How are you hearing no difference?

Here's a tip which costs nothing, nada, and you will hear a difference. Just cup your hands behind your ears. Even if you like the sound I know it's a real pain keeping your hands in place but you will hear a difference. I recall that too many years ago to remember a US company tried to market a cardboard device which looked like Mickey Mouse ears and you fitted to your head when listening. It looked ridiculous and therefore didn't sell but it did work.

I remember there being some leather versions of those "ear extenders"

Was I not the first? Ortho Ears was going to be my first product. They were based on Spock Halloween ears. Which I think is a smart look. That was 25 years ago.

Funny that this was mentioned. The hearing in my left ear is worse than my right. As I was learning about speaker position and listening position etc I cupped my hand behind my left ear and it made a big difference in the size and shape of the sound stage. But it did have a hollow 'sea-shell' quality to it so I tried different hand shapes and was able to eliminate that.

I'm glad no one saw me doing this...my wife already has plenty of reasons to have me committed. 

Anyway, this worked but is very impractical. Also, with a little more time and effort I was able to balance things out with minor adjustments to speaker and listening chair placement. So now I appear semi-sane while listening.

The cupped-hands technique definitely yields a "sea-shell" effect.
Closing the eyes always improves aural acuity.
Removing eye-glasses does too.
Still trying to prove to my wife I'm semi-sane also...