How about this. If we're on the topic of accuracy (or lack thereof), then IEC60318-4/711 would be
patently less accurate than the ITU-T Type 4.3 standard when it comes to emulating the acoustic impedance of the human ear. I know that there was a point on this forum where every 5128 publisher would be villified for even attempting to start a database on the new standard, but now even Harman sees merit in repeating the AE/OE 2015 research for in-ears on the 5128.
And even Dr Sean Olive admits as much, saying that the 5128 provides better human accuracy whereas the traditional 711 provides better precision
So since you're going on and on about
accuracy, how about we look at 5128 measurements of the Nova instead?
Even kept it completely raw for the folks who absolutely despise tilted-DF compensated data.
Still haven't learnt the difference between a tweet and actual science I see. But I really wouldn't expect
anything less. Desperate attempts to pivot to the usual 5128 propaganda to avoid addressing the issue won't help you. We're talking about the (in)accuracy of your knock-off '711' coupler
to judge Harman target compliance. You know, that target with scientifically controlled, double-blind listening tests backing it as most preferred / perceived neutral, which no other public target has (nor any for your beloved 5128 by the way, rendering its utility severely crippled until,
if, this ever materializes, and even then it still has
major issues over its
supposed '
high accuracy'). An accurate measurement apparatus is defined as accurate
to a known reference. We know measurements from genuine GRAS RA0045 couplers (used to devise the Harman target of course) are highly precise and accurate to IEC standards due to high quality manufacturing and tolerances as Oratory has testified. Therefore we can assess the accuracy of your knock-off coupler to judge the Harman compliance of an IEM via a like-for-like comparison to an RA0045 measurement, which I
presented for the Truthear Zero, clearly showing your coupler has significant inaccuracies not only to the known accurate GRAS coupler, but that fall outside of IEC tolerances too, which themselves are already pretty loose. I was in fact being
very conservative in my earlier post when I was talking about how much tighter GRAS manufacturing tolerances are than IEC tolerances. Oratory actually
said all the many GRAS couplers his company have are within ~0.2 dB
of each other (plus hitting the middle of the IEC spec no less), which means their manufacturing tolerance is in fact half of this at about ±0.1 dB (around the limit of audibility so effectively negligible). This is up to
22 times tighter than IEC tolerances, which your coupler doesn't even adhere to.
It's absolutely absurd for the post-truth pseudoscientists to claim these knock-off couplers can offer comparable accuracy to genuine GRAS equipment and so an accurate assessment of Harman compliance and therefore majority perceived neutrality of an IEM. Evidently the sunk cost fallacy of wasting their time, effort and money on these inaccurate knock-offs means they just can't bear to admit it. And what the logically-challenged are failing to grasp is that a single counterexample is sufficient to disprove a generalized claim. The claim here is that a knock-off coupler is accurate, within IEC tolerances. And if it were this would be true
for all measured IEMs. The Truthear Zero comparison clearly shows it is not. Of course this would not be a one-off case of knock-off couplers from dodgy untrustworthy companies sold on AliExpress being inaccurate either:
Note
none of this rests on Jaakko's analysis. That was indicative of a potential inaccuracy, but the like-for-like Truthear Zero comparison stands on its own and is all that's needed. Anyone denying this needs to show evidence of a confounder in this case that can produce that magnitude of error. In general the only other potentially significant variables at play could be:
1. High unit variation. (But we already know in this case this is low for the Zero
from Crinacle himself.)
2. Operator incompetence. (As a professional acoustic engineer with a Master's in metrology whose job it is to measure and help design headphones/IEMs, this obviously doesn't apply to Oratory.)
So if anyone is claiming either or both of these are confounding variables, that's tantamount to saying Crinacle/Truthear have been telling fibs about the Zero's unit variation (1), and/or producing erroneous measurements of it (2). Either result in the same conclusion as would be the case when these are not confounders and so the difference is due to inaccuracies in the knock-off coupler —
measurements from this source cannot be trusted to be accurate. Of course what would be utterly imbecilic is for anyone to think they're being really clever with a faux reductio ad absurdum by throwing CSGLinux's of Hypethesonics data into the mix, when that just adds more confounding variables that are known to affect measured frequency response, like this:
HypetheSonics’ headphone database is a self-consistent set of measurements for some of today’s higher-quality in-ear monitors and earbuds. All measurements on this database are produced using the GRAS RA0045 coupler. If needed (i.e., for shallow-insert earbuds), this coupler is also connected to a GRAS KB5010 artificial pinna.
Along with singling out a specific example of an
active, ANC, shallow-insert TWS earbud in the AKG N400, all of which are characteristics that can cause variations in frequency response, due to e.g. firmware/software version differences, environmental noise conditions, active feedback mechanisms etc. Yet again basic scientific principles like minimizing confounding variables in comparisons are clearly not being understood at all. And it's this lack of fundamental scientific literacy that's the crux of all this. Before any measurement can be taken seriously and judged accurate, the accuracy of the measurement apparatus used
must first be established and demonstrated. The onus is on the measurer to do this. The onus is
not on others to prove it is inaccurate while the measurer assumes it is and expects everyone else to take their word for it without valid evidence. Science doesn't work like that.
This ultimately means measurements from all these YouTubers and 'reviewers' using knock-off couplers (and relative to nonsensical, made-up pseudoscientific targets at that), no matter how many subscribers they have, will provide an unreliable depiction of majority perceived tonality of the Nova (or any other IEM/headphone) unless high coupler accuracy has first been proven, and so should be roundly ignored on a science forum if this is not provided, and only measurements from genuine known-accurate GRAS couplers considered, shown with the Harman target that has actual scientific research backing it.
.
