Amazing sound quality and value for money!
Everyone's ears are different, and everyones "hearing profle" is different, so it's a very personal thing.
You can read headphone "reviews" 'til the cows come home. and try to work out from the language of the reviewer whether you think a particular pair of headphones sound like they will be right for you.
But at the end of the day, there's no real substitute for sticking them on your head and listening to them yourself! This can be expensive, of course.
I have listened to many different headphones, over many years, professionally and domestically - including many so-called "audiophile" ones, and I have spent a lot of money in the process.
But I keep coming back to the Superlux HD668Bs.
For me - and my particular ears - the sound that comes from the HD668B is actually amazing - especially considering the price.
If it's "sound quality" that you're most interested in, they have to be among the best - if not THE best-value headphones on the market.
Just recently, I bought a pair of Beyerdynamic DT1990PROs - as I have always been a fan of the Beyer sound. These cost me £370 - and of course, they DO sound pretty good. But to my dismay, I still find that I actually prefer the sound of the Superluxes - and this last pair only cost me £26 !!!
I bought this second pair to compare with the first pair that I bought - back in 2013 (and they were more expensive then!) - and they sound exactly the same. So Superlux haven't changed the drivers.
The Beyers are beautifully made, great looking, and very comfortable though - and the design and the comfort factor is the big drawback with the HD668Bs.
They're not the most beautiful things to look at, and the drivers are mounted inside pretty plastic-y ear pieces, with plastic-y "faux leather" earpads. So you're definitely paying for the drivers, not the aesthetics - and this is a well known fact. Basically, I think they're designed to be robust enough to be chucked around by musicians in a studio. So the earpieces are attached to a very robust "wire" frame, and (like many others) I've found that once you've "bent them into shape", and replaced the earpads with some nice comfortable velour "Brainwavz" ones for example, you can transform the comfort factor, and you end up with a really nice, comfortable, pair of amazing sounding headphones that you can wear for hours without noticing the're there. And this for less than 50 quid!!
I would definitely recommend anyone to at least try them - at this price what have you got to lose?
If you like the sound - and at the very least, you WILL be surprised how good it is - buy some new earpads to add the icing to the cake!
After many years of trial and error, I think I've finally found my favourites.
I'll be selling the DT1990s, and I'll hardly miss the comfort at all - because in the end it's the sound that's most important.