Sound coming out of only one speaker

Sam:
Is this your problem?

http://www.danslagle.com/mac/iMovie/audio/1002.shtml

Sue

Hi Sam:

This may do nothing at all but have you tried extracting the audio , then coping the audio and dragging the copy to the second audio line?

Sue

I've been experiencing the same basic problem. In my case, it's audio imported from my DV camera. When it comes into iMovie HD, it's often (but not always) only in the left channel and doesn't sound very good (which may be because it's only in one channel). But if I plug my headphones directly into the camera, it's got both channels, and sounds much better.

I think that the DV camera (a Sony) records only in mono with the mics I have, so in that sense, it's different than Sam's problem. Extracting the audio within iMovie doesn't seem to make a difference, but I can see from the waveform that both channels seem to be there (albeit, both with the same information).

I'm not completely positive yet that it has nothing to do with the camera--I think I have gotten some clips that play only in one channel even when I'm plugged directly into the camera's headphone port. On the other hand, I've definitely had many instances where it's one channel in iMovie HD, and two-channel mono directly from the camera (for which I often use a Sony on-camera gun mic).

I don't mean to hijack Sam's thread, but it seems these might be manifestations of the same problem. Are there any known audio bugs in iMovie HD? I don't remember anything like this in previous iMovie versions.

Hi Twits:

Did you look at the site listed above?

http://www.danslagle.com/mac/iMovie/audio/1002.shtml

Sue

Sue;

The "..second audio line.." (..or 'track'..) is also a stereo track, just like the one above it. So, I'm sorry to say, dragging a copy down to the 2nd audio track will just give an exact copy of the original ..so it'll play slightly louder, as there are now two identical tracks with the same thing on, but it won't be any different: if it originally played out of one channel (e.g; left) but not the other (e.g; right) then it won't play any differently when a copy's been dragged to the other track.

Both separate audio tracks - like the audio track embedded in the video track above them - are stereo tracks, and iMovie doesn't allow any way to separate or combine individual left or right audio channels within those audio tracks.

One of the simplest and cheapest ways - assuming a person doesn't have GarageBand to do the mixing, etc - is to download a fortnight's free use of Sound Studio, and use that for separating or combining channels .. like this.

"..two-channel mono directly from the camera (for which I often use a Sony on-camera gun mic).."

Twits.. (?!) ..various mics do produce mono, and sometimes on one channel only - e.g; left only - when plugged into a camcorder. Sometimes add-on Sony 'gun mics' may give only one channel if the contacts aren't properly touching on a Sony 'intelligent' hot-shoe (..the shoe which grips a Sony add-on mic).

Using Sound Studio (..see above..) you can easily copy, say, the left channel's mono audio onto a soundtrack's right channel (..tho' it'd still be mono: same thing out of both the left and right speakers..) so that the sound is there on both left and right.

To do that, just 'extract' the audio from the relevant video clip(s), double-click the extracted tracks to see what iMovie calls each of them (..probably 'Voice 01', 'Voice 02', etc..) then open your 14-days'-free-use download of Sound Studio and use 'File' and 'Open' to navigate to your extracted audio file, and then Select, Copy and Paste the one channel to the other side, as shown here.

[..To get to your extracted audio file(s), navigate to 'Movies', then within that should be the name of your particular movie, then open that movie folder and go to 'Media' ..at least that's what it's called in iMovie 4: I can't remember how it's organised - slightly differently - in iMovieHD.. and there will be your 'Voice' (extracted audio) file(s).]

NOTE: do NOT look in the 'Waveforms' folder; that just hold pictures of the look of your audio files; it doesn't contain the audio files themselves!

When you've edited the audio in Sound Studio - or whatever other program you might use, like Audacity or GarageBand - just use File and Save, and the changes will immediately play in iMovie.

NOTE also: if your add-on mics have only mono mini-jacks (..a long metal 'shank' with a single separate contact on the end..) you can simply replace those with 'stereo' mini-jack plugs (..shank plus 'ring' and 'tip'..) - if you're handy with a soldering iron - by soldering together the 'ring' and 'tip' contacts of a stereo jack within that mini stereo jack plug. That feeds the mono signal to both the left and right channels, and should then solve all future problems.

[..Not the exact info you need, but these pics should show you roughly what I mean: ignore the RCA-plug pics, and just look at the mini-jack and socket pics to see the left and right contacts. Click on 'Start Slideshow' for bigger, easier to see pics..]

Sue and David,

Thanks for the info.

I did look at the Slagle site--but I'd already tried the same thing (i.e., making a "stereo" track mono) with Logic. Ironically, bringing certain environmental sounds into Logic was the very reason I'd shot the footage I was importing when I noticed the one-channel problem (better than having to shell out for a portable audio recorder). It does of course work in terms of making a left-channel only into a two-channel mono, but it's extra work that never came up in iMovie 4 or previous. I'm also not sure that this fix produces something that something that sounds as good as when I'm getting with my headphones plugged directly into the DV camera. Will do further tests. Also, I like what Dave was saying about the auto-update of the audio; one less step.

It's possible that David's right about a potential contact problem with the Sony mic; possibly I didn't have it set right at one point, or there was dirt in there. But then again, much (most?) footage that displays this audio problem in iMovie is two-channel on the in-camera headphone jack. So, I do wonder if there's some iMovie HD bug. I just got Final Cut Express HD; I'll see how it imports there once I get up and running with that.

Thanks,

TC (PS, David: Twits is, of course, a stage name, as it were--my parents weren't THAT cruel!)
----

I hadn't noticed that this was any more of an oddity of iMHD than in iM 4 ..but perhaps I'd solved my problems in iM4, and so they didn't re-appear in iMHD.

It sometimes happens though (..it's happened to me!..) that earphones don't get pushed in all the way into the headphone socket on the camcorder, so what sounds as though it's coming out of both earphones can be just a mono left channel, but being fed to both left & right phones because the jack contacts are touching both the left & right contacts of the earphone plug ..so the one channel comes into both ears.

On the other hand - or should that be "in the other ear"? - if you're hearing true stereo via the camcorder's headphone socket (..i.e; something different in each of the left and right ears..) then there really is something the matter with the recording or replay ..but that's very unusual.

[..NOTE that a year - or two? - ago, Dan Slagle & I compared notes about the Sony ECM-HS1 little gun mic, and he swore it recorded only on the left channel and was mono, and I swore that mine recorded on both left and right, and was stereo - hence the 'H S1', distinguishing it from the 'H M (mono) 1'. In the end I took mine apart ⚠ and found that it is indeed a mono mic, but it feeds that mono signal into both the left and right camera channels. In its switch's 'Gun' position it just replaces the camera's l & r audio with the mic's mono audio; in 'Zoom' position, it gradually fades its mono signal into the camcorder mic's stereo signal the more that you zoom the lens in! So faulty contacts in the hot-shoe can produce a mono left signal and nothing on the right channel when the clip-on mic replaces the camcorder's own audio with nothing at all..]

Cheers David-great info! "+"

Sue

Dan Slagle & I compared notes about the Sony ECM-HS1 little gun mic

Fascinating (I picture Leonard Nimoy as saying), because that's just the mic that I have. And I think I've noticed that the one-channel problem is more likely in gun than in zoom mode. (Though I still hadn't noticed this until iMovie HD)

And you're right, it's not true stereo--both channels seem to be the same.

Dan seemed to have a faulty one ..or had a faulty connection.

I've had two, and they've both worked fine, on a variety of camcorders. Maybe there's a bit of poor quality control, and a few faulty ones get through; dunno..

I changed my imput plug from a mono to a stereo-to-mono with a plug adapter.That way you will have both channels from a mono source.