[EYEdROP]

Im looking for some budget (under $30) IEMs that sound similar to the Monoprice 9927, but with good isolation. Ive tried all kinds of tips, but I think their semi-open design is the limiting factor in isolation. 
 
My favorite budget headphones so far are easily the Monoprice 8320 (9927). The bass is just right for me. Goes deep and all low frequency information is there but not highlighted at all. No extra punch or rumble, just ruler flat down to about 30hz. Alot like Ety's in the bass department. The mids are slightly tin can sounding, but still forward and clear with reasonable timbre accuracy. Very good for the price. The treble drops off early, which I prefer. It makes them sound smooth and not fatiguing at all. 
 
Ive tried the Xiaomi Pistons 2.0 and found them too V shaped in sound signature.
 
Also tried the phillips she3590 and again too V shaped.  
 
Tried the monoprice 9396, they were fairly balanced but veiled and muffled sounding in comparison to the 9927.
 
Other favorite headphones include: Etys, Beyer DT-48, HD-800, HD-600, LCD-2, HP-1000. 
 
The most important thing for me has always been tonal accuracy and isolation. If I could have a headphone that gets 20hz-5khz scientifically perfect with rolled off highs and no soundstage, I would be a happy camper  

 

[glove4]

Have you tried the Soundmagic E50? I think the E50 are similar to the Monoprice but better in comfort. Like the Monoprice, the E50 will not be accused of sounding "warm," but still a very smooth listen. I think the E50 could even sound somewhat thin on certain genres. Definitely not for bassheads.

 

[EYEdROP]

Interesting. Im also curious about the pl30. Though im also tempted to just shell out some more money for some Etys.

If my environment was always quiet, the 9927 would be sufficiently good for the rest of my life. They are that perfect for me. Ive probably spent thousands on several good full sized headphones and IEMs from grado, beyer, senn, etc... The 9927 is in the top 10 headphones ive heard, regardless of price.... not saying they compete with the likes of HD800. But ive heard far more expensive headphones sound much worse, with their skewed response and smeared details. But the lack of isolation really hurts the 9927

 

[glove4]

I have owned the 9927 as well. I really wish Monoprice would put the drivers in a different housing to improve isolation and long-term comfort. I want that SQ in a much better design that I'd be willing to pay more for. But the stuff Monoprice keeps putting out is crap for your average listener looking for cheap and muddled ear candy. The Soundmagic E50 is definitely a step above the 9927 and you're going to pay three times the cost of the 9927 at least. It is the closest I think you'll get to the 9927 in SQ and overall improved quality all around. I know of no other IEM under $50 that immediately compares with the 9927's distinct sound quality.

 

[Lad3]

I've "come around" again to the ole 9927. For some reason, it now seems to fit just right and feels comfortable. Plus, I've started to notice more subtlety in the sound and range - tho' I haven't played or burned them since I last put them away.