Does adding a cardioid microphone to an iPhone improve recording of classical guitar?

Question

I have recorded myself a few times playing classical guitar by using both the iPhone X selfie camera and the voice recording app with surprisingly descent results.

I have been thinking to look for ways to improve the quality without investing a lot in gear so I was looking at some microphones for smart phones on Amazon. There are quite several options and I am looking at a cardioid that comes with a handy tripod. The microphone sits on top of the phone in the tripod.

I've read that the best results are obtained when placing the mic somewhat close to the guitar in front of the sound whole or closer to the fretboard, in this case the mic would be on top of the "camera" between two and five feet away depending on the shot.

UPDATE: The purpose of these recordings is to upload videos to my YouTube channel. This does not pursue professional and/or promotion objectives. Just the enjoyment of "documenting" and bragging about my personal journey and improvements in my study and practice of classical guitar.

My question is, provided this mic does improve the quality of the recorded sound, is this something that would be worth it? I mean technically it would be the exact same setup so there should be an improvement but I'd love to have a more educated and technical answer.

I know I'm not supposed to ask about gear or equipment, but if the answer to this question is "not worth it at all" it would help to get a tip or two about how to improve the recorded sound quality with the phone.

Thank you.

Answer 1

I think I have some demo recordings that might demonstrate the kinds of differences you're looking for. They're all recordings of a classical guitar – though I'm not playing classical with it but folk music on it. Still it likely will give you some idea of the sound quality that's possible.

This was recorded using the built-in mic on my iPhone X in Voice Memos: https://timssockpuppet.bandcamp.com/track/a-la-claire-fontaine

I have a USB mic, the Rode NT-USB. With an adaptor it can go into my phone (though these days there's sometimes some annoying crackling, which is why the previous song didn't use it). I imagine it's similar to what you might get out of the cardiod mic. https://timssockpuppet.bandcamp.com/track/butcher-boy

Then this was recorded with a pretty serious mic, the Ear Trumpet Lab's Myrtle into an OK interface (a Zoom L-8). I also added some compression, a little reverb, and did some EQing in Audacity and Garageband. https://timssockpuppet.bandcamp.com/track/all-around-the-world-2

The conventional wisdom is to place a mic a foot or two from the 12th fret of a guitar, where the neck joins the body.

The sound you will get out of a mic changes a lot with fairly small changes in mic placement, so you'll hear a pretty big difference between 2 feet and 5, I think. A distance like 5 feet isn't necessarily recommended. But distance mic'ing can sound pretty cool, especially on loud things or when there's interesting ambient sounds, like from being outside in a nice natural place. Classical guitar's usually pretty quiet, so you might look into getting a longer cord that will allow you to get the mic close while the mic's farther back. That said, try it at a distance first.

I think my answer to your question would be that an iPhone can get surprisingly good sound alone, but that it's definitely possible to get better quality with an external mic designed for a phone or computer, and still better if you want to try a dedicated mic and recording setup. Maybe these sound clips will give you can idea if the difference is worth the extra dough and effort to you.

And to be clear in saying all this, I'm no expert, just someone that's done a bunch of home recording during the pandemic and watched a lot of youtube videos.

Answer 2

It’s not really possible to answer this question without knowing what the purpose of recording is. If the intention is to record your playing for release or a demo for distribution eg. to promoters, you’d be best to save up for a budget audio interface and either purchase or find an open source DAW.

If it’s for your own enjoyment you’ll need to spend quite a bit to better the iPhone microphone - most mics to recommend as set out above use phantom power which iphones obviously don’t provide.

Shure do a range of mics for smartphone use - I have not tested them for music but they are very suitable for professional field recordings for speech.