I am so pleased with my new Martin Logan Mikros 90 headphones, the bass goes very deep and is more detailed than my reference Grado SR325i's. On music that has a lot going on in the bass region, these headphones can sort it all out, its quite easy to distinguish between individual instruments. With heavy and fast drumming it is easy to follow the bass guitar lines, as the Mikros 90's do a wonderful job at reproducing fast transients and percussive notes with punch and authority. They definitely shine with acoustic instruments, especially in a well recorded venue, the sense of air and room reflections are not washed out, but give a very good sense of size and space. The plucking and percussion on Patricia Barber's Cafe Blue (MFSL UDSACD 2002)is just amazing to hear and these headphones seem to be made for jazz like this, anything of Patricia Barber's is meticulously recorded and makes for great listening. A quick word on break in period, 20 hours minimum, over 100 to really reach a point that seems to be completely settled in, I did run them a lot just plugged into my Ray Samuels Predator Dac/amp, burning them in. These really do scale well, when presented with quality input or power they respond in kind. Now with pricing online in the sub 100$ range everyone should own a pair or two. I have a second pair now, just finishing the break in period. Highly recommended There can be some issues with comfort, but the head band is flexible and bendable, so with some effort I was able to shape my headband to fit my skull more closely and reduce a lot of the "new" headband clamping pressure which also helped them stay in place better. Mids and treble are very neutral, cymbals have a very real shimmer and splash, without ever being strident or harsh. The midrange is voiced very close to the sound of my Grado's with a nice realistic presentation of female voices. Overall a very nice headphone, looks, feels, smells and even sounds wonderful, what more can you say.