Why do the mp3's I make through audacity have muffled sound?

I’m using Audacity 2.0.5.

My computer model is a Windows laptop from 2011.

I’m recording guitar and vocal tracks into Shure sm57 and sm58 mics. When I export the tracks as mp3s or WAVs, the sound is fine through my laptop speakers and through any sort of auxiliary device (i.e. car speakers, amplifiers) and headphones. However, when I try to play my exported file through apple iphone speakers as well or through macbook speakers, my guitar and vocal tracks are muffled and sound awful. My distortion guitar sounds like crackling and mixing broken glass.

My friends send me guitar and vocal tracks and I sync their tracks with mine and export them into the same mp3 and for some reason I can hear their sounds clearly but mine are near-silent or garbled and muffled as said before.

They are using more current macbooks.

What could be the problem?

…Shure sm57 and sm58 mics. When I export…

There’s a huge, very serious hole there between those two sentences. You can’t directly connect those two microphones to a computer. How did you do it? Detail description or part numbers.


My guess is that your recordings are too “hot” (the level is too high) so they are distorted, but the problem does not show up on your laptop speakers or car speakers due to limitations of those speakers. For serious audio work it is essential that you have reasonable quality speakers or headphones to listen to your work before you export it.

If you post a short sample audio file we can tell you if this theory is correct. See here for how to post an audio sample: https://forum.audacityteam.org/t/how-to-post-an-audio-sample/29851/1

My guess is that your recordings are too “hot” (the level is too high)

Nope. Depending on the connection method, the performer has two out-of-phase sound channels. This will create very serious sound damage depending on the tricks being played in the playback or speaker system.

The diaphragm inside an SM57 or SM58 floats. If you play your cards right, the soundcard will record the main voice and the protection signal (pin2 and pin3) “straight” which means two copies of the same show, one upside down.


A reasonable conjecture.
An audio sample will soon confirm.

We agree that the most likely cause is that the audio is damaged in a way that does not show up on the laptop / car speakers.

I’m on the edge of my seat.
(my knees are falling asleep)

If Koz is right and you have an out-of-phase stereo file that should really be a mono file, here’s a way to fix it:

Click the little drop-down arrow at the left of the waveform display.
Select Split Stereo Track.
Now the left & right channels should each have their own drop-down arrow.
To the left of the drop-down arrow, you’ll see the file name and to the left of that an “X”.
Click the X (either channel) and that channel will be deleted.
Click the drop-down arrow for the remaining track and select Mono.
Export the mono track to a new filename, and you should be good.

And in the future, don’t plug a balanced low-impedance mic into your soundcard!!! Get an audio interface with a proper XLR input, or get a mixer with the proper connection and plug the mixer-output into line-in on your soundcard. The mic input on a consumer soundcard or laptop is worthless for quality recording and it’s the wrong match for any decent stage/studio microphone.

You know the next complaint is how to do that now that the show has already been mixed with other, correct work. Koz

I use each microphone one at a time. So say, I’m using the SM57. It’s connected to an XLR cable, which is then connected to an XLR to 1/8"" TRS stereo adapter cable, which I then use in the microphone port on my laptop.

I’ll see if I can get you a sound bite.

Thanks for the feedback so far. I appreciate it all.

Attached is my sound file. It’s in WAV format. It’s got a rhythm track recorded from the sm57 and the lead vocal track recorded from the sm58. If I listen to it through apple speakers, you should only hear a backing vocal track (unknown recording device…probably good quality microphone), lead guitar (recorded through a Snowball microphone), and a synth bass and drum track (WAV exported from GuitarPro). However, through headphones or auxiliary devices you should hear everything.

and Koz gets the cigar.

Zoomed in a long way it is clear that the left and right channels of the stereo track are almost the inverse of each other:
When the two channels are played through one (mono) speaker, the channels are “mixed” together, producing a small waveform like this: (they almost cancel each other out)
So we’re back to Koz’s first question:
" You can’t directly connect those two microphones to a computer. How did you do it? Detail description or part numbers."

They said how they did it. An XLR to 1/8" TRS adapter connected to the Mic-In of the computer.

That’s not valid. If you have a computer that pays attention to both the tip and the ring of the show, it will result in an oddly damaged stereo track.

As somewhere up the thread, you can fix that before you combine that microphone signal with the rest of the show and all these problems will vanish. Or you can correct the adapter and not make this damaged track in the first place. This is such an adapter that I made. Note the little metal ring on the 1/8" plug is missing. This is a TS, tip and sleeve, no ring.


That illustration also publishes the special wiring for this adapter should you wish to make your own.

You can also do this with normally available parts, cables and adapters. A guitar amplifier microphone cable gets really close. It converts the SM-58 to a Tip / Sleeve 1/4" plug (not 1/8" plug).


These are common as dirt. Every rock band has one.

Then you add an adapter to get between the two connector sizes, such as this.


…Sorry. I had one from the HOSA company that’s been discontinued. Looking for a second supplier.


Here it is:


When you use this thing, you have to know that all the stress of the rest of the cable and adapter is resting on that one little 1/8" plug, so put a book on it or stabilize it somehow so it doesn’t move around.


It’s going to record mono this time so you’ll only get one sound channel, not one good one and one damaged one. You can record it as actual Mono which will play to both speakers in a music system, or you can duplicate that one channel and force it to be stereo.