On Amp:
Unlike with other players, you do not need an amplifier with HM-601 as it is powerful enough to drive headphones. I specifically asked because of the HO's variation in frequency response with IEM's impedance.
In other words,
HM-601's Head phone out == Signature of 601 + Signature of IEM + variations introduced due to output impedance of the player
HM-601's Line out = Signature of 601 + Signature of IEM
The second one is a little easier to guess for me. But, for the first one, I need to try the IEMs themselves to see how they react - some don't show as much difference compared to being driven out of other sources, some vary wildly.
Let me repeat - you
do not need an amp.
IEM:
Fatigue free listening with detail and good sound stage narrows it down a lot. These are impressions out of
Clip+ / UHA-6S. Their combo with HM-601 is yet to be tested, so take it with a pinch of salt for now.
Radius DDM-2 ($200 new from Musica Acoustics, Japan - Contact via E-mail to see if they still sell it):
Details and Pros:
- Good bass and mids
- Well rounded presentation.
Cons:
- Not a great build quality
- Zero isolation
- Not as engaging on first listen
- Good but not great in terms of IEM ranking.
JVC FX700 ($250 used from Head-fi, $350+ new from Japan):
Details and Pros:
- Great open sound stage and excellent imaging
- Gorgeous wood housing ensures good build quality
- Best timbre I've heard from an IEM - even if it's not perfect for every instrument
- Well detailed but far from dry sound
- Bass with good extension
- Treble is also very good
- Technically as well as musically good IEM
Cons:
- Shorter cable (needs the bundled extension cable for normal length)
- Not much isolation
- Bass quantity necessitates loose fit and low volume to make it balanced sounding
- Lower mids are slightly recessed and sound slightly cold yet very good unless you are a big fan of vocals
Earsonics SM3 ($450-500? new, $300 from Head-fi):
Details and Pros:
- Slightly thick sound with centering of the vocalist / main player
- A head surrounding sound stage that is unique
- Engaging mids, good bass, fatigue free for all genres
Cons: Highly polarizing
- Comparing to other IEMs is a royal pain. Loves to be loved in solitude
- Has details but it never shows through due to the slight veil
- Treble seems recessed at first listen but once you get used to it, it's not missing much except the extension, sparkle. Is dark, but not by too much.
- Sound stage puts you at the center of action and placement is a bit weird next to the normal IEM stage
- v1 was badly built - like dfkt remarked "looks like a corn flake". v2 was better built
- Every genre sounds the same - Death metal to Classical. If you like the signature, you don't need anything else, but if not...
Sony EX-1000 ($350 new in US):
Details and Pros:
- Perhaps the best quality bass I've heard - it manages to put a smile most times, but does not have great bass quantity
- Distant but engaging and sweet sounding mids
- Great sound stage size
- My favorite IEM for Classical and Jazz music
- Fast enough, effortless at times
Cons:
- Fit can be weird. I am fortunate enough to get a good fit most times
- Imaging does not use the full stage size like FX700. Imagine a half circle stage around you in a large hall. That's how it feels like
- A little thin sounding, not a con, but may be if thick sound is your preference.
- A little bit of upper mid/lower treble emphasis. With some sources, it does not show through. With some others (one mentioned HM601 as source and he disliked EX-1000), it can become fatiguing.
Hifiman RE262:
Details and Pros:
- Reverse of FX700, similar to SM3 and probably, SE53X. Very vocal centric. FX700 puts instruments ahead of vocals, while RE262 presents instruments as support act to vocals.
- Very effortless in presentation, good layering and sound stage which is out of the head
- Good dynamics
Cons:
- Not great looking, does not feel like $150 quality. Many failures reported in India.
- Due to higher impedance, needs an amp (not with HM-601, but) with sources like Clip+. Though it can work well out of Clip+ / J3, drains their battery in double quick time.
- Bass quantity is about ok, but quick decaying and hence not as much felt as it needs to be at times.
- Treble is slightly recessed next to well forward mids and hence treble detail is a little hard to hear
- Spatial positioning and layering is not always great. Not sure if it depends on source as I never owned it and have tried it only out of Clip+ mostly.
Triple.Fi 10:
Details and Pros:
- Excellent deep sound stage and imaging
- Unlike normal BAs, does not sound thin
- Bass punches hard, but not too much in quantity
- Sparkling treble
- Well detailed, but still lot of fun with it's slight V-Shape
Cons:
- Fit can be weird for some. Even if you get a great fit, it sticks out of the ears like an alien ear
- Mids are not it's strength. Like most BAs, does not sound natural. Most say that mids are lacking or too recessed, which is not how I hear it.
- Thicker sound makes the bass muddy at times
I will have to try what I have (EX-1000, SM3, FX700, TF10) and see how it goes with HM-601's headphone out.
