Floor Loudspeaker Reviews

Von Schweikert Ultra 55 loudspeaker Measurements

Sidebar 3: Measurements

Because of the Von Schweikert Ultra 55's bulk and weight, I drove my measurement gear to Michael Fremer's place in deepest, darkest New Jersey to perform the measurements. I chose a day that was forecast to be sunny with minimal wind, because I was going to measure the speaker in his driveway, so that the only source of reflections would be the ground. (Even so, the proximity of the ground necessarily led to aggressive windowing of the time-domain data, which reduced the measurements' midrange resolution.)

620von.meas

I first measured the speaker's spatially averaged response in Mikey's listening room, then we maneuvered one of the speakers onto a small dolly—easier to write than do, given the Ultra 55's 190lb weight and its spikes—and wheeled it outside. To avoid heating up the drive-units, I positioned the speaker with its back to the sun, facing the garage where I had set up my gear (see photo). I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Von Schweikert Ultra 55's farfield behavior and an Earthworks QTC-40 microphone for the nearfield and in-room measurements.

As always, I used my Krell KSA-50 amplifier for the quasi-anechoic measurements with MLSSA; for the in-room behavior the speakers were driven by the Valve Amplification Company Statement 452 IQ monoblocks that were reviewed in the May issue and that Mikey had been using for most of his auditioning.

Von Schweikert specifies the Ultra 55's sensitivity as a moderately high 89dB/W/m, which was confirmed by my estimate. The Ultra 55's nominal impedance is specified as 4 ohms. The solid trace in fig.1 reveals that, while the impedance does average 4 ohms in the treble, it is higher than that in the midrange. The minimum magnitude is 3.6 ohms at 2.3kHz. However, there is a combination of 4 ohms magnitude and a phase angle (dashed trace) of –50° at 2kHz. As music can have high energy in this region, the amplifier used with the Von Schweikert speaker must be comfortable driving 2 ohms. Although the electrical phase angle becomes extreme at low frequencies, the magnitude is extremely high in this region, mitigating any drive difficulty. This behavior is due to the use of a high-pass filter in the feed to the midrange unit and tweeter, because of the Ultra 55 using an internal amplifier to drive the woofers.

620VS55fig1

Fig.1 Von Schweikert Ultra 55, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

The impedance traces are free from the small discontinuities that would imply the presence of cabinet resonances. When I examined the vibrational behavior of the Ultra 55's enclosure with a plastic-tape accelerometer, the only resonant mode I found was on the sidewall level with the midrange unit (fig.2). This mode is high in both frequency and Q (Quality Factor) and is very low in level. It is safe to say that it will have no effect on sound quality. The Von Schweikert's enclosure is effectively inert.

620VS55fig2

Fig.2 Von Schweikert Ultra 55, cumulative spectral-decay plot calculated from output of accelerometer fastened to sidewall level with midrange unit (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

The two powered woofers behave identically. The blue trace in fig.3 shows the sum of their nearfield outputs, with their passband output normalized to that of the midrange unit. (There is a level control for the woofers.) The notch at 27Hz indicates that this is the tuning frequency of the 4"-diameter port on the rear panel. The port's output (red trace), plotted in the ratio of the square roots of its and the woofers' radiating areas, peaks broadly between 15Hz and 55Hz, suggesting that the Ultra 55 is a true full-range loudspeaker. The port's upper-frequency rollout is free from any resonant peaks.

620VS55fig3

Fig.3 Von Schweikert Ultra 55, anechoic response of tweeter and midrange unit on tweeter axis at 50", averaged across 30° horizontal window and corrected for microphone response, with the nearfield responses of the woofers (blue) and port (red), respectively plotted below 350Hz and 250Hz.

The woofers roll off rapidly above 200Hz, with the midrange unit (fig.3, black trace) rolling in above that frequency. Other than a slight excess of energy in the presence region, the Von Schweikert's output in the midrange and low- and mid-treble, averaged across a 30° horizontal window centered on the tweeter axis, is commendably flat. There is a gentle rolloff in the top audio octave, reaching –6dB at 20kHz. When I substituted the Earthworks microphone for the DPA, the response still gently sloped down above 11kHz.

The plot of the Ultra 55's horizontal dispersion, referenced to the response on the tweeter axis (fig.4), reveals that this apparent rolloff is due in part to the fact that the output of the tweeter drops off relatively quickly to the sides above 10kHz. Averaging the output over the 30° horizontal window centered on the tweeter axis downplays the flatter on-axis response in this region (footnote 1). The apparent peak just below 3.5kHz off-axis in this graph is due to the slight lack of energy in this region in the on-axis response filling in to the speaker's sides. Other than that and the top-octave rolloff off-axis, the contour lines in this graph are relatively even, which correlates with stable stereo imaging. In the vertical plane (not shown), the Ultra 55's response doesn't change over a ±5° window centered on the tweeter axis, which is 38" from the floor.

620VS55fig4

Fig.4 Von Schweikert Ultra 55, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

The red trace in fig.5 shows the Von Schweikerts' spatially averaged response in Michael Fremer's listening room, driven by the V.A.C. monoblocks, with the woofer and rear-tweeter level controls as set for his auditioning. (This trace is generated by averaging 20 spectra, taken for the left and right speakers individually in a vertical rectangular grid 36" wide by 18" high and centered on the positions of his ears.) For reference, the blue trace shows the spatially averaged response of the Wilson Alexx speakers that Mikey reviewed in the May 2017 issue of Stereophile and subsequently purchased to use as a long-term reference. (The Wilsons were driven by Michael's darTZeel NHB-458 monoblocks for this measurement.) The responses are normalized at 1kHz, and the Von Schweikerts can be seen to have a more even in-room response than the Wilsons from 400Hz to 6kHz. The outputs of both pairs of speakers between 80Hz and 400Hz are disturbed by room acoustics effects that have not been eliminated by the spatial averaging. Below that region, the Ultra 55s excite the lowest-frequency mode in Mikey's room to a greater extent than the Alexxes, something I could hear when I performed the in-room measurement.

620VS55fig5

Fig.5 Von Schweikert Ultra 55, spatially averaged, 1/6-octave response in MF's listening room (red) and of the Wilson Alexx (blue).

The Von Schweikerts' in-room output starts to shelve down in the mid-treble to a greater extent than the Wilsons, but then rolls off relatively quickly in the top octave due to the tweeter's limited top-octave dispersion. By contrast, the Alexxes have a little too much energy in this region. When I listened to some music, as I always do when I visit Michael—his system always sounds superb—the Ultra 55s did sound a touch too sweet.

Turning to the time domain, the step response of the upper-frequency units on the tweeter axis (fig.6) indicates that the tweeter and midrange unit are connected in positive acoustic polarity. The decay of the tweeter's step blends smoothly with the start of the midrange unit's woofer's step, which suggests optimal crossover design. I had the woofers turned off for this measurement to eliminate their reflections from the ground, but a separate measurement indicated that the woofers are also connected in positive acoustic polarity. Finally, the Von Schweikert's cumulative spectral-decay plot (fig.7) is impressively clean in the treble, though the slight excess of on-axis energy centered on 2kHz is associated with some low-level delayed energy. And as this measurement was taken on the tweeter axis with no spatial averaging, you can see that the gentle top-octave rolloff doesn't start until 15kHz rather than the 11kHz shown in fig.3.

620VS55fig6

Fig.6 Von Schweikert Ultra 55, step response of upper-frequency drive-units on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

620VS55fig7

Fig.7 Von Schweikert Ultra 55, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

Overall, the Von Schweikert Ultra 55's measurements indicate excellent audio engineering.—John Atkinson

Footnote 1: When the response is measured at a single position, some of the fine detail in the treble will be specific to just that one point in space. When I started measuring loudspeakers 30 years ago, I decided to implement some kind of spatial averaging to smooth out any position-dependent wrinkles in the measured response while leaving the significant information intact. Accordingly, my published responses are the average of seven measured responses, taken at 5° intervals across a 30° horizontal window centered on the reference axis.
COMPANY INFO
Von Schweikert Audio
1040-A Northgate St.
Riverside, CA 92507
(951) 682-0706
vonschweikert.com
ARTICLE CONTENTS

COMMENTS
Sibelius's picture
Submitted by Sibelius on June 21, 2020 - 7:56am

Actually, only the 7th Symphony has been recorded at the Centro Cultural Kirchner (07/2019). I was lucky enough to be present there the very same night this concert was recorded. The hall has got a fantastic sound, the orchestra never sounds dull, muffled or thick. On the contrary, all instruments are clearly presented and the bass is strong but never overwhelming. The Triple concerto was recorded in a whole different venue, in a whole different continent, Europe, three months later, on occasion of the 20th birthday of the East-Western Divan Orchestra (10/2019). The hall is the Berlin Philharmonie. To my ears, in spite of the outstanding sonic qualities of the Ballena Azul at CCK, the recording made at Berlin sounds much better than the one made in Buenos Aires.

Michael Fremer's picture
Submitted by Michael Fremer on June 21, 2020 - 5:50am

“Actually, only the 7th Symphony has been recorded at the Centro Cultural Kirchner (07/2019)”. What does this mean?

Sibelius's picture
Submitted by Sibelius on June 21, 2020 - 7:43am

Dear Mr. Fremer. My comment was aided at specifying the recording venue information that had been added as Footnote 1. I do not understand your urge to attack me. Was I being disrespectful for stating the correct recording information? I have read with pleasure your articles for many years. I just didn't know the author of those papers could be so aggressive, just because. Greetings from Buenos Aires.

Jason Victor Serinus's picture
Submitted by Jason Victor Serinus on June 22, 2020 - 2:52pm

As New York Jews of the same generation, Michael and I share many things in common, including the tendency to speak strongly and directly without apology. Having said that, I don't see Michael's comment as an attack. He was simply asking for clarification. Happily, that clarification has now come from both you and Jim Austin.

Thanks for wishing to set the record straight. It's important to do so.

Michael Fremer's picture
Submitted by Michael Fremer on June 23, 2020 - 9:12am

Honestly, my intent was not to attack you. I just didn't understand to what recording venue you were referring.....I tend to get directly to the point in these comments. I'm truly sorry if you felt I was attacking you.

Jim Austin's picture
Submitted by Jim Austin on June 21, 2020 - 7:29am

I added the information about the recording venue, during editing. So if there was an error, it was my error. However, I researched it and eventually found a specific reference to the recording venue. I wish I'd saved notes, but I didn't. I believe the information to be correct, at least according to existing (but hard to find) documentation.

If I have time, I'll go find it again.

Jim Austin, Editor
Stereophile

Sibelius's picture
Submitted by Sibelius on June 21, 2020 - 7:49am

Dear Mr. Austin,

I copied the information from the booklet that accompanies the high-res file. As it has been provided by the label, Deutsche Grammophon, we should assume it is correct. Most classical music labels are very precise when releasing recording data information on their booklets. They include producer, engineer, sometimes even the gear that was used for the recording and mastering process.

Greetings from Buenos Aires

Jim Austin's picture
Submitted by Jim Austin on June 21, 2020 - 11:25am
May apologies. I see the error now. I'm glad that it's clear that it is my error and not Michael Fremer's. Jim Austin, Editor Stereophile
tonykaz's picture
Submitted by tonykaz on June 20, 2020 - 1:10am

These guys are building passive Loudspeakers that adapt to the Room.

The typical audiophile remedy is to tune the room.

Pro-audio guys do both and then some.

For $100,000, I too would expect the Factory guy to do a presence visit to help sort out the variables and bring the entire system into balance. Audiophiles with lesser financials can achieve similar results using the DIY trial & error methodologies.

I wonder how much a Dealer has to discount these things in order to close the sale?, considering there is probably $50,000 in profit built into the MSRP and used Infinities are selling for a pittance by comparison. Hmm

Tony in Venice

ps. this Company intends their Loudspeakers to last a lifetime. Made in USA. I could own a pair of these in a colour to match Bamboo and might if the Economy doesn't crash again, like it's already starting to do!. ouch

avanti1960's picture
Submitted by avanti1960 on June 20, 2020 - 6:09am

any sound qualities that are ascribable to ceramic drivers in particular? Distinctive qualities that the end user might need to adjust to (for example)?

Michael Fremer's picture
Submitted by Michael Fremer on June 21, 2020 - 5:53am

A point I made in the review is that many companies use Accuton ceramic drivers but they all sound different.

noamgeller's picture
Submitted by noamgeller on June 20, 2020 - 11:16am

So, you take 3000-4000 Euro worth of Accuton drivers, add a titanium voice coil so you can call it off shelf product, implenting a cross over parts made by Mundorf (of course), add a digital amp and put everything in an MDF-HDF well braced cabinet.
Et Voila you declare it to be a 100,000 Dollar Masterpiece!
How simple is that! Nobody will argue with you saying it´s utterly ridiculous cause everybody knows these days you´ll be out of buisness if you wont stick a skyhigh price tag on it... who is to blame? We all know it´s bullshit... yet alas, it seems just to get worse

MatthewT's picture
Submitted by MatthewT on June 20, 2020 - 12:34pm

Looking forward to the review of the "noamgeller" competitor to this speaker.

Anton's picture
Submitted by Anton on June 20, 2020 - 12:38pm

If he criticized a Chevy Volt that was priced at 100,000 dollars, would you holler at him to go build a car of his own?

If you don't allow value discussions, then how do you approach the hobby?

JHL's picture
Submitted by JHL on June 20, 2020 - 1:49pm

...it's never a value discussion.

noamgeller's picture
Submitted by noamgeller on June 20, 2020 - 1:03pm

https://youtu.be/U7M-Vv18d_8

I would love if you'll take a good look at what I have built. Cost of materials =1500 euros

ChrisS's picture
Submitted by ChrisS on June 20, 2020 - 2:44pm

...build these speakers for a living, how much would you charge?

I have no shop, no tools, no woodworking/cabinetry/electronic skills, etc.

How long do you think it will take me to build a pair of these (or any) speakers and get them up and running?

ChrisS's picture
Submitted by ChrisS on June 20, 2020 - 2:57pm

...the one you refer to above, is a video on "How To Build A Magico Loudspeaker".

https://www.youtube.com/watch?v=r5OMquMru3Y

Do you think 1500 euros would cover the cost of even one of their smaller units?

noamgeller's picture
Submitted by noamgeller on June 21, 2020 - 12:15am

At least I know that Magico are building with materials that are not attainable for me... Working with exotic materials is a very smart move, you stay out of competition reach and have an answer when people complain about the cost issue. I have a lot of respect for this company...

Michael Fremer's picture
Submitted by Michael Fremer on June 23, 2020 - 9:17am

To what exotic materials are you referring?

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 23, 2020 - 10:25am

noamgeller may be referring to Graphene cones :-) .......

Anton's picture
Submitted by Anton on June 20, 2020 - 10:07pm

I would pay you twice that to make me a pair of those.

Amazing.

I am totally serious.

Glotz's picture
Submitted by Glotz on June 22, 2020 - 3:13pm

And the dude is simply masterful! Hearing is believing, but really fantastic job.

His language, regarding the speaker under review, is offensive and arrogant. He should know that VS speakers hold much the same pedigree Magico does.

noamgeller's picture
Submitted by noamgeller on June 22, 2020 - 9:03pm

With your comment, I was too harsh and arrogant with my comment. I do think thou it's time to put words which are not necessarily kind into the open... Since when a speaker of this complexity costs a 100,000$ and we call it normal? How come the beautiful vimberg tonda using more or less the same arrey costing 28,000eu? Have they somehow miscalculated their profit?

hb72's picture
Submitted by hb72 on June 21, 2020 - 10:31am

they look really nice! but are they better than say kef R3s? their selling price is 2k$ but they reduce component cost by mass production (not sure what this means in factor, but I suppose less than 50%), and their components are taylored to i.e. developed for the product..

noamgeller's picture
Submitted by noamgeller on June 21, 2020 - 10:45am

For the kind words. I do not know if they are better then say a 2000$ or a 10,000$ speaker... I just know I love those Seas excel drivers and always loved the magico mini looks. They do however make me shook my head and wonder about the pricing issues this days... Especially since there are some amazing companies who are making awesome products and do not charge just for the statement of it. After all, like a friend used to say, every body bakes with flour and water

hb72's picture
Submitted by hb72 on June 22, 2020 - 12:22am

but the real (commercial) companies have some fancy testing equipement. I am raising this point as I was also very tempted to build my own speakers (and I do not have much relevant measuring equipement). But in the end, I took a decision buying original manufactured ones, wisely for me, as I am prone to spend endless time tinkering around, and if I think of x-overs and their many components where I could add a small cap or resistor (perhaps limited with 6db slopes, but think of higher order cross overs..) I'd go mad with all possible variants to trial.. but I hope not everyone is like me :)

---

Having said that, a small series resistor on treble might help also on my oem speakers to align the somewhat dominant tweater, wouldn't it???

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 21, 2020 - 12:00pm

As an additional note ...... KEF R3 was reviewed by Hi-Fi News and Audio Science Review with measurements :-) ........

hb72's picture
Submitted by hb72 on June 21, 2020 - 12:09pm

yes and they measure very nicely. frequency response, angular dispersion, time domain, all very nice.

Michael Fremer's picture
Submitted by Michael Fremer on June 21, 2020 - 6:05am

Running a fantasy loudspeaker company from your basement can lead to your conclusions here but in the real world there’s a FACTORY to pay for, R&D development, INVENTORY, ACCOUNTING, WORKERS to pay, TAXES to pay, and many other costs associated with running a real business. There are costs involved in advertising and promoting the business at shows around the world. And of course there’s a need to make a profit. And then the product gets sold to DEALERS who run businesses that have similar costs and they too don’t work for free at your pleasure. Your “business model” is a fantasy. Parts cost is a useless metric for understanding the calculations that lead to a final MSRP.

noamgeller's picture
Submitted by noamgeller on June 21, 2020 - 6:38am

I do not own a company, nor would I ever venture in the audio business...and I really don't buy your fancy words about factory costs. They are selling a luxury item far more expensive than its actual value since they're competitors do it as well, and they have to charge for staying in the game... More expensive is better?? Not in my books. And some people still fall for it and buying this nonsense, an such keeping the prices in never ending circle upwards. By the way most companies started their way in the basement or garage (including your Wilson audio).

ChrisS's picture
Submitted by ChrisS on June 21, 2020 - 10:56am

...a nice hobby.

Not a business.

noamgeller's picture
Submitted by noamgeller on June 21, 2020 - 11:23am

And if I would have had a successful business I would probably be forced to charge as high as those guys do, just to stay in the game. It's the chicken and the egg kind of problem

ChrisS's picture
Submitted by ChrisS on June 21, 2020 - 12:11pm

....Some hobbies evolve into businesses.

But you don't have a business for very long when you only cover your costs.

If you were to build Anton a pair of speakers for the cost of parts, how would you eat and pay the rent?

You can't compare what you do with a business.

noamgeller's picture
Submitted by noamgeller on June 21, 2020 - 12:26pm

I am completely agreeing with you. I do not compare my hobbies expenses to a business expenses. Not at all. There are so many headaches on this way, I wouldn't sacrifice my quiet life for this roller-coaster... Still the question of the chicken and the egg remains. Who pushes those prices up the roof and into stratosphere where it ain't funny any more. The consumer or the provider? Those prices to my humble carpenter eyes are so laughable high it seems almost comic. Yet the joke is on us.

ChrisS's picture
Submitted by ChrisS on June 21, 2020 - 3:38pm

...economics.

Another page in the evolution of human activity.

Do you think all the items in a $0.99 store are actually worth $0.99?

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 22, 2020 - 2:10pm

We can get a slicer which can make French fries for 51 cents at Amazon :-) ........

ChrisS's picture
Submitted by ChrisS on June 22, 2020 - 3:32pm

...then it goes into the landfill.

Glotz's picture
Submitted by Glotz on June 22, 2020 - 5:39pm

You probably haven't heard them.

So, how are you so critical of these speakers? We're not critical of your speakers, and we haven't heard them.

I am critical of your business knowledge... you have very little and come off quite disrespectful to most here, while appearing hypocritical about Magico speakers, which are among the most expensive on the planet.

Lastly, while it would appear that you are superlative carpenter, my guess is you suck as a speaker designer.

BUT, because you come off showing some expertise in cabinets, everyone must assume you have skills elsewhere. That's a wrong assumption in audio.

I find your ability to question speaker costs (or business costs) a bit dubious.

I think many that have heard the speakers attest that every aspect of its design and implementation are on par with Magico and the caliber of its designers as well.

Please argue for or against that point, but to poo-poos these and exalt Magico, it throws your severely your bias (and knowledge) into question. MF said read the bio... you should.

ChrisS's picture
Submitted by ChrisS on June 22, 2020 - 5:31pm

...house for me and I'll pay for the materials.

Michael Fremer's picture
Submitted by Michael Fremer on June 23, 2020 - 9:26am

Do not know the costs involved in running these businesses. "Fancy words about factory costs"? Seriously? There's nothing "fancy" about running a factory, or having an accounting department, or keeping inventory of parts for every product you've ever manufactured, or of hiring outside contractors do perform certain functions etc. I've visited many factories around the world including those of companies I wouldn't consider "luxury manufacturers", but rather those who produce very high quality items at reasonable costs like Rega. They have the same "fancy" issues to deal with. They sell lower priced items at higher volumes. I always say if you can find higher performance or equal performance at lower prices, go for it. But you have a resentful tone and you seem to be okay with some companies in this "luxury" arena but not with others. As for Wilson starting in a garage, well that's all well and good. I have nothing against that or against you building your own speakers with Accuton drivers bought at Madisound. Good luck to you!

noamgeller's picture
Submitted by noamgeller on June 23, 2020 - 9:42am

Very right. I regret my resentful tone and apologise for it. I have been a bit hasty with my comment. I am not long enough in this world of hifi nor do I own a business and aware of the costs of production. I do know to recognise a trend when I see one... In the last 10 years or so companies are raising the prices just to stay a live and in the game... Not their fault, maybe ours?

tonykaz's picture
Submitted by tonykaz on June 21, 2020 - 6:56am

Manufacturers will 'typically' have 'real' Manufacturing Costs in the 20% range related to MSRP. The Low exception is P&G ( Proctor & Gamble ) who work in the 9% range.

Manufacturing costs can easily go out of control for an infinite number of reasons.

My long standing career in the Transportation Industry has been improving the efficiency of Manufacturing Plants.

The many Audio industry manufacturers I've visited are not efficient, they don't have the volume to develop best practices, they probably have to buy far more than they need, they typically lack the critical infrastructure and don't have a stable product line.

I manufactured Consumer Audio accessories ( in the 1980s ) and was happy to return to the stability of GM Corp.

Now-a-days, PS Audio, Schiit and Magnapan seem to have cost control 'well-in-hand' ( for Audio Outfits ) but the virus will probably knock out struggling Audio outfits ( most are struggling ).

Tony in Venice

James Romeyn's picture
Submitted by James Romeyn on June 20, 2020 - 2:28pm

IIRC your room is not exactly brimming with open real estate. During your reviews of other speakers such as this VS, what happens to your Wilson Audio speakers? Where do you put them? How many hours does it take to move them out and then properly set them up later?

Michael Fremer's picture
Submitted by Michael Fremer on June 21, 2020 - 5:45am

It takes 15 minutes to jack up the Wilsons, replace spikes with casters and roll them into a space directly behind the racks of records perhaps you’ve seen in videos directly behind my listening seat. I do this myself. Rolling the Alexx back into position and spiking takes a bit longer but blue tape on the floor makes easy returning them to the precise location.

a.wayne's picture
Submitted by a.wayne on June 25, 2020 - 4:54pm

Nice well thought out design ....

dcolak's picture
Submitted by dcolak on June 21, 2020 - 8:47pm

-6dB 20Khz?! +3dB 3Khz?!

Jesus, and 100K USD for this?!

What's wrong with Stereophile. Since when that's a good frequency response?! It's not, by any stretch of imagination.

Jim Austin's picture
Submitted by Jim Austin on June 22, 2020 - 6:08am

... what constitutes a good frequency response.

Please note however that the quasi-anechoic measurement is not made on-axis but is measured across a 30-degree horizontal listening window, as indicated in the figure caption. Response averaged across a 30-degree listening window is expected to be somewhat suppressed at the extreme high end of the audible range, relative to on-axis response. (Fig. 4 shows how the response falls off off the horizontal axis.)

As for the rest, you are free to draw your own conclusions.

Jim Austin, Editor
Stereophile

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 22, 2020 - 7:20am

Magico M2 also has similar type of high frequency, tweeter frequency response :-) .......

Jim Austin's picture
Submitted by Jim Austin on June 22, 2020 - 8:24am

horizontally across the listening window, which exaggerates the HF roll-off.

Jim Austin, Editor
Stereophile

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 22, 2020 - 8:36am

Yes I know ..... I mentioned M2 because the tweeters of M2 and VSA 55, FR appear to be similar ....... They both are Beryllium dome tweeters (may be sourced from the same manufacturer) ....... Also, from the listening position, both speakers appear to have similar HF roll-off :-) .......

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 22, 2020 - 11:07am

Here is a loudspeaker for JA2 to consider reviewing ........ Martin-Logan Classic ESL-9, $5,200/pair :-) .......

Or ...... ESL 11-A with powered woofers, $8,000/pair :-) .......

dcolak's picture
Submitted by dcolak on June 23, 2020 - 11:59am

How about NOT having +10dB/-10dB swings?!

Get any of GENELEC speakers, or ATC speakers or JBL pro speakers.

Now THAT is a GOOD speaker!

Compare it to:

100K USD for that atrocity of the frequency response?!

If I wanted such a bad speaker I'd do a randomize in a DSP. I'd turn on the tone controls and lower everything over 10Khz and bump up everything under 100Hz.

Jesus Stereophile! What's going on?

tonykaz's picture
Submitted by tonykaz on June 22, 2020 - 10:29am

Wasn't Mr.JA doing these quoted measurements on someone's driveway ?

Besides, this transducer system is a Tuneable Design suggesting they have the real world capability of delivering a range of output efficiencies, they can reproduce any curve you need them to reproduce.

Geez, I wish the Manufacturer's Design Engineer would step foreward and bring some useful clarity to this interesting discussion, not doing tries to convince me of their lack of interest in Consumers.

I wish that Manufacturers would realise that having their stuff reviewed is a commitment level involving participation with interested persons.

Tony in Venice

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 22, 2020 - 12:04pm

Many famous people in audio walked on that 'driveway' ........ That driveway is 'anointed' :-) .......

Michael Fremer's picture
Submitted by Michael Fremer on June 23, 2020 - 9:31am

Who I'm sure you know of. He certainly was into measurements. But he cautioned (and I'm paraphrasing accurately): The eyes are for looking. The ears are for listening. Do not use your eyes to hear what you see in measurements." That is what you are doing. As another great speaker designer, Joachim Gerhardt told me: Designing a speaker to produce flat on axis response today is very easy. There's no guarantee it will sound any good."

JaimeB's picture
Submitted by JaimeB on June 24, 2020 - 1:19pm
a.wayne's picture
Submitted by a.wayne on June 25, 2020 - 5:02pm

No one measurement tells the full story and Gerhardt is correct , yes you can measure flat and sound bad , other measurements can tell you why , if you know where to look ..

Fruff1976's picture
Submitted by Fruff1976 on June 22, 2020 - 9:48am

The JBL L100 Classic, $4,000/pair :-)....would flat out embarrass most speakers even remotely close to that price.

-Frank
JBL L100 Classic Fan Club President

Ortofan's picture
Submitted by Ortofan on June 22, 2020 - 10:57am

Compare these two speakers at the same price:

https://audio-pro.by/files/L100-Hi-Fi-News.pdf

https://www.excelia-hifi.cz/kef/test/kef-r11-hifi_news_05_19.pdf

Fruff1976's picture
Submitted by Fruff1976 on June 22, 2020 - 11:13am

I would take the JBL's over the KEF's if the KEF's were free and the JBL's were full price.

Anyhow, that's one review. Check out my fan site with (18) stellar reviews.

https://jbl-l100classic.com/

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 24, 2020 - 9:34am

The JBL L100 Classic comes with adjustable MF and HF tone controls ...... The FR measurements shown by Hi-Fi News are with the tone controls set at '0' :-) ........

a.wayne's picture
Submitted by a.wayne on June 25, 2020 - 5:05pm

Had the original , heard the current version , it was Ok in the 70’s and still just “ok “ today ...

dc_bruce's picture
Submitted by dc_bruce on June 22, 2020 - 2:28pm

Has done business under a number of names over the years. One of his companies (might have been "Von Schweikert Audio") went bankrupt some years ago. Which is not intended to be a reflection on anything other than the difficulties of being in the specialty audio business. The only relevant pricing comparison is not with the cost of materials and labor, but with other products offered at a similar (or higher) price level. Based on the review, it would appear that these are fairly priced.

It's nice to see Stereophile reviewing a Von Schweikert speaker. My recollection is that that doesn't happen very often.

Speaking personally, it would be nice to hear a $100K speaker -- if only to hear what I've been missing -- but it's leagues above my budget.

dcolak's picture
Submitted by dcolak on June 23, 2020 - 11:55am

You can have FAR better sound from MANY FAR cheaper speakers.

Start with Revel Studio 2, JBL, Genelec and ATC studio monitors, many many more options.

Glotz's picture
Submitted by Glotz on June 23, 2020 - 1:26pm

You haven't heard the '55, so your comments are pure conjecture.

dcolak's picture
Submitted by dcolak on June 24, 2020 - 6:10pm

They are ridiculously bad +/- 10dB !!!!

a.wayne's picture
Submitted by a.wayne on June 22, 2020 - 6:39pm

@JA ,

John you were right there , why not do a full Groundplane measurement no splicing or dicing .. :)

Regards

John Atkinson's picture
Submitted by John Atkinson on June 23, 2020 - 8:22am
a.wayne wrote:
John you were right there , why not do a full Groundplane measurement no splicing or dicing .. :)

With hindsight, yes, that was a wasted opportunity. However, I don't think a ground-plane measurement would have added much to what I already found out about the speaker's performance with the in-room and windowed farfield measurements.

John Atkinson
Technical Editor, Stereophile

Glotz's picture
Submitted by Glotz on June 25, 2020 - 8:07am

"Bad" is a relative term... and the scaling on your graph appears 'tighter', but it's not.

The variance from 'flat' appears very similar, less that bass region you seem to be freaking out over.

Anton's picture
Submitted by Anton on June 28, 2020 - 10:01am

I went back through the review, it is great. Some things clicked the second time through.

The back firing tweeter. I remember these going back to the mid-80s with Merlin Speakers.

The Snell E II and II did this, as well.

And, don't forget the father of rear firing drivers, Amar Bose! Bose took this idea to the extreme in the 901 with 8 rearward facing drivers and only a single forward firing driver.

The review mentioned "room filling sound," so maybe there is more to this rear firing tweeter stuff than we suspect.

I saw the pic of JA1 measuring the frequency response of this speaker outdoors, how would one go about factoring in this rear firing tweeter in the measurement or adequately commenting on the high frequency performance that was measured?

Also, is that rear firing tweeter in phase or out of phase, would it be a dipole or a bipole? Is there a switch the consumer can flip?

I wonder if the manufacturer offers adjustment based on what's behind the speaker...tapestries, sculptures, books, LPs, original Kinkades, stone, marble, plaster, alibaster, gold leaf? It seems that could really toss a wild card into the perceived performance.

They call it 'ambient retrieval system' but it seems somewhat broadly implemented. Sort of one rear firing tweeter fits all, so to speak.

Did Mr. Fremer note anything specific about placement, wall type, etc as he experienced this feature?

Also: "...(the) sloping front aligns the front-firing drivers' acoustic centers, ensuring, Von Schweikert says, that the wavefronts from the front-firing drivers are mechanically time-aligned without any crossover tweaks.

If this is the case, how did they time align the tweeter in back? Maybe this doesn't matter...but in "high end," "everything matter." This is a tough one to figure out. The back panel does off a treble adjustment for the rear firing tweeter, there is some degree of control.

____

Looking back at the MBL Extreme 101, it also has a extra "ambience tweeter" stuck on it, yet is is a true 360 degree radiating device.

Described in TAS:

https://www.theabsolutesound.com/articles/mbl-101-x-treme-omnidirectional-loudspeaker/?page=3

"...with a high-quality dynamic “ambience tweeter” nestled out of sight on its roof."

Ribbon, ribbon, ribbon...dynamic.

___

So, the trickle down part: it seems it might behoove the audio hoi polloi to consider sticking some extra tweeters on the tops and packs of their speakers. If MBL and Von Schweikert need to add those babies on top and behind their speakers to make them work/sound better, we should be thinking the same with our gear, which is likely lacking in terms of the advanced speaker technology most of us can incorporate into our more mundane audio lives.

Aperion and Fostex have lines of add on tweeters, or "ambience enhancements" that seem like their time may be coming!

Lots of fun stuff to think about and try incorporating at home!

Thanks again for explaining this product, there are hidden gems that we can take and use to enhance our own home set ups!

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 28, 2020 - 11:20am

Wilson Audio is also one of the manufacturers, who incorporate rear firing tweeters in some of their models ......

There are in-room FR measurements obtained for these VSA model, from the listening position ..... So, the contribution from the rear firing tweeters is incorporated in those FR measurements :-) ........

Anton's picture
Submitted by Anton on June 28, 2020 - 12:00pm

We may be on to something!

Yes, I saw the in-room data.

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 28, 2020 - 12:14pm

The Wilson Alexx speakers don't have any rear firing tweeters ...... They don't roll-off as much as the VSA in the high frequency :-) .......

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 28, 2020 - 7:25pm

Also, take a look at Sonus Faber Aida FR measurements, including in-room FR measurements ...... Aidas have rear firing tweeters :-) ........

John Atkinson's picture
Submitted by John Atkinson on June 28, 2020 - 1:02pm
Bogolu Haranath wrote:
There are in-room FR measurements . . . So, the contribution from the rear firing tweeters is incorporated in those FR measurements . . .

Yes, the Ultra 55's rear-firing tweeters were on for the in-room measurement.

John Atkinson
Technical Editor, Stereophile

John Atkinson's picture
Submitted by John Atkinson on June 28, 2020 - 1:07pm
Anton wrote:
I saw the pic of JA1 measuring the frequency response of this speaker outdoors, how would one go about factoring in this rear firing tweeter in the measurement or adequately commenting on the high frequency performance that was measured?

The windowed farfield response (fig.3) doesn't include any contribution from the rear-firing tweeter. I had originally wondered if the rear-firing tweeter would compensate for the gently sloped-down top-octave in the forward response, but the in-room response measurement (fig.5) suggests that it doesn't. As I wrote, the Ultra 55s' tonal balance was on the sweet side in Mikey's room.

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 28, 2020 - 1:52pm

Q: What did the sweet potato sing? .....
A: I yam what I yam :-) ......

John Atkinson's picture
Submitted by John Atkinson on June 28, 2020 - 3:26pm
Bogolu Haranath wrote:
Q: What did the sweet potato sing? .....
A: I yam what I yam :-)

Ha ha (not). You want to be on the stage, Bogolu? There's one leaving in 5 minutes!

John Atkinson
Technical Editor, Stereophile

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 28, 2020 - 3:47pm

Are you at a comedy club? :-) ......

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 28, 2020 - 7:10pm

Like Jackie Gleason used to say ..... "How sweet it is" :-) .......

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 28, 2020 - 8:26pm

'Life's not worth a damn till you can say .... I am what I am' :-) ........

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 28, 2020 - 2:23pm

Like Hercule Poirot said ... "Ah, dear sir .... The why must never be obvious .... That is the whole point" :-) ......

Ortofan's picture
Submitted by Ortofan on June 30, 2020 - 2:04am

... with a rear-firing tweeter is the Revel Ultima Gem, which was designed by Kevin Voecks - who was formerly with Snell Acoustics.
The Ultima Gem, along with the matching Ultima Sub-15 subwoofer and amplifier, was at one time the reference speaker for a certain JA1.
The system price of $18,500 in 1998 equates to about $30K today.
https://www.stereophile.com/standloudspeakers/89/index.html

Anton's picture
Submitted by Anton on June 30, 2020 - 9:41am

Thanks for that!

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 30, 2020 - 10:10am

Speakers like Magnepan, Quad and Martin-Logan electrostats are also 'rear-firing' :-) ........

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 30, 2020 - 10:14am

Open back headphones are also 'rear-firing' :-) .......

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 30, 2020 - 11:51am

Open baffle loudspeakers are also 'rear firing' .... may be not their tweeters :-) ........

Bogolu Haranath's picture
Submitted by Bogolu Haranath on June 30, 2020 - 11:57am

Some subwoofers have both front firing and rear firing drivers :-) .......

MikeP's picture
Submitted by MikeP on October 1, 2020 - 7:57pm

QLN Prestige 3 or the new Prestige 5 speakers
Spendor D7.2's or D9.2 speakers
New Brinkmann Voltair Hybrid Integrated amp
New Silversmith Audio FIDELIUM speaker cables

Audio Heaven is waiting for you !

MikeP's picture
Submitted by MikeP on October 8, 2020 - 10:57pm

I would take the Magico A5's over these any day !

https://www.soundstageaustralia.com/index.php/reviews/457-magico-a5-loud...

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