Ask Purrin and Anax, I apparently must have really thrown him in a tissy to make this thread.
...had generally less ringing even if they were smoothed in comparison.
Quote from: Shike on February 03, 2013, 09:05:44 AM...had generally less ringing even if they were smoothed in comparison.R U Dum?
Tissy?
Well, he did take the bait...
R U Dum?
Since you are starting to make sense:I have access to several dummy heads, but I don't use them for various reasons. Most of my very early measurements (never published b/c I felt the data was not useful), were done a a dummy head, until I got the idea to use various couplers. The sponge is an attempt to simulate a free air measurement. I also use two other couplers to take sealed measurements.The canals create resonances of their own when combined with earcups (especially those headphones which are sealed - think ported speakers!) The question is whether these canal / earcup resonances are actually heard or not. My sense is that they tend to not be heard. We don't hear in the frequency domain. We hear in the time domain. I've always suspected that our brains are smart enough to pick up on certain kinds of echos related to the canal and throw that information away. There needs to be more investigation in this area. It's these very issues which may me throw away all information on my IEM measurements past 8-9kHz because I haven't yet figured out a way to "sponge" measure IEMs.I wanted to get away from HRTF issues. Speakers are measured with a microphone in free air. When I build speakers, I take two measurements. One at 1m away from the tweeter, and another at the listening position. These two measurements are usually never the same because of room and boundary effects. The final tuning is always is by ear. It's kind of an art. Usually the final adjusted FR tune is somewhere between the 1m and sitting position measurements. I didn't see why a free air microphone approach couldn't be used with headphones, since that's what speaker measurements (Stereophile, Zaph, etc.) are calibrated against. JA doesn't use dummy heads for measuring speakers. Essentially what I am measuring is outside of the ear. It's simply another way of doing things (BTW, Stereophile had used a similar method in measuring the HP1000s).As an aside, the various proposed defuse field EQs are too iffy at the moment. (Although I feel that some sort DF EQ is necessary for IEMs.) Heck, it should be noted that many speaker manufacturers intentionally EQ their speakers in almost a reverse defuse field. This is well known as the "BBC curve." This BBC curve works well with playback in highly reverberant listening rooms or recordings from highly reverberant concert halls.The B&K HATS that GE uses does NOT have a ear canal. It does have a combined coupler/mic unit though. Many such $$$ systems actually don't utilize a real ear canal. LFF has a dummy head with an actual canal for binaural recordings. Some serious EQ actually has to be applied with his dummy head for recordings to come out right. You can search this site for his binaural recordings.Arnaud and I have actually worked with Tyll and used some of his raw data to produce CSDs. There seemed to be some early promise, but his software was decimating the data past 1-2ms. I suspect the software is intentionally and progressively hrowing away the later time data to reduce the resonance effects in order to produce good FR data. Maybe we'll revisit this later. The point I'm trying to make is that there's no war or "I'm doing it better than you" or "your stuff overstates ringing" nonsense, but rather there are just different methods employed. As for GE's results, I believe many here think they are inconsistent or at worst, have no correlation with what they hear. As far as I know, no one is trying to be "right". Well at least I'm not. I'm just trying to discover and learn. Most people on this site actually use other data points as well, i.e. Sonove, GE, IF, etc. to come up with the big picture. There are a few measurement sites out there which indicate I use X $$$ equipment and Y ISO calibration and Z HRTF, (appeal to authority) and thus everyone else's results are wrong. That's great for them - I hope the AES gives them awards. The approach here is "I think I have some interesting data, please listen and compare graphs, and let me know if this works." This does have some serious downsides - as you mentioned - there is no study to correlate subjective results of ringing, etc. - which of course requires learning the system, unless one if already somewhat familiar with speaker measuring techniques. I think most people have figured it out here. It's really not that hard unless you are lazy to figure things out like Steve Guttenberg or are not very smart. In some ways, the site and the people participating are really the study. And it's a study still in progress. I don't know if you were ever cognizant of this. Don't be surprised one day if you wake up and the measurements all look slightly different (BTW this has actually happened in the past).Whether my visualizations show more or less ringing, it doesn't matter as long as the measurements are compared relative to other measurements on the site. The measurements I produce were never intended to be absolute, but merely relative. This is probably one of the greatest misconceptions which people have of the measurements here.A lot of your questions in your first post can be answered if you browse through the site. It's all scattered. I apologize for the lack of neat organization or tidy scholarly articles, but this is a hobby to me and I'm not making any money off of it. Feel free to ask.There is a certain way you can ask or propose intelligent questions without coming off as a know-it-all asshole or presume or misconstrue certain things. BTW, one of the early slogans on this site was "the non-authoritative and irreverent site for headphone measurements" and I seriously meant it. CS is really an alternative take it or leave it resource - there's absolutely no sense for me to replicate Tyll's measurements (which I can perfectly do BTW.) But getting back on topic: it's obvious you are an adherent of nwavguy's style. I think he's very clever and has good some ideas. But he does come off as a self-righteous asshole. BTW, he wasn't the first one in audio. I believe Doug Self was the first. D. Self has done some great work with op-amps and was highly influential in audiophilia at one point. Like for a year or two. Now he's just a footnote.P.S. As far as the -36 floor instead of -30db, I normalize all plots (using a weighted average increasingly skewed toward the treble with a cutoff at 12kHz) at -6db. It never lines up perfectly because most transducers do not measure flat.
The B&K HATS that GE uses does NOT have a ear canal. It does have a combined coupler/mic unit though. Many such $$$ systems actually don't utilize a real ear canal.
