Within ‘The Box‘ when performing sound cues we use a Imac whose internal sound device used. For the best sound coming in from an external source it is better to use a dedicated sound interface to achieve this goal it also preferable to use an interface with out various outputs.. One of the biggest reason to use an interface such as this (apart from the improved sound quality) is that they have dedicated mic/line inputs which are usually a mix of xlr and 1/4 inch connectors (these maybe sometimes hybrid inputs allowing you to connect one or the other to the same port, thus reducing size of the units.
It should be noted here that when these are used there is often a button to select if you have a line or a mic input.
They are usually connected to the computer via usb though you may also find firewire devices. they may also require a power supply. Some devices can be used as a standalone device which can be used as a Mic Preamp at a push (they often have phantom power available), this does not replace a dedicated preamp but can be an option if nothing else is available.
- USB 2.0 then despite the number of inputs there will only be 2 channels recognised by the computer.
- USB 3.0 I believe allows for more channels.
- Firewire allows for more channels to be recognised by the computer so allows for greater flexibility within software.
For further information on the pros and cons about the different protocols Sound On Sound has a good article.
The inputs will often have a gain know for each of the inputs so you can alter the levels before the signal leaves the box.
Depending on your device you will have various outputs which will differ from device to device. Usually a stereo pair of some description but some will also have mono outs. It is often true that if a device has 8ins it will have the same number of outs. These multiple outs can be used by various different pieces of software and allow for routing opportunities.
Audio Interface ‘The Box‘
Matt Cooper 