Hi,
I’m brand new to Audacity 2.4.2, so I apologize if I ask a silly question…
I have recorded some cassette tapes with mono recordings. The source is the line output from the tape recorder, so I cannot adjust the recording level.
In the first place I found that the recordings had a poor volume level, so I recorded them as stereo instead with a very satisfactory result.
The idea was to later mix down to mono in Audacity in order to save disk space. However, if I do that I again lose a LOT of volume level. Even if I normalize the mono track to 0.0 dB the result gives nowhere near the same level as the stereo track does.
It doesn’t matter if I playback in Audacity or in VLC.
I have tried to pan the mono track all the way to the left and export. The export then becomes a stereo file with complete silence in the right channel, but it plays with exactly the same volume level as the original stereo track and hence much, much louder than the mono track.
I don’t understand this behaviour - can somebody help me or explain why I am stupid?
Thanks…/Kim
It sounds like the left & right channels are out-of-phase (one wave goes up while the other goes down and one speaker pushes-out while the other pulls-in). If they were perfectly out-of-phase and otherwise identical, you’d get pure silence when mixed to mono.
Try this -
[u]Split Stereo Track[/u]. That allows you to edit the channels separately.
Select one channel (it doesn’t matter which one) and then apply the [u]Invert[/u] effect.
Export as mono.
If that doesn’t work you can simply delete one channel after splitting, and then export to mono.
Thanks, DVDdoug.
Sorry, I still don’t get it. I perfectly understand what you are saying, but what I see is confusing.
Firstly, what do you mean by “Export as mono”? As I see it, I first have to mix the two tracks together (Mix & render), then mix down to mono, then export. I don’t see an option for exporting two independent racks as one mono file? If I do this I get the same bad result no matter whether I invert one channel or not.
Secondly, I find that it is the Pan setting that is the culprit. I tried the following (exactly as described):
- Opened the original (“stereo”) file.
- Mixed down to mono
- Exported as file MONO
- Moved the Pan slider all the way to the left
- Exported as file LEFT
- Moved the Pan slider all the way to the right
- Exported as file RIGHT
Now, the levels of the LEFT and RIGHT files are the same as the original file, while the file MONO is very, very weak.
But hey, the LEFT and RIGHT files have been converted to stereo files with a silent right and left track, respectively!
So, I still don’t have a clue of what’s going on.
I think I will have to stick to the stereo tracks. I have already wasted more time on this than it takes to buy a new hard disc with room for the stereo tracks 
Sorry about that - I forgot how to make a mono file. (If you are exporting as MP3, there is a mono option when you export.) And you forgot to invert one channel before making it mono.
- Split Stereo Track.
- Invert one channel.
- Make Stereo Track.
- Split Stereo to Mono.
- Export.
The idea was to later mix down to mono in Audacity in order to save disk space.
FY’I - If you use a compressed format making it mono will make little or no difference. But, it’s still a good idea to fix that out-of-phase issue.
Hi,
Well, I did exactly as you described, with the described results. As I said “I get the same bad result no matter whether I invert one channel or not.”
OK…
Split stereo to mono.
Click the “X” to delete one channel.
(Amplify or Normalize if you wish)
Export.
Yeahbut… done that several times and still way reduced volume level
Unless I move the Pan slider, but then it won’t save as mono anymore.
Still I don’t understand what’s going on, because even when I play back a stereo file with one channel empty I still get sound in both L and R channels of my headphones. Hmmm, perhaps I should check the properties of the playback device…
If the volume is reduced when the pan slider is centred, then there’s something wrong with your playback system.
How are you listening?
Still I don’t understand what’s going on, because even when I play back a stereo file with one channel empty I still get sound in both L and R channels of my headphones.
Ahhh! Your headphones (or the headphone connector) have a BROKEN GROUND CONNECTION and there is NOTHING WRONG with the original recording.
Most likely it’s the headphone cable so try different headphones or speakers. If that doesn’t fix it, it’s the headphone jack on your computer and the easiest fix is to replace the soundcard or if you have a laptop get a USB soundcard.
…That’s another way to get L-R subtraction which is similar to a vocal removal/vocal reduction effect. Some of your stereo music recordings probably have the “center” vocals subtracted-out where anything that’s identical in the left & right channels is “killed”.
Hi DVDdoug,
Congraulations! Your diagnosis was 100 % correct. It was the ground connection in the headphone cable that was broken. I first tested with another set of headphones and afterwards tested the cable. I did not suspect that the cable was out of order as it has molded plugs and shows no sign of damage.
Thanks a lot for all your help and your patience!
Case closed.