The decision to purchase a FireWire® recording interface should not be taken lightly. You can easily spend your savings on a single device and end up with an interface that isn't right for your recording needs. To choose the right FireWire® recording interface, search for an interface that is compatible with your computer, provides enough inputs and outputs and has the correct bit depth and sampling rate for your recording purposes. You also should make a list of additional features that might speed up the recording process, such as onboard effects and mixing controls.
FireWire® is available in two forms: Firewire® 400, which transmits data at 400 megabits per second, and FireWire® 800, which transmits data at 800 megabits per second. Different types of FireWire® connectors are used for each form, so you should choose a device that provides a connector that is compatible with your computer's FireWire® port. You also should choose a FireWire® recording interface that is compatible with your operating system and your computer's hardware specifications, such as its processor speed and the amount of random access memory (RAM).
The number of inputs and outputs on a FireWire® recording interface can range from a single input channel and stereo output to more than 16 input channels and 16 outputs. To choose the correct number of inputs and outputs for your recording sessions, make a list of every instrument, including vocals, that you plan on recording simultaneously. You also should write down the number of microphones that you use to capture the sound from each instrument. To select the correct number of outputs, think about how you mix your music. If you want to route the sound that's being captured to external hardware effects and monitor the sound, you need a minimum of three output channels.
In addition to choosing the right number of inputs and outputs on a FireWire® recording interface, you need to select the right types of inputs and outputs. If you record condenser microphones, for instance, an interface with XLR inputs and onboard phantom power will provide your microphone with power and compatible connectors. The output connectors should be compatible with your monitoring speakers and the external hardware to which you route sound. Most interfaces provide 0.25-inch (0.64-cm) tip, ring, sleeve (TRS) outputs, and some provide XLR outputs or a combination of TRS and XLR outputs.
The technical specifications for each recording device lists the audio sampling rate and bit depth used while recording. The sampling rate and bit depth affect the quality of the audio as it is recorded. If you are producing professional-quality recordings for sale, you should purchase a FireWire® recording interface that records 24-bit/96-kilohertz (kHz) sound or better. To produce demos or live recordings, 16-bit/44.1 kHz works well.
Some audio interfaces provide onboard effects, such as reverberation and chorus effects, and hardware mixing controls, such as faders and knobs for controlling your audio-recording software and recording volume. In general, affordable or cheap units that provide a variety of effects do not provide the same audio quality as similarly priced units without effects. Units that provide hardware mixing controls generally cost more than audio interfaces that do not include them, but if you need to manipulate the audio levels and software controls while recording, mixing controls can help you manipulate the sound more quickly. Alternatively, you can use a musical instrument digital interface (MIDI) controller to perform these functions.