Kevin Haskins said:
And they will never achieve the same level of envelopment from their home theater that they do at the commercial theater. I don't go to commercial theaters - the sound isn't any good. And as far as reaching Audio Nirvana - good for them.
And I think you guys should do some real calculations of levels and power etc. 100 dB @ 1 meter is not a lot at 5 meters. It takes a lot of power to get to those upper SPLs no matter how brief they are. Small speakers just don't do it, no way, no how. And turn off the "A" weighting when you measure your room levels as this is eroneous to a loudspeaker designer.
Get some real numbers, do some real calculations and you will see that it takes some real power (with low compression) to get a really clean playback of a movie or live performance.
I wasn't challenging you. I was just asking. For all I know it could be the bass that was hitting 125db.
I've been in your HT room and listened to that Cream DVD, you played. It was quite loud. You mentioned it was probably around 110db. It didn't seem that loud, but maybe it was. Was that 110db at the listening position or 1m?
I've been in your HT room and listened to that Cream DVD, you played. It was quite loud. You mentioned it was probably around 110db. It didn't seem that loud, but maybe it was. Was that 110db at the listening position or 1m?
JoshK said:
That was at the listening position and that is exactly my point.
It doesn't seem that loud when its clean. You have to do the numbers and the numbers say what I am saying. You could never have played a dome tweeter at the levels that you heard - it would have sounded terrible for a few seconds, then the tweeters would have burnt out.
I checked out that Accutron tweeter and all I can say is that $250 apiece for a dome tweeter is not in the real world. The compression driver that I use was $65 and I can get them for $18. And, on a waveguide the compression driver is constant directivity - unlike the dome.
Off course it makes sense to talk about which frequency bands that carry the energy. And when you know the average power and peak/dynamic demands you can get an understanding on what you need from the different drivers in a multiway speaker.
Movies and music do play specific frequencies scientifically spoken. I think mr Fourier would agree with that at least.
Fine, but I doubt stronlgy that you have sustained spl's from the tweeter range at that level. Again.. you have done spectral analysis so that should be obvious.
I don't see anyone critisizing your design objective. Perhaps your arguments that doesn't seem to hold water.
I think we have done some calculations. You could argue that 100dB at 1 meter means much less at 5 meters.. but that goes for the Summa as well and since there seemes to be dome tweeters around that matches the Summa one has to question your claims and arguements.
Big (relatively spoken) speakers is needed for high spl's... in the lower registers. Not in the top.
Again we have.
I didn't know we were talking performance within a specific budget here.. you said "no dome tweeter" and so on.
Also it's not against the law to put a dome tweeter in a wave guide. Probably the better dome tweeters in a wave guide would perform better than the tweeters in your Summa according to what mine and your measurements is showing.
/Peter
I would also like to add that high quality dome tweeters handle 110-120dB peaks (10ms or thereabouts) without thermal compression.
Now, 85dB sustained level with 20-30dB peaks is enough for me at least... in the tweeter range.
/Peter
Now, 85dB sustained level with 20-30dB peaks is enough for me at least... in the tweeter range.
/Peter
My top priority is distortion over SPL - one seems to have to be compromised in order to achieve the other. If a dynamic tweeter distorts and burns out at a certain SPL, and a compression driver has no problem with it, that is one thing - I still need to compare overall distortion measurements between the two drivers - the compression driver may have higher distortion throughout its operating range; it may remain clean up to the high SPLs, but if the dynamic driver is cleaner from the beginning then that's what I'll go with. I can live without the super high SPLs/transients in favor of more accurate reproduction at the levels I normally listen.
The Accuton tweeter is overpriced considering there are superior dynamic tweeters for even less than the $65 retail price of the compression tweeter - so it's not exactly apples to apples.
Virtually all of the most popular designers here - Zaph, Tony G., Troels, etc. use dynamic drivers, so I have to give weight to that. Everyone has their biases and preferences, but the high efficiency group seems to be a smaller one, so I for one have to ask why.
I am sure people like those mentioned above have investigated high efficiency drivers, but they don't, by and large, use or prefer them. I am certain that if these drivers offered equal or lower distortion than dynamic drivers, which often cost much more, they would design with them in a heartbeat.
If some subset of high efficiency drivers can be shown to beat a subset of dynamic drivers in performance/value (in terms of distortion - MY priority), let's get the numbers up here on the forum - show the distortion graphs and prove the case. I'm not saying such data doesn't exist - but if it does let's see it.
The Accuton tweeter is overpriced considering there are superior dynamic tweeters for even less than the $65 retail price of the compression tweeter - so it's not exactly apples to apples.
Virtually all of the most popular designers here - Zaph, Tony G., Troels, etc. use dynamic drivers, so I have to give weight to that. Everyone has their biases and preferences, but the high efficiency group seems to be a smaller one, so I for one have to ask why.
I am sure people like those mentioned above have investigated high efficiency drivers, but they don't, by and large, use or prefer them. I am certain that if these drivers offered equal or lower distortion than dynamic drivers, which often cost much more, they would design with them in a heartbeat.
If some subset of high efficiency drivers can be shown to beat a subset of dynamic drivers in performance/value (in terms of distortion - MY priority), let's get the numbers up here on the forum - show the distortion graphs and prove the case. I'm not saying such data doesn't exist - but if it does let's see it.
I offer my anecdotal evidence for comparison purposes only...
--When my wife and I are really into listening to music, we are usually listening at 85db (A-weighted) average at the couch, which is around 3m from the speakers.
--I'd say the vast majority of our music, even classical has peaks around 10db, guessing, to 15db for the better recordings. This is based on eyeballing the needle on the meter. I woud need to take a bunch more measurements with a better setup, but haven't yet.
-- I'd say this is pretty darn loud, louder than most of my audio buddies listen. Its not as loud as we were listening to at Geddes's theater though.
--The speakers I am using now have a dome tweeter.
I think the objectives Dr. Geddes is aiming at, and ones the vast majority of denizens of this forum are aiming at are different. I could be proven wrong but I presume the general masses here are two channel hi-fi fans who listen in smaller rooms at much more modest levels.
With different objectives, it is no wonder we have different solutions. Even still, I am fond of Dr. Geddes's solution in some regards.
--When my wife and I are really into listening to music, we are usually listening at 85db (A-weighted) average at the couch, which is around 3m from the speakers.
--I'd say the vast majority of our music, even classical has peaks around 10db, guessing, to 15db for the better recordings. This is based on eyeballing the needle on the meter. I woud need to take a bunch more measurements with a better setup, but haven't yet.
-- I'd say this is pretty darn loud, louder than most of my audio buddies listen. Its not as loud as we were listening to at Geddes's theater though.
--The speakers I am using now have a dome tweeter.
I think the objectives Dr. Geddes is aiming at, and ones the vast majority of denizens of this forum are aiming at are different. I could be proven wrong but I presume the general masses here are two channel hi-fi fans who listen in smaller rooms at much more modest levels.
With different objectives, it is no wonder we have different solutions. Even still, I am fond of Dr. Geddes's solution in some regards.
sdclc126 said:
Now I'm curious. Which tweeters are you thinking of? And in what aspects are they superior?
/Peter
Thanks.. I'd be curious to hear your motivation though. 🙂
I'm familiar with Zaph's work and I see no tweeter that is superior among those.
/Peter
I'm familiar with Zaph's work and I see no tweeter that is superior among those.
/Peter
gedlee said:
The midwoofers are the limiting factor in the smaller speakers though, not the 1" dome tweeter.
I think we have to different design goals so we are talking apples/oranges. I need to build something people can live with first. In the vast majority of situations people fit the speaker to their lifestyle, not the other way around. If what you are advocating was actually desired by people, they would buy it. The fact is, 99.999% of people don't want what you are proposing.
The argument is as simple as that from my standpoint because I need to design something that people will actually buy.
a metadiscussion about Earl's arguments (1 of 3)
About five days ago, Earl wrote
Earl claims to be rational and non-personal and feels slighted by my last personal post.
I find this very interesting because of the Alice in Wonderland nature of this. He and I both think the other
So the following two posts will contain a meta-discussion about the two points we've been debating. The reader can determine for themselves which of us has been arguing with logic and which has been resorting to various rhetorical devices. This is very important to understand, since much of what passes for technical insight to the non-technical readers of this (and most other) forums is often spin on a few points to "sell" the reader.
So as he invites us, let's "go back and read what [he] wrote." I will detail the course of two arguments in the next two posts. These arguments were fostered by my initial disagreement of his post #15.
(continued...)
About five days ago, Earl wrote
Earl claims to be rational and non-personal and feels slighted by my last personal post.
I find this very interesting because of the Alice in Wonderland nature of this. He and I both think the other
- is/isn't providing real data
- is/isn't showing an attitude
- is/isn't being personal and subjective
- is/isn't sticking to the argument and engaging in debate
So the following two posts will contain a meta-discussion about the two points we've been debating. The reader can determine for themselves which of us has been arguing with logic and which has been resorting to various rhetorical devices. This is very important to understand, since much of what passes for technical insight to the non-technical readers of this (and most other) forums is often spin on a few points to "sell" the reader.
So as he invites us, let's "go back and read what [he] wrote." I will detail the course of two arguments in the next two posts. These arguments were fostered by my initial disagreement of his post #15.
(continued...)
sdclc126 said:
Nice toys. 😀
Just to throw the cat among the pigeon's, real HF driver here:
http://www.alconsaudio.com/site/technology.html
Test data here:
http://www.alconsaudio.com/site/products/pdf/AlconsQR36_test_eng.pdf
Oh dear...
a metadiscussion about Earl's arguments (2 of 3)
(...continued...)
Argument 1 - Linkwitz isn't into high SPL
Earl: post #15
Linkwitz hismelf admits that his designs are not intended for high SPLs - he's not "into" that.
Eric: post #175
Obviously, you haven't been to his place when he's having fun with high SPLs! (references to Beethoven speakers omitted)
Earl: post #177
I was at his AES talk when he described the design criteria and he said his target was in the 90's dBs. I asked him about this being such a low target and he replied that he was not into high SPLs....I will stand by my claims.
Eric: post #178
I've heard him demo VHSPL bass and he tells you he's not into it, while his Orion++ does VHSPL bass quite well. I wonder why the discrepancy.
Although you didn't state which "design criteria" you were discussing with him, Earl, nor at which talk, they were probably for the Orion,.... But your generalization doesn't apply to everything he has done and continues to do with his dipole designs, including the Orion++.
In Earl's next posts, he doesn't elaborate on which speaker/design they were talking about, nor does he answer the measured and observable fact that my Orions reproduce live levels. So the question of what Linkwitz is "into" never gets resolved. Earl stands by his statement but discounts by observations.
(...continued...)
(...continued...)
Argument 1 - Linkwitz isn't into high SPL
Earl: post #15
Linkwitz hismelf admits that his designs are not intended for high SPLs - he's not "into" that.
Eric: post #175
Obviously, you haven't been to his place when he's having fun with high SPLs! (references to Beethoven speakers omitted)
Earl: post #177
I was at his AES talk when he described the design criteria and he said his target was in the 90's dBs. I asked him about this being such a low target and he replied that he was not into high SPLs....I will stand by my claims.
Eric: post #178
I've heard him demo VHSPL bass and he tells you he's not into it, while his Orion++ does VHSPL bass quite well. I wonder why the discrepancy.
Although you didn't state which "design criteria" you were discussing with him, Earl, nor at which talk, they were probably for the Orion,.... But your generalization doesn't apply to everything he has done and continues to do with his dipole designs, including the Orion++.
In Earl's next posts, he doesn't elaborate on which speaker/design they were talking about, nor does he answer the measured and observable fact that my Orions reproduce live levels. So the question of what Linkwitz is "into" never gets resolved. Earl stands by his statement but discounts by observations.
(...continued...)
a metadiscussion about Earl's arguments (1 of 3)
(...continued...)
Argument 2 - Summas will blow everything away at high SPL
Earl: post #15
Summas will blow-them-away at very high spl, particularly open baffle designs
Eric: post #175
Linkwitz' commerical designs (like the Beethovens) play extremely well at high SPLs
...
Orion drivers can handle significantly more power than the design is advertised for.
...
I've played them at these levels after coming home from concerts at which I've measured 105-110db SPLs. The Orions were hands down *cleaner* than live in one case and as good in another...
Earl: post #179
I'm sorry, but your claim that any piston driven tweeter can equal a compression driver for max SPL is simply not credible and as such I have to discount the entire discussion.
Commentary:
Earl attributes a claim to me that I never made as not being credible and then "discounts" the discussion. That's one way of declaring point made over an interlocutor who's arguments make no sense. But that was not an argument I made...This is pure sophistry: arguing against a strawman.
I point this out to him:
Eric: post #180
I wonder where you'd find that I made that particular claim? And what has it to do with the topic anyways? Perhaps you can get higher (than necessary) SPL out of a given compression driver, but with more distortion. Wait, I'm letting you sucker me into a dead end distraction with your rhetorical twist...
Commentary:
Earl stops posting. Robh3606, LineArray, Rybaudio question my numbers, whether it's even feasible to get the SPLs I measured from the drivers, subs, etc. I thoroughly show that the numbers do add up in post http://www.diyaudio.com/forums/showthread.php?postid=1473299#post1473299. Magnetar chimes in in support of power compression being a limit ("Reality!") and I reply with the reality of compression driver distortions and some links, including one I found that I would like to read some day. Sensing an opportunity, Earl tries to score:
Earl: post #188
You probably should that paper since Regina failed to find a statistically valid relationship between audiblity and distortion level.
While on the other hand in "Subjective Testing of Compression Drivers", JAES Volume 53 Issue 12 pp. 1152-1157; December 2005 the authors showed that for 25 blind listeners no one could statistically detect any nonlinear distortion in the compression driver.
If you are going to quote real data (which appears to be rare), its wise to quote something that supports your thesis.
Commentary:
Here, Earl not only puts forward his own paper without disclosing he's the author as proof of something, but uses a put-down inside another strawman argument:
- he claims I don't provide real data (the put-down)
In the previous posts to others, I provided all the data I have. Earl provided none.
- he "suggests" that I should quote articles that support my thesis (the strawman)
My thesis is that dipoles can play very high SPL and that Earl misrepresents what Linkwitz has done. I'd be surprised if an article on compression driver simulations supports or refutes either point.
In post #193 to Robh3606, I wrote
I agree with you about an SPL contest. But this thread is about our experiences with home hifi, and I've pushed my home hifi to live/stadium levels and got better-than-live results.
But we haven't agreed on what is "high SPL".
Earl winds up with the following, all in post #211. I've added numbers for reference.
(...continued...)
Argument 2 - Summas will blow everything away at high SPL
Earl: post #15
Summas will blow-them-away at very high spl, particularly open baffle designs
Eric: post #175
Linkwitz' commerical designs (like the Beethovens) play extremely well at high SPLs
...
Orion drivers can handle significantly more power than the design is advertised for.
...
I've played them at these levels after coming home from concerts at which I've measured 105-110db SPLs. The Orions were hands down *cleaner* than live in one case and as good in another...
Earl: post #179
I'm sorry, but your claim that any piston driven tweeter can equal a compression driver for max SPL is simply not credible and as such I have to discount the entire discussion.
Commentary:
Earl attributes a claim to me that I never made as not being credible and then "discounts" the discussion. That's one way of declaring point made over an interlocutor who's arguments make no sense. But that was not an argument I made...This is pure sophistry: arguing against a strawman.
I point this out to him:
Eric: post #180
I wonder where you'd find that I made that particular claim? And what has it to do with the topic anyways? Perhaps you can get higher (than necessary) SPL out of a given compression driver, but with more distortion. Wait, I'm letting you sucker me into a dead end distraction with your rhetorical twist...
Commentary:
Earl stops posting. Robh3606, LineArray, Rybaudio question my numbers, whether it's even feasible to get the SPLs I measured from the drivers, subs, etc. I thoroughly show that the numbers do add up in post http://www.diyaudio.com/forums/showthread.php?postid=1473299#post1473299. Magnetar chimes in in support of power compression being a limit ("Reality!") and I reply with the reality of compression driver distortions and some links, including one I found that I would like to read some day. Sensing an opportunity, Earl tries to score:
Earl: post #188
You probably should that paper since Regina failed to find a statistically valid relationship between audiblity and distortion level.
While on the other hand in "Subjective Testing of Compression Drivers", JAES Volume 53 Issue 12 pp. 1152-1157; December 2005 the authors showed that for 25 blind listeners no one could statistically detect any nonlinear distortion in the compression driver.
If you are going to quote real data (which appears to be rare), its wise to quote something that supports your thesis.
Commentary:
Here, Earl not only puts forward his own paper without disclosing he's the author as proof of something, but uses a put-down inside another strawman argument:
- he claims I don't provide real data (the put-down)
In the previous posts to others, I provided all the data I have. Earl provided none.
- he "suggests" that I should quote articles that support my thesis (the strawman)
My thesis is that dipoles can play very high SPL and that Earl misrepresents what Linkwitz has done. I'd be surprised if an article on compression driver simulations supports or refutes either point.
In post #193 to Robh3606, I wrote
I agree with you about an SPL contest. But this thread is about our experiences with home hifi, and I've pushed my home hifi to live/stadium levels and got better-than-live results.
But we haven't agreed on what is "high SPL".
Earl winds up with the following, all in post #211. I've added numbers for reference.
- he later agreed with my first statement,
- Go back and read what I wrote - that OB could never achieve the kinds of SPLs that a system like mine does - and then Eric's discussion where he admits that OB will loose in an SPL race, which agrees with what I said and what he was criticizing me for
- But my statement was not subjective, it was simple science, and it was not incorrect.
- Note the tack above - instead of addressing the issue impersonal and technical (which apparantly was deleted) it became personal and subjective.
[/list=1]
Commentary:
- I never agreed his statement that "Summas will blow-them-away at very high spl, particularly open baffle designs" Nothing in my experience can reproduce, at the levels I defined as high, any cleaner or more realistically than the Orions. I can play a PA system louder but it sure won't blow the Orions away with all the distortion. Are Earl's Summas more capable? Unknown.
- Earl never says what the SPLs his system produces, nor did he or I post the SPLs the Orion *can* produce. Neither has he provided distortion figures at those SPLs. As I said in the so-called "admission" to Robh3606, we need to define what we mean by high SPL, and I choose to define it as real-world live amplified music, not space shuttle engine reproduction. And I also pointed out that anything higher than 110dbA would burn a hole in your head. Anything higher and driver distortion becomes moot when our hearing apparatus distortion becomes dominant.
- Again, no numbers about SPL and distortion for his system or for the Orions. How can this possibly be considered simple science and not subjective?
- Except for my post #208 where I gave up on fruitful discussion with Earl, my arguments have been neither personal nor subjective, but objective and rational. Earl's have not been rational.
[/list=1]
In the course of these two arguments, Earl has resorted to evasive rhetoric when logic has failed. All of the rational arguments I've provided were met by him with two strawman arguments, one put-down, one "discounting" of the argument, and several relevant questions ducked. I would go on and analyze the argument(s) since Peter started to challenge Earl's statements. There are many twists in there too. But perhaps someone else would like the chance to do it?
- Eric
- I never agreed his statement that "Summas will blow-them-away at very high spl, particularly open baffle designs" Nothing in my experience can reproduce, at the levels I defined as high, any cleaner or more realistically than the Orions. I can play a PA system louder but it sure won't blow the Orions away with all the distortion. Are Earl's Summas more capable? Unknown.
ShinOBIWAN said:
Are there distortion graphs in there? I should state that though I need distortion data I don't know how to read and compare the graphs myself - I rely on others here to interpret them for me. So I would ask somebody here to assess this data, especially as it compares to Zaph's measurements.
Thanks.
Distortion data is in there for both the single(Q18 model) and dual(Q36) tweeter models.
Don't compare them to the domes, its a completely different animal that I threw in just to show what state of the art is. Some distortion highlight: 120dB/1m above 2Khz with 1% or 130dB+ at 10%, both for the single tweeter model.
Don't compare them to the domes, its a completely different animal that I threw in just to show what state of the art is. Some distortion highlight: 120dB/1m above 2Khz with 1% or 130dB+ at 10%, both for the single tweeter model.
gedlee said:
This is a very interesting argument.
In the baffle plane, dipoles create ring-shaped velocity nodes that propagate away from the drivers as the plane waves travel outwards. As for the location of the other velocity nodes, perhaps Earl is right about them complementing what would otherwise be pressure nodes.
But the most interesting part is: So what? A velocity node is a region where there's high air velocity, and also little or no pressure variation. No pressure = no sound. The power losses in a dipole are driving these silent velocity nodes. Silent unless there's a house plant in one, then you might hear the breeze rustling the leaves.
This argument is kind of like saying that a room full of equalized sealed monopole (sub)woofers with smooth and flat in-room response is incorrect. Why is it incorrect? Because the response inside the cabinets is not flat.
- Eric
sdclc126 said:
Ok so it's not your opinions but Zaph's?
Obviously I was thinking on the Accuton since that was the one that you claimed being outclassed by much cheaper tweeters tested on Zaph's site...
Your motivation is low distortion but later you write in a post that you don't know how to read distortion graphs?
Okay..
/Peter
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