Converting Stereo Files to Mono - Losing Sound

[Patrick Hinds]

Hi There. I'm a podcaster. I record two person interviews using a tascam dr-40. We use external mics. When we edit the episodes and then convert the stereo file to mono, the volume on the person recorded on the right channel drops almost completely out. At first we thought that our tascam dr-40 was broken or damaged somehow and that was causing this issue. However, we purchased a new tascam and we had the same issue. I don't believe this is a problem with the converting process. We use audacity and have had much help ensuring that we are doing the conversion correctly. Is this a common problem using the tascam? Any thoughts on what I might be doing wrong in the recording process?

 

[Gravity Jim]

I am assuming, by the way you describe this, that you are recording the interview in stereo, with one voice hard right and one hard left, for ease of editing. It sounds like what's happening is the voice on the right channel is actually being recorded on both channels, and when you collapse to mono, it cancels itself out (except for the bleed into the other mic, which is far enough out of phase to leave a trace of the cancelled voice in the mix).

I would double-check the routing before moving on.

 

[Patrick Hinds]

Thank you SO much for your reply. I'm a total novice. Can you tell me what you mean you mean by checking the routing and how I can check it? Again, thank you SO much!

 

[Gravity Jim]

Well, I mean just make double sure that you re not sending the output of the problem mic into both right and left channels. If you are, that would certainly account for the cancellation of signal. I'd just about bet a dollar to a donut that's the problem.

 

[joel schlecht]

If you are in audacity, you can split the stereo track to 2 mono tracks. Then select one of the tracks, doesn't matter which. Apply the effect -invert- and that will reverse the phase. If the signal being out of phase is your problem, that will fix it.

 

[Gravity Jim]

Joel, are you playing a prank?

Flipping the phase of one side of a stereo recording 180° out of phase will cause total cancellation of anything mixed completely down the middle. This is the old "vocal remover" trick. It will also likely remove the bass and bass drum leaving behind nothing but sounds that are panned left or right (and only that portion that doesn't appear in both speakers). Try it: it won't "fix" anything. It will leave you with only the ghost of the original recording.

Also, thanks for the "zombie thread." This question was answered almost a year ago.

 

[joel schlecht]

I know this is old but I just read over this again and have to save my credibility. From what I understand, he is doing an interview panned hard left and right for the two subjects. (I don't know where you got bass and bass drum from) So, A. There shouldn't be anything in the middle (he is mixing down to mono to make it sound all in the middle) and B. His signal is ALREADY 180 out of phase which is where his problem is coming from. This is due to the distance between the microphones and the frequencies used. Flipping the phase will put the signal BACK IN PHASE and fix the problem. This is done when micing drum sets all the time (many mixers and software have a reverse phase button) because of the multiple microphones and works just fine when you know what you are doing and understand the principles involved and not just using a rule of thumb. And, if your not sure, it is just as easy to flip it back if it doesn't fix your problem. Also, while you have the original file split into two mono files, you can independently modify the volumes much easier which may also help. May as well have and arsenal of possible solutions to your problem than putting your eggs in one basket. The question wasn't answered because if these were interviews than can not be re-recorded, trying new mic techniques will do nothing for him, he MUST fix it in post.

Also, I don't see a problem with "zombie threads" as you put it. Many people do searches looking for answers to their questions and would like as much information in one place as possible. I know I appreciate it. I don't see how a little extra text could bother someone. I joined this site and saw that a lot of questions about the dp-01 which I own were unanswered and I thought I would help out a little but if that's a problem I can go.