I suspect this is an easy fix for someone with basic knowledge in this area. Here’s the issue:
I have a PA with a “monitor line out” port. When headphones are plugged into that port, sound only comes out of one side of the phones. I have tried this with two different sets of headphones with the same result. Both headphones have a 1/4" jack adaptor with two bands on it.
I have also noticed this same phenomenon with a metronome that I used to use. The click would only be heard in one side of the headphones.
Both headphones that I mentioned above work perfectly with other devices.
Please educate me on what is going on here and what I can do to fix this!
OK, so is there any type of adaptor or something that would split it so that there would be mono in both sides of the headphones? It is very annoying to listen to headphones with sound only coming out of one side.
They do make mono headphones; they have a different type of plug than stereo ones do. I assume you can get an adapter that does the same thing, but I would bet finding headphones that are built that way would be esaier.
The sound is sent separately to both ears because there are three wires (and the connector has three separate metal contacts). Headphones and earphones for non-stereo equipment (like your public address system and your metronome) have a very similar connector but with only two contacts (= 1 band instead of 2). So your equipment’s (female) phone receptacle only has two spring-loaded contacts (one for the tip, one for the side). When you plug your stereo headphones into the PA system, one of the metal contacts on the side of the (male) connector remains unconnected.
As scr4 said, there are adapters for this sort of thing. However, the one he/she points to has 1/8-inch connectors; you should be able to find an equivalent for 1/4-inch.
The 6.5mm (aka 1/4 inch) phone plug was originally used in telephone exchanges. It had two wires - and these connect to the tip, and the sleeve. Later versions added additional wires. When used with three wires you get a ring between the tip and the sleeve. (There are variants with more rings.) A mono wired system uses two wires, and the plug uses the tip and sleeve (TS). A stereo plug adds the ring (TRS). Notice where the ring is - it replaces some of the sleeve. The tip and the ring are the left and right signal, and the sleeve is a common return. If you put a stereo plug (TRS) into a mono socket (TS) the ring is connected to the sleeve, and only the tip is connected to a signal. So you only get signal in one channel.
There exist adaptors. It simply wired so that the signal on the tip is connected to both tip and ring in its socket. Most pro sound places will have them. Avoid the cheap ones, mechanical tolerances are not good on these and you end up with intermittent connections that will drive you nuts. One that is actually made as a plug, some wire, and an in-line socket is usually preferable to one that is a single lump, but no matter what, buy the best one they have.
NOTE: you must be clear that the adaptor is for headphone mono to stereo use. There is another, very common, adaptor that looks identical that is used to adapt a singled ended to balanced connection. It is wired differently, and won’t work. Label your adaptor so you don’t get caught out later.
If your headphones are only ever used for mono monitoring duties you could also replace the plug, but you will probably prefer an adaptor.
That could be part of the problem. I think some monoral jacks have a contact to both sections of a stereo plug. As far as I remember all the ones I got monoral sound in both ears were the mini jacks.
You try pulling the plug out very slightly hoping to maintain contact with the tip and getting both sleeve contacts of the plug in contact with the single sleeve contact in the jack.