I’m working in Audacity 2.1.3. My question: When I concerted my Audacity file to MP3, inversion somehow kicked in. In other words: I was working from two stereo tracks–one for music; the other involved narrative from two sources. When I moved it to MP3 it you couldn’t hear my voice. I have no idea if I accidentally pressed a button, but I have no idea how to undo it. Any ideas?

Do you still have the original music and voice files? It is highly recommended you export WAV backup copies of the work you’re going to use in your show.

If you have the two stereo tracks in Audacity (four blue waves) and they play at the same time the way you want, a simple File Export should mix them together into the final show.

If you had the music track selected and you did File > Export Selected, then you would have gotten only the music in your show. No voice.

You need to get back to the original voice track. If you have not closed Audacity, Edit > UNDO until the two original tracks come back. There’s two ways to see if your stereo voice track is damaged. The simplest way is magnify the blue waves until you can see the individual up and down waves. I expect most of them to be going the same way.
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If you made a mono MP3 file and it’s damaged, there is no way to get back to the original work.

Let us know. We can only go with what you tell us. If you only have damage, I will tell you how to make a test recording so we can tell if your microphone is damaged.


Is it your voice? Describe your microphone and how you connected it to the computer.


It’s a Shure VP64AK and it’s connected directly into my desktop.

With one of these (or very similar)?
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Shure VP64AK

Google couldn’t exactly find that, but a VP64 isn’t a “computer mic”. It apparently has a regular low impedance, balanced connection (standard for stage/studio mics).

Depending on your computer’s mic input and the kind of adapter cable you use, that balanced connection can create left & right channels that are out-of-phase (inverted relative to each other). If you mix the left & right channels to mono, they will cancel-out.

It’s a good quality Dynamic (moving coil) microphone. That’s exactly why we need to know about the adapter used to plug it into the soundcard. If that is the adapter used, then yes, the performer is creating damaged tracks.

Which way to go to “fix” it…

Obviously, the correct computer adapter is indicated, but if everything else is going perfectly correctly, I’d be tempted to fix it in post.

We wait on the edges of our seats. This forum has pretty snappy response times, so don’t go on vacation between postings.


That is the kind of adapter I have. It occurs to me: 1. Maybe I should plug the microphone into my Marantz 660? Or 2. Maybe I should get a different voice microphone. Suggestions?

Maybe I should plug the microphone into my Marantz 660?

That’s the best solution! If the Marantz works as a “soundcard” or USB audio interface you can record with Audacity. Otherwise, record to the Marantz and transfer the digital files to your computer.

You could simply delete one of the out-of-phase stereo channels, or set-up Audacity to record in mono*, or get a different adapter… But, the interface is still “wrong” and the mic preamp built into most soundcards is usually lousy (noisy). A [u]Microphone Transformer[/u] will convert from low-impedance balanced (3-wire) to high impedance unbalanced (2-wire) but, you’d still be using your computer’s “cheap” preamp, and since most of these transformers have 1/4" “guitar” plugs, you’d need another adapter cable.

Most people doing serious home recording use a [u]USB Audio Interface[/u] with a proper microphone input.

Another popular option is a “studio style” [u]USB microphone[/u] (AKA "Podcast Mic). With either of these solutions, you are bypassing your computer’s soundcard.

The downsides to a podcast mic are that you can generally use only one USB mic at a time and you can’t use it with a mixer or PA system (or with your portable digital recorder).


  • Of course, a single microphone is mono. And a single-channel mono recording will play back through both speakers, so there’s no need duplicate the audio recording in two channels unless you are mixing with an existing stereo recording.

Marantz 660

Oh. I didn’t know you had one of those! That is without question the best solution. Nobody wrote you had to go through the computer to record your voice. That solves lots of problems in one swipe.

I think you need one of these, right?

As above, if you’re trying to do conferencing, communications, gaming or live streaming, then we need to talk. Then you’re stuck with the computer.

I’m writing a paper about the bad adapter. Do you have a model number or manufacturer? It’s not “bad,” but it’s not appropriate for your use.


Marantz 660

Since you’re the proud owner of a 660, how do you get the work into the computer? Thumb drive? Data Transfer Cable? Both?


How are you recording your voice?

Dynamic (moving coil) microphone plugged into an XLR to 1/8" stereo adapter and straight into the soundcard. It’s almost certain this is producing out-of-phase stereo tracks by adapter mismatch.

It’s also almost certain all these problems will vanish if they start using their 660 recorder which has direct XLR connections. That was the original recorder used by NPR in the field. Highly recommended.

We also know in other messages that TimKiska is looking at another microphone. I tried to be very firm that he post here before he writes a check. It may save us some work.


Forum links just did something very weird there and missed off most of the forum thread :confused:

Forum links just did something very weird there and missed off most of the forum thread

Did you offend it in some way?