Audio Zenith PMx2 Redux and Quick Impressions

Discussion in 'Headphone Measurements' started by purr1n, Sep 28, 2015.

  1. Bill-P

    Bill-P Level 42 Mad Wizard

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    Huh? Really?

    From Tyll's measurements:
    https://www.innerfidelity.com/content/pono-player-and-promises-fulfilled

    Pono Player, 3.27 Ohms;
    AK240, 3 Ohms;
    AK100II, 3.47 Ohms;
    Fiio X5, 0.52 Ohms;
    iPad Air, 0.8 Ohms;
    Galaxy Note 4, 0.9 Ohms;
    Auralic Taurus, 0.9 Ohms;
    Simaudio Moon Neo 340HA, 0.35 Ohms

    My AK120 has a similar 3.2 ohm OI. I think ZX2 is around 4-4.5 ohm.

    I mean... not to say you're wrong or anything. I think it might have been something else. Pono wasn't particularly bad IMO. Just that the sound was a bit too smoothed over. Or maybe I just like the sound to be still slightly brighter than that.
     
    Last edited: Jun 16, 2017
  2. Merrick

    Merrick A lidless ear

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    Well, looks like I had some bad info. I thought the OI on the Pono was much higher. Perhaps it does smooth things out too much, which is why I found the pairing to be poor.

    I should plug the Andros back into the Pono and see if I like them more now. I leave mine on and plugged in pretty much all the time because it doesn't sound its best without a lot of warm up.
     
  3. Bill-P

    Bill-P Level 42 Mad Wizard

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    Yeah, really, not to say you're wrong. It's just that I found the pairing to be okay, but... not as detailed as I'd like.

    AK120 is almost equally as smooth but with a bit more treble details from what I can hear. That makes all of the difference for me. But I can imagine some folks liking Andro with Pono.
     
  4. TheIceman93

    TheIceman93 El pato-zorro

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    @Bill-P - you are welcome to borrow the Lake People to test anytime, just shoot me a PM.

    So I've got about 5 hours on these so far. I only listened to them briefly at @brencho's on the Lake People and the MJ2 with Western Electric 396A's (If I'm remembering correctly), I used the 4pin XLR on both amps. I've done all my critical listening on the RS-08 and here are some brief thoughts. I hope to post more detailed impressions before I ship them off. Keep in mind that these are the first headphones I have used on this amp since they both arrived the same day and I didn't have another amp to test with.

    The first words that pop into my head are detailed, refined and relaxed. The clarity immediately stood out to me. To my ears, these are definitely reference level headphones. I can see some people thinking these are a hair too bright but I'm less treble sensitive than a lot of people here so it didn't bother me. I successfully owned some Beyer DT-1990's for 8 months without wanting to kill myself so I would say that the PMx2's treble was certainly not fatiguing, but YMMV here. I think the Lake People may be a bit bright as well, I will need to test it with other headphones to get a better sense of how it sounds but so far, I think the RS-08 and the PMx2 make a lovely pairing. Detail for days ... maybe the bass is a bit too polite but I think that's just a limitation of the PM2's driver. Tonally, these are spot on, this is what neutrality sounds like to me. Soundstage is a little more intimate that I would prefer but instrument separation is very good, it is super easy to pick out the faintest of details deep in the track. These things are pretty easy to drive as well. Even on low gain, the PMx2 on the RS-08 starts to get uncomfortably loud around 10-11 o'clock on the pot.

    Overall, I'm really impressed. My next step is to add my iFi iTube 2 buffer to the chain to see how it responds to a bit of tube magic. My hope is that the iTube doesn't dull the PMx2's technicalities ... it hasn't so far with other headphones I've tested but I've never had a headphone in my system with this much detail.

    As a side note, since the Oppo PM2 is no longer in production, it would be awesome if Alex went the ZMF route and built his own headphones from the ground up. I think that would be something very special indeed. My brief time with his creation gives me a great deal of confidence in his tuning abilities.
     
    Last edited: Jun 16, 2017
  5. MrTeaRex

    MrTeaRex His head's not fat, he's my brother!

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    Alex modified my PM-2 at the end of May and I wanted to provide my personal findings related to amps and the PMx2. Some have noted (most recently @Hands in his updated measurements) that the proper amp is very important to the PMx2. It is not as tolerant of sub-optimal pairings as other headphones.

    To set the stage, it takes me a while to form impressions and my ears and audio vocabulary are nowhere near as nuanced as many on this site. My preferences generally lean towards headphones with downward sloping frequency response, NOS DACs, and well-implemented OTL amps (which makes me far from an expert on planars). The two sonic characteristics my ears can tolerate the least are extreme bass roll-off and obnoxious treble anomalies (I’d rather spend every day at the dentist than listen to any more Grados). The following impressions are based on these preferences and YMMV based on personal preferences and/or tolerances.

    I listened to the PMx2 with a variety of SS, hybrid, and tube amps. Normally these amps are connected to different DACs in different rooms of my home, but to minimize variables, they were all fed by a Holo Audio Spring for the following impressions. The amps are listed in order of preference.

    1. Apex Peak (hybrid) - I feel that the PMx2 prioritizes clarity and transient response. The PMx2 also requires ample power to properly control it’s extended bass. Although not the most powerful, the Peak provides enough juice while it excels in resolving and articulating transients. On the downside, it can sometimes lean towards brightness and etch. This has the potential to become noticeable in certain situations due to the PMx2’s FR around the transition between midrange and treble. An appropriate 6SN7 tube can help alleviate some of the brightness and I found the PMx2 matched well with a Sylvania green label, top getter, GTB variant.

    2. Inspire IHA-1 (OTC) - I originally had the IHA-1 farther down the list because it sounded too soft with the PMx2. At the time, I was using a pair of the same Sylvania tubes as the Peak. Swapping in some Ken-Rad mil-spec VT-231 tubes helped remedy the issue. I believe the benefits that the Sylvania provided the Peak (softening the brightness) was too much with the IHA-1. The drawback of the IHA-1 is that it can not keep up with the speed of the Peak and did not have equally tight control over the bass. (Note: This IHA-1 includes the additional step-up transformers in the input path to increase voltage gain and allow the amp to take more advantage of it’s rated power output.)

    3. Bryston BHA-1 (SS) - This was initially my favorite pairing with the PMx2 as it had enough power and didn’t result in any obvious FR oddities. The combination also demonstrated respectable transient response. However, it falls behind the Peak and IHA-1 in clarity and dynamics, as I find is typical of full SS amps. Once the FR concerns of the top two amps were mitigated (or I possibly became accustomed to them them) the BHA-1 slid a couple of spots down the list. This is the last of the amps I would consider a good pairing with the PMx2. The remainder range from mediocre to flat-out bad.

    4. ECP T3 (hybrid) - With many headphones, the potential for the T3 to be a little tubby and full in the bass is welcomed (personally, I welcome these attributes in my women too). However, with the bass emphasis of the PMx2, this characteristic became distracting and overpowering. The smooth treble and clarity of the combination was enjoyable, but I could not get past the emphasis on the low end. I used GE 12AY7 tubes and do not own many 12A*7 variants to roll in the T3 (I’m more of a 6SN7 zealot). It’s possible different tubes could properly adjust the sound as they did with the IHA-1. (Note: This T3 includes all Beezar upgrades.)

    5. Apex Teton (OTL) - The Teton is by far my preferred amp when paired with my favorite headphones. However, the PMx2 sounded loose and generally weak in the low end with my preferred 6080 tube. The natural suspect is the high output impedance preventing the PMx2 from receiving the current it needs. I swapped in a 5998, which reduces the output impedance by about half. This did result in improvements, but not enough to consider the two a good pairing.

    6. HeadAmp GS-1 (SS) - Ouch, too bright. The treble bump, possibly in combination with the mid dip, in the PMx2 FR was exaggerated by the GS-1. I couldn’t listen to this combination for very long and it appeared that the GS-1 was also lacking the power to properly control the PMx2. I didn’t care to listen long enough to know for sure.

    7. Bottlehead Crack (OTL) - I love the Crack, but the issues noted with the Teton were even more apparent. I didn’t expect much due to my experience with the Teton and didn’t listen much before sending it off to a fellow member as a loaner.
    Overall, pairing the PMx2 with different amps has been an enjoyable experience as it results in larger differences than I have observed with other headphones. The PMx2 also does not pair as well with my favorite amps as it does with some of my underutilized hybrid and SS amps, which can be a refreshing change of pace. Hopefully, those considering a PMx2 can find something here that could help predict how it would behave in their environment.
     
    Last edited: Jun 24, 2017
  6. Audio Zenith

    Audio Zenith Custom Title KGB

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    Thanks a lot for all the impressions my friends. I would like to comment on amplification/pairing.
    With original PMx2 most commented on it sounding good with pretty much any amp but there was also some criticism, regarding it being too plain. Can't say this was bugging me, as the main principle with all audio gear for me is linearity/neutral FR. What happened to the original PMx2 then, if I thought it was perfectly neutral?

    First was a small low frequency boost, everything below 100Hz went few decibels up. I found such little tilt to be very pleasant and addictive. It reminded me of properly EQd loudspeakers in a well treated room. Nevertheless, for quite some time I was contemplating to either keep it or not and actually said to a few original PMx2 owners this change wasn't worthwhile.

    Other complaints were regarding soundstage and perceived resolution. To mitigate this I decided to go with leather earpads and changes to the front baffle. These brought a slight increase in high frequency department, along with further extension. Knowing how general preference leans towards slight brightness I figured this was another positive and just made sure to keep HF from being hot with a perfectly neutral amp. Ragnarok is my absolute reference in amplification department and all sounded great with it.

    I figured new PMx2 tonality will be sitting right on the edge of neutrality in both low and high frequency departments to make it worthwhile for rev. 2 name. Then, almost accidentally I figured how to drastically reduce distortion and that finalized the deal.

    To be honest, I didn't think that bringing tonal balance to the edge of neutrality could backfire with amplification issues. First sound impressions from you uncovered this mistake, I went ahead and bought Mjolnir 2 with collection of highly rated tubes (thank you, @Ice-man). Then, just in case I purchased Jotunheim. Both amps have sound signatures slightly north of neutral and their pairing with PMx2 had to sound good.

    Personally I can hardly accept compromises, especially with tonality. No way you can find me listening longer than couple of minutes if sound is less than perfectly neutral. In case of both aforementioned amps; while paired with Jotunheim, resulting sound signature just barely tipped over into brighter than neutral. It isn't fatiguing or bothersome and I would easily accept/approve this pairing.

    Mjolnir 2 was a bit more difficult and I had to discard couple of well rated sets of tubes for sounding too bright paired with PMx2. Most neutral tonality came with Raytheon '74s and NOS Toshiba's. While lacking resolution in comparison with some others, they definitely sugarcoated the least. Though have to admit, a few sets of tubes took Mjolnir with PMx2 into unacceptable sounding territory for me personally.

    Lyr 2 with LISST @Bill-P described as sounding too bright at the show and I completely agree. So yes, with brighter than neutral amps/dacs PMx2 rev. 2 will slightly tip over neutral and won't be as forgiving as original version. I don't think this necessarily is a bad thing but hey, there is always toilet paper ;-). Just kidding, I much prefer to use toilet paper where it belongs.

    Reducing excessive energy in high frequency department is easy, especially when it's just a db or two. I will bring another pair, with a bit less HF to a July 15th meet for @brencho and @Bill-P to try with Mjolnir 2 and most offensive tubes. Will be interesting to check their impressions.

    Finally, here is a distortion plot at 95db SPL and slightly tipped up HF for one of the latest drivers and I just love it ;-)


    Same PMx2 in the works.jpg
     
    Last edited: Jul 1, 2017
  7. paranoidroid

    paranoidroid Friend

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    I spent a few days with the PMx2 loaner and really enjoyed them! They reminded me of my old long gone HiFiman HE-500 with better technicalities. I wish I had them to compare to the PMx2, but it reminded me what I liked so much of the older HiFiman series. That planar organic warmth is how I would describe it. My headphones right now are the HE-1000v2 and Utopia. The PMx2 is very neutral across the board, but they don't sound as dry as the HE-1000v2 and especially the Utopia. There is a bit more mid-bass than both headphones adding to a nice hint of lushness.

    The PMx2 represent my ideal tuning. There isn't anything I would change. The HE-1000v2 are a bit splashier in the treble and the Utopia could use more bass and run bright. I was surprised how deep the PMx2 could go and it doesn't have the recessed treble of the original PM2. Treble is neither too bright or recessed. For my tastes it's perfect, just like the rest of the spectrum.

    Technicalities wise they do fall behind both my HEK and Utopia but they are both in different price classes. It doesn't seem fair to compare it to both of these headphones, but that's what I'm running and have to compare.

    Compared to the HE-1000, the PMx2 have a much smaller soundstage. However the HEK sounds further away and combined with its polite nature has less solidity in its sound than the PMx2. The impact of music is more apparent on the PMx2 but the HEK sounds more encompassing and the imaging more precise. There's a huge difference in driver size between the headphones and there are just going to be physical limitations. The PMx2 is closer to compact travel side headphones than either of these full desktop headphones. I'd still say the PMx2 can swing with the HEK and what someone would prefer would mostly come down to presentation.

    Compared to the Utopia I much prefer the frequency response of the PMx2. Without EQ the Utopia are short on low bass and combined with its bright treble make for a headphone on the lean side. Unlike the HD800 they are listenable stock, but I generally run the Utopia with an EQ curve that adds about 4.5db on the low bass. Without EQ the PMx2 sound much more natural and pleasing. Once the Utopia is EQ'd, the technicalities of the Utopia pull them far ahead. Dynamics (especially drum impacts), imaging, soundstage width/depth and resolution are noticeably better on the Utopia. The driver limitations of the original PM2 are especially evident when compared to the Utopia but again, they are over twice the price and for me need permanent EQ. Needing permanent EQ doesn't make for a transportable headphone since I basically have to run them on a computer with my desired EQ curve.

    All in all, if these PMx2 were my only headphone I would be very happy. It's only in these direct comparisons with these much pricier headphones where you can see some limitations in technicalities. But I'm being very picky and I loved listening to the PMx2 and was sad to end my time with them. These are definitely the best sounding headphone that are also easily transportable that I've heard.

    When I bought the Audeze Sine a while back I was looking for a compact & transportable planar headphone that would also compete at the level of main desktop headphones. I ended up selling them and I realize what I really wanted are these PMx2. They're compact in the case and they're very sensitive making it easy to play on portable players. Their superb end to end frequency response, looks, transportability and ability to also be the centerpiece desktop headphone make for a very tempting package. Thanks a ton to @Audio Zenith for putting these on the loaner tour!
     
    Last edited: Jul 18, 2017
  8. Mystic

    Mystic Mystique's Spiritual Advisor

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    Some brief impressions from the loaner. Unfortunately did not get a whole lot of time with these due to a busy weekend and the Atticus loaner hitting me just a day apart.

    I really enjoyed them, well worth the asking price. Very premium fit and finish. Slightly heavy but was comfortable on my head. Head-bangin approved, they sat firm on my head for the most part. Tuning was spot on, couldn't really pick out anything wrong with the sound which made for a great all-rounder for my wildly varying genres.

    Brief comparisons:

    Compared to my HD800S:
    + fuller upper mids, not as thin sounding
    + more even frequency response, goes down low
    - this is a given, but the soundstage could not compete
    +/- both had good dynamics

    Compared to my Eikon:
    + more open sounding (Eikon is pretty open sounding for a closed, but is still closed)
    +/- again, both had very good dynamics and a healthy amount of bass extension

    More differences than this I'm sure, but I would have needed more time with them.

    Overall, if I could only have one headphone, the PMx2 would be high on that list, or at least I would try and get an even further extended demo with them. For those that don't need a single headphone though is where I think a combo 1-2 punch of an 800 + 650 would make for an excellent pair that could cover just about any kind of music out there. It would be a difficult decision for me I think, which is saying something as a longtime Senn fan.
     
  9. wrestler

    wrestler Acquaintance

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    Is there a compensation curve used on the measurements? If not, what is your measurement setup? (if this is already answered, sorry. Just give me a link to the info)
     
  10. Maxx134

    Maxx134 Dunning–Kruger effect poster boy

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    Look at those CSDs!
    They are the best that I have seen on any Planar headphone yet..
    Everything under 1ms all way down to 1k..(!)

    Has anyone realised how clean (for a planar) these CSD/waterfall images?


    This this is like the big pink elephant in the room..

    There is no ortho wall...either...!
     
  11. Armaegis

    Armaegis Friend

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    It's also remarkable how much the distortion has been improved from early models. I'm still curious what is the source of that D2 hump though. Is it an enclosure or diaphragm resonance?
     
  12. Maxx134

    Maxx134 Dunning–Kruger effect poster boy

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    Looks like a 300hz artifact barely above noise floor wich is not plotted.
    Interesting to look at but a non-issue in my view.
    Also could be the area of the bass that the diaphragm exceeds most.
     
  13. Audio Zenith

    Audio Zenith Custom Title KGB

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    Thanks for all the impressions guys and let's keep them coming ;-).
    No compensation curve and I personally want to think PMx2s sound just the way they measure. At least that's what I wanted while building this measurement system. A lot of controversy has always been around this and it would be up to you personally to decide if I succeeded.

    As for comparisons with Utopia; no doubt it sounds awesome, up until you realize how it keeps on singing it's own song no matter what. Adding few db's to the bottom probably helps, but most certainly brings more distortion and I wish it was the only issue.

    I honesty wish there was a set, capable of combining hyper detailed resolution with exceptional neutrality. Unfortunately it doesn't exist.

    For what it's worth, I would rather look at a real beauty from a distance, then see a gorgeous parody in hyper detail of a close up.
     
  14. AllanMarcus

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    Hi. unless I missed it, you failed to mention your source and amps. I find the Utopia works well with a good less harsh DAC and a tube amp, one that can add a bit of lushness and smooth out the treble. The PMx2 works very well with a SS amp, like a Schiit, that is a bit dryer. The right pairing really helps both of these headphones.
     
  15. smithyy

    smithyy New

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    How does the PMx2 (new version) compare to the HD650M?

    What would I be gaining/giving up?

    Is it as musical?
     
  16. AllanMarcus

    AllanMarcus Friend

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    Not much of a difference. Like going from a high end Toyota Corolla to a a top of line Lexus.
     
    Last edited: Aug 23, 2017
  17. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    I think the HD650 is still airier and more spacious sounding. I also think it can out resolve the PMx2 with the right amp, but it's close. I also prefer the upper mid response on the HD650. But the PMx2 has cleaner bass, is possibly faster and less veiled sounding, and works well from portable sources.

    So, more like different cars in the same tier rather than an upgrade to the luxury line, IMO.
     
  18. AllanMarcus

    AllanMarcus Friend

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    I imagine if you like the HD650, you like it. It's a great bargain, but I found its bass mushy compared to the PMx2, and its highs too rolled off (modded 650, not stock). I also have the first gen PMx2, and the second gen is even better. Of course we are comparing $300 cans to $1800 cans, so the price performance goes to the HD650. Unless you have the perfect amp and DAC and you love the 650, side by side I'd wager most would choose the PMx2.

    Each person has their own tastes, obviously, so the only way to know is to try.
     
  19. smithyy

    smithyy New

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    I love almost everything about the HD650, especially since it's been modded, but bass is still its weakest aspect. If the PMx2 improves upon its bass, along with being a touch faster and less veiled, although I hope it still has some sense of warmth, I may be very interested.

    The only question is how it fares with tube amps. Probably going to buy an Elise or Euforia, which the builder says is suitable for 32 ohm headphones and others have enjoyed planars on them.

    @TeaWrex above found that on tube amps the PMx2 doesn't sound best, which is to be expected.
     
  20. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    You can keep throwing dynamat all over the HD650 to help with bass (to an extent).

    Just be aware that while you might gain in bass quality on the PMx2, I find the HD650 still has better resolution, detail, staging, and a more coherent midrange and treble presentation. You win some and lose some. Or you might totally prefer the PMx2. Only one way to find out!
     

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