1st, document what you are actually receiving at your ears, seated position
cd with test tones
Amazing Bytes CD with 29 1/3 octave Test Tones
Sound Pressure Meter, with bottom threaded hole for tripod mount
Meter on tripod, at seated ear height, at listening position.
Meter doesn’t need to be that precisely calibrated, you will get more or less answers relative to adjacent frequencies.
Make enlarged copies of the insert with test tone list so you can write down the results
Go forth informed
IF you have any tone controls, you can measure the results, and you can make adjustments for your personal taste, perhaps you have age related diminished hearing of high frequencies.
also, great tools to accurately measure the effect of alternate placement/toe-in.