Etymotic ER4B: the original

Discussion in 'IEMs and Portable Gear' started by Degru, Nov 20, 2019.

  1. Degru

    Degru Facebook Friend

    Joined:
    Jul 22, 2017
    Likes Received:
    136
    Trophy Points:
    33
    Location:
    Portland, OR
    As old as this IEM is, I don't really see that much info/impressions about it, that or it is overshadowed by modern stuff too much.

    In any case, I really feel it is a hidden gem these days, and am curious to hear more opinions and impressions about it.

    Personally, I feel like it is the most accurate sounding IEM I've tried. I am not merely talking about the diffuse field FR; the dynamics and timbre this thing has are really impressive in general, let alone for a single balanced armature.

    One thing I need to clarify first: this is NOT merely a frequency response difference from the ER4S. I have EQ'd ER4S to the exact same frequency response as ER4B and vice versa (confirmed with measurements) and it does not sound the same as the real thing despite having the same frequency response and physically being the same driver.

    Misc. impressions:

    Detail: same as ER4S, which is to say about HD800 level or maybe above. Hard to say conclusively, since so many factors affect perception of detail resolution.

    Tonality/FR: Pure diffuse field. Definitely not for everyone, and many tracks are simply not mastered for this kind of tuning so it's not something I would recommend to anyone right off the bat. Not much to say about it past that, because its real strengths lie elsewhere..

    Comparisons:

    - vs ER4S: I should note that I compared ER4S and ER4B in both stock form, as well as EQ'ing one to the other (with measurements) to try to eliminate bias due to FR difference. The physical difference between the two is only the cable; the driver units are the same ones. Anyways;
    The ER4B is MUCH more dynamic than er4s. Where the ER4S has a more dry timbre and sounds flat and sterile, the ER4B is much fuller sounding, despite having a brighter frequency response. When the ER4S is EQ'd to the exact same FR, it is still no comparison. Bass on ER4B has actual impact, and dynamic contrast in mids and highs is super obvious whereas on ER4S most tracks sound "about the same". It's really obvious on live and binaural recordings; the ER4B has a much more accurate sense of depth, whereas the S has everything at about the same "layer".

    - vs ER2SE: For all the improvements that ER2 has over ER4S, the ER4B builds upon almost all of those while bringing all the strengths of ER4 along with it. ER4B is more dynamic, detailed, smoother in the treble, though the ER2 still has a bit of a lead in upper treble extension.

    - vs Sony IER-M7: ER4B has considerably faster/more resolving bass; the M7 appears to be pushing its bass drivers a little too hard to yield a truly clean response, though it has a more consistent response in the lowest subbass compared to the ER4B. Dynamics and timbre are impressive for a BA IEM, though not on the level of ER4B. Detail resolution on M7 is worse, though not sounding lacking.

    - vs HD800: IMO ER4B has better dynamics. Faster. HD800 more laid back, wider and more diffuse in presentation/timbre, whereas the ER4B is much more focused and forward. However I'd say HD800 is one of the closest comparisons sound-wise, despite having entirely different kinds of presentation and FR. HD800 has better really high treble extension, and a more physical response in the lowest lows (expected, comparing IEM to over-ear). HD800 does sound cleaner in the mids in some cases, though this is hard to compare due to IEM vs over-ear, presentation, etc.

    - vs Utopia: ER4B definitely faster. Has noticeably better separation in the low mids and bass. Highs on Utopia seem a little bit compressed in comparison, although more sparkly in tuning (though more uneven). More perception of "clarity" in that region, though it ends up sounding a little fake. I feel both ER4B and HD800 are more dynamic and accurate in general, FR/tonality aside. Utopia has overall a little bit "too clean", "larger than life" quality to its timbre that makes it sound more impressive at first than it really is, which is a quality I have noticed on the lowly Creative Aurvana Live as well. Not a bad thing, just an observation.

    Cons:
    - ER4B is still a single balanced armature, so it will fall behind in subbass below about 35-40hz. Understandable, due to how physically tiny the driver/diaphragm is. This can be alleviated substantially with a little EQ though, and still surpass most BA implementation I've tried.

    - Treble air/extension, though improved from er4s, is less spectacular than a good dynamic driver headphone. Again, understandable since it's a single BA, however it still impresses in this regard considering the limitations.

    - Very picky about how you insert it. Angle and depth matter a lot. Loses a lot of dynamics from lack of insertion depth, and loses a lot of clarity if you don't angle it right and it's pointing at the wall of your ear canal at the bend.This is however also true for ER4S and any other ety, tho still worth mentioning.

    - Definitely not for all music. Lots of EDM tracks for example suffer from the extremely fast decay, and lack of dynamics in the track becomes painfully obvious compared to a headphone with bassier or less bright tuning. Not an IEM for sitting back and relaxing, though I've gotten more or less used to it and can do so just fine .

    Speculations:
    From what I've read/understand, the filter circuit used in the ER4B compensates for some of the electrical properties of the BA, which allows the amplifier to drive it a lot more effectively, this being the primary reason for the improvements over ER4S mentioned above.


    Anyways, would love to hear others' thoughts about this thing. Hopefully what I wrote makes sense. Trying to be as honest/accurate as possible with my impressions considering my relatively limited experience with different audio gear.
     
    Last edited: Nov 20, 2019
  2. Lyander

    Lyander Official SBAF Equitable Empathizer

    Friend
    Joined:
    Feb 25, 2017
    Likes Received:
    8,601
    Trophy Points:
    113
    Location:
    Pasig, Philippines
    Haven't tried loads of Etymōtic gear, and certainly not the ER4B specifically, but while I definitely dislike their target curve I can appreciate how "neatly" they present sound. They're almost never muddy (not defined here as a function of bass bleed), though the models I've tried (ER4SR/P-T/6i) have all been sterile in a way that highlights coarse detail but loses nuance in recordings. Good positional cues, ludicrous channel separation, but way too fast in decay, enough so that there's no real sense of weight to anything. Dead air up top to boot, which kinda bites but isn't an instant deal breaker for me.

    Of course, the newer Ety models are supposed to have alleviated those issues. Might be worth investigating if someone wants that sort of uber-clean, "hyperreference" sound. I don't know about resolving more information than the HD800, but then again, the 4B is unknown to me. I do agree that their line is rather forward-sounding, but not in a particularly pleasant way.
     
  3. Degru

    Degru Facebook Friend

    Joined:
    Jul 22, 2017
    Likes Received:
    136
    Trophy Points:
    33
    Location:
    Portland, OR
    Your description of ER4S pretty much matches my own. You should try out the new budget ER2 model; its price does not dictate its performance. Since it is a dynamic driver it's a whole different beast, and much more fun sounding overall, even the SE model. I recommend it to people over er4 nowadays because it's a much more engaging listen than the usual BA models, and er4b is too clinical of an FR to recommend to just anyone.

    A note on er, note weight on er4b. It has a lot more punch than the S, though it still has the fast decay. Things will sound properly full on the attack, but if the recording does not have the decay you're looking for it still won't do anything to alleviate that. Dry coarse timbre is all gone though, and nuance in the track carries across well, as long as it isn't totally incompatible with the DF tuning.
     
  4. Lyander

    Lyander Official SBAF Equitable Empathizer

    Friend
    Joined:
    Feb 25, 2017
    Likes Received:
    8,601
    Trophy Points:
    113
    Location:
    Pasig, Philippines
    Aye, price doesn't totally dictate performance as far as I'm concerned, I've tried a few scary pricey headphones that, while still very pleasant, weren't nearly worth asking price to me (e.g. Hifiman HE1000 V2). I'm not really in the IEM game since the Galaxy Buds aren't entirely horrific and serve well enough as earplugs for when traffic is ridiculously loud, but I actually have been excited to try the new Etys myself just as a data point after someone brought them up elsewhere and gave tentative impressions.

    I'm fine with systems not adding decay where none exists, though I'm not mad when they do so as long as it's tasteful, I'm just personally miffed when it takes away from something that feels like it should be there. Probably explains my preference for tubes and hybrids— sins of commission > sins of omission, as it goes.
     
  5. Degru

    Degru Facebook Friend

    Joined:
    Jul 22, 2017
    Likes Received:
    136
    Trophy Points:
    33
    Location:
    Portland, OR
    Mm, I kind of want to try getting an amp with character like that. I got to try Headroom Millet Hybrid at a store and it sounded quite spectacular. Drove cans really well, and had a nice weight to the sound. Couldn't tell if it was due to tubes or just being a good amp in general tho. However the two pure tube amps I've tried have been disappointments; though they were some multi-thousand-dollar memes from companies I've never seen talked about much, so I guess they lived up to expectations? Gotta get my hands on a Crack or something and see what actual good tube implementation is like.
     
  6. dietwater

    dietwater Acquaintance

    Joined:
    Jan 17, 2020
    Likes Received:
    63
    Trophy Points:
    18
    Location:
    India
    Hijacking OP for a technical post. This is the electrical parameter model difference between the etymotic variants.
    https://m.imgur.com/gallery/7AIbRZI
    Please understand that the natural impedance and inductance of the er4 ba module is something I reverse extrapolated from the graph and may not be 100% correct. It's the shape of the graph that I'm stressing here than the points in the graph itself. Actual point of asymptote could be anywhere from 3-8khz depending upon how parametrization changes.
    A post by rinchoi
    http://rinchoi.blogspot.com/2012/03/etymotic-research-er-4b.html?m=1
    Pease go down to comments, to you'll see one comment that describes some of the equations of BA drivers.
    First up, a ba is very similar to a dynamic driver, just small and encapsulated (think of something like a cooker whistle). By its own it cannot push high amplitude displacement over the low frequency region. Think of amplitude displacement as the number of wavelengths of the wave that is set into oscillation. This is the reason why most BA need deep seal so the amplitude displacement requirement becomes lees. If you're thinking this is cheating, it is the same principle by with designs that are typically tweeters in speakers like the hd800 ring radiator or focal utopia m-beryllium are able to make bass by virtue of being close to the ears.

    It is important to understand that not all BA are created equal either. While etymotic uses Knowles BA 29689, guided by a set of filters by etymotic, shure and Sony make their own ba, some of which are physically larger and can do higher amplitude displacement in bass. The textural/transient qualities don't stop with bass but also can be there till mids/treble. A tubeless mid ba implementation is the reason why Andromeda midrange sucks (imo) with zero texture or pizazz. Like chorus has zero definition between the images. All of the air push is getting eaten away by air turbulence. Now I know there are people who'd prefer this because it will reduce the harshness for poorly mastered music, but by pure engineering approach, andromeda is as ridiculously wrong as you can get with fidelity on a balanced armature.

    Now I'll excuse myself from the physical filter design part for BA since it is very complicated and my knowledge in it is minimal. It has to deal with channelizing the waves and making proper selective amplification/attenuation of different frequencies.
    https://earphonediylabs.com/shop/ea...of-knowles-ed-29689-balanced-armature-driver/
    You could probably make your own etymotic as well if you can get to know the filters used. Here's a diy variant.
    https://earphonediylabs.com/shop/diy-kit/etymotic-research-er4p-b-x-extended-range-in-ear-monitors/

    Now let's get into electrical parameter modelling. Please look at the image I have liked above. Imo, this is one of the most genius electrical compensation I've seen implemented on a headphone, outside of the current feedback amplifiers like my apogee groove. This electrical compensation is first and foremost guaranteed to give you better phase coherency in the drive primarily because of the way the load sharing is now done. Apart from the phase coherency, there's a beautiful side effect of the parallel cap as well. It will now store the energy for bass and give it more impulsively for the ba. If the ba can mechanically handle the bass, you'd get some of the best bass available just because of this load sharing optimisation. In terms of physical meaning, I can probably relate this to be the difference you get on a hd800 when going from a limp amp to a good amp. This electrical compensation improves the bass transients just like a good amp does, but a lot more efficiently and coherently than a good amp.

    Diverging from the current post, let me tell you what the groove does. Apogee refuses to leak it's internal specifications. Basically it's a current feedback amplifier, but with some compensation to have minimal alteration of headphone fr. Most of the amplifiers shape the output voltage to be the shape of the input digital signal (music). When these interact with the r-l + back emf load of a headphone, the resultant current will have a phase shift. Now it is important to understand that the actual physical movement happening is due to interaction of current with the magnetic field of the headphone. The phase skew due to designs from a voltage shaping amplifier will affect the mechanical phase/transient response and you'll get a somewhat non true to input signal integrity since these interactions will muffle/cancel each other, albeit not typically highly audible. Now there's a catch with typical current feedback amps, it's not exactly a problem of current feedback amps, but rather a compatibility issue. Most headphones have their fr tweaked to be the expected target from a voltage drive source. Some headphone like a hd598 have an impedance spike in the bass to reduce the energy shared at that region since too much energy over there will mechanically distort the driver - high impedance, same voltage will result in low current. A current feedback amp will have less consideration of that since the current is constant and it'll throw your headphone off whack. My hd598 distorts with my apogee groove because of this reason. The groove has some compensation to let the fr be as much unaltered as it can but it's still a current drive topology in pure essence. There is zero reason to worry about the 21 ohm oi of the groove. It doesn't do anything since the parametric model of the amp is now completely different. You should be more worried about compatibility of your highly voltage drive compensated headphones like hd598 impedance spikes, or the voltage drive tuned crossovers in multi ba setups. It's not a problem of the groove, it's not a problem of your headphone. It is a compatibility problem.

    Apart from current drive, Of course there's also things like srd7 for electrostats and there are stuff that tap speaker output to headphones or systems like raal sr1a, but that's cheating and not an energy efficient design either (they are just brute a lot in and throw away 99%).

    Back to etymotic, I find it interesting that @Degru found the etymotic easier to drive. With the parameter modelling I could find that they should actually get harder to drive. To get better bass you'll have to drive the capacitor properly. To get better treble you'll have to drive the inductive part of the ba properly. And there's also an asymptote of impedance maybe around 7khz. If there is not enough driving force and slew there either in the source and sink part of the amp I assume that that freqeuncy might get a little offsetted and might come in coarse due to only half of it being driven well. I expected that if the ba could handle the pressure, the bass performance would be much more solid and capable and from your post it does seem that it does have the capability.
    For those wondering, the er4b with all its electrical compensation was etymotics original variant. It was meant for binaural diffuse field accuracy first and foremost. People complained the brightness was too much with compressed music, hence etymotic removed some of the filters and made the earphone "softer" with the er4sr. The fr change is a side effect of this softer transients and not the other way around. You cannot get a er4s to sound like er4b unless you have a really powerful amp + attenuator making the er4 follow the amp voltage shape just like speaker amps drive headphones. Er4b was the step down from their professional er2 (not the new er2 dynamic driver) which was a earphone meant to be coupled with a special head simulator + mic assembly. As of today, etymotic has withdrawn the er4b from retail/consumer channels and it sells directly on their own site.
    Last but not the least. It is important to understand that this design is from nearly 3 decades ago. All sorts of enhancements have come up in ba designing and acoustic filters and I expect something from Logitech UE or Jerry Harvey or other good iem manufactuers (sorry I don't have faith in non pro companies like campfire audio, having disappointed by Andromeda) to have overtaken the er4b for pure fidelity and ruthless accuracy. I believe ue900 pro is one of those targeted to take down etymotic. There's also the Sony ex1000 which is apparently diffuse field and highly technical but I personally haven't heard yet. Yet, I just can't simply stop drooling over how amazing stuff etymotic has pulled off with a 20$ pair of ba and some genuine engineering thoughts that work on electrical and mechanical principles. In comparison, the lack of engineering insight in most of modern iems is distressing, especially when they cost like 4x the etymotics (looking at you, andromeda!)
     
  7. Mochill

    Mochill Rando

    Joined:
    Apr 7, 2017
    Likes Received:
    4
    Trophy Points:
    3
    Location:
    USA

Share This Page