Right, apologies if I'm preaching to the converted here, but I'm new at this headphone lark and I've just made a rather pleasing discovery I thought was worth sharing.
I own (for my sins) a pair of Sony TMR-RF850R Wireless (FM) headphones. Circumaural, very comfy, largely pleasing - if forward - sound. Ideal for nighttime telly viewing anyway.
These have the standard red and white phono sockets on the back, the intention being that you plug in the supplied cable that terminates in a standard 3.5mm jack, and push said jack straight into your headphone socket. All well and good so far.
Trouble is, you then spend ages trying to find the perfect channel/seating position to minimise background static that you inevitably get with FM transmission. Frankly, it's a pain.
So tonight, I tried something. I took a male-to-male phono cable, stuck one in the back of the DVD/CD player, the other into the rear of the headphones' transmitter base. Holy moley! What a difference!
With the output from the player going direct to the transmitter, the experience is vastly improved. Picked the ideal channel, and now I've got the equivalent of a really strong FM radio signal pumping out through the phones - and almost NO STATIC! As for volume control, it's right there on the cans. Problem solved!
Just thought I'd share this in case anyone was going through the same hassle with similar RF cans.