right. well I have spares I just didn't feel like wasting them that's interesting from an FR perspective though.

I am also using the RE-600 with the tiny bi-flanges and I get a good seal/fit without breaking the connector, just sits well.
that's pretty unfortunate though, my cable feels kind of nice. maybe the build is better on the 600, I don't really know.

so while I'm not sure if you heard the RE-600, I find the midrange to be a lot cleaner and less 'dry' on the 600 vs the 400... do you think the filter change would keep the midrange of the 600, or is that like the filter doing that?

thanks!

There's really no way it can be more refined, other than better channel matching. Which can and does happen - my RE-400 pair are well matched, only mismatches are ~ 2 dB in 8 and 12k range.

Note to self: do not use dodgy sine generators displaying 0.5x actual frequency. Note to self 2: shut up about lack of peaks unless there are actually none.

Have a screenshot of my RE-400 correction. It is not precise enough in the highs, I've ran out of parametric eqs - really have to write a better equalizer.
This is off the Hilo phones output.

Accudio sucks. By sucks, I mean it will turn your IEMs into highs depleted bass monsters most of the time. RE-272 (lower impedance) damper brings out the treble, so does deep fit. (in addition to improved soundstage) It also slightly speeds up bass. The 20kHz actually is at -18 dB. (roll starts at 16k)
They do remain superbly controlled and super smooth while not being imprecise. That's low distortion, no ringing and good decay times for you.
Head to head with equalized B2 - B2 keeps the "BA edge" and is not refined in the bass at all, mids and upper mids are gritty in comparison, only the highest end is comparable... but it is also extended to 18k.

The subbass boost is 6 dB, which is very close to O-W. No, I neither use any compensation curve nor the graphs while equalizing by ear.

The mismatch in RE-400 is at resonant freqs - they're slightly off, by 200 Hz or so.

Planx - I'm in the same boat. I don't like the W4 and find it, as you say, competent but utterly boring. The massive upper-midrange suckout that Tyll recorded - I hear that. Plus a peaky treble, and a lot of dryness, and just generally not very clean mids. When I posted about it on HF I got shouted down, just as when I posted negative impressions on the W3. At least this time there were no PMs from vendors concerned that I was interfering with their business.

I don't hear any of that with the UM3x, and I like the UM3x a lot. It's far from perfect - the bass is loose, the treble is rolled off, and in general it has a very mid-heavy, almost vintage-headphone sound. But considering what passes for sound quality in universal-fit IEMs, the UM3x is about as good as it gets. It's not fatiguing, it has nice mids, good detail extraction, nice dynamics, and it's one of the few universal IEMs that are comfortable for me.

Fit matters hugely in IEMs, and I have friends who swear they don't hear the same thing as I do, whereas when it comes to headphones and speakers we usually agree. So YMMV.

I don't much like the SE535 either, and I don't hear the same thing that others do. Yeah, they're nice and linear from the deep bass to somewhere around 1-2khz, but then up from there they're a mess. Piercing, metallic highs, and unnatural upper mids. No idea how anyone could find them natural, but again, I suspect I'm not getting the best fit here.

I also never liked the Etys much - they did a lot right up to the treble, but the highs were so overblown that I could never get them to sound anything but thin and brittle at normal listening levels. I guess diffuse-field equalization just isn't for me. Plus they were about as comfortable as having drill bits stuck in your ears.

So far the only custom I've had was the ES2, and while in terms of detail it doesn't outdo today's universals, the tonal balance was better than any universal so far. I'm not going to try the ludicrously overpriced SE846 simply because I don't want to support the trend of headphone price gouging but the ES5 or something similar may be in my future.

I think in general Westone's pro products are far, far better than their consumer line. I liked the UM2 for its time too, though now it's a bit obsolete.

Agreed to your agreement catscratch!

Even though you and I share different opinions about the ER-4, which I completely understand as it can be quite bothersome to some, I think it's fair to assume that most of the people who try the W4 share similar thoughts as us, until they become loyalists to the W4 for a particular reason I cannot seem to understand. With the owners of the W4, I've even had them agree that the W4 sounds dull and there's a problem with the upper-midrange. Great. The problem arises when these "loyalists" continue to argue that the W4 is the best IEM they've ever heard.

I'm sort of fed up with these stubborn people and I choose to avoid clashing with them, but for the people who share the same thoughts and experiences, lets just spend our good money on something else worthwhile.