This is what I have: SUPERLUX HD668B (with AKG velour earpads), and Audio-Technica ATH-CKM55.
I use mostly the Superlux, but on the road not.
The basses with them well defined and dinamic, goes deep enough. It seem I can distinguish between them, not washed together.
It seems a bit weak and for some cases I need more bass, as candy for my ears...(but the EQ is not working).
The mids just fine, I have not heard any better yet...Even the piano good to hear (because I dont like the digital sound of this).
Ther overal sound is with plenty of details, far more than any of my portable player does or what i heard before.
I compared to my HarmanKardon AVR-255 (sorry but this is modified too:) but really better that the stock),
I can't tell which is better...booth has holographic deep and wide stage, not in the face now sound.
In CK4 the presentation maybe the highs are too much for me. But 'Im quite sure that this is on the safe side.
To be hones I dont want to tell too much about the sound now, because I cant critize that too much (and my english not soo good).
I was pleanty of times on Hifi/High-End shows too, I know what is good (for me).
Now I heading to some portable headphone amp, with some warm sound (a bit tube like).
(like Headstage Arrow (4G?), iBasso T3/T3D/T4...but 100-250EUR)
The music what I tested (Just the directory list from the player now) (Click to show)
Flac albums - [192-24]:
Ali Farka Toure - 1990 - The River
Alice in Chains - Jar of Flies
Allan Taylor - 2000 - Colour to the Moon
Bebel Gilberto - 2004 - Bebel Gilberto
Coldplay - 2008 - Viva La Vida or Death And All His Friends
Gotan Project - 2003 - La revancha del tango
Mari Boine - 2006 - Idjagiedas
Melody Gardot - 2005 - Some Lessons (bedroom sessions)
Melody Gardot - 2007 - Worrisome Heart
Melody Gardot - 2009 - My One And Only Thrill
Natalie Merchant - 1998 - Ophelia
Natalie Merchant - 2001 - Tigerlily
Natalie Merchant - 2010 - Leave Your Sleep
OST - Tron Legacy - 2010 - Daft Punk
Quimby (<- Hungarian)
Robert Plant & Alison Krauss - 2007 - Raising Sand
The Cult - 1993 - Pure Cult - Greatest Hits
The National - 2007 - Boxer
The National - 2010 - High Violet
Yasmin Levy - 2009 - Sentir
Yonderboi - 2005 - Splendid Isolation
Zero 7 - 2001 - Simple Things
HD (WAV):
Trondheimsolistene - In Folk Style - [96-24]
Trondheimsolistene - In Folk Style - [192-24]
Yim Hok-man - 1998 - Master Of Chinese Percussion [88,2-24]:
Yim Hok-man - Poem of Chinese Drum.wav
Some samples from the Norvegian 2L Records - [192-24]:
Simple Symphony op. 4 - Boisterous Bourree (192 kHz).wav
Joseph Haydn (1732-1809) - String Quartet In D, Op. 76, No. 5 - Finale - Presto.wav
Vivaldi - Recitative and Aria from Cantata RV 679.wav
Some Grover Washington, Jr. Vinyl rip - [192-24]:
Grover Washington, Jr. - Just The Two of Us.wav
Grover Washington, Jr. - Mister Magic.wav