Advantages of a dedicated audio interface device over microphone jack on desktop

Question

I have been doing some recordings from an OP-1 synth using the line out on the OP-1 connected to the microphone jack on my desktop and then using audacity to record while playing to my headphones. I was told this is a very amateur setup and I should use a dedicated audio interface so I borrowed a friends Scarlet 2i2 and tried recording with that and I really can't tell the difference between them. The only possible advantage I see is the 2i2 lets me record 2 inputs at once but other than that I can't see any reason the dedicated device is better.

What are the advantages to these devices that I am missing? Is there a good reason to buy one over just using the microphone jack?

Answer 1

I was told this is a very amateur setup

It's probably not very useful to think of equipment in terms of how 'amateur' or 'pro' it is. As your question alludes to, it's better to think about what is a match for your requirements.

Some advantages of external interfaces may be:

• Drivers (such as ASIO drivers) that allow lower latency. This is useful if you're playing a virtual instrument on your computer, or using virtual effects. ASIO drivers also allow the computer to compensate for the overall amount of latency, so that what you record stays in-sync with previously-laid tracks you were listening to.
• Possibly less noise and distortion (although some computers have inputs that are ok for line-level sources)
• related to the above, higher sample rates and bit depths (though these are only of benefit in certain situations)
• better interfacing capability (balanced inputs, more gain, high-impedance inputs).
• multiple inputs and outputs

Is there a good reason to buy one over just using the microphone jack?

Well, for you, it doesn't sound like there is - at least until you need more tracks, low-latency thru monitoring, or are recording from other sources (like microphones).

Answer 2

The mic jack on a computer is designed to take the sort of head-set microphone used for e.g. Skype calls. It won't work very well with the sort of better-quality microphone we'd normally choose for recording vocals.

But modern electronics are very forgiving. If you can deliver the sort of level from your synth that won't overload the mic input (and remember, overload occurs BEFORE the input is digitised and can be affected by any controls in software) and the result sounds good, maybe a 'proper' audio interface won't make much difference. It's even possible that the computer's 'Mic' input will auto-detect the synth's signal and switch to being a 'Line In'. Anyway, if you're getting an acceptable result, don't argue!

But, I repeat, I don't think you'll be so lucky if and when you want to add input from a microphone to your recording projects.

Answer 3

I like the requirements comment above. If you're a "bedroom musician" like me, most of your music composition is just done on a laptop or desktop. I think the advantage of a dedicated audio interface is more apparent if you are singing or playing analog instruments that need more sophisticated microphones. I use the exact same scarlett interface, but use it with an MXL studio microphone for my singing tracks or if I'm live recording acoustic guitar. I'll record a whole tune, all of the instrumental tracks. Then drop those tracks to one mp3 file as a reference and save it on my phone. Then with headphones connected to my phone, I'll listen to the track and sing my vocal parts or play guitar via the USB Scarlett interface into Audacity on my laptop. The interface offers better headroom, less distortion, more gain, better dynamics, and of course that 48Volt phantom power for cartioid mikes.

Then I'll drop the Audacity audio track to a WAV file and import it as a new track into my DAW software (Propellerhead Reason version 10). Ultimately my laptop CPU can manage 15-20 tracks of midi note lanes, audio tracks, and some VST's.