Yeah this was about seven years ago: Great Waveguide List
I believe they may have been done during the econowave craze.
Just in case you don't know; the horn OMF has is a progressive transition waveguide (2384). It's actually not very constant compared to some horns and beams some. Again, everything is relative.
That's interesting. Also: I assume you mean David Griesinger? I've not seen it before, but his web page looks interesting.
What does sensitivity mean here - threshold of detection, lowest point on an equal loudness curve, or something else?
Also: do you know if the usually quoted numbers are based on data from institutions using young test subjects (e.g. uni students, soldiers)?
The linked paper appears to show the area of max sensitivity as being age related.
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Looking at figure 1 (threshold of detection), the young group is most sensitive at 2kHz.
Looking at figure 3, (lowest point on equal loudness curve), young listeners seem more sensitive at ~4kHz.
However, the median older listeners (especially men, figure 4) no longer have this peak. Their hearing is least degraded <2kHz, so that range is where they are most sensitive.
Am I interpreting this correctly?
Does this change have practical effects - e.g. if the region of max sensitivity changes with age, will things like the best place to put a crossover, or the amount you need to control driver breakup also be age related?
Is this a(n extra) reason for younger listeners to be cautious of the advice / subjective judgments of older listeners?
EDIT; trying link again
https://www.jstage.jst.go.jp/article/ast/35/5/35_E1370/_pdf
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Thanks, so the TG9 4 ohm drivers are out of the question then, I just stick with the TC9 as first planned. The IDS-25 of Roger Russel is of course a great source of inspiration.
The Wisdom Audio LS series has a 19mm tweeter with a 750 Hz crossover. I guess that should work. It also has copper foam at the back of the diaphragm for heat management and a 5000 W power rating.
Interesting speakers for sure. Too bad they are targeted the luxury market, and are far too expensive. I also see that these installations often have too short line array. These speakers are modular and should go floor to ceiling in my opinion. If I win the lottery I will try and let you guys know how it works out!
Yes, sensitivity is basically the threshold. Also true is the fact that virtually all acoustic testing is done with young people.
I agree with your interpretation.
It is well known that older subjects become less reliable, that's not really a surprise. Toole makes a strong point of this. And yes, it would be logical to lessen the import of older peoples subjective judgments, except for two factors: 1) older people may have more experience and hence the loss of ability is offset by experience; 2) I don't take individual judgments very seriously no matter what the persons age is. But I would trust a group of young people more than a group of older people.
Lidia and I only ever use young people in our work. And each one is screened for "normal" hearing
I would guess that it is an econowave with a DE250 on it. I did do those measurements and post them.
Couldn't agree too much more but you seem to overlook Godel's Theorem. But there's an "oral history" that says IM distortion evolved after folks found harmonic distortion didn't quite match faults they were able to hear. Around 1940? Not possible to say with certainty that some sound flaw caused by, say Doppler effect, and for which nobody today bothers to assess by physical measurement, won't call forth a new kind of measurement someday in the future.
I am rather compulsive about keeping my tools sharp. But recently I've grown somewhat concerned that my mic-based EQ leads to worse sound with my ESLs than simply no EQ. Maybe its my mic technique or maybe its my clean and clear ESLs.
Sorry if this just muddies the waters.
B.
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The Wisdom Audio LS series has a 19mm tweeter with a 750 Hz crossover. I guess that should work. It also has copper foam at the back of the diaphragm for heat management and a 5000 W power rating.
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Interesting speakers for sure. Too bad they are targeted the luxury market, and are far too expensive. I also see that these installations often have too short line array. These speakers are modular and should go floor to ceiling in my opinion. If I win the lottery I will try and let you guys know how it works out!
That has got to be some of the most egregious BS I've ever seen in a loudspeaker ad, and I've seen some whoppers:
http://www.wisdomaudio.com/products/ls4/
Where to start?
1) There isn't a tweeter in the universe that can handle 5000 watts. Even the massive "ANYA" array, which is large enough to rock a crowd of 10,000 people, uses an array of tweeters with a power handling of 30 watts each. If someone says they sell a tweeter with a power handling of 1000 watts they're lying, if they say it handles 5000 watts they should be struck by lightning.
2) Their add says their speaker is capable of producing 130dB at 12'. For this to be possible, their speaker would need to have a sensitivity of 100dB with a power handling of about 5000 watts. Again, I know my prosound stuff, speakers like this do not exist. Yes, you can make a sub play 130dB, but getting 130dB from 20hz to 20khz is nearly impossible. The tweeter is the weak link, if you look at the big Danley Jericho speakers, you'll see that the high frequencies droop... Because it's really difficult to generate a lot of output at 20khz.
I'm not surprised that Wisdom provides no data to back up their ridiculous claims. In fact I can't find a single measurement of their speakers online.
Sorry to flip out over this, but I see this all the time in the audio world. I work in tech and I've met a few millionaires and a handful of billionaires. Companies like Wisdom Audio prey on these dudes. They basically make claims that are completely outlandish, and as long as 5-10 rich idiots don't know any better, they make out like bandits. Every millionaire I've ever met is itching to have The Best and they frequently don't know a whole lot about the toys that they buy. These are the guys who lecture me on my audio system and tell me that it can't possibly be good because I'm not using the right amp or the right speaker cables. I just grin and bear it, "there's a sucker born every minute." But it's claims like these that have turned the stereo market into an arms race for people with more money than knowledge.
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For some years now I have used my daughter for critical listening tests, and also paid her friends for more serious A/B testing. I apply a very small weighting factor (approaching zero these days) to my own auditory assessment of a design.
So true, totally agree with Patrick.
Plus one... Great post!
PS Your post on the B&O patent / tech is fantastic.... Thanks for all your time and effort.
Plus one... Great post!
PS Your post on the B&O patent / tech is fantastic.... Thanks for all your time and effort.
You may be right, and I agree about the tweeter. Anyway there is no music with that much high frequency content, so if it plays 130dB in the bass it can be much lower in the highes and still keep up. They said somewhere online that they fed these speakers with some LabGruppens full throttle without breaking them. The diphragmas are supposed to be very rigid. These speakers were the last work of David Graebener before he passed away from cancer some years ago.
Despite the lack of measurements and the oligark price tag I think these speakers may have some merit.
".... IF it plays at 130dB IN THE BASS..."
IF is a big word.... There is no way it does that.
On wall ( in wall even better) sealed box bass systems are a superb idea and there are ways to make 120dB at 1 meter at 20Hz possible...
Using multiple (depending on room size and listening position) 5 inch voice coil 15 and 18 inch Pro drivers combined with 2Kw to 8 Kw of ultra clean power and serious DSP (not mini DSP!) and 3 / 6 / 9 dB boundary / wall / corner room gain one can hit "120 at 20" in room.
BUT this wisdom model is not one of them!
IF is a big word.... There is no way it does that.
On wall ( in wall even better) sealed box bass systems are a superb idea and there are ways to make 120dB at 1 meter at 20Hz possible...
Using multiple (depending on room size and listening position) 5 inch voice coil 15 and 18 inch Pro drivers combined with 2Kw to 8 Kw of ultra clean power and serious DSP (not mini DSP!) and 3 / 6 / 9 dB boundary / wall / corner room gain one can hit "120 at 20" in room.
BUT this wisdom model is not one of them!
I don't want to look like an advocate for overprised products with bold claims, but I also think the critisism should be fair and not out of context like some of the posts above.
The Wisdom Audio LS4 is a 2m tall 100dB/2,83V/m linesource intended to be used above 80 Hz. The above comment is therefore without relevance. (I think) It has a SD of about 7600cm2 for 80 - 750 Hz. The thinfilm obviously can't move much, but this is SD about the same as six 18 inch drivers. So I don't know if 130dB is possible or not. It may be close though.
It is intended to be used with double 15" tapped horns below 80 Hz by the way. I still think it look interesting.
The Wisdom Audio LS4 is a 2m tall 100dB/2,83V/m linesource intended to be used above 80 Hz. The above comment is therefore without relevance. (I think) It has a SD of about 7600cm2 for 80 - 750 Hz. The thinfilm obviously can't move much, but this is SD about the same as six 18 inch drivers. So I don't know if 130dB is possible or not. It may be close though.
It is intended to be used with double 15" tapped horns below 80 Hz by the way. I still think it look interesting.
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