What is this and why is it important?

The maximum frequency for a project is one-half the sample rate. The sample rate for a commercial CD is 44.1 kHz, but higher sample rates are frequently used in projects. All sample rate support is dependent on the capabilities of your audio interface.

Bit depth determines the dynamic range of a project or session.  The standard bit depth for a commercial CD is 16 bits which produces a stereo dynamic range of 96 db, but higher bit depths are frequently used in projects.

Dither is used when going from a higher to a lower bit depth.  Using dither adds a small amount of noise to the signal, but prevents distortion at low amplitude levels that is caused by truncating the extra bits.  POW-r and Apogee UV22 are generally considered to produce better results than the more common Gaussian, triangular, and rectangular dithering algorithms.

A stereo pan law controls how the volume of a track changes as it is panned from center to either left or right.  In order to keep the perceived volume constant, the db level must increase.

Track formats that are interchangeable  between mono and stereo increase your flexibility in a project.

Freezing a track creates an additional audio track with all of the plug-in FX and other dynamic processing applied.  This function is useful for conserving CPU processing.

Most products have a list of preferred audio cards at their website.  However, they generally attempt to support most audio interfaces.  Pro Tools continues to hold to the philosophy of support only specific audio interfaces.

Both ASIO and WDM drivers can be configured for low latency.  Most professional audio interfaces are supplied with both types of drivers.

What is this and why is it important?

Editing is primarily cut, copy, paste, trim and join functions.  Products differ in philosophy as to whether they provide separate windows for editing or whether editing is accomplished in the track timeline window.  We have made no judgment here as to whether one approach is better than the other.

Fades are used to gradually increase or decrease the volume of a clip.  You can also specify the shape of the fade curves which control how fast the volume fades up or down.

There are several standards for FX plug-ins, all of which are proprietary.  VST is probably the most widely accepted.

Mixing plug-ins are largely FX such as reverb, chorus, flanging, compression, etc.  Several products add value to their offering with high quality third-party plug-ins.  However, a comprehensive rating of these plug-ins is beyond the scope of this analysis.

Mastering plug-ins are identified separately.  Several products include basic mastering plug-ins such as multiband EQ, multiband compression, and limiting.

Batch processing editing includes such functions as normalizing, fades, time stretching, gain, and DC offset removal.  Note also that in all products (except Acid which doesn't offer batch processing) FX plug-ins can be applied in batch.  While most products focus on real-time processing, batch processing can be useful for several reasons:  (1) Your CPU utilization can be reduced during playback; (2) Some batch processing functions, particularly time stretching and pitch shifting, can produce higher quality results; (3) You may want to permanently alter a file with such changes as normalizing or gain if you intend to use it in multiple projects.

A spectrum analyzer show the frequency distribution of amplitude levels for a given slice of audio.  This function can be very useful in confirming EQ and compression levels in mixing and mastering.

What is this and why is it important?

Although the implementation varies considerably, all products have a separate window that is intended to emulate a hardware mixing console. 

Although the details vary, in all products you can route tracks to buses and main outputs and buses to buses and main outputs.   This gives you the flexibility of creating several levels of submixes.

Inserts provide the capability of applying FX in series with the audio signal.  They are typically used for FX such as compression and EQ.

Sends  replicate the audio signal so that FX can be applied in parallel.  They are typically used for FX such as reverb, flanging as well as applying side-chain effects.

Sidechain features provide the ability to control the action of one FX plug-in on a track or bus based on audio input from a different track.  Typically sidechain features are provided for gates and compressors and can be used to control drum pumping or voice ducking as well as special Electronica effects.

Some plug-ins can introduce considerable latency in the audio signal.  Plug-in delay compensation refers to the ability to automatically compensate for this delay so that all tracks are in sync.

External FX integration is the capability of routing a bus directly to and from an external hardware FX processor.

Multiband EQ is available for all products.  Since applying EQ is very common, building EQ directly into a track or bus strip is more convenient.

What is this and why is it important?

Most music production software products support a variety of audio file types for both import and export.  Export in this category refers only to lossless files.  MP3 is rated separately.

CD ripping means creating a computer audio file (usually wav) from a CD audio track.

Because of the small file size, MP3 is a popular format for sharing files in the Internet.  Some products charge a license fee for an MP3 converter.

Open Media Framework is a format that allows you to share projects among music production software.  So, for example, you could export a Pro Tools session in OMF and import it into Sonar or Cubase.

This function refers to means that an audio folder can be automatically created and maintained with the audio files that you use in a project.  Normally you have an option to copy your original track files to the folder and any recording or batch processing changes will be stored in the folder.

There may be good reasons not to copy your original audio files to a project audio folder.  For example, the file may be part of a library or there may be a large number of files or large files that you are maintaining on offline media.  A Project Logical Folder allows you to view and manipulate all the original audio files for a project no matter where they are physically located.

The may be times where you will need to transfer a project to another computer, another person, or different media.  All of these products have the facility to collect and transfer all project assets, not just the project or session file.  In addition some products have the capability of bundling the entire project into a single file for transfer.

Fast Bounce is the capability of exporting to a file in significantly less time than is required to play back the material to be exported. 

A Logical Library functions means that the product can create and maintain a logical grouping of audio files, for example, kick drums, that is separate from any project or session.

Metadata refers to maintaining additional data about an audio file such as author, copyright, engineer, notes, etc.  As used here it is different from "Acidized" metadata which is discussed in the Loops & Remix category.  The data can be stored either as part of the file or in a separate database.

It is common when recording or editing a project to create a number of internal project files which may or may not be used in the final version.  Thus there needs to be a function to identify files that are not used in a project.  Cleanup will be less of an issue in projects which use primarily dynamic processing, since no internal files are created.