How do I play back one channel into both ears of my headphones?

Jack Clark · #1 08-22-2009, 01:39 PM

I've tried searching for this, but no luck.

All I want to do is playback the right channel (only) into both ears of my headphones.

My situation: I'm using iTunes (or Audiolobe) on a Macbook to play back play-alongs into headphones. The Macbook headphone jack is stereo. My headphone plug is stereo. I tried buying a stereo-to-mono adapter from Radio Shack: It has a male stereo plug and a female mono jack. I set the balance control to output right channel only. I know that works because I hear only the right channel in the right ear of my headphones. Then I put the adapter I bought between my Macbook and my headphones, but I still hear the right channel in my right ear only. [CORRECTION: With the adapter in place, I hear the right channel in my left ear only. -JHC 8/25/09.]

Have I got this backwards? Do I need an adapter with a male mono plug and a female stereo jack instead?

Anybody know how to do this?

Thanks!

dvmweb · #2 08-25-2009, 08:45 PM

You'll need to split off just the right channel and then put in both buds. Analog simple wiring problem.

Do you have any kind of recording/mixing software on you laptop? You should be able to do with that, ie. split off R channel and send it to a stereo track and on to earbuds. Audacity is one program that is free on internet. That would be complicated in that you'd have to re"record" your music to mono tracks.

You could do it with a small mixer. Less than $100 and nice to have. Laptop stereo output R rca plug into mono channel. Then signal to headphone from mixer will be the R mono and in both ears. I have mixers and that's how I'd do it. Old school.

You may need to make your own adapter. Mini stereo to R and L plugs (female). From the R plug in-Mono to mini stereo (female) to plug your headphones into. So, then the R hand signal goes to both ear buds.

Walt MI/USA

Jack Clark · #3 08-25-2009, 11:21 PM

Hi, dvmweb-

I checked out Audacity, but I don't want to go that route. For one thing, Audacity appears to have to make a new file every time you want to change a tune's pitch or tempo. Audiolobe just does it on the fly while the tune is playing, without making any new files. For another thing, Audacity does so much more than I need for playing back play-alongs, that Audiolobe's simplicity is just more convenient. Also, I've been communicating with Audiolobe's developer and he wants to add recording sound on top of the play-along sound into a new file, and direct access to Audiolobe through iTunes in an upcoming version, which I think will make it a perfect musician's practice tool.

I can see that your combination of adaptors would do the trick for what I want to do, but I'm thinking that with a little soldering I can make a more compact one that will work, too. Please check me on this, though, dbmweb, okay?

I bought a male stereo plug and a female stereo jack. I intend to solder a connecting wire between the sleeves on each. Then solder a connecting wire between the male plug's ring and the female jack's ring and tip. Then when I plug my stereo headphones into the female jack, I should get the right channel in both ears, right?

I bought another set to rig up to put the left channel in both ears, which I think will be useful in transcribing the bass lines that are in the left channel.

Sound right?

dvmweb · #4 08-26-2009, 07:41 AM

Yes, that should work. The only thing may be that you need to turn up the volume because you'll be splitting the channel into two speakers, the ear buds. I've done this in the past.

Good Luck
Walt MI/USA

Jack Clark · #5 08-26-2009, 08:32 AM

Thanks, dvmweb. (Are you a veterinarian, by the way?) Yes, I expected that I would lose some volume in each earphone, but it is giving me sound from two of them, and I have plenty of volume to spare, anyway, I think.

dvmweb · #6 08-26-2009, 08:01 PM

Good Job.

Yep, I'm a dvm in northern Michigan.

Walt MI/USA

Jack Clark · #7 08-28-2009, 07:20 PM

Hey, dvmweb-

I just rigged up both of those adapters--the "right" one that plays the right channel into both ears for accompanying play-alongs, and the "left" one that plays the left channel into both ears for transcribing bass from the left channel. They both work great. You still need to move the balance lever all the way right (or left) because of slight cross-over between the channels, but that's no problem.

Having drums and piano in both ears is far more natural and listenable, sounds like I'm accompanying real people now.

Here's a pic of the final products.

Thanks for your help!

dvmweb · #8 08-29-2009, 07:08 AM

Nice looking job. I usually have a guy at our local music store make my special cables. Yours look professionally done.

Walt MI/USA

Jack Clark · #9 08-29-2009, 10:16 AM

Well, thanks, DVM. But they don't look as nice on the inside. I had a couple of do-overs with the soldering iron. (Not to mention my old bugaboo from when I made other types of connectors decades ago: I forgot to thread the second cover on to the cable before I soldered on the final jack. (sigh) I wonder how many times I've done that? A dozen, maybe?

I did notice a certain decrease in eyesight and increase in hand shakiness since the last time I soldered other types of connectors, so I don't think I'll be going into business making these out of my home. :-]