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

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.
Yes, this is the very Topping amp that supposedly destroys headphones. Can anyone let me know if I got one that that has the fixes? I did made sure to take anti-static precautions. In a nutshell, the L30 is among a handful of amps that measure spectacularly, so I decided to buy one and try it out for myself. Do I feel the L30 is absolutely transparent from a subjective point of view? Nope, absolutely not. I actually think it's a rather colored amp that commits both sins of commission and sins of omission. But enough of this for now. The reason people want to buy this is because they think subjective impressions are full of crap and want to see the SINAD numbers. Of this, I will happily bring such numbers to you and more.

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$80 on sale. Quite pleasant. Prefer to 400se I heard this week... Better highs, bass about even, and some needed warmth. SHP9600 is about on level of Koss Porta Pro aka GOAT headphone :) except this is full-sized with a bigger sound stage. Less efficient than Porta, or THX00, or Grado. Comfortable, fabric mesh pads, ears don't touch driver/baffle, and semi-open front baffle like a Sennheiser.

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^ Silk baffle vents. I think I roughed up driver front filter paper when I was trying to figure out how to take the rest apart.
Many moons back, I decided to write a series of posts re-examining classic Grados such as the RS2, but with TTVJ Deluxe Flat Pads. The reason is that once Grados seemed to be en vogue with the audiophile crowd (this was back during the days of veiled Sennheiser vs. bright Grados) and then suddenly fell out of favor. Tyll was well known for not preferring Grados for being too bright. I wanted to present a possibility that Grados didn't need to sound bright at all when using different pads. I mean, I had already done my spiel on why the Sennheiser HD650 and its variants were great headphone, so why not Grado?

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Lo and behold, imagine my surprise when Grado released their Hemp with their version of the flat pads, the F-cush. And now it looks like Grado has completely revamped their Prestige series, of which the SR225X and SR325X now come with the F cushions! So course I had to grab what was known as the most aggressive and energetic of the Grados, the SR325, and take it for a test run. This time however with the included F cushions. I will also see how the F cushions perform vs the TTVJ Deluxe Flat Pads on various Grados later on in the thread.
The BLON BL-30's claim to fame is the big-ass 70mm driver. This piques my interest because there's no replacement for displacement when it comes to bass. Whether we are talking about woofers, car motors, or solder suckers. (Yeah, try a small solder sucker and see how useless they are compared to a big one). The problem of course is how will such a larger driver handle the highs? Usually here is a price to be paid, but how much? What compromises can we live with to get good bass.

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Now before I get into the measurements or subjective impressions (which were quite good), I have to point out something hugely disappointing. The ergonomics and construction are first rate shit and what gives people the impression that China makes garbage. (This is not true). @tommytakis sent these to me in a box (thanks for the Korean treats - we just visited Houston and loaded up a cart at H-mart - however, kids and I pretty much devoured everything in a week) and by the time they arrived, one cup unscrewed itself from the gimble and the wire mesh cover fell off. It took me some effort and tin snips to put the wire mesh properly back on.
APx555 outputting from Sine generator via AudioQuest Mackenzie 1.5m XLR cables into input 1 of the preamp.
Input impedance set to 200kohm. AC coupled. 20khz AES17 bandwidth limit.

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4v input 4.2v output (closest I could get to unity gain with inbuilt vol control at 90)
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MODERATOR ADD:

This is a new thread split off from here where @purr1n initially found some discrepancies with the measurements of SINAD chart topping Soncoz SGD1 DAC on Audio Science Review. These discrepancies were significant to the point of downgrading the Soncoz DAC from the one of the "leaders of the pack" to one the laggards behind the leaders. Some people felt the initial discrepancies were because of differences in measurement gear, first a AverLAB, and then an APx525 vs. the state of the art APx555 (ASR).

Further investigation with two additional samples of the SGD1 DAC using the APx555 have confirmed @purrin's initial findings. One positive aspect is that the "IMD hump" fix has been corrected. We do not know if the significantly worse SINAD measurements are the result of this fix or if ASR received a cherry-picked sample from the manufacturer. However, we think it is necessary to let the buying public know that the spectacular SINAD results could not be duplicated with three off-the-shelf production samples, especially to those who rely on measurements to make a determined buying decision. In addition, a third sample showed worse measurements in one channel compared to the other.


ORIGINAL POST STARTS HERE:

So I just put the SGD1 on the APx555 and @purr1n looks like you were right, this is NOT measuring the same as ASR is showing.

-0.5dbfs (to match voltage shown on ASR measurements):
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