Why would near field measurments need to be tossed when they agree with published specs of 6 of the 7 drivers ?
My range of hearing, as usually talked about, does may not have the HF extention that XRK's has -- i don'tknow his age, or what kind of environs he has worked in. Extensive serious listening training (10,000 hrs of this in the generalized metric) has given me the ability to maximize what i do have. And this does not even considered the temporal hearing mechanism that does not degrade near as much over time (and BTW has resolution higher than 20k)
I do not use just my ears but also a number that are much younger, some who have bat-like amplitude accuity.
dave
I know exactly what Byrtt was refering too.
It is not. It is variable depending on voltage, temperature, barometric pressure, and to a lesser extent himidity & likely other factors.
dave
Because they were taken under invalid measuring conditions... they broke measurement guidelines.
And are different. Your earlier 12.x cm VIFA FR (rescaled tomatch) in the background of your 1/2 m measure.
dave
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In the strictest sense yes, resonant behaviour is breakup. But your connotation of break up can be defined as "uncontrolled breakup".
The holey grail of a FR driver is that after some point, the inner cone decouples from the outer cone (inner & outer a function of radius) so that as frequency goes up the radiating part of the cone has a smaller & smaller diameter. This would be a "well-controlled" breakup and if it could be achieved the driver would show no evidence of resonance in its FR measure.
Ted Jordan has been working on this "forever". They were part of the Jordan-Watts modules i was playing with in 1975. Part of the rational behind the variable thickness cone of the diatone PM510. BiFlex cones, wizzer cones, the aluminum reinforcement of the back of the cones in (name escapes me, vintage british driver), even whizzer cones which are a very explicit realisation of the idea.
That you think this is evidence that by breakup you mean uncontrolled breakup.
Here is the impedancs curve of a FE127e. It has an uncontrolled resonance peak at about 7kHz and another at about 11kHz, but is startingyo go into resonant behaviour at about 650 Hz, As i mentioned earlier it also shows a train of resonances as frequency increases.
dave
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This is exactly what I was going to say. For temperature, humidity and pressure to have an impact on measurement, there has to be significant departure from comfortable conditions for human beings. The differences between X's measurement and the CHN70 published specs cannot be ascertained to the differences in the measurement environment. Besides, all the other drivers match what's published in their spec sheets. That is more proof that X's measurements are very much valid.
Anyway, let's keep this thread clean and talk about objective measurements only. Like X has repeatedly said, there is no point talking about personal preferences, and anecdotes here. On the other hand, I think it is fine to talk about how the objective measurements would be subjectively perceived.
From my experience, the 9db shelf in the CHN70 is going to sound incredibly shouty and piercing. Maybe some high frequency hearing loss can compensate for such a response. On the other hand, looking at the comparatively smooth, flat response of the Vifa, it will sound non-fatiguing and pleasurable with a wide variety of music. Some might call it boring, but you can be guaranteed that it will give you good sound over the long run. And once you get used to it, it will be easy to hear the coloration of other non-flat drivers.
Because they were taken under invalid measuring conditions... they broke measurement guidelines.
And are different. Your earlier 12.x cm VIFA FR (rescaled tomatch) in the background of your 1/2 m measure.
dave
That difference in the LF is due to gate of 4ms giving 250Hz resolution. If I increased the gate at 0.5m it would match (average) but have ripples due to reflections.
I have a pair of those. Hard to call it a FR. Difficult to get anything below 200 Hz out of it.
AFAIC power handling specs are irrelevant. And given no industry standard meaningless across driver brands.
The FF105wk is a very good driver, giving up a little DDR to the FF85wk in exchange for greater bass capabilities.
dave
I haven't seen an impedance curve of the little Vifa. I will see if i can make one sometime this week.
But i suspect that it may be hard to find. The VIFA so far exhibits poor DDR. And little uncontrolled breakup.
I speculate that the engineers who designed this driver knowing it was for the TV market heavily damped its behaviour yielding smooth response and poor DDR knowing that that would be good for the low resolution audio often associated with TV programming.
Great for MidFi, not so much for HiFi.
dave
Yes exactly. A good reason totoss the measure out. And does not explain the differences in the HF.
dave
DDR is enhanced audibility of low level detail resulting from a driver that exhibits ringing in the inpulse response. It generate a longer duration equivalent of an acoustic "after taste" that is not there in the recording. A driver with clean inpulse will be accurate to real trabsients and percussives but show poor DDR, as you have seen. I posit that DDR is now measurable and proportional to the amount of ringing at the higher breakup mode frequencies. I am fine with not having DDR if it means I hear the recording as it was intended by the mastering and mixing engineers.
Be careful with what you call midFi as comparing to some poorer performing drivers that are less accurate make them now lowFi.
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This thread moves so fast. I wanted to respond to Tux's comments above.
1. Agree that when the off-axis follows on-axis, there is no breakup. This is why both X and I were saying that it's the central element that is radiating the sound. I think P10 agrees, though not fully sure.
2. HF hearing loss is typically progressive, meaning that it goes from high to low frequencies. I'm not sure how the brain can compensate for hearing loss. It cannot create information that is not there. It can fill in missing fundamentals in the bass, but it needs harmonics above the fundamental to fill it in. I haven't read anything that says the brain can fill in the high frequencies that it does not hear. Do you have any data to back up this claim?
3. Agree. And this is a very important point. It's like calibrating your HDTV. When James Cameron adjusts colors for Avatar on his calibrated HDTV monitor and that master is used to make the blu-ray copy you own, do you not want your HDTV to be calibrated to the same standard? Or do you accept watching it with highly saturated reds? It's the same with sound reproduction. You do not want the reproduction chain to add any color of its own. If the mastering engineer masters on JBL M2 monitors, with a frequency response looking like this:
do you want the reproduction to happen on a speaker with this response (looking at 200 Hz onwards only)?
(Note the different scales in the two measurement. JBL's measurement is on a 50 db scale with 5 db increment lines. The second measurement is on a 75 db scale with 20 db increment lines, making the variations appear to be smoother than they are.)
5. I remember reading in Toole's book that musicians were above average when it comes to listening skills, but trained listeners are better. BTW, trained listeners do not mean your average audiophile. Trained listeners are those that can identify flaws in the loudspeaker's response.
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Noit is not. Ringing will bury low level information, degrading DDR.
You seem to be grasping at straws.
dave
P10 does not agree. But i think it is more to do with what people's connotation of breakup is.
As pointed out earlier, resonant behaviour is breakup in the strictest sense. But most people's conotation of breakup is actually "uncontrolled breakup".
For a FR driver tohave good off-axis performanc as frequency goes upit needs to have good resonant behaviour (ie "controlled resonance") so that the radiating area of the cone decreases with increasing frequency.
dave
You are saying that if the "surface of the ocean" is flat then you have accuarcy, whereas hifi is about "the entire volume of the ocean".
Trying to use your definition of accuarcy to describe what a hifi should do is very short-sighted.
Again the "if theonly toolyou have is a hammer, everything starts looking like a nail" analogy applies again.
dave
DDR = Deformated Dynamic Ringing ? 😕 😀
A case from the past comes to my mind when I listened a metal cone full range driver first without measuring it before. I could hear many high frequency details I had never heard before on familiar recordings. Amazement occured. Then I measured the driver, there was a +10dB resonance around 10kHz. I tried to kill the resonance by EQ with moderate success. Those small details never heard before were gone as well...
Later, after I learned the characteristic sound of the driver, it put a high frequency whistle on top of every recording. That driver had to go.
Lesson learned: Never trust a metal cone full range driver 🙄 😀
PS. It was Mark Audio driver too, but I don't want to shout it too much here, since otherwise it was a good driver. One day I may sweep the dust out of it and use it again, maybe.
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