When I record guitar, the sound coming from the microphone is still low even when the input is turned up to max. Why this is, as other people don't seem to have their audio interfaces turned up this much? I am using a Shure SM57 and a Presonus Audiobox 2 in, 2 out. Do I need phantom power to boost the signal?

  • SM57 is dynamic so doesn't require (or benefit from) phantom. Are you recording electric guitar cabinet or acoustic/classical? On what distance? Is the low level an issue (i.e. do you have much noise after amplifying?) Note that for acoustic recordings it's good to have some dynamic headroom. Commented Sep 11, 2020 at 0:38
  • @user1079505 I do acoustic recordings, the mic is about 1 foot from the 12th fret and to get the desired sound I want i usually boost it by 5-10db
    – JSASCS
    Commented Sep 11, 2020 at 0:52
  • 5–10 dB seems like a healthy amount of headroom. Perhaps you can live with it? Is the noise level an issue? Commented Sep 11, 2020 at 1:43
  • @user1079505 the more I boost it the more "buzz" I get in my recording, im trying to avoid it i can live with it but I was just wondering if I am doing something wrong to make the volume low
    – JSASCS
    Commented Sep 11, 2020 at 1:56
  • If turning up your input gain results in a noisy signal, look at your preamp setup. SM57s are lovely mics for recording acoustic guitars. Of course I'd prefer my U87, but if I only had an SM57, which is what I started with, then it really can do a decent job on an acoustic. They are not inherently noisy.
    – Tetsujin
    Commented Sep 11, 2020 at 8:06

2 Answers 2


If the signal is 5–10 dB below max in your DAQ it's good – you need that headroom for louder sounds. What is a problem that you need to crank the input gain to the maximum to get that. This results in amplification of analogue noise.

Acoustic guitars are not very loud and dynamic microphones have limited sensitivity. This might be the best you can get from this equipment. I found this thread: https://www.gearslutz.com/board/newbie-audio-engineering-production-question-zone/1108511-why-does-my-sm57-need-so-much-gain.html discussing issues similar to the one you have.

Placing the microphone 1 foot away from the 12th fret seems to be reasonable to capture natural sound of the instruments. Classical guitars are often recorded at even larger distance.

However, with your present equipment reducing this distance might be your only chance to get stronger signal. This requires some trial and error. In particular you may want to avoid fretting hand noises, and boomy sound from the sound hole.

I once tried placing the microphone against the soundboard. I had to try several spots, and it still sounded a bit unnatural (nasal), but the results could have been acceptable for some types of recordings.

  • I never saw that thread it seems like its just normal for the shure sm57. Thanks
    – JSASCS
    Commented Sep 11, 2020 at 3:34

Try this:

*Record with two microphones at the same time. The are lots of thecniques on internet, like 1 mic on 12th fret and another mic on the guitar hole

*Use Reafir plugin by Reaper or Isotope RX to remove noise you hear from the silence (air, computer, electricity...)

*As the noise is reduced, the headroom increases. You have more space to volume up again

*Use Multiband Conpressor and/ou Harmonic Exciter

  • Stereo is nice for acoustic guitar, but it doesn't help at all with signal level. And compressors, exciters etc. actually reduce the SNR, so it's extra important to have a clean signal to start with. Commented Sep 11, 2020 at 16:00

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