Audio theory on "upgrade or expand". - Page 6

@arnyk:

I'm currently on vacation so I only have my phone, and thus I'll perhaps be a bit short in my answer. Anyways..
Sure, my post was provocative, speculative and deliberately so, but perhaps not a post that I am particularly proud of (I actually think B&C makes good products for what they are meant for). Nevertheless, I know a thing or two about driver design -perhaps a little more than many here (still, there are many that know more, for sure).

As you say, pro grade drivers are designed with a different set of objectives than "consumer" drivers. High efficiency, durability and high SPL are some of them. But, as you know, designing a driver (or a speaker) you are basically facing a number of conflicting parameters to "optimize". If you optimize on one parameter you'll be forced to make sacrifices in other areas. It is an excersize in making the right sacrifices for the application.

In this particular case, ruler flat on-axis response and very low distortion was put forward as absolutely essential. A property, the B&C coax does not excell at. If that's the only criteria there are other alternatives that are way smooter and better behaved - coax drivers as well as parrallax combos that produce lower distortion and at the same time a flatter on-axis response. Naturally, these have other drawbacks that you as a designer needs to address to find the best compromise (like most likely less efficiency and/or max SPL).

How can you control vertical dispersion, doppler distortion, phase integration, dispersion, impedance, linear excursion etc etc etc. What is most important, what set of parameters will get you the closest to the "ideal" for the application you are targetting?

These are requirements that are not foriegn to speaker systems for use in professional audio.

So far I see no evidence to support that claim.

I see no evidence to support the apparent cleim that this particular B&C driver is deficient in this regard.

I see no evidence to support the apparent cleim that this particular B&C driver is deficient in this regard.

I see no evidence that support that my claims are wrong. Or that the ofset driver on the QM60 infact cause a diffraction problem of any dicernible magnitude. But point taken .

How do you tell about the distortion of speaker driver by looking at its frequency response curve?

I know it's not what you meant, but linear distortion is still distortion.

This got lost in the wash.

Can you load the two pictures into paint or something, and circle with red what you see as the differences???

I can't see the point you obviously have in mind, but it might be clearer if you could do something like that.

(am genuinely curious, as I say I can't see what it is you see)





What is YOUR estimate of the probability of that?



Amongst other things!

A ways? Sure. Everything is a ways from something else eh?

So what is it? 600 miles or so?? That is not far, esp given a few factors. Eg, "In US terms"....

I mean we are not talking britain or new zealand are we, where the thought of a hundred kilometres is WTF! And air fare (as I understand it) is ridiculously cheap internally in america.

Every year we have the 'big gtg' here, and many (talking tens) of people make a journey of over a thousand kilometres to come, often far greater than that.

Guess I DID make assumptions that might not have been correct. In australia the thought of long distances is automatic, we don't blink an eye about it. I thought that might also apply to a country the same sort of scale as australia.


Incoherent? Sorry, I thought I was being clear. Will try again...Finally, by the efforts of others, some small aspects of the design used by the most obnoxious, self righteous and self serving arrogant arsehole on any audio forum come to light.

Hope that was clearer this time.

Reading troubles?

Obviously, because the question was 'Which of the two scenarios do you feel applies to danny not visit you despite the number of pleas from you to do so'?

However, you did get something right, a LOT of thought went into how to get those drivers on the baffle, and then into a suitable box.

The overriding constraint was the question 'how DO I get a hulking 18 inch driver into a box that looks acceptable'?


Sure I posted those words, are you unsure?? That (of course) you took them out of context is neither here nor there.

Still, I stand by them.

No, I did not blow up THAT you posted graphs, I took great delight in showing all how you are a completely dishonest coward and a liar...you DID grasp my earlier explanation of how these terms are completely interchangable?

That in trying to show 'diffraction problems' you took a graph that did not apply to the situation at hand and substituted a completely different set of circumstances.

Cowardly and dishonest conduct.

Hevi showed that in your pathetic attempt to 'paint the guru speakers in as bad a light as possible' you again substituted a graph, and called it something else.

We all saw you prattle on about 'wildly varying driver diameters' even tho yours is a tweeter crossed from a 12 inch driver.

So, the final delicious icing on this monstrous cake, it turns out that your design exhibits each and every single 'flaw' you have tried to deflect onto other designs.

As we have discovered, nothing but an empty troll.

What is the saying? It is the empty bottle that makes the most noise.




Thought halloween was later in the year. Still, for all I know, it might just be a commentary on your physical appearance or online persona.

Cept, as it turns out, you're not scary at all. You just think you are.

C'mon dio! Can you do this?

I AM curious what it is you see.

That's not the driver AJ's using. Nor the correct maker.

I know because I've seen the drivers he's using in a set of speakers he did for a DIY speakerbuilder gathering in Atlanta back in 2006 or 2007.

But I will say that a well-done completed loudspeaker using that 12" B&C driver you're pillaging will blow the crap out of any 7" 2-way in measured performance and sound quality. Certainly anything with a giant flat lip right under the tweeter...

(No, I don't use it. I use 12" and 8" Tannoy Dual Concentrics, and 5.25"/4.5"/3" KEF Uni-Q's in my home systems.)


Dude, dude, dude, it's very obvious that you've not seen many pro drivers. Compare a JBL, or ATC, or Volt, or TAD, or B&C, or BMS, or even Peavey driver to some crappy hack from Morel/Dynaudio/Focal, or even a TC Sounds subwoofer, and you'll very quickly see which is built to a higher standard. (I don't think anyone in the industry is as notorious for their poor unit-unit consistency and generally sloppy build as Morel. Yet their drivers also manage to be quite expensive.)


Spoken like somebody who's never heard, let alone used, a good speaker. For the record, the better "pro" drivers measure better than the 7" toy crap from ScanSpeak or Seas etc., and they sound better too. For example, Vance Dickason's comment on the BL(x) curve (motor linearity over stroke) in Voice Coil on a recent B&C 15" driver was "textbook performance."



That may be true, but the good ones are exceptional performers in terms of audio fidelity terms, too. Show me a single "hi-fi" driver with BL and suspension linearity better than the B&C 18SW150, as tested in Voice Coil magazine last year.


Not speakers that are just magma cum laude, I assume.

But AJ's coax ist aber kein B&C.


Indeed, the Q900 measures pretty well. Their flagship speaker uses an earlier generation Uni-Q coincident, and measures absolutely superbly. Sounds it, too.

Andrew Jones' TAD and Pioneer Elite speakers uses a similar driver (Jones did a lot of development work on the KEF Uni-Q before Pioneer hired him) and seem to have exceptional measured performance as well as rave reviews as well.


I actually agree with Bigus on this one. A hard center channel is hugely beneficial for a stereo image.

oops, more later

Sure looks like it!

Wanna bet if we will actually find out which driver he uses? He's not game to let us all see.


Ok, got you.

but the question is, which one did you hear? Maybe he just upgraded the cabinet, but atm there seems to be two distinct speakers under discussion.

There is this one




and then there is the one hevi is referring to







Now, the bass driver looks very much like a peerless xls 12.

And they are obviously two different speakers (unless as I said, it was re-veneered or sumthin)

Now, here is a pic of the bass driver used in *something*, dunno if it is even one of these two or not!



In any case, if the other bass driver WAS an xls 12, well this one ain't.

So, which one did you hear? Because, the one hevi is discussing sure does look like the one he linked to.

Dio, are we going to get your explanation or not? If not, remember not to bring **** up again ok?


well about the lip, maybe, maybe not. That has been covered before by ME posting the correct graphs, not the lies from the ankle ferret.

Still, we shall reserve judgement on 'well done' till we see his response eh?


C'mon, we know you are coming in to bat for oxy, but don't ACT like him yeah? Have you heard the gurus? or do you too go solely by FR? If you do, make sure you don't go by the misleading graphs the ankle ferret posted. He lied natch.


still undecided in my book

Do these speakers have a diffraction problem?

Lots of drivers look similar. That's not dispositive of anything.



I do think he has said what it is in a different thread, if you care to look. But lemme tell ya, if he shows you, you still won't be able to figure it out.


The coaxes are the same, the bass drivers are different. The "cabinets" (baffles, really) and the bass drivers in the version I heard were different from the ones in both of those speakers as well.


There's no maybe there, sorry.


I'm not going to bat for anyone, per se. If AJ's as wrong as hevi was, and it's something I care about, he would get a similar response.

The fact of the matter is, if someone thinks a too-small, inefficient, high-diffraction 2-way is a good example of anything except for botched design, s/he simply hasn't heard real speakers.


I don't need to smell the defecation of a pig to know that it's an unplesant odor. I can do that just by looking at it.

Without seeing any measurements whatsoever, based solely on its geometry (the inadequate midbass size, the pathetic excuse for a "waveguide" on the tweeter, that infernal lip, etc.) the Guru is an unacceptable design for me. I know what it'll do. I've built similar speakers myself, before I figured things out...

Thanks DS



Yeah, they tend to follow the same basic form, so hardly surprising that a lot look alike.

AND, of course, is why the question was asked. "is it THIS driver? or not"

That we will never get a straight answer indicates a lot, just not about driver identities.


What words do you suggest I put into the search field?? Would you agree that for a guy who continually demands and bombards others with questions he should have the sugarlumps to answer very simple ones directed towards him?


Thanks. Again that we have to get answers from another is telling.

So, regarding the pics (and performance thereof) of the speakers in THIS thread, you have in fact not heard them? So if we do not know the secret identity of the actual drivers, and have no measurements at all to evaluate you are as in the dark as the rest of us whether or not they even match the performance of the gurus, let alone exceed them?


Plenty of maybe, sorry. Is that not the mantra of the objectivist? that it has to be heard blind, that above all audibility is the king?

Wanna see something on a graph, sure, measure it. IS that squiggle audible? that is the song sheet is it not?

What about things NOT seen in the FR graphs shown here? Time for example. Of course, a perfect sin2 response then mean the sin2 impulse tests is a contrived one no?

If you dispute the audible benefits/differences between a time coherent speaker and one that is not, then it would come across like this Spoken like somebody who's never heard, let alone used, a good time coherent speaker.


I don't know what your response is, so it was couched as possible.


Well, dissect the ankle ferrets design.

Square edges, driver placed centre of baffle, a 12 inch crossing to a one inch (?) tweeter, no idea in the slightest of it's performance, dipole, small bass driver, drivers not recessed, tiled floors in the room, speakers in an alcove, coffee tables in the way (your one, personally I doubt it's effects would be audible thru the rest of the room rubbish).

Does not look too much like he has addressed any of the problems he directs towards other speakers does it.

The answer to that is, "no."

The exchange reminds me of that scene in the West Wing, when Dr. Bartlet is talking to the White House Counsel:

"Do you know what time it is?"
"Yes."


"Never" is a strong word. Perhaps he's waiting until the end his audio show to say. Or has his own reasons, whatever they are. It's his personal toy so he can reveal what he wants about it in whatever detail to whomever he wants to at whatever time he wants to.


Your homework, not mine.


Didn't he answer the question actually asked? If not, then again, it's his toy, he can reveal whatever he wants to (or not) about it.


No. I mean what I actually wrote: I heard an earlier, preliminary iteration of them at a DIY audio gathering several years ago.


"We" is incorrect. "You" don't. (Mostly, at least. I don't know anything about that driver with the 12-spoke basket except its maker.)


Because a 12" coax competently done is always going to be better than a pea-shooter with a directivity mismatch in the midrange, especially one with a giant step under the tweeter!

(A $250 Behringer B2031P would be a higher-fidelity speaker than that "guru")


Part of being an educated adult is developing the ability to draw reasonable inferences from past experience...


Let's see...reasonably constant directivity from the penultimate octave all the way down to the low bass, high efficiency, very high quality drive-units with superior motor design, multiple subwoofers to smooth out room modes, etc. Overall, it sounds like the bones to make a good-sounding system.

Most of your criticisms seem to stem from a basic misunderstanding about how dipoles work. Some of them, such your beef with centered drivers, stem from a larger misunderstanding, likely based on excessive reliance on on-axis frequency response measurements over sound power measurements.

That said, his system isn't the one I would do for myself. Mostly because I'm not a fan of dipoles for a variety of sonic and aesthetic reasons. Also, I've found I greatly prefer the sonic image from a three-channel front stage. (Though I'd take his speakers over any pea-shooter with a midrange directivity mismatch and a giant lip under the tweeter.) But is it consistent with the ideas he espouses? By and large, yes, a reasonable person who knows what s/he is looking at would have to say it is.

I'd still get the coffee table out of the way, though.

again, thanks.



Sure, it's argue-o'clock!




He had plenty of time in this thread and others to answer the questions directed towards him. You, no doubt, saw many from me along that line? And I feel it was entirely appropriate for me to ask those questions, as I encouraged him to dissect my design as he was wont to do anyway.You did note his withdrawals when challenged? Does not take much does it. Just shows that the initial criticisms were/are a smokescreen.

So yeah, happy to use the word never. it will either be true (which I put my money on) or it will 'shame' him into coming clean.

that he has no shame kinda indicates against the last option. (watch the evasions to come, with again the outwardly directed insults and lying)

We'll wait till after the show m'k?


Get that. I tried 'lying POS driver selections' and variations on the theme, nothing haha.




Oh, I see. He has the option of withholding data whilst demanding it of others?

Did he get permission form anyone (apart from me, twas freely given) that is was OK for him to trash talk their systems?

You did not address the time issue I asked.


(I did say this was argueo'clock did I not haha) No, *we* IS correct, *you* do.

Just joshing, and my is it not a relief in the atmosphere of the place when certain audio shows are on?

How is that?




Yep, giant step. We got it. Rather small changes in the TRUE graph, but we got it.

And, again, the crux of the matter. *We* don't know if it was competently done do we. And we will never find out.


Sure. Then why do you seem to feel we will get answers from the ankle ferret?

What does past experience tell you about that?




No, I have really no thoughts as such on dipoles, other than I personally do not like them and would not have a pair.

But, here is the difference. I have zero problem with people who like and want them. See the difference?

Apart from that, any 'criticisms' I have had of the design are purely the same ones directed outwards towards other designs.

It is not criticism per se of the design, but criticism of the criticism. It simply shows this guys essential hypocrisy, that his own design (except for that gigantic humongous lip...like all lies it too seems to be growing haha) exhibits every single one of the same 'flaws'.


Haha, thanks. I still reckon it would be inaudible amongst the rest of the room rubbish.

Personally, for your budget, I think (Everyone is entitled to thier own opinion ) that your money will be better spent/invested into a decent subwoofer.

The reason for this is that, in modern day, finding a pair of tower speakers to produce even decent bass (to my standards), is extremely hard, and if you want those, its going to cost you a lot. A few brands like Definitive Technology and Cerwin Vega make speakers with large drivers 12-15'' for a good bass response, however the speakers worth spending on to produce that bass is going to devour your budget, so I would instead get maybe decent set of towers (don't expect any bass really, concentrate on a good frequency response for highs and mids), or bookshelf speakers and pair them with a good solid subwoofer. And I've listen to many speakers and even the ones for example from DT, or Cerwin don't quite make the bass that low and as loud as I like, simply because the box isn't big enough...its as simple as that I think, I'm comparing them to my speakers which have big drivers and a enormous box for huge bass response. And I have other kenwoods built during the late 90's when subwoofers were barely used, everything was stereo speakers.

For example for 2500, you can get a pair of Klipsch RF-82 II's or a pair of DT BP7006's. And then couple them with a nice Elemental Design sealed 18'' subwoofer for $850 or a ported 15'' for $1200, although sealed subs sound better. The towers won't really give you bass, but the sub will knock you off your feet, I've heard it personally and when its rath is unleashed...it makes paper out of your walls. If you get a cheap sub and really expensive floor standers, you will get less bass, because bass producing floor standers are generally way more expensive, compared to cheaper subs that give great bass.

Plus I've found that surround receivers, not so sure about really expensive ones, don't send that much bass to the fronts (maybe I don't know how to configure them, but I've used all settings I can find including equalizers and even manually placing resistors to high and midrange woofers to turn it up onto the larger woofer. I have a kenwood amp from the late 90's, a specific stereo amp and it sends wayyyy more bass to the fronts then any other surround receiver built recently that I've heard does, so the amp depends a lot also.

But then again, this is just from my experience, its what I've noticed, I could be wrong.

I re-read, and he answered the question presented (to paraphrase, "is that this B&C driver") in an entirely appropriate manner.


I'm much less interested in the personal BS than in the technical merits of the design. I learned recently in a show report that in addition to the dipole midrange (I assume the they're monopole in the tweeter's range), he's doing something really interesting with those speakers in the bass. He's basically combining a monopole radiator with a dipole radiator to create a cardoid pattern in the modal region.

Kinda annoying, really, because now I want to try it myself and compare his approach to the one I've found to work best, multiple subwoofers arrayed and set up using Dr. Earl Geddes' methods.

To be sure, there are other modern speakers designed along similar lines as AJ's. Emerald Physics' stuff comes to mind, as does Gradient's Revolution; in the the bass John K. is doing similar stuff with his NaO). But I must say, there is real thought going into AJ's speakers. Much more so than a casual observer may notice. Which one just cannot say about some little mini-driver toy with a giant sharp-edged ledge under the tweeter.


Has anyone asked for the drivers used in another speaker? No. Why? The salient issue isn't the drive-units, but the crappy design.


If someone puts something out there in public, then that gives license to talk about it. No need to be so thin-skinned.


\\

You obviously don't understand how diffraction works. First, even though it's a linear phenomenon, it is actually perceived non-linearly. That is to say, it's more annoying as things get louder.

But besides that, I didn't see any useful measurements. Just on-axis stuff, which is a system with a gigantic directivity mismatch smack-dab in the midrange doesn't mean much. Did someone post a polar map?


It tells me that AJ might tailor the depth of his answers based upon his assumptions about the intentions of the asker. I know I've asked him questions recently about things he's done, and he's answered forthrightly.


What kind of dipoles? There's a difference between a panel speaker or other line-source-ish speaker, and a point-source. Most commercial dipoles tend to be the former two. Point source dipoles tend to be well-reviewed. Stereophile has named Linkwitz's Audio Artistry speakers as product of the year a couple times, and Peter Azcel uses the Linkwitz Orion as his reference. Also, Gradient and Emerald Physics speakers are generally well-liked by those who hear them as well.

What didn't you like about them?


There's nothing technically wrong with the dipole approach. But there are just plain wrong about speakers with:
a) a large directivity mismatch smack dab in the midrange (what I call a "mushroom cloud" power response),
b) a very high diffraction cabinet, and
c) small, low-efficiency drive-units

Not to say one can't use and like such speakers, but from a fidelity-to-the-source-material standpoint they are objectively poor designs because of those two flaws.


I have to conclude that you think so only because you still lack a basic understanding of how they work. Please re-read my previous post.