Mahler's are great speakers. I have owned them for 5 years now and only just moved on and still missing that BIG bass sound a little.
First, they have a BIG bass, uncontrollable with almost all tube amps and just big with SS amps. they will always add a certain amount of bass to every recording from 45hz down would be my guess.
They need to be a far out into the room as possible to control the bass output.
the midrange is full and the treble a little subdued, so bad recordings will be tolerable, however you will lose a little transparancy.
The voicing of the speaker is from the uppermids/lower treble and quite laid back.
These speakers crave current and only really come alive at mid to loud volumes. They don't sound that convincing at low volumes, hence their microdynamics are not as good as there macrodynamics.
headroom is no issue and these will play til well over 105db!! very well made, made my old Von Schweikert's look like junk from Wallmart.
overall a great musical speaker.