procure and support something that is a system unto itself and that users will intentionally constantly modify?
How does this fit into any computer/IT policies? I've seen schools and corporations that will not allow anything other than 'standard' machines and prohibit third party software they do not approve and load. And what happens in regards to updates, upgrades, replacement, etc. for the computer?
What happens if the person that put everything together and may be the only one that knows your system leaves? With a digital console and even to some dgree with SAC there is direct manufacturer and/or community support related to live sound applications, but a custom 'one off' system may not have a strong level of support, training resources, etc. and rely heavily on an individual.
Is on screen computer control of everything acceptable? Will you have applications or users where some sort of physical user interface beyond a screen and mouse is desired? And taking that a step further...
Is rider acceptance, familiarity of use for outside users or any similar considerations a factor? A custom, DIY system may be a benefit for personal use since you can form it to your personal approach and preferences, however it may not be the best thing in terms of acceptance or use by other parties. Anything tailored to a specific individual or application can become less effective for other users and applications.

The basic point is that I see custom computer based mixing systems being a better option where you have a limited number of users and some continuity of users, but perhaps having a number of challenges in many institutional and corporate applications.


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## TJCornish

GrantHughes said:


> Although there are some videos on the internet, none of them seem to quite accomplish this task.
> 
> Here's what I'm thinking. I would like to not use a mixer of any form (no USB mixers). I would like to have several channels going into my computer in a way that allows my computer to recognize them as seperate. I would, then, like to use Logic as the mixer. Then I would like to use an XLR for output into the House Speakers.
> 
> If there is anything out of this that I'm willing to sacrifice, it would be, in order:
> 
> I am willing to use a USB mixer if it doesn't somehow conflict with my overall goal.
> *[*]I am partially accepting of not having seperated sound input. (If it all just melted together as one sound input)*
> I will not sacrifice using Logic (because the whole point is to use my computer)
> I will not sacrifice using XLR output to House (because, once again, that's the whole point)
> So, is this possible, then?



You're not mixing if you are willing to just sum all the inputs together. Individual channels need individual mute control, EQ, and if possible, individual dynamics processing. Merging all that together defeats the whole purpose.

Reasonable multi-IO interfaces to your computer are not all that much cheaper than low-end digital mixers like the Presonus Studiolives (though the Studiolive isn't great for use of scenes due to audio cutouts when scenes are changed) or the Yamaha 01v96, and as others have stated, live audio on a computer can be challenging to say the least.


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## FMEng

GrantHughes said:


> I want to continue to do sound further through my career, but I have had no teacher of any sort. I know literally no one more educated about sound than myself. Thus, I have little understand/ability. Although I have been quite successful this far, I am wanting to find out the other ways that I can do things so that I'm not locked into one way that I actually understand.



You'll learn more by doing the job with the available equipment. Shows have been successfully mixed for decades on analog consoles without computers. The trick is learning to use all of the console's capabilities efficiently, and organizing yourself with cue lists that work well for you. If you continue, you will get experience with more and different systems.

If live mixing with a computer were effective and affordable, I can guarantee that there would be several manufacturers filling the void. The fact that this isn't being done more should be a strong hint. At this point, only Mackie is offering an iPad based console, with a limited number of channels, and it is intended for small bands to mix from stage. It uses dedicated, DSP hardware to handle the audio, with the iPad just acting as a control interface.


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## BobHealey

SoundMan will do some, but not all of what you want. Its built around playing back a cue stack, but it can handle routing inputs to outputs and similar. Definitely not designed for real time control however.


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## Altman364

I've put some serious thought into the aspect of a computer as a sound mixer and I definitely see the possibilities. (Thus I'm replying to this old thread)
I've been thinking about experimenting and trying to do it myself because the next production I'm doing requires complex sound mixing yet I (currently the only person capable of doing good live sound mixing) can't be behind the board. My idea was to make a very simple cue based system that any person could run just by clicking at the right time, using digital effects to do all the true hard work. 
As to answer the original question: 
In my case my school has a ton of these USB-RCA interfaces lying around, each has an input and an output
Behringer: U-CONTROL UCA202
I would just get a USB hub and there we go. 

Now I assume there could be lag issues and what not but I'm going to test it out on my own and see how it works. They sell devices specifically for what you are trying to do, this is just what I had at hand.

This one looks much nicer: Behringer: FIREPOWER FCA1616


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## avkid

Altman364 said:


> This one looks much nicer: Behringer: FIREPOWER FCA1616


 Very nice for $250!


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## museav

Altman364 said:


> I've put some serious thought into the aspect of a computer as a sound mixer and I definitely see the possibilities. (Thus I'm replying to this old thread)
> I've been thinking about experimenting and trying to do it myself because the next production I'm doing requires complex sound mixing yet I (currently the only person capable of doing good live sound mixing) can't be behind the board. My idea was to make a very simple cue based system that any person could run just by clicking at the right time, using digital effects to do all the true hard work.


You might want to look at EXPERIMENTAL. Charlie has been offering computer based and/or computer controlled audio and show control going back to COMMAND/CUE running on Amiga PCs. Many of my college mixing experiences were on a Richmond Sound Design 816 console with AutoPan.


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## ykanjee

depending on the budget and other pieces of equipment, such as speakers, etc.; you might want to look into audiaflex. you can have up to 64/64 IO per audiaflex. you can also either run them on cobranet or without the cobranet module. 
you can also create your own dsp on a per channel basis. 

the only catch is that you have to develop your own UI using davinci.


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## DuckJordan

ykanjee said:


> depending on the budget and other pieces of equipment, such as speakers, etc.; you might want to look into audiaflex. you can have up to 64/64 IO per audiaflex. you can also either run them on cobranet or without the cobranet module.
> you can also create your own dsp on a per channel basis.
> 
> the only catch is that you have to develop your own UI using davinci.



which the only catch with davinci is the fact it was never intended to be used as a live mixer. We have it installed at the convention center and it is a pain to do on the fly mixing.


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## museav

DuckJordan said:


> which the only catch with davinci is the fact it was never intended to be used as a live mixer. We have it installed at the convention center and it is a pain to do on the fly mixing.


At one time there was a company in Australia that created a physical user interface for a mixer that could then be used with several various matrix DSP boxes but that company seems to have taken that concept in a different direction.

One factor in any UI developed for pointing devices like a mouse is that many of them only allow one physical operation at a time. You may be able to create a DCA or group controls but you may not be able to adjust multiple controls simultaneously. Adjusting multiple controls at once, adjusting or being prepared to adjust controls by feel, rotary controls and detents are aspects of physical controls where I find pointing or touchscreen devices lacking and I don't see fixes for some of those. That and the person who noted that at one event their mixer was responding to flies landing on the connected iPad.


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## macwhiz

avkid said:


> Very nice for $250!



Yes, but its 16 in 16 out, whereas the UCA202 is 2 in 2 out for $25 and the Firepower is also Firewire, so there would be less latency than USB


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## museav

macwhiz said:


> Yes, but its 16 in 16 out, whereas the UCA202 is 2 in 2 out for $25 and the Firepower is also Firewire, so there would be less latency than USB


Which versions of USB and FireWire are you comparing? How does any difference in latency inherent in USB versus FireWire compare to the latency related to the specific interface and its drivers, the bit depth and sample rate settings, the hard drive/computer and the processing itself? Simply saying that there are likely to be a number of factors in the latency experienced with either product other than just their being FireWire or USB.

The I/O seems to be one of those cases where 16x16 versus 2x2 could be a significant advantage if you might ever need or want more than two in and/or two out, but otherwise might be irrelevant. A bit like when people compare audio mixers and address one having more inputs, outputs, aux sends, etc., a comparison that can be significant if it represents some benefit in actual use but a bit pointless or perhaps even representing a disadvantage if it is comparing numbers that aren't really relevant to the intended use.


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## Chris15

Altman364 said:


> In my case my school has a ton of these USB-RCA interfaces lying around, each has an input and an output
> Behringer: U-CONTROL UCA202
> I would just get a USB hub and there we go.



And you would be going into a world of clocking pain...
As each one would be doing its own thing for clocking, you'd either need to source rate convert everything (if you can do so in the software world - it will be resource intensive) which WILL add non trivial latency or you end up with the clicks and pops we all know and love when digital goes out of clock...


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