Pros: great stereo imaging; detailed midrange and treble
Cons: slightly heavy bass
On these headphones music that i have known all my life from the 80's sound great. Whether Michael Jackson or Roxette or Duran Duran or Celine Dion or AeroSmith, the overall sound is balanced and the vocals come through nicely, but also any instruments in the mix sound authentic.
The bass is a little bit excessive in some way, but similar to the Sony MDR-XB500, however, i am inclined to say that 'slightly' more bass is more preferable than not enough bass when comparing to the originally mixed song; there's nothing worse than not being able to hear enough bass in a song; a 'bit more' bass is always more preferable than not enough IMO; but on the Denons the bass is nicely presented which extends low, and for the most part the only boominess on these headphones is from any song which has been mixed badly at the studio.
I find the treble and midrange clarity in these very good, but especially when used with a good headphone amp; also, if there are faults in the original recording you will hear it, these headphones are high definition.
I have owned Shure 840's and 440's and i now realize that the Shures cannot match the overall balance that these Denon's offer, and i find that the Shures do not have sufficient bass which makes them sound inadequate.
All-in-all these Denons have a nice wide stereo-image and display plenty of detail but they are a warmish sounding headphone, and the bass in the Denon AH-D1100 does bleed into the midrange just a tad but the definition of the overall sound spectrum still shows clearly and the details are all there. Like many on this site i am a connoisseur of music and i expect any song to be represented faithfully on my headphones, and these Denon's do a commendable job of presenting all the frequencies with poise and fast dynamic response.
These Denon AH-D1100's are easy to drive; you could easily spend $500 on a pair of headphones and still not get the quality of these, i mean, how do you improve on a headphone which unashamedly cracks open the champagne when presenting the music.
Answer: Do nothing, keep these until they wear-out and then grab another pair; they make my Grado 125i's sound inadequate, and my Sennhesier HD 280's sound ordinary next to theses Denon's, so you know what that means.
If you get these Denon AH-D1100's just give them 20 hours burn-in and you will enjoy the sound.
I have not heard another headphone which can show big bass but still present clear mid-range clarity and treble as good as these. But take note, i used three amps with these when auditioning them, and two of the amps did not show them in their best light, so actually the quality of the amp does indeed make a difference, so the amp needs to be of sufficient quality to drive them expertly, and the amp i have found to work wonders is the FiiO E12; quite frankly the FiiO E12 is a winner, it drives these Denon 1100's beautifully, these two work well together. If you get this combination then really i think you will be in the upper echelon of headphone audiophile territory, so no need to spend $1000 on any other combination. If punchy bass is your thing then these are the bomb, because they still give good mid-range and treble clarity while producing solid bass. Good luck.