An audio interface connects microphones, instruments and speakers to a computer. Choosing the right one starts with the way you record, rather than the largest specification on the box. The number of performers, the equipment you already own and how you monitor a performance all matter.
Start with the inputs you need
A microphone normally requires a microphone preamp. A guitar or bass connected directly may need an instrument input, while a synthesizer usually uses a line input. Some combination sockets support several input types, but their operating modes still need to match the source.
Count the signals you want to record at the same time. Two inputs may be sufficient for a solo voice and guitar, while a band or a multi-microphone session needs more. Check whether the advertised channel count includes digital inputs that require additional equipment.
Plan your monitoring connections
Speaker outputs and a headphone socket serve different purposes. Check that the interface has outputs compatible with your monitors and enough headphone connections for the people recording. Independent headphone mixes can be useful when performers need to hear different balances.
Direct monitoring lets you hear the input without waiting for it to travel through recording software. Software monitoring is useful when you want to hear plug-ins while performing, but its delay depends on the driver, buffer settings and computer workload.
Check compatibility before buying
Confirm support for your computer’s operating system and connection type. A USB-C connector does not, by itself, tell you the required USB protocol or whether an adapter will work. Follow the manufacturer’s connection and driver instructions.
Microphones that require phantom power also need a compatible supply. Check the microphone documentation before enabling it, especially when using unusual wiring or older equipment.
Choose for the whole workflow
A useful interface fits your actual sessions, leaves reasonable room to expand and provides controls you can operate comfortably. Compare input types, output routing, monitoring options and software compatibility together. That will tell you more about its suitability than sample rate alone.
Technical reference: PreSonus guide to recording latency.