In my quest to find a good sounding, isolating pair of IEM's, I recently purchased and demo'd several of the top contenders available from Shure and Ultimate Ears:
Shure SE530
Shure SE420
Shure SE310
Ultimate Ears Triple.Fi 10's
The two aspects I was looking for in a pair of IEMS were:
1. Sound Isolation - as my most frequent use of IEM is for cross country flights to California
2. Balanced / Neutral Presentation - I appreciate an accurate presentation, with little coloration to any aspect of the frequencies. My full sized headphones of choice are Beyer DT880's (600 ohm) and AKG K701's
In listening to each of the above referenced earphones, I do so using a flat equalizer setting on my Cowon iAudio 7 player.
The top two models from Shure (SE530 and SE420), are great earphones...with an emphasis though on presenting a warm sound. On both models the Bass / lower frequency were outstanding. Kind of reminded me of way a number of the Sennheiser Headphones sound. Out of the SE530 and SE420, I preferred the SE530...as the highs were better represented.
Next, I tried the Ultimate Ears Triple.Fi 10's...
The Triple.fi 10's are really great sounding IEM...amazing sound reproduction throughout the entire musical spectrum (lows, mids and highs). Definitely more balanced than either of the top Shure models (SE530 / SE420). The highs of the Triple.Fi 10's were excellent, not being far behind the highs presented in my Etymotic ER-4P's...
The two reasons negitive aspects of the UE Triple.Fi 10's were:
1. They didn't provide good sound isolation from the outside world I needed
2. Vocal representation - I felt on some songs, the vocals were "slightly" recessed (a common signature trait of UE's)
Both of these issues were really minor, but the more important of the two was the sound isolation.
So next...I decided to try the Shure SE310 model (after reading the review on Headroom). Additionally Tyll gave the SE310's high praise.
In listening to the Shure SE310, I felt this IEM provided excellent balance between the frequency spectrums (lows, mids and highs). Bass was not overpronounced like I felt on the SE530 and SE420. Clarity on the SE310 is excellent and the vocal presentation crystal clear and upfront.
In the end, I surprisingly chose the Shure SE310 as the keeper. For my purpose and musical preference, it met all the criteria. If I want to add a bit more warmth to the sound of the SE310, I simply tweek the equalizer on my iAudio slightly...that all. Additionally, the SE310 was the cheapest IEM of the group.
Considering that I allocated a budget of $500 for an IEM purchase, I must say that I surprised that my choice was the cheapest of the three...the SE310.