Wilson Audio Specialties Alexandria XLF loudspeaker Aspherical Group Delay

Sidebar 2: Aspherical Group Delay

Wilson claims that its Aspherical Group Delay technology is as effective harmonically and texturally as it is spatially, helping to precisely reintegrate, at the listening position, the frequencies that have been separated by the crossover and sent to the various drivers.

To do this, each of the three drivers in the Alexandria XLF's MTM array can be independently adjusted fore and aft, as well as rotated on its polar axis. Of equal importance, once the appropriate position has been found, each module can be rigidly locked in place with tether bolts of various lengths, secured with wing nuts. Each module is moved along a pair of rails, each with a center notched track. There's one set of rails atop the woofer box, and one set each atop the lower-midrange and tweeter cabinets. There's also an assortment of spikes of different lengths. It's a major feat of mechanical engineering and precision manufacturing that needs to be seen to be appreciated.

All you have to do is measure the distance of each drive-unit from the listening position, and the height of your ears when you're sitting down, and Wilson's charts tell you into which numbered notch each spiked module should sit, and which length of tether bolt should be used to set the module's elevation. But no, you don't do any of this—your Wilson dealer will.

The goals are to time-align the drivers so that the combination of their outputs produces the equivalent of a single point source, and, by adjusting the modules' polar axes, to precisely focus the sound propagation on the actual listening position—not at a theoretical point a set distance from the speakers dictated by a design that might not suit the realities of the room. It's sort of like the difference between cameras with fixed and adjustable lenses.—Michael Fremer

Company Info
Wilson Audio Specialties
2233 Mountain Vista Lane
Provo, UT 84606
(801) 377-2233
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GeorgeHolland's picture
Leave it to you to bring up

Leave it to you to bring up something not even related. [flame deleted by John Atkinson].

ChrisS's picture
Everything's relative....

As I've told JRusskie in the Forums, I'll tell you as well... Dear Georgie, the way you form your arguments and present them in these discussions make for great study material in the research of logic, cognitive skills, and personality. Would make a wonderful project for an undergraduate study, since the two of you are not very complex.

If you haven't noticed, my posts are only to you and JRusskie. And they're always relevant to something...

In many respects, how you and JRusskie argue against John Atkinson and his staff at Stereophile actually confirms that they are on the right track.

Michael Fremer's picture
Your iggnorance is only mached

by yor spellllling. 

Staxguy's picture
2c

I'll chime in my 2c.

1) I agree with the frequency response plot: looks ridiculous, and would expect at most a +/- 3db variation over 20Hz to 20 KHz, wishfully at most +/- 1 db, given the price.

2) I've loved the sound of the Wilson X1 in the past. Not so much the Sophia and Sasha as of late, but my tastes have changed, and so have the partnering electronics. Size wise, the Alexia is more suited to my present condo than the XLF.

3) I'd love to hear this speaker and see how it compares to the Focal Grande Utopia EM and the more recent Magico (Q7).

4) Anyone else waiting to see the Avalon Tesseract? :)

BillK's picture
So what would you compare it with?

There are lots of other cost-no-object designs; which of them measures +/- 1 dB of flat in a real room from 20 - 20K?

soulful.terrain's picture
If I had..

 

 

...the disposable income, I'd buy them. Why not?  Wilson Loudspeakers are the best in the world..period.

And yes, I have heard all of them except the Thor's Hammer sub.

Great write-up Michael!

Eznirt's picture
The real world of audio engeneering

As professional loudspeaker engeneer for 30 years I would like to give my compliments to Mr Atkinson for his ever realistic quotes about the measurements;we use same equipment and I measured same speakers with same measurement results in past.The discussion i red above here is more emo-/phsycological than about real facts.200k is lot of money;and blind-staring at frequency-responses within 0,5dB is like drilling to water on the moon.

As every commercial product,at any price,the direct costs are about 1/8 from retail price.We all buy that,every day.I know a car is about 1/10th direct cost;and we all by cars (stil).

So wake up,dont focus on direct costs,imagine-or try to-how many hours of development  for a new design like this?Some high-end speaker (direct information)manufacturers spend one year with 30 people à 150/h to design a new speaker.Take your calculator now.I measured on many Wilson products and to my opinion its real well build,units are modified very clever;that's the "x-factor" say the magic why some speakers sound so very good.Wilson excells in this.Btw i have no business-relation with Wilson.

I never read DIY fora,gives me bad stomach of nitwit people 99% of the time;everybody with bucks can buy a scanspeak or accuton;and think they can do it better.So,if than,elevate a company and sell your speakers worldwide! What a real good design is,is not that flat freq curve,not that ripple-free imp curve or symmetric cross-over curve,but the sum of 100 other parameters;and thats a very intensive and intelligent process,besides of taste etc.

Better talk about design philosofics;aiming the goal;relation between measurements and what you hear.thats the clue.Thank you.

Grtz from Holland

billyjul's picture
i know that , but the

i know that , but the frequeney response is a part of the sound quality, bad frequency responce make bad speaker, the sound is better when the fréquency response is flatter, and a ripple in the imp curve in usable fréquency response is for  below average driver

wilson audio have make a bas speaker for the price, adam in deuchland have really good engeenering speaker, very clever design, excellent tweeter, when they see this design they probably laught

for a fraction of this price i can buy an adam audio s7a mk2, whith good implémentation this speaker have not the bad mesuring and the sound of the wilson audio, it is better, they know how utilise good driver, the high-medium air motion transformer is an exceptionnal driver

the only problèm is the size and the basic black finish but good finish

this technologie if it corectly use, is beter than any dôme, except the french acoustical beauty driver whith no iron in the and a ferrofluid join in the motor

GeorgeHolland's picture
Please include your

Please include your professional affiliation at the end of your postings here or be banned. Just a fair warning, it's required on Stereophile

So you like to think DIY is 99% of the time nitwits?  That attitude right there makes me dismiss anything you have to say. Pompus thinking like that is for the nitwit themself.

Mike Lomond's picture
Pot, meet Kettle

"Pompus thinking like that is for the nitwit themself".

I would say that sums up your posts pretty well, George.

GeorgeHolland's picture
Like I care what you think? I

Like I care what you think? I see Stereophile likes to delete honest answers but allows really vile posts to stay on here when it benifits them. Stay classy Sterophile.

Mike Lomond's picture
Yet you care enough to reply

You're full of opinions about the Wilson.  Though I get this feeling you've never heard it.

Right or wrong?

John Atkinson's picture
Deleted Posts

GeorgeHolland wrote:
I see Stereophile likes to delete honest answers but allows really vile posts to stay on here when it benifits them.

I have now posted several warnings in various threads that I will delete without notice comments that are nothing more than flames, in my opinion. If a comment, while being strongly worded, expresses a sentiment that I feel deserves to see the light of day, whether pro- or con-Stereophile, I leave it up, though I may well delete some of the content if it consists of flames.

I try to be consistent, but if you have a problem with our moderation of this site, then there is nothing that compels you to post to it, GeorgeHolland.

John Atkinson

Editor, Stereophile

nothingtosay's picture
I registered here just to say

I registered here just to say this. This was my first time on the Stereophile website and this was the first review I read. In reading the comments I was quite surprised when I realized the guy who was making some of the worst, most flaming comments was the guy who wrote the review himself.

If your policy is to delete posts that consist of nothing more than flames or to delete that content from those posts, I think you need to do some serious work on Michael Fremer's own comments. What is a flame if not "Your iggnorance is only matched by your spellllling," period; no further content? His remarks are extremely unprofessional, discourteous, knee-jerk, insulting, and I would say go beyond anything said about him by a wide margin (unless something considerably nastier than what remains was removed earlier). I'm surprised there is no policy in place that staff should be above whatever chaos occurs in the comments and should always maintain some manner of decorum when participating. Frankly, in many, if not the vast majority of, professions, his behavior would be worthy of serious reprimand/firing.

commonman's picture
total lack of professionalism

Im just her to say that I used to read stereophile, found the magazine completely snobby, and useless to real people, and i completely agree with nothing to say.  I also feel that mikey boy needs to calm down and actually have a conversation rather than simple berate others that do not share his opinion.  I don't exactly agree with george either.  But if I were editor, mike would be in the unemployment line.  I believe he is being overly defensive because he knows he wasted $200k on speakers that could never be worth that much..  Good luck trying to get your money back.  But I'm sure mike will just call me names as well... Not that anything he says has any meaning.

 

and those speakers are ugly as sin.

Regadude's picture
Oh Georgie!

You're making friends left and right there Georgie! Speaking of your friends, Johnny hasn't been around today...

 

Maybe he finally got the boot! yes

Eznirt's picture
To:Megalomania&Co

@Mr GH;so,if you are in the biss of the DIY-what i read between the lines-,or maybe feel connected;than,i can understand you feel not OK by my text about my quote that 99% of the DIY designers are nitwitts.I dont talk to- or point in direction to people who buy a DIY-kit.I aim on the people (pfff...see my text before) who buy expensive drive-units and think they can copy (what is illegal by law;is "intellectual property"-issue) a renowned/famous/expensive design or think that they can even make it better.Almost zero chance-seen that.Besides,what i told in my previous post,is related to 30 years of experience in the speakerworld.Been there done that.Ego is biggest ennemy of forward thinking and end-result;so i stepped on it?Sorry for you.As you are probably or maybe  an inmortatant player in the DIY industry you feel not OK with my pure personal conclusions.Reality hurts,sometimes.Thats life.I dont even give a blink about your megalomane quote about banning.And;whats your "affiliation"??Or are you the God of speaker-industry who thinks he is above all?see header.

@Billyjul;thank you for your kind and fair reply;I am familiar with these AMT's-say Air Motion Transformers-i measured them on a reference baffle (IEC) as we do with every drive-unit; and my conclusions are same as yours;the only minus is a trade off in the horizontal beaming,since the width of the membrane is quite wide the beaming starts at relatively low frequency;(343/width membrane in meters-than divede to 2 is average frequency start beaming)so,in practice,the horizontal spational-amplitude response is worth considering.Nothing is perfect.Tune the filtering to flat response on 15dgrees to 10Khz..Distortion is about 0,05%measured at 95dB;not cheap drivers but for real high-end systems one of the best solutions.

Grtz to all audio and music lovers;from Holland

Btw,in my opinion,200K issue;see my previous post.

Ariel Bitran's picture
Georgie is right

please state your affiliation.

this is one of our policies.

Paul Luscusk's picture
As Sly Stone said Different Strokes for Different Folks

If Micky wants to send his money on Wilsons that's his choice. I've been in the "Hi Fi Industry for 30 years, and I have yet to hear a Wilson product that really knocked me out. But thats just me. 

Mike Lomond's picture
And your point is?

Have you heard it Pauly.  Or are you another critic that, depite being in the "Hi Fi Industry for 30 years" ( Who with, what doing?), can judge a product without listening to it.

I have no idea what it sounds like.  It may sound awful or it could transport me to realms untravelled.

What gets me about the Stereophile comments section are the naysayers, the armchair critics, experts on products they've never seen, let alone heard.

"David Wilson, amateur!  That guy just throws a few drivers in a box and wants 200 grand.  I could do better than that".

Give me a fucking break.

Many posters here try to suck the joy out of all that's fun and positive about this marginal, slightly bizarre, yet wonderful hobby.

Thanks JA.  Enjoy the mag.

 

 

 

 

Paul Luscusk's picture
FYI

Mike among the companies I worked  for as a rep where Mc Intosh, Dynaco, Hafler, and Hafler Pro, Sherwood,Rockford  Fosgate Jim Fosgate,AR, NHT, ADS, NAD, PSB,  Ixos, and Esoteric Audio. I also worked as a Buyer for 8 years,and did  two of the LA Stereophile shows. SO you give me a break. I have heard many Wilson speakers(Not this one) and I'm not impresed by them. I have never judged a audio product without a listen.If you had read my post I was defending Micky's choice  to by the Wilsons. I just said they don't do anything for me as a audiophile.

BillK's picture
Have you listened to the newer Wilsons?

I ask this simply because I'd never heard anything I liked from earlier Wilsons, including generation of W/Ps and the Maxx 2s, and even some newer models like the Sophia 3, but to me the Sasha and Alexia have been truly special sonically, finally not suffering from the "cones in a box" disease of most dynamic designs.

billyjul's picture
@Eznirt it is not difficult

@Eznirt

it is not difficult to do excelolent speaker for good DIYER

they no mistake 

if you use corectly a driver, you can't go wrong, on internet there a quantity of utilitise to simulate parametters, listenig for learn how make a speaker

but construct a driver is far difficult, it is a crutial point, a good speaker bigin whith good drivers, and goods drivers choice to have a good intégration

whith a good reflexion you can make not a good, but a very good speaker in 2voice, a three voice is more complicate

i think, 

 

"David Wilson, amateur!  That guy just throws a few drivers in a box and wants 200 grand.  I could do better than that"

yes, i agree his speaker have problem, the integration of the drivers, in the cabinet and the design of this are the problem i think

an exemple, the focal berylium tweeter have to be flush mounted on the cabinet, is you don't do this , the response curve is awfull, not flat, flush mounted it is excellent, and the sound is realy better

 

whtih air motion transformer you can do to directive driver, i think one of the best design is the adam adio x-ART but the model whith the most powerfull magnet, for the high-end speaker

and they have an high medium whitch is a very interesting driver, he goes lower than most other, and they are no to long and vertical directive

they make reference direct radiation drivers for 800hz to 20000hz 

 

sommovigo's picture
Measured Response on Measured Response ...

As I said at the beginning of this section, there are practical limitations when measuring so large a loudspeaker. While I am confident that my measurements regime fully characterizes the performance of a small speaker (such as KEF's LS50, which I reviewed last month), with a speaker as large as Wilson's Alexandria XLF, the measurements offer suggestions rather than certainties.

I'm not sure I understand what the implication is here - because it would seem that, by this statement, you could be confident in the response of the speaker above a certain frequency (let's say somewhere above the high pass moving from the bass drivers to the mid/tweet module) - and that those measurements, per the assumptions you derive from your methods ordinarily, would be more of the "certainty" variety and less of the "suggestion" variety.

Would you say that you are cnfident in the response of the speaker above ca: 150Hz?

Michael Fremer's picture
A SAD THREAD...

I tend to stay away from the comment section following reviews, mine and those of other reviewers, and this thread is a good reason why. 

The arrogance, stupidity and ignorance is simply appalling and depressing.

I have had many of the world's greatest speakers in my room and I've heard others in other settings: homes, stores and shows around the world.

There are MANY different sounds that are valid and designed for different tastes. The inability of some here to understand that, not to mention understanding how to interpret measurements, is just plain pathetic.

Were I to be led around by measurements, all of which are CRUDE compared to the ear/brain, I'd be listening to CDs... 

This hobby combines science, art and human perception. 

Some of the comments here are sub-human, I'm afraid...

MVBC's picture
Speakers sound starts with drivers parameters

Beyond the finished product measurements, drivers parameters can help figure out the style of sound, especially in bass.

For instance, the difference of sound between 18" pro bass drivers JBL 2241 and 2242 can be traced to certain parameters such as BL and moving mass:

JBL 2241  BL 19,  mm 145g, 98dB/w/m versus JBL 2242 BL 24, mm 158g, 99 dB/w/m

Despite a slightly heavier moving mass, but thanks to a more powerful motor, bass from 2242 are much tighter offering better transient response and allowing more freedom in upper frequency cut off while bass through 2241 are more of the rolling type.

Similarly one can compare the same parameters in JBL pro offering versus the Focal drivers used in the Wilson family design:

In 15"

Audiom 15 BL 18, mm 137g, 92 dB/w/m versus JBL 2226 BL 19, mm 98g, 97 dB/w/m

In 12"

Audiom 13 BL 18, mm 108g, 90 dB/w/m versus JBL 2206 BL 18, mm 65g, 95 dB/w/m

Clearly, with a low BL and heavy moving mass, the Focal drivers exhibit quite a low output for such large drivers - a serious problem when trying to recreate live dynamics-, and won't physically deliver faster transients than their JBL pro counterparts, that is clean, lean bass. Other factors such as cone rigidity might help compensate but from the start, I would expect the Focal sound to be plump. Conversely, the 2226 won't go as deep as the Audiom 15, yet its bass will be tighter, punchier. My recent audition of the Focal Grand Utopia confirmed that feeling versus the quickness and tone of the JBL. And here we keep the comparison to bass/upper bass, as cone midranges versus compression would add another level of challenge for the expensive speaker as it did with the Utopia.

So the Wilsons or Focal are of course beautifully crafted, well designed speakers destined to plush interiors and lovers of a certain kind of sound, just as Cadillacs can deliver a certain style of ride. Fine. Yet at $200,000 there is plenty of space for DIY audiophiles to challenge them at more reasonable costs, especially when using active networking designs. Notwithstanding the choice of pro monitoring speakers that are much more affordable than these luxury items. Therefore, some DYI can proudly defend the quality of their bespoke work; however, others could tone down their arguments of authority, checkbook arrogance and quick tongue.

BillK's picture
As I said earlier, let's see the results.

I have no doubt that a good DIYer could build a speaker with better frequency response, but I'd still like to see the plots and hear what a reviewer had to say about the sound (I've heard any number of components with impeccable response graphs but that sounded simply horrible.)

That of course ignores what price you'd have to sell it for to afford a full-blown factory with staff to produce it in the US, but let's just start with that.

There are any number of "hot rodders" who can build a Porsche-beater for less than the price of a new 911, but they too tend to be one-offs rather than something you can walk into a showroom and purchase.

MVBC's picture
Sure...

Check the price differential between some Watt/Puppy and a 4348 JBL pro studio monitor and compare the sound... Your answer is there. At the price of this professional gear, even DIY are almost getting not economical.

billyjul's picture
plat frequency response for a

plat frequency response for a driver used in a speaker is just the beginning, but with active crossover witch contain an equalizer, you can correct the response of a speaker, to make better, butt, good driver hame flat frequency response there are other parameters, you have to look, when you make a speaker, parameters, that most audiophile , don't know and a speaker tha measure good on overall parameter can't be a bad speaker, it is not the case for this wilson audio and the jbl mansionned is better than this for much lower price, beaucause jbl know what to do and have developed all the excellent driver to achieve their desgn

NMMark1962's picture
Loads of TROLL POOP here

WOW, what a load of TROLL CRAP here.....some people here need to get a life and if you hate Wilson so, then get the hell out of here....you will NOT convince one person with the anti-Wilson spew.....I agree with others....build us your own XLF and prove that Wilson is building garbage or perpetrating a fraud....

When your fabulous speaker is built, let me know so I can buy your wonderful effort and save myself tens of thousands....

To some of you.....quit feeding the idiotic trolls who shit all over these and other forums....i guess that these trolls were run out of the asylums for audio elsewhere...

By the way, for you Wilson haters....I am planing an ultra high end system for late this year...the XLF's are on the list...for the turd here who claims to be able to build an XLF for way less, let me know and I will add it to MY list....hehehehehe...and I bet it will sound oh so sexy.....

GO DAVE WILSON!!!!!

MUHAHAHAHAHAHAHAHAHAHAHAHA

Cheers,

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