Every single 3.5 mm adaptor I have purchased or worked with throughout my career and life has had a short in it. Some of the frequencies will come through, but not all. Sometimes it's the highs and mids, but not the lows. Left channel, but not right. And I always have to turn it slightly to get a signal, pull it out a little bit for it to work or it just doesnt work at all! Honestly. At this point I don't know why they even sell this bs. Should I even bother wasting my time with adapters to 3.5 mm Jack's? Is there a solution to the horrible signals?
Listen mate, if you are having a problem with every single 3.5mm adapter you have purchased, it's probably the socket.
I used to design and build audio circuits. Loads of them. I probably bought over 500 3.5mm jack plugs, sockets and adaptors. All worked perfectly.
Occasionally I messed up a connection, and so needed to sort out a short. In those cases one or other channel was missing. In no instance were highs/mids/lows affected - a short will just not do this. To affect a particular frequency range you need a filter (eg a hi-pass or low pass) and these require a component which provides frequency dependent response (such as a capacitor or inductor)
A short is not frequency dependent (in any of the circuits you are going to be talking about - there are some exceptions up in the high GHz scale, but that's a very different beast)
So as @Mark said, you probably have a problem with your other hardware, such as your socket. If it's on multiple hardware, maybe you are being too rough with them and damaging the contacts.
Though I'm in complete agreement with yourself & Mark on this... there is probably a very good reason pro rigs don't use mini-jacks... XLRs you could probably smack with a reasonably weighty hammer several times, with no adverse effects.– TetsujinDec 30, 2016 at 14:55