ZMF Aeolus Measurements

Discussion in 'Headphone Measurements' started by purr1n, Aug 24, 2020.

  1. purr1n

    purr1n Finding his inner redneck

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    A while back, @zach915m sent me two headphones for review: Verite and Aeolus. The first headphone I opened up and tried out was first was the Aeolus. The reason being is that I loved the Atticus, so I was curious how an open-backed Atticus would sound. The Aeolus uses a biodyna TPE driver, which has a certain timbre, shared with the Fostex dynamics and even the Sony R10. I would have spent a lot more time with the Aeolus, but unfortunately, the Verite sucked most of my time, and as a result, I really didn't spend as much time covering the Aeolus as I would have liked.

    I won't be spending much time covering impressions of the Aeolus as this has been covered in depth already by other members here:

    https://www.superbestaudiofriends.org/index.php?threads/zmf-aeolus-impression-and-measurements.7006/
    https://www.superbestaudiofriends.org/index.php?threads/zmf-new-headphones-vérité-and-aeolus.6893/

    The plan here is to provide a comprehensive set of measurements before I ship them off to @Lyander via the way of @gixxerwimp (if it's OK to forward to you first - I will cover shipping expenses if you are willing).


    ZMF Aeolus
    Frequency Response
    Top: miniDSP EARS with SBAF compensation
    Bottom: Flat Plate (no ear) Coupler (compensated)
    upload_2020-8-24_9-2-33.png

    Notes:
    • FPC 8kHz dip could be a measurement artifact. We will check CSDs later on to confirm.
    • EARS 4kHz dip is probably there but not as pronounced as shown?

    This one below is from the foam coupler that attempts to some extent to simulate a free air measurement. There could be some advantages to gaining some insights into the nature of the higher frequencies as this measurement will be somewhat isolated from ear and head reflections. This also shows us how sensitive the bass frequencies are to seal since these measurements are in effect not sealed, therefore take anything under 2-3kHz with a grain of salt. Lower frequencies and midrange may be underreported, sometimes severely. With orthos and some dynamic drivers that rely on a seal, peaks may be exaggerated.

    ZMF Aeolus
    Frequency Response
    Foam "Free Air Sim" Coupler
    upload_2020-8-24_10-7-33.png
     
    Last edited: Aug 24, 2020
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  2. Lyander

    Lyander Too sensitive for SBAF

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    Wasn't the Atticus and Aeolus a TPE driver? Biocell as far as I'm aware are Eikon and Auteur, and given my obsession with the HP-3 I'm actually sad I can't meet the one dude I heard who owns an Auteur in the Metro Manila area to demo just now, sigh.

    But hey apparently diaphragm material isn't the end-all, be-all of sound; I'm just curious how a biodyna might perform when not in a soft surround or how a traditional plastic driver might in a soft surround.
     
    Last edited: Aug 24, 2020
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  3. purr1n

    purr1n Finding his inner redneck

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    Oh yeah, that is correct. It sounds damn good though and could have fooled me.
     
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  4. Lyander

    Lyander Too sensitive for SBAF

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    Poisoning the well but eh, I've been reading through all the ZMF dynamics stuff as they were going on and recently too so may take a while to divest myself of expectations while I'm evaluating it... eventually.

    Having massive troubles with both the forwarding service I use and DHL alike, each have two not-inexpensive (to me) parcels not technically "missing" but unavailable just now so I dunno, take your time with this, but if you send it off earlier gixxerwimp will get to play and compare with the awesome Focal duo for longer :p
     
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  5. purr1n

    purr1n Finding his inner redneck

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    ZMF Aeolus
    CSD
    Flat Plate (no ear) Coupler (compensated)
    FPC Aeolus L.jpg
    FPC Aeolus R.jpg

    So it turns out that the 4kHz dip seen in the both the EARS and FPC measurements is a ridge 4.5kHz in disguise. A peak near 5kHz will result in some edge. I'm not totally sure that I hear this (I suspect I may have some hearing damage that results in a deep narrow null around 4-5kHz). The ringing is narrow and sometimes this may be more difficult to discerne.

    The taller and broader, but more short-lived ridges at 6kHz and 9kHz were more noticeable, oftentimes heard as glare and stridency. In general, these peaks weren't an huge issue because the slightly lifted bass balances and masks these out. The peaks aren't jutting out like a high mountain like on the HD700.


    Let's take a look at CSDs from the FAC to confirm since this coupler will have less bounce around of sound waves inside the cup. Note that the 4kHz ringing is confirmed below, it's not from internal cup reflections. It more likely the driver. It also appears that the 8kHz dip from the FR plots may not really be there, and that the mid-treble and upward are smooth.

    ZMF Aeolus
    CSD
    Flat Plate (no ear) Coupler (compensated)
    FAC Aeolus L.jpg
    FAC Aeolus R.jpg
     
    Last edited: Aug 24, 2020
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  6. purr1n

    purr1n Finding his inner redneck

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    I curious to get your thoughts. I know you like the Klipsch Heritage HP-3. This is similar sounding, but less extreme. From memory (and my memory always seems to be right despite my constantly doubting them), the Aeolus is more resolving of fine details. TPE = biodyna tone and timbre, but better microdynamics and plankton. Of course these things could come down to the motor, magnet, etc.
     
    Last edited: Aug 24, 2020
  7. Lyander

    Lyander Too sensitive for SBAF

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    Happy to share them when I'm at least reasonably sure the parcel doesn't get Vanished into the aether! Besides other stuff in life missing parcels are stressful lol.

    Yeah the Klipsch is grand other than some treble hotness (midrange recession = fake headstage!), but the fact that aftersales is nonexistent, replacement pads can't be sourced, and they've apparently been quietly discontinued irks me. Klipsch sucks for that and the headphone now gets a sad DO NOT RECOMMEND from me, much as I love the sound.

    I think I've asked elsewhere but if you could get FAC on the Klipsch or Fostex biodyna that would be ace; from what I could tell trying to convert the MiniDSP to an FAC with open cell foam the ridges on HP-3 are definitely more pronounced, and bass level just TANKS. Thought the sealed CSD made more sense for them, which is why I was wondering at your assertion that FAC response was more likely representative of what is perceived.

    Maybe closed designs or ones where bass response is more reliant on seal require a seal for measured decay to make sense? Not sure, nowhere near enough subjective data points on my end.

    Bowing out of the thread temporarily, I know I'm excited but I've been trying hard to keep my SNR down. HD700 thread was hard :))
     
  8. purr1n

    purr1n Finding his inner redneck

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    As far I am concerned, you can crap post all you want including talk of any South China Sea politics. Crap-posting is a privilege. You've earned it.
     
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  9. Lyander

    Lyander Too sensitive for SBAF

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    You've mentioned before but I'm trying to keep things audio-related cuz many members I respect on here do just that.

    Also I'd be at my keyboard for a solid week if I ranted about all the shit going on my end now and I should be trying to start a new thesis from scratch because my old one required I gather data in person and... yeah that isn't happening. The quip about the West Philippine sea (;)) informs me you know of at least one of the things currently contributing to my developing into a cantankerous old fart though.

    (I am aware that this is a shitpost.)
     
    Last edited: Aug 24, 2020
  10. purr1n

    purr1n Finding his inner redneck

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    ZMF Aeolus
    Attack and Decay Envelope for Ten Burst Sine
    B1696 Aeolus.wav_burstenv.jpg

    I'm curious about the 4800Hz attack. It's sort of the anti-Grado. I wonder if the extended decays in the mid and higher frequencies are a result it being a semi-open can. In time, we'll get more data and see what other headphones exhibit this behavior.
     
    Last edited: Aug 24, 2020
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  11. purr1n

    purr1n Finding his inner redneck

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    Distortion plots below. Note that Aeolus does not like being pushed hard. These are at 100db. Will provide lower level distortion plots. In time, I'll figure out a visualization that shows 80db to 100db.

    ZMF Aeolus Left
    Distortion (Traditional and Alternative)
    1kHz approximately at 100db SPL
    upload_2020-8-24_11-19-50.png

    ZMF Aeolus Right
    Distortion (Traditional and Alternative)
    1kHz approximately at 100db SPL
    upload_2020-8-24_11-24-0.png
     
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  12. purr1n

    purr1n Finding his inner redneck

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    Here are 90db and 80db SPL approximate respectively. Note D3 and D4 rise. We are hitting the noise floor with decreased output. It's kind of messy with so many plots. In time, I'll figure out a way to display this in a nicer way, and with more granularity. It's nice to know at what level when stuff "goes south", how it goes south, and whether it be the bass (usually) or in the highs or mids.

    ZMF Aeolus RIght
    Distortion 1khz to 90db SPL
    upload_2020-8-24_11-26-25.png

    ZMF Aeolus RIght
    Distortion 1khz to 80db SPL
    upload_2020-8-24_11-28-21.png
     
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  13. purr1n

    purr1n Finding his inner redneck

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    ZMF Aeolus
    Impedance Curve
    YEL = Free air
    GRN = On head
    upload_2020-8-24_11-53-38.png
     
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  14. zach915m

    zach915m MOT: ZMF Headphones

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    This could very well just be the descrepancy between my AP measurement rig and Marv's rig - but if those are the distortion measurements on the set Marv has it might be worth me checking them out to make sure nothing is wrong with those drivers, and the descrepancy is just between my rig and Marv's rig vs an issue with the headphones.

    For reference an off the shelf aeolus I have here THD at 90 dB:

    aeolud_THD90.JPG

    And at 110 dB

    aeolud_THD110.JPG

    The aeolus driver does indeed distort more at volumes above 100 dB due to the smaller magnets vs our other headphones, as they are n35 instead of n50. But they should have nowhere near 10 percent distortion regardless.

    Again this may just be descrepancies between rigs and environment as I do use an anechoic box we built, but I'd rather be safe than sorry with a headphone that's going out on a tour. I'll send you an email @purr1n
     
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  15. DEATHxMACHINE

    DEATHxMACHINE Friend

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    Why is there a such a huge difference in ohms between on head and free air? Does the air pocket when it is on your head provide enough resistance/pressure to nearly double the impedance?
    It also interesting there is no spike in the sub bass region. It actually dips. Would be interesting to see an overlay of impedance vs frequency and db vs frequency to compare free air vs on head. But recording free air db would be kinda weird.
     
    Last edited: Aug 24, 2020
  16. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    The 5KHz ringing is pretty audible, but also mitigated, along with other treble irregularities, by messing around with headphone placement on your noggin. It's not too severe regardless, mind you.

    Otherwise, these to me sounded like a muscular HD650 on amphetamines. Big bass, but not what I'd call basshead levels my any means, balanced mids and treble, but with a bit of extra zing and sharpness. Bolder, more vivid sort of HD650 sound.

    As much as I appreciate the Verite and other ZMF cans, I own an Aeolus myself, and it wasn't because of monetary reasons. I just dig them overall.
     
  17. purr1n

    purr1n Finding his inner redneck

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    It's likely I'm running at higher SPL. Different rigs and calibrations and all. Let me recheck.
     
  18. purr1n

    purr1n Finding his inner redneck

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    Yup, maybe just a bit of some edge sharpening. Despite this, no graininess, sandy, or anything off with the timbre.
     
  19. ChaChaRealSmooth

    ChaChaRealSmooth SBAF Gearmaster

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    Interesting CSDs; I've noticed that the Atticus has some similar behavior in regards to the 4kHz ringing, so this may very well be driver behavior:

    [​IMG]
    [​IMG]
    *note that these measurements are with the stock pads (Ori?)

    Curious that the ringing is much more pronounced in the Aeolus. I certainly don't recall any ringing in the Aeolus bothering me (my thoughts are that ringing in the mid-to-upper treble region might bother me the most judging by the RAD-0, but I really need to get my ears on more headphones to make sure). I'm wondering if the differences shown here has anything to do with damping.
     
    Last edited: Aug 24, 2020
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  20. murphythecat

    murphythecat Friend

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    @purr1n id be curious (and im sure many others) as to your impressions on the Aeolus!
     
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