In order to be clear, let me define what we're comparing here. On one hand, we have the specialized film mixing consoles from such companies as Neve, SSL and Harrison as well as numerous other smaller manufacturers and on the other hand, we have the Pro Tools system on a high-end PowerMac G4 computer with a large number of DSP cards in a rack mounted Chassis connected to the ProControl user interface via Ethernet. Pro Tools would be connected to a Film Monitoring Matrix such as the Otari PicMix and would also likely have a multi-format audio interface giving AES/EBU, ADAT and TDIF inputs and outputs in any combination and with built-in sample rate conversion.

Capability
Capability is undoubtedly the most important factor to consider. Can the system do the job? And the answer for both alternatives is a resounding yes. Obviously large format film mixing consoles can mix feature films because they have mixed hundreds of films over the years so that is not in question.

Can the Pro Tools system mix a feature film? The answer here too is a yes because Pro Tools has already been used to pre-mix and mix numerous feature films including the Oscar Award winning Traffic. Other notable films mixed on Pro Tools include Dancer in the Dark, Lagaan, Dil Chata Hai and Nayak.

When we talk of capabilities, let us define what is needed to mix a feature film as opposed to any other type of mixing. Then we can see if Pro Tools has the required capabilities. Thus, the argument can be reduced to one of logic and the answer, to one of undeniable fact.

The first capability one needs is a large number of audio tracks for each of the parts of a film sound track.
For dialogue which is usually the simplest part of the sound track though often the most important, one needs between 8 to 16 tracks. Fortunately, only 2-3 tracks will be active or contain sounds at any one time and one needs the larger number of tracks in order to logically separate different characters which might each need separate acoustic treatment such as equalization, reverberation and panning. Almost any Indian feature film requires less than 8 tracks of dialogue.

Songs and Background Score usually require the most number of audio tracks, between 16 for the simpler scores to over a hundred tracks for the more complex songs. Fortunately, here again there is unlikely to be actual sound in more than half the available tracks - and even that is very unlikely - and the larger number of tracks required is more due to alternative takes of a performance and the need to keep different instruments on different tracks due to varying processing requirements.

Sound effects and ambiences usually need a significant number of tracks, between 8 to 32 for sound effects and between 8 to 24 for ambiences. Sound effects including foley and CD based library sounds are also like music and dialogue in that they are not present continuously but may still have tracks reserved exclusively for them. Ambiences however are different. Since ambience sounds are by nature continuous, most of the tracks reserved for ambiences will likely have audio content all the time.

During pre-mixing, the mixing console or mixing system must be capable of handling the largest number of tracks expected at any time. Thus a conventional music pre-mixing console may need a hundred input channels or more.

Pro Tools can have 64 internal tracks and up to 72 external inputs and outputs right now, though this number continues to go up with advancing technology. One key fact is that the 64 internal tracks of Pro Tools refers only to active tracks. Thus, tracks with no sound present do not matter at all on Pro Tools system. And another incredible advantage in the Pro Tools is that alternative versions of a sound do not need to occupy extra tracks. Each track in Pro Tools can have any number of alternatives hidden beneath the current version! This is why Pro Tools is perfectly capable of pre-mixing even the most complex musical scores and indeed has been used on the top music albums and film scores worldwide. It is widely acknowledged that Pro Tools is simply the best method of recording and mixing music today.

Dialogue pre-mixes are easy on Pro Tools as well but it is in effects mixing that the system really shines. The kind of mixing required for complex effects oriented action films is best done on a computerized system such as Pro Tools. Mixing automation is discussed in greater detail in a later section of this article.

Another important requirement for a feature film mixing console is the patching and routing capability.
There are two methods of routing employed in mixing consoles. The first is the simplest and most commonly found option - the Patch Bay. Patch Bays are nothing more than a large number of high quality connectors carrying audio. Short Patch Cables are used to route the audio from one connector to any other. This is simple technology and causes no audio degradation. Unfortunately, what is missing here is automatic routing recall. To move from one complex routing setup to another using a Patch Bay requires extensive notes and a large amount of manual labour!

An alternative method of routing is an automated system that routes audio from one connector to another. In the analog world, such a routing system would invariably cause some small loss of quality but in the digital world, this is entirely lossless and has all the advantages of a Patch Bay with the additional benefit of automated recall and stored setups. Thus, moving from one type of job to another could be as simple as recalling the right setup on the routing matrix.

While large format consoles employ one method or another and charge large amounts of money for automated routing capability, being a computer-based system Pro Tools has extensive routing and patching capabilities right out of the box. Any input on Pro Tools can be routed to any channel on the internal mixer and similarly, any insert point on a channel can be routed to and from any existing inputs and outputs.

Not only are these routing setups automatically saved in Pro Tools, they also become an integral part of the project you are working on. Thus, if you recall a certain project you were working on last year, the system will bring up all the input, output and insert patching exactly as it was when you last saved it.

That makes it even better than a mixing console where you might have to separately recall the routing setup or even manually patch the audio.

One more important requirement for mixing movies is a large number of busses.
Busses in a mixing console are used for various purposes such as the individual channels of a 5.1 channel mix, for sending various signals to a reverb unit, etc. Having at least 8 busses is essential to do a film mix but for any serious work, you would probably need many more.

Pro Tools can be configured on a project-by-project basis with as many busses as required for the project subject to a maximum of 64 busses. Even the most complex project won't require that many so we can safely conclude that Pro Tools meets that requirement.

Conventional consoles must usually be purchased with the maximum number of busses that one expects to need over the life of the console though with more digital technology, some amount of flexibility in the number of busses and their configuration is coming even to the more expensive conventional consoles.

On the whole, Pro Tools certainly scores on this front as it has these capabilities built right in.

The next requirement for a film mixing console is the monitoring matrix.
Feature film mixing is greatly aided by having a well thought out surround sound monitoring matrix. A monitoring matrix would allow you to solo or mute individual channels of a multi-channel mix so that you can instantly check just the surrounds or the center channel without actually making any changes to the mix.

You can also listen to one pre-mix as a reference while you are mixing another. Effects and music pre-mixes are best done listening to the dialogue pre-mix as a reference as that helps you set a consistent level for other sounds in the mix. A monitoring matrix should make such operations simple. Of course, you should also be able to isolate the pre-mix you are working on from the reference pre-mix at any time to check something.

Finally, the monitoring matrix would also let you select the reference level you are listening to. 85dB is the reference level adopted by the various film sound formats but during mixing, the mix engineer and the director often need to check their mixes at higher and lower levels for creative and commercial reasons. A monitor matrix would allow this to be done accurately and perhaps with digital calibration.

Like many other conventional consoles, Pro Tools would need to use a third-party monitor matrix. Such devices are made by several manufacturers with Otari's PicMix being one of the most sophisticated and popular products.

While many of the top console manufacturers each integrate their consoles with their own film matrix, there is no specific advantage in this. A monitor matrix has a defined set of functions and should necessarily be installed in the audio chain after the mix console. Thus, having an Otari PicMix or its equivalent gives Pro Tools all the film sound monitoring functions that one might desire.

Mix Automation
The capabilities of the automation system truly define what you can and cannot do with a mixing console. The automation system is meant to remember the mix engineer's every move so that once a control has been moved and the action recorded, every time you play the same part of the picture, the mixing console will automatically re-create the move.

For example, on a conventional mixing console, one can make a mixing move such as a pan or a level change by moving the appropriate knob at the moment when we require this change. The automation system records every such move when it is in the record mode and during the next pass, the computer will make this move for you while you make other moves. This makes it possible for one person to build up a complex mix bit-by-bit.

Finally, when the mix sounds approximately correct, the mix engineer can begin to fine tune the mix and make small but important changes to levels or other parameters. With this iterative process, one can finally hope to achieve perfection in the mix.

While almost any mixing console used for a film mix today would have automation, several factors distinguish the different automation systems used. The important comparison points are the ease of use, the parameters that can be automated in each system and the automation editing capabilities that are available.

Ease of use often depends on the user's background and point of view. In the past, computer based systems were considered difficult to use simply because audio engineers were not really computer savvy. This is still true of an older generation of audio engineers but few people today can avoid computers or in fact resist the many compelling applications that computers have.

All automation systems are therefore computer based though those attached to conventional mixing consoles might not be based on standard operating systems such as Windows or Mac OS but on proprietary operating systems. Pro Tools is of course available for both Windows and Macintosh computers and anyone with a knowledge of either of these systems and audio engineering would find the automation very intuitive and easy to learn.

What sets Pro Tools system apart from all the others is the number of parameters that can be automated dynamically. On the Pro Tools, one can automate all the usual parameters such as level, surround pan, aux send levels, etc. as well as every other parameter that one is likely to need such as EQ, dynamics, reverb parameters, pitch-shift, etc.

Why would this be useful? Let's say the director wants a little more expression in one dialogue during the final mix. Does one stop and call in the artists to redo that line? No! One simply adds a little inflection by pitch-shifting the dialogue under the precise control of the automation system! You wouldn't even dream of trying this trick without automation.

The Digidesign Pro Control console has several dedicated buttons that choose the automation mode of each channel, i.e. the Read, Write and Update modes. This is exactly the same on any conventional console automation system. Since the Pro Control faders are touch-sensitive, the update and write modes can be triggered automatically by touching the faders that one wishes to manipulate. This is certainly the most intuitive method of working on the system.

But the Pro Tools system also provides an incredible level of power on-screen. Any or all of the automated parameters can be seen on screen as a set of keyframed levels. Each keyframe can be selected individually or in a group across a region of time and manipulated as desired to achieve perfection. For example, one could work in such fine detail as to select the start of a level change and move it a tenth of a frame forward or one could select all the keyframes during a scene and reduce or increase them all by a relative amount.

One can also copy, cut and paste automation moves between channels and between clips so a perfect automation move from one place could simply and easily be replicated across to several other places. And best of all, automation data is also tied to clips within the system so if one should move a sound within Pro Tools, one can also have the automation moves on that track move along with the sound to its new location.

This reduces the amount of work you have to do to make a change in the last minute. For example, let's take the case of the sound of a passing airplane in the background behind a dialogue. Let's assume the engineer has already made the level changes necessary to sound like the plane is passing overhead. If during the final mix, the director suggests that the plane's sound be moved just a bit later to prevent any interference with the dialogue. On a conventional system, one would have to move the plane's sound on the audio workstation, then cut and move the fader moves on the console's mix automation system.

Instead on the Pro Tools, one can just move the sound clip and all of the associated automation moves will automatically follow! Thus, the system makes it a pleasure to experiment and make changes even in the last minute and after all, this is what improves the creative quality of a sound track.

The Mixing Surface
The features of the mixing surface are extremely important to the mix engineer as he or she will have to spend many hours working on it. The quality and "feel" of the faders are also of the highest importance, especially when the faders are motorized. Motorized faders are usually touch-sensitive so that the motors disengage and the faders respond to any manual changes the instant they are touched by a finger.

The ProControl employs high quality touch-sensitive motorized DigiFaders™ based on patented optical technology. These 100mm, 10-bit faders have a much longer life and a better feel than most conventional faders. With 10 bits of precision, we get 1024 levels which the system interpolates to 24-bit precision. The ProControl's faders respond instantly to touch and move effortlessly, making them a pleasure to use.

The ProControl is purely a control surface for the Pro Tools system and no audio needs to enter the system at all. All audio is processed in the digital domain within the computer and its DSP boards with the ProControl system being connected to the computer only through Ethernet. The use of Ethernet allows the ProControl system to be placed as far as necessary from the computer with no penalty on quality or ease of operation.

The use of Ethernet also allows a great deal of expandability with multiple ProControl Fader packs and the ProControl Edit Pack all connected to an Ethernet hub and the hub being connected to the CPU.

The amazing fact is that the audio level meters on the ProControl and the scribble strips on the console are all computer controlled. In fact, the scribble strips even feature an automatically abbreviated version of the track name from the Pro Tools software thus making the faders very easy to identify. There are multiple knobs as well on the ProControl system for pan, aux levels, EQ, dynamics and other functions. The legends below these knobs change to reflect their function.

The ProControl Edit Pack also features two high quality motorized touch-sensitive DigiPanner™ joysticks and eight high precision 40-segment master level meters along with a dedicated, colour coded keyboard and other function buttons.

As you can see, ProControl combines the speed and ease of use of hand-on control with the flexibility and total recall of Pro Tools software, giving you capabilities way beyond any other analog or digital console.

Signal Processing and Sound Quality
The sound quality of any digital system is dependent on just a few factors unlike analog systems where hundreds of factors from circuit design down to the selection of individual components like resistors and capacitors will affect the output.

Basically, the factors that affect the sound quality of a digital audio system are the Analog-to-Digital and Digital-to-Analog conversion quality, the precision of the internal mathematics used for audio calculations and digital mixing and the algorithms or processes used to perform such operations as EQ and dynamics.

We can therefore compare Pro Tools in each of these key areas with high-end digital mixing consoles to arrive at an answer to the question of whether there is any difference in sound quality between these systems and if one or the other actually "sounds" better.

A/D and D/A conversion is most definitely a key area that affects the sound quality of a digital system. Naturally, during the course of mixing a feature film, there may not actually be much need for A/D or D/A conversion these days owing to the fact that more and more material is brought on digital formats to the mix and any audio engineer worth his or her salt would try to preserve these sources in the digital domain and avoid unnecessary conversions.

Pro Tools has several I/O options with varying levels of quality. The fortunate thing is that even the most economical option available for Pro Tools uses high quality 20-bit A/D and D/A conversion. However, given the fact that we're comparing Pro Tools with consoles that probably cost many times more, we can safely compare just the high end converter choices. These are the Digidesign 888/24 I/O and the Apogee AD-8000. While both are excellent 24-bit converters, there are some who simply love the wonderful conversion quality of the Apogees with their patented soft-limit feature and rich, transparent sound. There is simply no doubt that no off-the-shelf mixing console's conversion would measure up to an Apogee in quality.

Internally, Pro Tools uses 48-bit fixed point precision in the mix buss. This is better than or equal to most of the top consoles out there. Having a greater bit precision allows many more signals to be mixed together without overloading a system and also allows audio track levels to be boosted significantly without distortion. Suffice it to say that one would be more than happy with the quality of the Pro Tools mixer!

That brings us to the algorithms used for EQ, dynamics and other DSP (Digital Signal Processing) functions within the system. Rather than define what sounds good for these operations which is something of an impossible task on paper, let's approach this from another point of view.

Suppose we ask all the respected audio engineers on planet Earth which EQ they like the most, what answer would we get? Suppose we asked these same engineers which compressor they liked the most, which system would they choose? Well, I can't possibly answer for all the audio engineers out there, especially since there are likely to be so many different opinions! But one thing is very certain: Focusrite and Drawmer will be names that figure very often indeed. Now, these very same highly respected manufacturers make software versions of their products for the Pro Tools system as Plug-ins.

So, on Pro Tools and on Pro Tools alone, you could fit every channel of your console with a Focusrite EQ and with a Focusrite or Drawmer compressor/limitor. And best of all, you could do this by spending just a small amount of money buying one plug-in of each type. You couldn't ever afford that if you bought a Focusrite unit for every channel on your conventional mixing console. Not if you wanted to ever hope to build a financially viable studio at least!

Pardon my over-enthusiasm here but the fact is that the single greatest feature of Pro Tools is its plug-in architecture and the more than hundred respected third-party suppliers who make these TDM Plug-ins for Pro Tools.

While I've mentioned just a couple of names here, believe me there are many, many wonderful plug-ins out there, each performing a unique and innovative job. You can't get that at any cost on other systems.

...and listening tests demonstrate they sound the same.
In an attempt to resolve an argument from some prospective customers that "Pro Tools changes the sound", Digidesign engineering staff travelled to New York to perform listening tests at the studio of Mick Guzauski, one of the most popular and successful producer/mix engineers in the industry. Recent clients of his include Mariah Carey, Toni Braxton, Christina Aguilera, Paula Cole, LeAnn Rimes, Brandy, Monica, Back Street Boys, Jennifer Lopez, Eric Clapton, Will Smith, Kirk Franklin, Boyz II Men, etc. Mick is up for the Grammy award for audio engineering this year.

Identical 24-track mixes were created on his very expensive Sony Oxford console and within Pro Tools with faders at various positions, and also using extended Aux sub-mixing within Pro Tools.

During over ten hours of blind listening tests, Mick, his assistant engineer and Digidesign staff could not reliably distinguish between his Oxford console and Pro Tools playing the same mix; everyone guessed wrong as often as they guessed right.

To reinforce this point, when the Pro Tools mix and the Oxford mix of the same material were combined and the polarity (phase) inverted, the signals completely audibly cancelled; even when the monitors were cranked to their maximum gain, no signal was heard. Complete technical details are posted on the Digidesign website user conference at www.digidesign.com.

The bottom line is confidence in Pro Tools' ability to deliver excellent mixing capabilities and audio quality today, and to get real-world projects done with incredible price/performance.

Surround Features
The Pro Tools software has a powerful surround mixer built into it. Not only can the system mix all existing surround formats such as LCRS, DTS, Dolby Stereo, Dolby Digital and SDDS but it can even mix to multiple of these formats at the same time.

Let me explain this a bit more. The Pro Tools software allows you to define each channel of the mixer as a multi-channel track with LR, LCR, LCRS, 5.1 or even 7.1 stems. And one can create multiple surround busses with signals from each channel going to one or more of these surround busses.

Thus, one could have a 5.1 master buss and a LCRS master buss with all the source channels going to both these busses. So when you do your 5.1 mix, you're automatically also feeding your LCRS mix. Powerful isn't it?

Every channel also has a surround panner built right in. And this is no ordinary panner. It is a high-precision graphical on-screen panner which is of course fully automated and has a number of parameters that allow you to perform the most exotic of panning moves. And where tactile control is necessary, the two motorized joysticks on the Edit Pack can be assigned to any of the channels.

Compare the Pro Tools surround features to conventional consoles and you might well find the latter lacking!

Speed
There's no doubt that there is a learning curve attached to a computer based system for older mix engineers who haven't had the benefit of having been reared on a staple diet of bits and bytes. The ProControl system was designed precisely to solve that problem. It instantly takes away the computer from Pro Tools!

Within a few days and certainly by the second film, any quick witted mix engineer will be flying with the Pro Tools system. And he'll wonder if there ever was a better way to do the job.

ProControl looks like a conventional console, performs like a conventional console and feels like a conventional console but its best feature is that it still lets you unleash all of the power of the computer within.

But again, there's no way to prove this point unless you've had the pleasure of working on the system yourself...

Upgradability
The best thing about computers and software is that they're always upgradable. With nothing else can you just spend a little more and get this year's new and improved model… how many times have you bought that expensive little gadget only to find out there's a wonderful new version just out that can do all of those additional things you're dying to have.

With Pro Tools, software upgrades have always been very reasonably priced, usually in the region of about $200-$300. And hardware upgrades are very reasonable as well. Given the low cost of the system already, there's no excuse not to take advantage of the latest and greatest as soon as it's out.

Now, just try that with a conventional console. The key here is not just the purchase price of a system but the much talked about total cost of ownership over a period of time. With that factored in, the Pro Tools is bound to look even more attractive.

Sure, the digital consoles available today probably have software upgrades too but they're unlikely to improve the product too much. Perhaps, they'll add a feature here, improve another feature there but moving the older console a generation forward with a software upgrade isn't something you should hold your breath waiting for. And hardware upgrades on conventional consoles can cost an arm and a leg…

The Prestige Factor
There's one final argument that you'll surely hear from the large console manufacturers. It's their last ditch, desperate defense and it's a pathetic one at that so I'm addressing it last.

Wouldn't you rather fly than take the train they'll ask... Wouldn't you rather have a Rolls Royce they'll ask...

With all due respect, let's get that analogy right. Pro Tools is a hot-rod sports car and that's what today's creators would rather have. Leave that gleaming Rolls spotlessly clean in the garage and drive the sexy sports car that grips the road and responds to your slightest touch.

But more practically, the fact is that in the Indian industry at least, no one really cares about the console you have. It's just the audio engineers who even know the difference between one console and another... and they would be hooked onto Pro Tools if they got to use it on just one project.

As for producers and directors, they only want a fast, flexible, high-quality system and we've already seen how Pro Tools is all that and more.

But if you want even more of a prestige factor, consider the fact that within just three months of Media Artists commissioning its Pro Tools based studio, some of India's most prestigious films released during this period have used the system for the mix. And the producers, directors and the audiences have been very pleased with the results indeed!

Oh, did I remember to mention that a 48-fader ProControl system looks very impressive too.

Conclusion
I know this has been a rather long article and if you've read this far, you're really trying to understand the issues involved in choosing between Pro Tools with ProControl and a conventional mixing console. Let me therefore diverge a bit, then leave you with a thought...

In 1986, when Media Artists began to use ¼" 8-track tapes locked by timecode to film in order to record dialogue, there was a lot of skepticism. How could that tiny tape sound anything like 35mm mag, people asked. How could you get sync without sprocket holes on the tape people asked. It'll slip is what they said. But the actors who dubbed on the system found it fast and efficient and best of all, they loved the sound quality. That 8-track recorder from Fostex cost less than the head block of a 35mm 4-track recorder but it used low cost consumer-oriented, mass-produced technology to achieve its low price and relatively high quality. Timecode is now used freely all over the country without a second thought... and 35mm mag never did recover from that first blow.

In 1993, when Real Image first introduced non-linear editing to the Indian film world, it was a difficult task. It was hard at first to get film editors who had never used computers to learn the Avid Media Composer and then to begin to appreciate the power and flexibility it brought to them as creators. Today, there's no doubt about the best way to edit a feature film.

This is a very apt example indeed because the exact same non-linear power that Avid gave to the editor is what Pro Tools gives to the sound engineer. I could give you a few more examples but I think you'll surely have got the point by now.

And now for that thought I said I'd leave you with...

Can you see the future?