True but it shows where we stand and how limited our knowledge is. Another very good read is Barry Blesser's "Spaces Speak". Highly recommended.
Best, Markus
Yeah, probably. I had a quick look thru on Google Books. But the fundamental knowledge is always welcome.
Why do we need to explain how your little felt monster* works? You want us to believe that it is the best thing since sliced bread.
Do you know what it does and how it works? Then please explain ("It controls the back wave" is not enough). Would love to learn something new. But be prepared that you talk to people that have some knowledge about diffraction and absorption.
*)
Damn, is there a thread for that crazy beast?
That would be an interesting experiment, Panomaniac. I would love to play around with both drivers but I'm a little strapped for cash as it were. So you liked the Beta-8 as a mid? I wonder how it would do as a midwoofer, maybe with too of them working together.
Yes, this one and http://www.diyaudio.com/forums/multi-way/154539-what-happened-diyaudio-9.html#post1973076
Very entertaining
Hmmm. I seem to detect plenty of content above 10khz from percussion, horns and transient information from plucked instruments. Now, I would agree that there are no tonal fundamentals above 10khz from any acoustic instrument I know of.
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Agreed. In theory, sound quality is completely subjective and everyone has individual preferences. In reality, I find stuff that measures better sounds better nine times out of ten.
The quick answer on this one is that a driver that big is going to run into problems well before you hit 1.2khz, and a 15" woofer in a home speaker will often be able to play an octave lower with no difficulty.
The majority of PA woofers are optimized for use between 1.5khz and 100hz, where they're usually crossed over to a PA sub. In contrast, a 7" ScanSpeak woofer can easily be run from 40hz to 2.5khz.
Of course, just because you CAN run a driver this wide doesn't mean you SHOULD. Nonlinearity at excursion, intermodulation distortion, and various other issues can cause all sorts of problems
Two work well together, that' how I first heard them - one rolled off lower than the other. But jut one Beta 8 sounded better, when the system was reconfigured.
But so much of that is system dependent. Gary P's system is so clean, so dynamic. What part of that is the driver, the amps, the crossovers, the enclosures? Only dropping in another driver would start to answer that question.
Some time, I hope to do experiments like that. Swap in a few different wide band midrange drivers in my system to listen to the differences. New ones, old ones, etc. Should be enlightening.
I copied this post from another thread... it really sets a conundrum for how high a system needs to go... seems that even those with hearing <10k or so can detect time differences that invert to as high as 200 kHz.
I've started reading. Very interesting.... start with the HiFi Critic summary.
He has shown that humans can detect time differences on the order of 5-6 usec (1/t = 200-167kHz).
As interesting was some of the lengths he had to go to to not have the test gear corrupt the results.
dave
No you fool yourself, there are enough data to prove you wrong. I've just learned from the pro's that we are all wasting our time to design and build CD players, pre-amps, amplifiers and speakers that have flat freq response to more than 20kHz because there are nothing beyond 10kHz in music. 🙄
Strange though, I've found this link in another thread (thanks SY), maybe I will hang on to my system for a little longer before trading it for a portable MP3 player. 😀
There's life above 20 kilohertz! A survey of musical instrument spectra to 102.4 kHz
Interesting. But the statement that is made "Our recent behavioral studies on human subjects proved that humans can discern timing alterations on a 5 microsecond time scale, indicating that that digital sampling rates used in common consumer audio (such as CD) are insufficient for fully preserving transparency." is not really correct. The second claim does not follow from the first as "proven" (admittedly he used the word "indicating", but I still think that word is too strong. I would agree with "might be insufficient"). It is an interesting hypothesis, but existing data along these same lines contradict this claim, so valid proof is essential before making such statements.
That temporal aspects of an audio system are far more important than previously thought and that frequency response is not the whole story, or even the major component, is very similar to my own beliefs. And the claim that f = 1 / T does not hold up for the ears complex evaluation mechanism is also most certainly true. But I was seriously bothered by the lack of rigour shown by the above statement.
That temporal aspects of an audio system are far more important than previously thought and that frequency response is not the whole story, or even the major component, is very similar to my own beliefs. And the claim that f = 1 / T does not hold up for the ears complex evaluation mechanism is also most certainly true. But I was seriously bothered by the lack of rigour shown by the above statement.
It really gets annoying when people don't try and understand what it is that's being said and then pass on disinformation that is only destructive for someone trying to really learn something.
That HF signals CAN BE detected is not the issue, I agree with that - at what level is an important aspect, but detection, OK, they CAN BE detected. That SOME instruments have signal content this high when close mic'd is also not in contention because its easy to create signals this high. That they CANNOT propagate in air in the real world beyond a few feet is also a point that has to be considered, because this fact means that there would not be any "natural" reason for our hearing system to develope an accurate assement of signals this high.
The real point here is this; If you take and make a system that is perfect above 10 kHz and then have a jurry compare it to one that is not, you will find a very weak correlation, or in other jargon, a very small "contribution" to the total subjective impression as a result of the better performance in this frequency region. Now if the system with the excellent performance above 10 kHz is compared with a system that is actually better below 10 kHz, then in a blind jury evaluation the judgment will ALWAYS be for the system that is better below 10 kHz because the small contribution from the above 10 k region is not going to be enough to outweigh the overwhelming importance below that frequency.
You have to put things in context. Don't elevate something that is simply "detectable" to the importance of a major aspect of sound quality. This is what is often done and it is how marketing and charlatans are able to ellminate rational discussions in audio.
Bats use frequencies up to ~50 kHz for navigation in air. Their chirps can be detected from several tens of meters (I've done it myself, around 30 kHz chirps), so I would not say that ultrasound doesn't propagate in air. Yes, it is absorbed by air more than lower frequencies, but not enough to become totally useless (I'm talking about 20...50 kHz). IIRC, sperm whales use strong ultrasound impulses to stun prey - it certainly affects organisms, even if they can't actually hear it.
On the other hand, my speakers go up to about 13 kHz (16 if EQ-d) and I'm perfectly happy with them. All professional drivers, of course - Eminence Alpha 6 midrange, Celestion HF50 tweeter and Visaton BG20 for bass.
The best moment - the very same system was set up on a small outdoor stage for a small party, playing this and this. If I didn't knew, I would have thought that there really IS a live jazz band on the stage. And I wasn't the only one - several ordinary non-audiophile people commented exactly the same.
I don't precisely know the situation w/ bats, but it seems to me that their abilities would only be very nearfield, certainly not "tens of meters". If you do the calculations I think that you will find that the attenuation of a 50 kHz signal over 20 meters would be 20-30 dB - double this for the trip back. Bats "sonar" is only going to work for a few meters at best, which is clearly what its used for. Of course you did use that ultimate "fudge" word "detected". We can "detect" a lot of things that play no part in way things work on a macro scale. That's why I really don't like using "thresholds" for audio discussions. They don't really say much, if anything, about "importance" or "significance".
Yes, it's equally annoying when people start with comments like "hogwash", "audiophile dogma" or call for data once an argument doesn't suit their 'perfect solution for everybody's hi-fi needs'. BTW, I didn't pass on disinformation, it was meant as a sarcastic comment which I believe everybody noticed.
Ahh, that's better, not the same as this post anymore:
Regarding your comment: "because this fact means that there would not be any "natural" reason for our hearing system to develope an accurate assement of signals this high".
If so, then why do we still hear higher freq's? If we neglect the reproduction of higher frequencies, how will we be able to recreate musical transients? I believe you need midrange to provide detail for bass and you need HF to provide detail for the mids.
Sure, nobody will deny that but that only prove my point that building loudspeakers for optimal performance in a certain application will always be a compromise, you have to decide what aspects are most important for the intended application.
To some it may not be important, to me every little detail is important, that is what make me enjoy listening to music. If it doesn't sound like a realistic and believable performance, I would rather go and mow the lawn.
Not very helpful.
There is nothing inconsistant about those two posts, they both say the same thing. That above 10 kHz is simply not that important.
Thats the point, basically we don't. You call "detection" hearing, I don't. Hearing is that process that provides information to our brain, extreme HFs don't. They are there, we can detect them, we can measure them, but they add littel to nothing to the information content that our brain receives.
Yo are misusing the term "transient". It does mean "above 10 kHz." Even a 10 Hz signal can be a "transient.
Again, audiophile dogma. If you get things right below 10 kHz nobody will miss things above. Except those who view data sheets and marketing claims as necessary conditions for sound quality. At any rate, your minds as made up as mine and we disagree. I've spent a little more time at this than most.
If you say so.
And extreme HF is above 10kHz? The reason why I question your statement is that I can hear differences in SQ when making small changes on the HF filter in my CD player, in this case we are talking about relatively small differences in FR and phase response. Same for my amplifiers, some changes only affected FR far above the audio range but still it influenced SQ. If we talk about pro audio systems, I might agree with you but in quality hi-fi, everything is important, at least to some of us.
By "transient" I'm referring to sound from percussion instruments. That result in signals with sharp rise-times and I do believe our ears are sensitive to that.
So your speakers are perfect in every aspect for every use and everybody's ears?
If you mean by audiophile dogma, those who appreciate high quality audio reproduction, then you are right, except then your "nobody" claim is incorrect.
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