[AudioCats]

must be:
1) non-custome
2) single driver (sorry, not a fan of tantalum capacitor cross-overs)
3) good sound isolation (otherwise I'd just use my Stax 001/003)
4) at least as good sounding as the ER4.
5) within $350 budget (new or slightly used).
 
Thanks for any ideas...

 

[phntmsmshr]

Klipsch x10 ticks every box on your list

 

[AudioCats]

Checked some reviews on the X10, seems that it is bass-heavy but not as nice as ER4 in other areas.
 
anything else?

 

[phntmsmshr]

that's not really true to be honest, the x10 are surgical in their precision, it's true that the high frequencies are a little recessed but it doesn't detract from the SQ since the separation is so good that you still pick up the treble easily. To say that they're bass-heavy is also not really accurate, just that they really shine on the low-low bass, and have as good a response on the sub-audible stuff as a dynamic driver. My main criticism of them is build quality, they look and feel frail and the cables aren't replaceable which would be good for an IEM between $280-350. My experience with ER4(P) is limited to a test listen only but I wasn't impressed with them enough to buy them so I guess YMMV. 

 

[yello131]

ortofon e-q7 or e-Q5 are Single Balanced Armatures
Seems like both of this may suit your needs..
most recent review here; http://anythingbutipod.com/2011/01/ortofon-e-q5-review/
 
another option is Final Audio heaven A1
 

 

[AudioCats]

any other options?

 

[goodvibes]

ER4? I'm sorry but what don't you like about the ER4? It may help recommendations. If it's a bit too hot, the HF5 could work. The Shure 315 has more bass and less etched. Klipsch X5 gets great reviews. The last 2 have vents so may not isolate as well but you'll have to try. The finals with a large vent don't isolate especially well. The MAs isolate OK but not as well as the batch below.
 
Shures, ETs and probably Westones isolate the best with foam or multiflanges. I don't know about the X5 which fits your other requirements. What I would tell you is to not get too prejudiced over X-overs. I'm also sensative to phase and currently use a single driver phone but one or 2 tants and resistors in an IEM isn't the weakest link in a portable chain if done well. It's the done well part that matters and I'm sure is noticable more often than not. 2 ways like the 535 are absolutely seamless. If you don't like it, it's not because of the X-over. There's will be others that also fit that description.

 

[Pianist]

How much isolation do you need? Does it have to be similar to the ER4 in this regard? I highly recommend JVC FX700 if you won't mind isolation on par with an average over the ear closed back headphone. It works OK for most environments with just a little bit of extra volume applied. I listen to them on the subway, albeit the subway here in Toronto is pretty quiet. It works fine for me. Of course, you won't be able to hear small nuances in your music, but then I don't think that even ER4 isolation level is enough to hear all details in music in a noisy public transportation.
 
But anyway, the real deal with FX700 is the sound. It's simply phenomenal. Your ER4 will run away in fear. FX700 stomps all over the ER4 in just about everything except clarity and frequency response. FX700 is not a studio monitor tool like ER4, so it's not as flat, but it is far more enjoyable to listen to. Next to it, the ER4 has a very limited dynamic range, frequency extension, detail, soundstage, timbre - pretty much everything. Those who think ER4 is really detailed are fooled by its small dynamic range that causes quieter passages in music to become louder and more audible. FX700 doesn't do that - it has a huge dynamic range with the proper contrast between loud and quiet sounds in the recording. Its wooden housing also gives it a much more natural timbre than what ER4 can muster. FX700 has a similar quick attack to the ER4 when the music calls for it, but it also has a much longer, far more natural decay, whereas the Etys cut sounds short and do not reproduce the full harmonic palette.
 
Don't get me wrong, I am not an ER4 hater. In fact, it was the best sounding IEM I've heard until I tried the FX700. Then I realized that BAs simply can't compete with a well tuned dynamic driver. I don't think you will find another IEM in this price range with sound close to FX700 in quality, although if you do need great isolation I recommend Ortofon e-Q7 as a nice alternative to the Etys, with a warmer, less analytical sound, but less detail. Another good option may be Hifiman RE262, but it needs an amp to sound best. RE252 is its low impedance easy to drive brother with a more neutral sound that is very similar to the ER4 in overall balance and character. RE252 housing, however, has a really odd shape and may not fit many people's ears properly. The Hifiman products offer more isolation than the FX700 as well, but are quite a step behind in sound quality to my ears although they do compete very well against the ER4.

 

[AudioCats]

 
 
This is not for portable. It is for desktop / bed side use. isolation is the #1 priority. Otherwise I would just use the Stax ( being an electrostatic guy). 
 
I don't dislike the ER4, that is why it is used as the reference model here.

 

[Pianist]

Quote:

This is not for portable. It is for desktop / bed side use. isolation is the #1 priority. Otherwise I would just use the Stax ( being an electrostatic guy). 
 
I don't dislike the ER4, that is why it is used as the reference model here.

 
So what is it that you don't like about the ER4 that makes you want another IEM for this purpose?

 

[AudioCats]

sorry my first post might have been "mis-leading". I do NOT have a pair of ER4, but I kind of remember how it sounds.   I like the ER4 alright, that is why it is the reference model here.
 
The reason I asked for "other options" is because, well, ER4 is about $200 new (BH photovideo had a sale last week, the final price was $190), and my budget is $350 for new or slightly used. I thought there might be a definitivly better choice with the extra $$..... I have not follow the IEM trands ( I don't believe they can sound better than the electrostatics

), I am considering them now mainly for the sound isolation.
 
I am in the process of getting a pair of ER4 right now.

 

[Pianist]

There is no IEM for $350 or less that sounds definitely better than ER4 and is also a fully closed design with good isolation. However, there are more fun sounding choices that will sound better with weak portable sources, such as Shure SE530, Westone UM3X and Ortofon e-Q7.

 

[Dubwicht]

[size=small]You must consider the Ultimate Ears triple 10’s.  These can be had for less than $200 on Ebay stores – fantastic value.  Not sure why the price for these has dropped so much.  I have been testing the ER4, the Triple 10’s and the Westone 2’s for about a month now in my car and like the Triple 10’s the best.  They have most of the detail of the ER4s’ but more bass and a more balanced sound and are more efficient.  The sound isolation is similar to the ER4’s.  The only down side is that they are a bit clumsy on the ears.  The Westones’ are very good as well but finicky with placement in the ears.  The Westone’s fit tight in the ears and do not protrude beyond the ear lobes.  .     [/size]