I just received my IE80's yesterday. I have put probably a good 5 hours into them already and so far I am happy however I sold my Urbanites and Momentums to get these. I have been wanting an IEM for a while and besides my 598's for home use, over ears have been getting annoying to carry around as I am a student. My first impressions were good although I am certainly not the only person to believe that the "bass adjustment" does very little to change the sound. I saw multiple EQ graphs of these and the only thing i can tell is that the adjustment only makes a slight change in the sub-bass aspect.
They play very nicely on my Fiio E10 DAC/AMP. But when I have the +3dB bass boost on, the sub-bass sounds similar to a long, progressed fart. Anyone else experience this? Also, when listening to music from my Note 3 or S5, I get some sibilance at higher volumes and sibilance is my worst enemy. I know they are still new and forums say they need about 40 hours to really come out and shine but right now, i very much regret selling my Sennheiser Momentums. After watching reviews on YouTube, especially LinusTechTips' review, I cant help but slightly regret my decision. In Linus' review, he mentioned "jawshaking" bass and i have not once experienced that. I am most certainly going to put 40 hours through them within the next couple weeks, but if they sound no better, I will probably sell them and look for a different IEM. I love Sennheiser as you can tell, but for the extremely high price of these, i am not astounded by the sound quality... yet.
these have the best most visceral bass you are going to get. ever.
there are some mistakes in yourt audio chain that can make them sound bad.
i have had ie8 for 5 years now, and first 4 years i had them using with a cowon j3. they sounded meh, a little veiled and not worthy of their price point, i got no soundstage, no treble detail, no microdetails, the bass was meh, and everything in general was meg about them, and the price was huge.
for the last year i have been using ie8 with a fiio x5, and it made a world of a difference, it added soundstage, iunstruments began appearing out of nowhere, treble was clear, non sibilant [sometimes i need more treble, to be sincere], these iems are the second iems in the worls, the first being ie800.
to sound a little more coherent, as more people said this, ie8 are one of the most potent iems in the world, they change sound signature a lot with tips, and sources.
what i also did was stick my half tape mod, or stick a normal tape over the vents, and punch a hole in it, to not make the driver over-pressurezied. then, the mid-bass will be better, and sub bass will be.... visceral. classical music has never been so meaty as it is with ie8.
also, do a little eq-ing, do not use the bass sliders on fiio equipments, with ie8, but use an EQ app, and do this, raise 40-60hz area by +2db, lower the 100-150hz area by -2 and leave the rest as it is. it should sound... better.
one last piece of advice i can give you is to try all tips, and insist a little more with double flange medium or big, and do not try to insert deep. these tips really make ie8 shine.