User-Configurable Inputs and Outputs
Pro Tools systems put a new twist on the concept of inputs and outputs. As opposed to dedicated jacks on traditional recording consoles, they offer generic inputs and outputs that can be customised to meet your specific needs. The I/O jacks on the Digidesign Audio Interfaces function much the same way as the good old patch bay - they can be used as track inputs, outputs, inserts, effects sends and returns, or bus sends and tape returns. It's easy to configure the interface jacks the way you want within the Pro Tools software. By eliminating redundant connectors, we can use a smaller number of the highest quality Analog-to-Digital and Digital-to-Analog converters at a very reasonable cost. The real benefit of this generic I/O scheme is that you only need to invest in the amount of hardware that you need and this will vary depending on how you plan to use your system.

Integrated Digital Mixing
A lot of people choose to mix everything in Pro Tools and use software Plug-ins to help them do this. Plug-ins are mini software programs that provide additional processing capabilities for your system. These users may need a lot of tracks and processing power but they can often get by with just one audio interface that provides 8 channels of input and output. Others might want to use their existing mixer. Then they would need an output for every track, requiring multiple audio interfaces - up to three for a 24-bus mixing console. Most users would be somewhere in between - they use Pro Tools as the mixer along with outboard effects units like a vintage tube compressor or their favourite reverb unit. In this case, they can choose to add audio interfaces to get more connections for effects, sends and returns or inserts.

Pro Tools systems come with one of the worlds most sophisticated mixing consoles built-in. The Pro Tools | 24 Mix, for example, lets you build a mixer with over 100 channel strips, 5 mono/stereo aux sends per channel, 32 internal busses and 64 tracks of record/playback - an incredibly powerful environment that, with traditional hardware, would cost nearly a crore of Rupees. Of course Pro Tools systems are completely modular and can be customised to your needs. Besides the flexibility and power, the Pro Tools mixing environment offers several other advantages, including instant and total recall of every single mix parameter. That includes mutes, levels, pans, sends, returns as well as the parameters of the software Plug-ins. All these parameters are also fully automated. And thanks to the incredibly intuitive graphical user interface, anyone used to a traditional mixing console will be up and running with Pro Tools in no time.

Outboard vs. Internal Processing
Imagine if you could buy a mixing console and tape machine that had virtually unlimited potential for the future. By adding software, you could suddenly have a new reverb or a compressor on every channel, or more insert points, or more busses. Pro Tools' TDM- based mixing technology makes this vision a reality. Just like our open ended "generic I/O scheme," Pro Tools provides an endlessly powerful and modular signal-processing environment.

The Digidesign TDM Bus
The foundation of Pro Tools mixing capabilities is an open platform called the TDM Bus - a 24 bit, 256 channel "Data Highway" that gives you full-featured, versatile digital mixing and real time digital signal processing (DSP) capabilities. Basically, stated TDM is like having a patch bay that goes to every track, every input and output, every bus, effect send, return or insert... One of TDM's most significant benefits is that it gives you the ability to add your choice of over 100 optional, high quality, software-based TDM Plug-ins directly to your Pro Tools mixing environment.

DSP Farm and MIX Cards
These PCI computer cards are important hardware components of TDM technology and feature powerful DSP chips that handle mixing, as well as TDM Plug-in signal processing. Pro Tools | 24 comes standard with one DSP Farm (in addition to the d24 card, which provides the system's record and play back capabilities). Pro Tools | 24 MIX is a newer, single card system designed for the ultimate mixing and processing power. The MIX Core card provides both the system's engine and mixing and processing power, freeing up more PCI slots on the computer. Pro Tools | 24 MIXplus includes a MIX Core and MIX farm card for upto seven times the DSP power of the entry-level Pro Tools | 24. And if you really want to go crazy with real time processing and mixing, you can keep adding mix farm cards to any Pro Tools | 24 MIX system.

Audio Suite vs. TDM Plug-ins
Both Audio Suite and TDM are Plug-in specifications designed by Digidesign that give outside development partners the parameters they need to create solutions that work seamlessly within the Pro Tools software and hardware systems.

Audio Suite Plug-ins provide file based processing, meaning they process or alter the sound-file and create a new file with the processed sound. Audio Suite Plug-in work with the entire Pro Tools line up, because they use the computer to process the files and don't require a DSP farm.

TDM Plug-ins operate in real time, without altering the sound file. They actually function just like outboard gear, where the audio passes through an algorithm during playback. However, there are a number of advantages to using TDM effects over their outboard counterparts. First, you don't need to use messy patch cables. You simply open up an insert menu on any track, and the Plug-in window automatically opens for you to adjust its parameters. Second, your processing remains 100% digital within a 24-bit mixing environment (TDM), so the sound quality is exceptional. Third, the integration of TDM Plug-in with Pro Tools lets you enjoy full automation and total recall of all TDM Plug-in parameters. The automation capabilities go above and beyond what any hardware equivalent can offer, giving you the ability to review your movements visually and make adjustments to your movements quickly and easily.

Aside from the functional advantages of TDM Plug-ins, there are economic advantages as well. As long as you have enough DSP power, you can use any particular Plug-ins as many times and on as many different tracks as you want. Imagine the luxury of having a Focusrite or t.c. EQ on every single channel of your mixer!