Do I need an audio interface for recording if I have a mixer with a built-in USB?

Question

I have Volca series synths and Behringer xenyx 802. I can record each Volca separately with an audio interface to my computer but If I want to play them and record them together (which is better for me), would I get a better sound quality if I plug in the mixer to the audio interface? or is it the same as if I was recording from the mixer itself (with the usb cable to the computer)?

Also, if my synthesizers had stereo signals and I recorded them in stereo with the mixer, and then connected the synthesizer with the mono input of the audio interface, the output would be mono yes? but does that mean that the stereo sound of the synthesizer would sound as if it was lacking something? I think I can't understand the difference between recording in stereo\mono and listening to the output of the work in stereo\mono (transferring it from one to another)

Answer 1

I don't know about your interface issue. Like Your Uncle Bob said in the comments, depending on the wiring/circuitry in your mixer, the interface may provide a cleaner recording. I would test both configurations and see which sounds better to you.

As for recording/listening in Stereo and Mono, think of it this way:

• If you record in Stereo and listen in Stereo, you hear the panned (off-center) sounds in the individual speaker/headphone they are panned to
• If you record in Stereo and listen in Mono, those panned (off-center) sounds are coming through both speakers/headphones, but are going to be quieter or sound "off" because they aren't in both source channels when the channels are overlaid
• If you record in Mono and listen in Mono, you're hearing one channel back through one channel. You will get 1-to-1 duplication of the source channel because you don't lose any fidelity to panning the sound
• If you record in Mono and listen in Stereo, you're hearing the same signal duplicated through both channels, this is functionally identical to listening in Mono

Answer 2

According to the documentation on Behringer's website, the Xenyx 802 is a simple 8-2 analogue mixer with no USB output. So I think your only choice is to feed the mixer audio output to your audio interface.

If the mixer DID have a USB connection, allowing it to act as its own 'audio interface' it would doubtless sound the same as any other competent interface. But as you don't tell us WHAT audio interface you own, it's impossible to comment.