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post #181 of 481 Old 02-20-2009, 02:32 PM
 
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Originally Posted by Alimentall View Post

The Maxx2 was measured in Stereophile as /-8dB.

Over what frequency range. Without specifying a frequency range, the +/- db range tells you nothing.
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post #182 of 481 Old 02-20-2009, 02:34 PM
 
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Originally Posted by Alimentall View Post

Well, I think it just depends on the subjective and objective results. If steeper crossovers work better, maximizing multiple parameters while only being worse in one, so be it.

Unless of course the one parameter that is worse makes the speaker sound bad.
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post #183 of 481 Old 02-20-2009, 02:36 PM - Thread Starter
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Originally Posted by Morbius View Post

The Xd graphs just show that it was designed to get good frequency response - but
the Xd is a "one trick pony". It does one thing well - but not the pantheon of multiple
characteristics that I expect in a great speaker.

That's not true, it does many things extremely well, that's the whole point! It has exceptional, even SOTA FR. It has exceptional, even SOTA horizontal dispersion. It has exceptional, even SOTA vertical dispersion. It plays extremely loud without audible distortion or fatigue. I would say the same as you substituting $100K speakers. They are usually the 'one-trick pony'. they play loud with low distortion and big bombastic bass. But little else. If you stand between two Xds, it will sound coherent and natural. If you stand between a 'high-end' passive speaker, it will sound like a disorganized, out of phase mess. I think a speaker should sound good most anywhere in your listening room, not be optimized for a ~3'x3'x1' area where you can put your head.
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The Xd is like the amps and receivers of the '70s that had tons of negative feedback
so that they would measure well on a THD benchmark when fed a 1 kHz sinewave.
Yes - those amps really "locked in" on that 1 kHz sinewave and got great THD metrics.

Not really, because DEQX optimizes *multiple* parameters simultaneously. Not just one. That's the beauty of it. Leaving the engineer with fewer problems to solve. What's that term you use? Fewer areas of constraint or something to that effect?

John
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post #184 of 481 Old 02-20-2009, 02:38 PM - Thread Starter
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Quote:
Originally Posted by faberryman View Post

Over what frequency range. Without specifying a frequency range, the +/- db range tells you nothing.


John
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post #185 of 481 Old 02-20-2009, 02:41 PM - Thread Starter
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Quote:
Originally Posted by faberryman View Post

Unless of course the one parameter that is worse makes the speaker sound bad.

I think that's what I just said.

John
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post #186 of 481 Old 02-20-2009, 02:43 PM
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Originally Posted by FrantzM View Post

I have heard the X-2 and my ears tells me very few speakers are in its league.. Very few.. Those who have heard it can attest to that..


May I ask what speakers are in the same league as the X2, according to you?

Sound and video is not magic, it is pure physics. Physics that can be magical
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post #187 of 481 Old 02-20-2009, 02:47 PM
 
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Quote:
Originally Posted by Alimentall View Post

I think that's what I just said.

Actually what you said was:
Quote:
Originally Posted by Alimentall View Post

If steeper crossovers work better, maximizing multiple parameters while only being worse in one, so be it.

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post #188 of 481 Old 02-20-2009, 02:49 PM - Thread Starter
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Quote:
Originally Posted by faberryman View Post

Actually what you said was:

Semantics. I'm saying you do whatever improves the *overall* performance, however you define that as an engineer or designer.

Do you have anything to add to this thread besides 'devil's advocacy'?

John
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post #189 of 481 Old 02-20-2009, 02:51 PM
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Quote:
Originally Posted by Morbius View Post

I listened to the X-2 and I listened to the Xds.

There was just "something" about the Xds that sounded "un-natural" There was something
about what I was hearing from the Xds that said "You are listening to a reproduction."

The Wilson X-2s were saying "You are listening to the real thing"; and although I knew
I wasn't listening to the real thing - the Wilsons were VERY convincing.

I think that while it is useful to know that the people who heard the two apparently universally preferred the Wilson/Lamm over the Xd/DEQX, there are too many variables here to draw any conclusion re the merits of active digital crossovers. For instance, my understanding (and I don't own one) is that tube amps actually add to their output the type of harmonics present in live music, while SS doesn't. And obviously, the speaker drivers and cabinet sizes differed vastly.

A more appropriate experiment, as you pointed out, would be to compare the exact same speakers using the same amps, with only the crossover different. The comment from Dennis Murphy I think is useful in suggesting that digital active, comparing an HT3A to an HT3, has some promise, but makes only a subtle difference in itself, and to many, might not be worth the cost.
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post #190 of 481 Old 02-20-2009, 02:56 PM
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Quote:
Originally Posted by syswei View Post

A more appropriate experiment, as you pointed out, would be to compare the exact same speakers using the same amps, with only the crossover different.


I agree

Sound and video is not magic, it is pure physics. Physics that can be magical
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post #191 of 481 Old 02-20-2009, 03:00 PM
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Quote:
Originally Posted by Alimentall View Post

It plays extremely loud without audible distortion or fatigue.

In the Soundstage measurements it exhibited power compression in the 120-700Hz range at 90dB, and this became very dramatic (like -5dB) at 95dB. And as I've pointed out, distortion is worse than the PSB Synchrony One that your store carries.

Quote:
Originally Posted by Alimentall View Post

It has exceptional, even SOTA vertical dispersion.

KEF Reference series is better in that department.
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post #192 of 481 Old 02-20-2009, 03:01 PM
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Quote:
Originally Posted by Morbius View Post

NO - Leo Spiegel was NOT attempting to combine a dipole and an omni. This interview
was on the design of the Apogee Stage - which is a ribbon tweeter and ribbon woofer.

You are right --- that was my mistake. However, this introduces new problems. Ribbon drivers are a large fraction (and often larger) than the wavelength of the top of their passband, compared to the relatively small drivers on the Xd. At 600 Hz (as cited in the article), we're talking 2-foot wavelengths, and the woofer ribbon's size is in that ballpark. Also, its behavior, like most ribbons at the top of their passband, is certainly far from pistonic, as resonances in the ribbon's physical structure are proportional to the wavelength of that frequency, too. I am not surprised that they would have integration problems with steeper crossovers.

The only reasonable conclusion one can draw from the Apogee story is that perhaps steep, analog, passive filters may not be appropriate for full-range ribbon speakers. Steep, analog, and passive are also three filter characteristics that do not play well together. I would suggest that Apogee's experience has little bearing on a modern, high-powered DSP system that's optimized for thousands of FIR taps applied to drivers that are far better behaved and placed in a much more forgiving context.

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The other is the pre- and post-ringing that one can get with a digital filter.
The ringing of the Xd is something that I heard when we demoed the Xd at OB's house.

To be precise, you would get pre-ringing with FIR filters. Post-ringing can happen with any kind of filter. Have you tried Keith Howard's ringing test? If so, how was your performance on it?

Quote:


The Wilsons with OB's fine front-end electronics gave a very convincing illusion of a
"you are there" sound; while the Xd's seemed to call attention to the fact that they were
a reproduction.

You can only determine this if you were present at the original recording session. For example, the Xds may have been more truthful to the actual recording, and the X2s may have been euphonic.

--Andre
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post #193 of 481 Old 02-20-2009, 03:08 PM
 
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Originally Posted by AndreYew View Post

You can only determine this if you were present at the original recording session. For example, the Xds may have been more truthful to the actual recording, and the X2s may have been euphonic.

So if you were there at the original recording session, only it didn't sound like you were there but it sounded like you were listening to speakers which made it sound like you weren't there, then the Wilson X2s would be euphonic if they made it sound like you actually were there.
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post #194 of 481 Old 02-20-2009, 03:14 PM
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John

That this where we don't agree.. It is simply not possible to infer that a speaker sounds better than another by simply looking at a FR graph... Indeed the FR measurements of the XD with the DeQX are remarkable. It continue to beg the question that such results can be achieved with most speakers using Digital Room Correction.. whether they are active, passive, analog, Digital or whatever... This by the way does not in any way diminish the solid value and the good performance of the XD on that most everyone agrees... My problem is the way you portray the XD as the speaker by which any other should be judged NOT verbatim but in essence that is your position: The XDs are not. That the Xd system represented an excellent value , yes! That they represent the ultimate in speaker design NO! Emphatically. This I am stating whether you implied it or not call it pre-emptive strike...

Wide dispersion is not always desirable, it could even be said it is best to avoid it in the high frequency where it leads to a tilted "light" sounding balance.. The speakers start sounding thin.. so limiting the horizontal dispersion in the treble can be and often IS a design CHOICE! Steep Crossovers present many problems and these are audible. Where we converge is that Room Correction applied to most any speaker is likely to lead to better sound...People who have used such do not go back. The technology is not mature as we (I included) would like to think. Given a Tact or other most people are likely to do more harm than good, I am reminiscent of a session that I had with an Audiophile friend in NYC who had the TaCT/Boz system... It was clear from his FR reading that their was in the FR a clear bump around 6~7 KHz and he corrected it, resulting in a the disappearance of that 2dB bump. Fine; but now, horns and brass no longer had that "plhtlaaaat" throaty characteristic sound, they sounded too much the same no difference between a hautbois (don't remember the name in English ) and a trombone or a flugelhorn .. so we left the bump alone and the brass came golden and fine.. that is an anecdote indeed but the audiophile in question could attest to that.... The issue of better frequency response does however point to the use of DSP to ameliorate in Room response of speakers after , of course room treatment.. I must also say I am not defending expensive .. There are too many Audio Products on the Market whose sole attribute is their expensiveness not their performance. I don't think the High End Audio has delivered performance commensurate with some of the price tags ( $30,000 speaker cable being my favorite huh, nonsense) and this , to me needs to be reversed and I sincerely think it shall be..

Frantz
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post #195 of 481 Old 02-20-2009, 03:57 PM
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Quote:
Originally Posted by Alimentall View Post

Not really, because DEQX optimizes *multiple* parameters simultaneously. Not just one. That's the beauty of it. Leaving the engineer with fewer problems to solve. What's that term you use? Fewer areas of constraint or something to that effect?

John,

You don't always want fewer constraints.

You can have too few constraints - in which case your system is "under-determined".

You can have too many constraints - in which case your system is "over-determined"

The key is to have the number of constraints match the "degrees of freedom"
[ Do you remember that term? ]

If you have a linear system of "n" equations in "m" unknowns; then
n > m is overdetermined
n < m is underdetermined

if n = m; only then can you have a unique solution.

Dr. Gregory Greenman
Physicist
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post #196 of 481 Old 02-20-2009, 04:01 PM
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Quote:
Originally Posted by AndreYew View Post

You are right --- that was my mistake. However, this introduces new problems. Ribbon drivers are a large fraction (and often larger) than the wavelength of the top of their passband, compared to the relatively small drivers on the Xd. At 600 Hz (as cited in the article), we're talking 2-foot wavelengths, and the woofer ribbon's size is in that ballpark.

Andre,

Since the ribbon is a dipole - it's not the length that matters - it's the width.

The ribbon dipole acts like it is infinitely long with a limited horizontal dispersion. The
horizontal dispersion is the characterisitic "figure-8" radiation pattern of a dipole when
viewed from above.

Dr. Gregory Greenman
Physicist
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post #197 of 481 Old 02-20-2009, 04:23 PM
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Quote:
Originally Posted by AndreYew View Post

You can only determine this if you were present at the original recording session. For example, the Xds may have been more truthful to the actual recording, and the X2s may have been euphonic.

Andre,

I think it is valid to hone in on the sound of something like a cymbal. I know what a
real cymbal sounds like - and there really isn't that much variation in the sound of
cymbals.

Additionally, I know well from the PHYSICS of how a piece of metal like a cymbal
is going to sound. I know I am going to hear the strike of the drumstick, at which time
the rest of the cymbal is silent because it doesn't know it has been hit yet. The rest
of the cymbal finds that out as the pressure wave propagates out from the hit site.

I know that the cymbal is going to ring before the waves reflect from the edges of the
cymbal. I know after the waves reach the edge and reflect and criss-cross the cymbal;
it has the distinctive "shimmer" sound.

Listen to a real cymbal; and you will hear the dynamics of the cymbal crash.

The Wilson X-2s presented all this information to me in a a life like way - just as one
would expect from a real cymbal. The Xd just flat out didn't do that. It didn't present
the detail - it just "mushed" it all together into a "shhh" sound.

I don't need to be at the recording session to know that the Wilson is not being euphonic.
John tried that argument the first time I posted this. He suggested that what was on the
recording was the mushed "ssshhh" sound - and that the Wilson created all these
transients and microdynamics because it was being inaccurate.

BALONEY. The Wilson speakers are not "smart enough" to take a mushed "sshhh"
and deconvolve from that the microdynamics that one expects from a cymbal.

No - the simple analog crossovers and drivers in the Wilson can't do that. Those
microdynamics HAD to be on the recording.

The DEQX in the XdA is really "smarter" than what is in the Wilson - it's a computer
after all. However, the computer is using its "smarts" in processing the sound in a
way that makes it worse.

The problem, as Keith Howard's article and the graphs of the various filters show; there
is a "conjugate" relationship between temporal and frequency response. If you attempt
to go for maximally flat frequency response - you mess up the temporal response.

Look at the three "all pass" filters - numbers 5, 6, and 7 in Howard's article at:

http://www.stereophile.com/reference...ng/index1.html

These 3 filters have the best frequency response of any of the filters - ruler flat as
seen in the third column. However, they also have the rattiest temporal
response of any of the filters.

That's what happens - when you optimize for the best frequency response; you get
inferior temporal response. Conversely, if you optimize for the best temporal response;
you don't get the best frequency response.

The best solution is to seek a compromise. The "best" solution won't be perfect in
either the frequency domain nor the temporal domain.

When someone shows you a curve that shows "perfect" response in one of these
two domains - it just means that they NEGLECTED the other one.

Dr. Gregory Greenman
Physicist
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post #198 of 481 Old 02-20-2009, 06:00 PM
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if the NHT's were so Awesome John... i would think there would be more people on your side.

When i see these discussions i am reminded of dennis...

Quote:


Dennis: You're foolin' yourself. We're livin' in a dictatorship! A self-perpetuating autocracy in which the working classes...

Woman: (interrupting) Oh there you go, bringing class into it again...

Dennis: That's what it's all about! If only people would...

Arthur: Please, please, good people, I am in haste. Who lives in that castle?

Woman: No one lives there.

Arthur: Then who is your lord?

Woman: We don't have a lord.

Arthur: What?

Dennis: I told you. We're an anarcho-syndicalist commune. We take it in turns to sort of act as a sort of executive officer for the week.

Arthur: Yes.

Dennis: But all the decisions of that officer have to be ratified at a special bi-weekly meeting...

Arthur: Yes I see.

Dennis: ...by a simple majority in the case of purely internal affairs...

Arthur: Be quiet!

Dennis: But by a two-thirds majority in the case of more major...

Arthur: Be quiet! I order you to be quiet!

Woman: Order, eh? Who does he think he is?

Arthur: I am your king!

Woman: Well I didn't vote for you!

Arthur: You don't vote for kings.

Woman: Well how'd you become king then?

[Angelic music plays...]

Arthur: The Lady of the Lake, her arm clad in the purest shimmering samite held aloft Excalibur from the bosom of the water, signifying by divine providence that I, Arthur, was to carry Excalibur. THAT is why I am your king!

Dennis: (interrupting) Listen, strange women lyin' in ponds distributin' swords is no basis for a system of government! Supreme executive power derives from a
mandate from the masses, not from some farcicial aquatic ceremony!

Arthur: Be quiet!

Dennis: Oh but you can't expect to wield supreme executive power just because some watery tart threw a sword at you!

Arthur: SHUT UP!

Dennis: Oh but if I went 'round sayin' I was Emperor, just because some moistened bink lobbed a scimitar at me, they'd put me away!

Arthur: SHUT UP! WILL YOU SHUT UP! [Grabs Dennis]

Dennis: Ah! Now we see the violence inherent in the system!

Arthur: SHUT UP!

Dennis: Oh, come and see the violence inherent in the system! Help! Help! I'm being repressed!

Arthur: (muttering) Bloody peasant!

Dennis: Oh, what a giveaway! Did you hear that? Did you hear that, eh? That's what I'm on about! Did you see him repressin' me? You saw it, didn't you?


Proud Daddy to Anastasia and Christopher.
Born October 26 2005.

Ob was the delivery doc.

Since i cannot rant on a soapbox in the town square...
http://commonsensehasdied.blogspot.com/
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post #199 of 481 Old 02-20-2009, 06:16 PM
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I suspect it's not entirely the digital crossover math / slopes causing the sonic issues some hear with the NHTs.

The DEQX is terrific, but the analog stages (and clock and power supplies) are far from truly amazing, at least with the older model most have heard. IME there is a significant "artificial" imprint that largely goes away with modding. (That's with the older units. I have no experience with the latest iteration which is supposed to have better analog stages, power supplies, clock, etc.)

On a related note, I'd be surprised if Dennis wouldn't hear a large improvement in the HT3s with an upgraded DEQX. Even so, he's an incredibly talented crossover designer, and I've really enjoyed owning some of his work; the passive HT3s are incredibly transparent and musical.

I've never heard the NHTs and have no ax to grind either way.
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post #200 of 481 Old 02-20-2009, 08:00 PM - Thread Starter
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Quote:
Originally Posted by syswei View Post

In the Soundstage measurements it exhibited power compression in the 120-700Hz range at 90dB, and this became very dramatic (like -5dB) at 95dB. And as I've pointed out, distortion is worse than the PSB Synchrony One that your store carries.

Power compression in the low midrange won't give you fatigue. You start to get a sense that the midrange can't keep up quite as well, but it still plays very loud without fatigue. The SynchronyOne also plays very loud without strain, but doesn't have the resolution or imaging of the Xd. But it is a great speaker also, especially for the money, especially for being passive.
Quote:



KEF Reference series is better in that department.

True. Coincident design has some advantages. NHT actually considered a coincident design (I asked Jack about this), but found that they could get better subjective performance with closely stacked drivers and high slope crossovers.

John
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post #201 of 481 Old 02-20-2009, 08:14 PM - Thread Starter
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Quote:
Originally Posted by FrantzM View Post

John

That this where we don't agree.. It is simply not possible to infer that a speaker sounds better than another by simply looking at a FR graph...

I didn't say you could. You can infer that one speaker is more tonally accurate than another by simply looking at a FR graph (measurement procedure being equal).
Quote:



My problem is the way you portray the XD as the speaker by which any other should be judged NOT verbatim but in essence that is your position: The XDs are not. That the Xd system represented an excellent value , yes! That they represent the ultimate in speaker design NO! Emphatically. This I am stating whether you implied it or not call it pre-emptive strike...

I did not state this. Why do you keep arguing this way? I would say, however, that Xd is a speaker that should be used as *a* reference, especially for certain traits that passive speakers struggle and often fail to achieve.
Quote:



Wide dispersion is not always desirable, it could even be said it is best to avoid it in the high frequency where it leads to a tilted "light" sounding balance.. The speakers start sounding thin.. so limiting the horizontal dispersion in the treble can be and often IS a design CHOICE!

True, though it *is* desirable in a well treated room or else you will end up with a dull sound.
Quote:



Steep Crossovers present many problems and these are audible.

Yes, but as I keep repeating, drivers that are singing the same tune present even more problems that are even more audible.
Quote:



Where we converge is that Room Correction applied to most any speaker is likely to lead to better sound...People who have used such do not go back. The technology is not mature as we (I included) would like to think. Given a Tact or other most people are likely to do more harm than good, I am reminiscent of a session that I had with an Audiophile friend in NYC who had the TaCT/Boz system... It was clear from his FR reading that their was in the FR a clear bump around 6~7 KHz and he corrected it, resulting in a the disappearance of that 2dB bump. Fine; but now, horns and brass no longer had that "plhtlaaaat" throaty characteristic sound, they sounded too much the same no difference between a hautbois (don't remember the name in English ) and a trombone or a flugelhorn .. so we left the bump alone and the brass came golden and fine.. that is an anecdote indeed but the audiophile in question could attest to that.... The issue of better frequency response does however point to the use of DSP to ameliorate in Room response of speakers after , of course room treatment.. I must also say I am not defending expensive .. There are too many Audio Products on the Market whose sole attribute is their expensiveness not their performance. I don't think the High End Audio has delivered performance commensurate with some of the price tags ( $30,000 speaker cable being my favorite huh, nonsense) and this , to me needs to be reversed and I sincerely think it shall be..

I agree. Speaker response correction is one thing. Room response correction over 300Hz is mostly a magic trick that fakes most people out. UNLESS, the speaker is set up improperly. We find that Audyssey can make a mediocre system sound quite decent. But struggles to make a good system sound any better or even as good.

John
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post #202 of 481 Old 02-20-2009, 08:18 PM - Thread Starter
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Quote:
Originally Posted by Morbius View Post

John,

You don't always want fewer constraints.

if n = m; only then can you have a unique solution.

If you have fewer constraints, you can have more than one right answer to the remaining problems. That is a good thing. One unique solution is not the desire goal. The goal is to remove as many design constraints as possible so you can find the *best* of multiple solutions.

John
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post #203 of 481 Old 02-20-2009, 08:20 PM - Thread Starter
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Originally Posted by Dizzman View Post

if the NHT's were so Awesome John... i would think there would be more people on your side.

Well, I think most any Xd owner would be mostly to completely on my side, but there are less than 200 nationwide. About half of those have 2 or 3 sets. Only about 5 or 10 on AVS and only one or two in this forum.

John
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post #204 of 481 Old 02-20-2009, 08:22 PM
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Originally Posted by faberryman View Post

So if you were there at the original recording session, only it didn't sound like you were there but it sounded like you were listening to speakers which made it sound like you weren't there, then the Wilson X2s would be euphonic if they made it sound like you actually were there.

That's tautological. If you weren't at the original event, how can you say that a speaker transported you to the original event? At best, you can say that the speaker's reproduction reminds you of an event that you've previously attended.

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Originally Posted by Morbius View Post

Since the ribbon is a dipole - it's not the length that matters - it's the width.

The ribbon dipole acts like it is infinitely long with a limited horizontal dispersion. The
horizontal dispersion is the characterisitic "figure-8" radiation pattern of a dipole when
viewed from above.

Measurements of ribbons say otherwise. The response, especially near the top of the passband, is ragged, not at all smooth, and hardly a figure-8 since they do not have enough horizontal dispersion for the front and back wavefronts to meet appreciably. Again, look at the wavelengths involved, and the dimensions of the ribbon (horizontally).

Vertically things matter since ribbons exhibit vertical standing waves that break up their pistonic motion among many other things. This is trivially observable as kinks in the speaker's input impedance at the frequencies of the resonances.

And ribbons would only be infinitely tall if they go from floor to ceiling, and both floor and ceiling are perfect reflectors.

Quote:
Originally Posted by Morbius View Post

I think it is valid to hone in on the sound of something like a cymbal. I know what a
real cymbal sounds like - and there really isn't that much variation in the sound of
cymbals.

Sorry, but I'm not buying this. There are many, many problems with this line of argument. For example, the room where the cymbal is played greatly affects its sound, as does the miking technique, mic response, mastering, and mixing. If it's also played by a drummer whom you've never heard live, then the musician's technique is another uncontrolled variable. How can you tell any of these effects apart from what you think the speaker's doing to the signal, and whether the speaker's doing the right thing or not?

And you keep bringing up the Keith Howard article without addressing the fact that experienced audio listeners had a very hard time hearing the effects of his filters. Please explain how that jives with what you've said about ringing.

--Andre
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post #205 of 481 Old 02-20-2009, 08:23 PM - Thread Starter
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Originally Posted by Morbius View Post

and there really isn't that much variation in the sound of
cymbals.

Hah! Try telling that to any drummer!

Besides, the NHT treble is +/-1.5dB. The Maxx2 tweeter is +/-5dB, more than 3 times as inaccurate. Not sure how you can accurately produce a cymbal when it is objectively that inaccurate. I do believe they are the same tweeter, no?

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post #206 of 481 Old 02-20-2009, 11:49 PM
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Originally Posted by Alimentall View Post

I didn't say you could. You can infer that one speaker is more tonally accurate than another by simply looking at a FR graph (measurement procedure being equal).

I would say that is not nearly as simple as that statement.

It's true however, IF one listen to ONE speaker in anechoic chamber on axis (no stereo effect involved). If listening is done in a real room, one can not just look at a FR-graph and say A is more tone accurate then B. At least that's not my belief.

/Chuck

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post #207 of 481 Old 02-21-2009, 12:00 AM
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just a quick question on the ringing of steep filters (I won't go into audibilty etc).

re the deqx, it can go up to 300 db etc, but afaik even deqx does not recommend (usually) that steep a slope.

How steep is too steep? (with digital x-over slope I mean) I guess morbius would say 300 is too steep, but is 48 db too steep? 100?

This I guess relates back to the 'uncertainty principle' in audio? the more we tighten the FR the more we screw the time, and reverse. Is it all down to the individual case, where for a given set of drivers what works best is not the same as another set?

I think that some of the problem here is that units like the deqx are NOT plug and play (perhaps historically we have become used to simply plugging something in and that is that), it can take a lot of time to get a handle on using it a system before we get the optimum results.

Do we reckon Dave Wilson got his desired results in an afternoon?

Similarly, to get the optimum result with a unit like this could very well take longer than an afternoon!!

Frantz (?), I can relate to your anecdote about fixing the midrange measurement with the tact. I have only a little direct experience with it, but that experience is consistent with yours. The trouble ( I suspect) is that the added eq was trying to fix a room problem. It is perfectly valid to fix rooms problems in the bass with eq, but fraught with danger perhaps at the higher frequencies.

That is my own personal 'objection' with the full range corrections from the LP...too much room in it. I'm sure there are a lot of successful results gotten (as the supporters can attest to), my own view is that the correction should only apply to the speaker, make it as accurate as it can be (by whatever measure is best for you), then (ignoring the bass room interaction) 'whatever you get in the room is what you have in the room'.

(Then fix the bass that you get in the room)
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post #208 of 481 Old 02-21-2009, 12:46 AM
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Originally Posted by Alimentall View Post

Well, you still get ringing with any crossover. Meridian says that it has made what they call 'apodizing' filters, which, if I understand their press material (which remains press material), they are able to emulate a 'perfect' filter with little or no ringing. Or that's what they seem to imply.

I'm responding in reverse order.

An apodizing filter has absolutely nothing to do with crossovers. It's used to remove artifacts of the initial process -- which causes pre and post echo in the impulse response. Removing the pre-echo results in a much more natural sound.

Removing the post-echo is handled by the human interface, i.e. our brain throws it away as it is masked by the louder sound of the impulse.


As far as digital crossovers, M uses a 48dB per octave crossover, and the only artifacts are 130+ dB below the main level signal. That's literally inaudible.

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post #209 of 481 Old 02-21-2009, 12:56 AM
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Greg:

Any filter is capable of introducing pre and post-echo it is not specifically limited to crossovers.

The actual process of A/D at 1x FS itself creates pre and post-echo in the impulse response. As FS goes up, the amount of pre- and post-echo diminishes.



Best,

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post #210 of 481 Old 02-21-2009, 01:07 AM
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Quote:
Originally Posted by AndreYew View Post

And ribbons would only be infinitely tall if they go from floor to ceiling, and both floor and ceiling are perfect reflectors.

In fairness to Greg, he did say "acts" infinitely tall, not that they were in fact infinitely tall.

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