Pros: Slight "V" signature (which I like), Excellent bass extension & soundstage. Great for Rock-N-Roll & Watching Movies.
Cons: Can be slightly fatiguing to some on the high end if not properly amped.
I'm in a situation where I generally can't try out headphones before making a purchase so I really have to do my research; and I did a ton before deciding on these.
I wanted a an "open" over the ear headphone with a large soundstage lots of detail and good bass extension. I wouldn't call myself a "basshead" but I know that I also don't care for cans that don't have any bass punch. My initial "wants" brought the 990's right into the picture.
I tend to listen to mostly Rock-N-Roll, some pop and a lot of alternative and electronic from the 60's-80's. Modern is mostly hard rock with some pop (Yes I pretty much skipped most of the 90's crap). Also toss in some Classical. I'm open to most forms of music except..........country!
I also watch a LOT of movies. My Go-To's are my Pioneer DIR 1000 IR wireless Dolby Headphones.....they are still kicking it after 11 years of regular use. The 990's however add a whole another level of bass the equation while only giving up a smidge of soundstage (always seems to be the case).
Mostly I wear them while working from my home office. I just ripped my entire CD collection into FLAC (after getting the 990's).
A lot of people mention recessed mid's but to me the mids are there just fine. They just tend to be slightly overshadowed by the nice bass and crystal treble. I did end up paring these with the Bravo Audio Ocean tube amp and I must say they are an excellent compliment to the 990's. Softens the treble just enough and adds a touch of warmth to a very detailed headphone.......perfect!
These do need amplification.....you won't be happy with them until you do. I tried them straight out of my PC when I got them and I started to wonder if I had made a mistake. But a DAC and amp took away any qualms I might have had......instantly.
Next on my hit list is a nice over the ear "closed" set........and right now I'm eyeing the NAD Visio HP50's.