Super Best Audio Friends

The evolution of the original irreverent and irrelevant and non-authoritative site for headphone measurements, i.e. frequency response graphs, CSD waterfall plots, subjective gear reviews. Too objective for subjectivists; too subjective for objectivists

I don't think I will get to everything today, maybe in the next few days. What we have up are the following:
  1. @rhythmdevils modded HiFiMan HE560
  2. @rhythmdevils modded Fostex T50RP
  3. @ext1's JAR HD600
First up is the HE560. I took these to work and listened to them for days at my work desk. Here is the funny thing: I thought they were modded HE5s with the fast transient response, tight sound, and clarity. Well, that is until I realized that I wasn't getting that last little bit of low level information which I knew the HE5s were capable of extracting. Then I noticed a touch, just a bit, barely noticeable plasticky timbre... I took the headphones off, examined them, and then realized the gray HE560 letter on the black. Haha!

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I came into this review expecting a very different sound than what I hear with the AirPods Max. I expected a fairly laid-back sound with a tuning not too unlike the 2016 to 2020 Audeze Era or the STAX SR-007, but with a bass boost.
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Instead what I got was a brutally honest, revealing and neutral midrange and treble, but with still the same bass boost. The midrange tuning of these headphones is so spot on to my own tastes that it's almost scary. Seriously, the midrange reminds me more of my modded HD800s than my UERMs or, frankly, any other headphone does. I have no clue how Apple arrived at their target, but I know it's not a Harman midrange tuning (albeit the bass is very close to Harman tuning). Either way, hats off to the engineers who came up with the tuning. Think HD600, but kinda smoother somehow?.
I guess I will throw in my two cents with respect to the version 2 of the HD8XX. To be clear, I've been slightly involved in the tuning process for them. The prior HD8XX was pretty good already; but understandably I think people wanted more than a tweak; and the folks at Drop I'm sure wanted more. Something more evolutionary rather than a mere tweak. Well this is it. Well over tens ago, maybe around twelve, there was a rumor going around that Sennheiser would release a successor to the HD800. That this HD800 successor would not be bright, but be voiced like the HD650 or even the Audezes, but have the technicalities, fine detail, soundstage, etc. of the HD800. Instead we got the HD700. Yup the HD700. The colossal piece of this was that combined the worse aspects of the HD650 and HD800.

Well finally, I honestly believe that we have it! This the truly the HD800(S) for the folks who do no like the tonal signature of the HD800(S), but appreciate everything else it can do. During my time with the sample (one of many of which this turned out to be the production version), I thoroughly enjoyed every minute. Wait I thought - this possibly can't be anything based on the HD800(S) - it's not bright at all!

Drop x Sennheiser HD8XX v2 Frequency Response
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Some of you may remember my AmpCamp amp project posted here in a recent thread in August. Part of that project was to build up a pair of GR-Research X-LS Encores as speakers. Some of you may remember the photos of the cabinets in the ACA thread, well, those were damaged irrevocably in shipping, so the cabinet maker made me up a pair in "birch red" to match the Dynaudio Special 40s.

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Once I had the cabinets lined with No-Res, the crossover and drivers installed, I have to say for an ~1.2 cubic foot standmount, these speakers are heavy! The cabinets are very stiff and also well-damped. I have beefier pair of speaker stands coming for them. My cost including built, veneered and stained cabinets, and speaker premium crossover parts and $45 sheet of No-Res: ~$915. This included the trick components in the crossover, like the Miflex copper caps (which are pretty pricey).
This DAC is an odd one. Subjectively whilst it's too soft sounding for me to want it as an 'only' dac, I do quite like it for many genres. For an R2R dac especially at this pricepoint it seems to do very well. BUT, the claim that it is a NOS dac is absolutely untrue. The 'NOS' mode on this dac is simply linear interpolation at 768khz/705.6khz. It is not NOS.

Additionally, whilst measuring this DAC there have been some....oddities which haven't occurred on other devices. It seems that Denafrips is doing a fair amount of DSP on this DAC which hinders some measurements.
John Atkinson of stereophile found that he was completely unable to even do a linearity test as the transfer function made it present a strange stepped zigzag result. Whilst testing this device I found that swept sine tests behaved unusually, with frequency response results often looking either outright wrong or with a strange 'rippling' toward the end which differed in appearance dependent on the length of the sweep.

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This is expected to ship March 2021 and retail for $2500. I live near theSourceAV who is a McIntosh dealer, so hoping they will add one to their demo showroom and I'll have the opportunity to hear it and post impressions here. It does not have a built-in DAC like the MHA150, and also lacks the speaker outs and cross-feed. They've added 4-pin XLR and stereo 3-pin XLR outputs and four selectable impedances. I'm not sure what topology "Unity Coupled Circuit output transformers" implies.

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Demo'd the MHA200 at theSourceAV today. Thank you to Wayne there for keeping me informed and letting me know when they came in, then assisting me with the listening session.

I heard two different units, one with stock tubes and the other with a pair of GE Military 5751's from Upscale audio. The stock unit took input from RCA's coming from a Chord Qutest and the 5751 unit had balanced inputs from an SPL Director. I was very curious how it would sound with a good R2R DAC like Yggdrasil or Gungnir Multibit, although I had none to try. Both amps were brand new with minimal break-in. Headphones demo'd were HD6XX, HD800SDR, LCD2.1, LCD-X, LCD-4, Utopia, Clear Mg,
Audeze Penrose X Review. Gear: iPod touch 7th Gen Bluetooth -> Penrose. How simple is that? No fussy cables, or extra amplifiers. Just a phone or DAP and the headphones.

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Build: Simple, and solid. No problems. Just one quirk. The cups rotate so that they face down when the headphones are placed down on a surface. But they rotate the wrong way. When you’re holding them the way you wear them, with the left cup in your left hand and the right cup in your right hand, as if you just them off, the cups rotate towards you, which you can’t really do with your wrists, and certainly can’t put them down that way. They only rotate half way away from you. This feels like someone just goofed and they got 10,000 pairs in the mail and cursed to high heaven. Not that big a deal, it’s funny more than anything else. The headband doesn’t fold so it does’t really affect their use, it’s just a little awkward putting them down. I wind up just putting them down on their side instead of twisting the cups so they are facing down.
Wuut? When did the Loki Mini+, a revised Loki suddenly appear? That's the question no one seems to have an answer for - except for @rhythmdevils who I believe may have snagged one not too long after he was defrosted - after being trapped in the ice for decades by fascists. Oh wait, that's a movie.

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The original Loki I never really gave much thought to. As an audio purist somewhat, the OG Loki was just another unnecessary piece of gear in the signal path, mucking things up. Yes, I could hear the OG Loki when it was switched in the signal path. However, the truth is that I didn't know what to do with the wide EQ bands of the Loki. I knew how to use PEQ and/or digital EQ to get the results I wanted - in a surgical way. This is where @rhythmdevils came in. I've always loved his approach because it's experimental as he uses his senses without the aid of measurements, numbers, etc. It's a human approach. Probably too much to the chagrin of today's objectivists. But who cares? When was the last time we went to a headphone to meet up with real people with shared interests and bumped into an objectivist. Never. Anyway, I heard that @rhythmdevils that the Loki EQ is supposed to be fun, a right brained activity. Do it Marv, you have good ears. Use the Force. I know you don't need measurements. Have fun. And you know what, he's absolutely right!
Audeze LCD-XC Review (Including Comparisons to LCD-X and ZMF Eikon). Gear Pi2AES > Gungnir A1 > @Fallenangel SOHA1 > LCD-XC, LCD-X, ZMF Eikon

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Sound
Say goodby to the “Audeze veil”! A slightly bright Audeze! The LCD-XC is much much better than I ever imagined it would be. I consider Audeze’s drivers the best planar magnetic headphone drivers ever made (I’ve heard them all, and I’ve modded Audeze headphones and heard the drivers with what I consider better acoustic treatment), but I don’t think they have figured out how to put them Ito an enclosure and implement acoustic treatments that allow them to really shine. They do much better here than I anticipated. I thought the LCD-XC would be a resonant mess. It’s actually pretty well controlled. Though not perfect.
HD650 technical measurements And how single number metrics provide extremely limited information

Measurement setup
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Klippel QC analyzer
Furman SP-20A headphone amp
ACO Pacific 7052SYS microphone
Brüel & Kjaer 4231 mic calibrator
Mr BlockHead™ flat plate coupler
density similar to average human head 1.08 g/cc
width consistent with average human head 15.25 cm

Historically a low distortion 1 KHz sine generator would have stimulated the electro-acoustic transducer using a low distortion amplifier. Then a steep 1 KHz notch filter removes the stimulus and the measured level of what remains is compared to the stimulus level. That ratio results in THD+N. Now consider the capability of a modern acoustic analyzer.

Single number metrics used for audio component performance rankings are absurd when one realizes how much information is missing.
Audeze has changed their earpad design for their LCD series headphones and use the new version on all LCD models now. It’s not a subtle change. They are shallower, and made with a radically different kind of foam. The old pads use dense memory foam, while the new pads use low density regular non memory foam. It’s a good choice, most memory foam actually does not have great acoustic properties. Though it does work in ear pads sometimes. Eearpads’ affect on sound is extremely complex and I believe is not a science for any headphone manufacturer but a matter of guess and check pretty randomly until something works.

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The new earpads still have the suspicious felt material between the adhesive ring and the earpads which seems to be an intentional filtered leak to increase soundstage. It seems to be there on purpose and this is what it would achieve. Better soundstage while holding onto bass response. The most important thing though is the difference in sound...
With the recent acquisition of an AP analyzer, my intention was to leverage its automation capabilities to offer an alternative more developed set of measurements to simply SINAD, specifically SINAD at 1kHz into a 300-ohm load at 2Vrms and sometimes 4V RMS with a bandwidth of 20kHz. It's not that I do not believe in "SINAD", but rather in how it as a single number was effectively being used as a dogmatic litmus test and yardstick for sonic transparency by Audio Science Review. My intention was to present a related but alternative to SINAD, that is THD mapped to a matrix of low, midrange, and high frequencies vs. voltage levels more reflective of actual use with popular headphones. The idea was the make things a bit more complex as things in the real world are complex, while keeping things simple enough for us to digest and relate to.

The first rationale for this testing using real headphones was to ascertain the effects of back-EMF with respect to global negative feedback. A resistor load will not provide back-EMF. However a headphone driver really isn't that much different from a microphone. If we shout loud enough into a headphone driver and measure at the phono jack, we will see voltage. The second rationale was to ascertain the effects of back-EMF with respect to current capability. It was cited that USB dongle AIOs exhibited sloppier more one-note bass than desktop headphone amplifiers.

Lo and behold, I most certainly did not expect this! A real headphone load (Sennheiser HD650) resulted in up to 50db worse THD than a dummy 300 ohm load at 37Hz with the Topping L30 amplifier!
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Anyway, the One Ring is vanquished. F the Eye of Sauron.