Bryston Model T Floorstanding Speakers

[gene]

As Promised, here is our article:
Do Loudspeaker Manufacturers Really Make Their Own Drivers? | Audioholics

 

[3db]

Same thing can be said for automobile industry as well.

 

[DS-21]

It's refreshing to hear Ian is placing more importance on cabinet bracing (at least for Bryston products) these days. In my last conversation with him, he was quite adamant about using less bracing to lower the frequency of panel resonance which is the exact opposite of what most (if not ALL) credible loudspeaker designers agree upon.

That's not quite true, Gene, though I'll grant you it's the conventional wisdom. With increased rigidity comes increased Q of cabinet resonances. Too often speaker designers fall into the trap of building cabinets that are basically just massive bells.

In truth, damping is far more important than rigidity in loudspeaker cabinets. Go back to the old Harwood and Mathews BBC paper, which is still the best empirical treatise on loudspeaker cabinet design.

IOW, except for subs (where the cabinet can be made stiff enough to push resonances out of the passband), the smart way to do a cabinet is relatively thin walls with constrained-layer-damping, inner-wall damping pads, lossy adhesives, etc. Alan Shaw's "cracked bell" approach on his Harbeth speakers (screw-on front and rear panels) makes some sense, too, though it's hard to cleanly implement.

Now, I suspect the Axioms (and Brystons) don't exactly have cabinets engineered to the degree of, say, the old Snell XA References in terms of faithful application of the Harwood principles, so perhaps you were more railing against Axiom cheaping out on cabinets than anything else.

The question is, did those Dunlavy buyers KNOW that the drivers were CHEAP when they bought them?

IOW, if we told all those buyers right before they bought those speakers that the drivers were only $17 each, would they still buy the $25,000 speakers?

The Vifa D27TG-35 Dunlavy used was more like $25 in the late 1990s.
The same tweeter (renamed, due to the Tymphany divorce; ScanSpeak got all of the Danish tooling and renamed the old Vifas they kept in production) is now about $50.

And yes, it was common knowledge. Likewise, go back and find Ken Kantor's comments on the ~$30 Seas tweeter used in his flagship, the NHT Model 3.3. While not $20k, the 3.3 is, in real terms, more expensive than the base Bryston Model T. (And much better finished. And, alas, much better designed. Sad that an expensive loudspeaker introduced in 2013 loses out to similar-class loudspeaker introduced ca. 1993 on that...)

Well...it would appear that OPPO's prices are becoming more in line with the likes of Krell & Lexicon....fwiw..

Huh? Their current standard universal disk player (103) is in real dollars cheaper than my Oppo 83 was several years ago.

Ok gents,

The Soundstage NRC test results are in for the Model T

SoundStageNetwork.com | SoundStage.com | NRC Measurements: Bryston Model T Loudspeakers
***

Thanks both of you for the NRC and (presumably) internal measurements. The measurements clearly expose the flaws of the design, which to be fair are shared with every other loudspeaker with the same midrange size and tweeter flushed on a 180deg waveguide.

While the data are poorly presented, look at the midrange off axis rise (what I call the "midrange mushroom cloud") from 2-5kHz, where the tweeter's pattern is much wider than the midrange's. That radiation pattern inevitably leads to an excess of midrange energy in the room, compared to a well-designed speaker, such as the aforementioned Revel Salon2 or KEF 207/2.

***the KEF 207/2 would require quite a bit of thought but then the KEFs are much more expensive than $6495. ***

The KEF 207/2 also doesn't come clad in plastic, and the curved cabinet is a lot more expensive to construct than a box.

But I'm curious, like for like (i.e. the Model T clad in veneer finished to the KEF 207/2's standard), what is the price difference?

Expensive speakers are luxury items. IMO, they should be appointed like it.

Probably wouldn't know what Axiom is or even existed. Or they would probably view them as just another not so great mass market brand like Polk, Pioneer, Infinity ect... Not worthy of being considered "good sounding".

Polk (current LSiM line is quite good), Infinity (various over time), and especially Pioneer (EX line, TAD) make far more interesting loudspeakers than Axiom ever has...

 

[gene]

That's not quite true, Gene, though I'll grant you it's the conventional wisdom. With increased rigidity comes increased Q of cabinet resonances. Too often speaker designers fall into the trap of building cabinets that are basically just massive bells.

In truth, damping is far more important than rigidity in loudspeaker cabinets. Go back to the old Harwood and Mathews BBC paper, which is still the best empirical treatise on loudspeaker cabinet design.

IOW, except for subs (where the cabinet can be made stiff enough to push resonances out of the passband), the smart way to do a cabinet is relatively thin walls with constrained-layer-damping, inner-wall damping pads, lossy adhesives, etc. Alan Shaw's "cracked bell" approach on his Harbeth speakers (screw-on front and rear panels) makes some sense, too, though it's hard to cleanly implement.

Now, I suspect the Axioms (and Brystons) don't exactly have cabinets engineered to the degree of, say, the old Snell XA References in terms of faithful application of the Harwood principles, so perhaps you were more railing against Axiom cheaping out on cabinets than anything else.

Thin wall, heavy damping has merit for budget designs but there is NEVER a downside to increasing cabinet stiffness if the bracing is done correctly. You can see the FEA results that David Waratuke ran. FYI, David has a Masters Degree in Structural Engineering and designs Skyscrapers for a living which is far more complex than a speaker cabinet.

Loudspeaker Cabinet Bracing: A Detailed Look on Do's and Dont's | Audioholics

 

[gtpsuper24]

Polk (current LSiM line is quite good), Infinity (various over time), and especially Pioneer (EX line, TAD) make far more interesting loudspeakers than Axiom ever has...

Yes I totally agree but my comment was that some Bryston dealers probably don't know anything about Axiom and would view them as a Polk Monitor or other cheap Bestbuy type speakers. Which IMO they are fairly bland and basic speakers that are priced fairly high compared to their real ID competition. I agree that there at a lot better choices out there than Axiom and at the current price the Bryston isn't anything special either.

 

[DS-21]

Thin wall, heavy damping has merit for budget designs but there is NEVER a downside to increasing cabinet stiffness if the bracing is done correctly. You can see the FEA results that David Waratuke ran. FYI, David has a Masters Degree in Structural Engineering and designs Skyscrapers for a living which is far more complex than a speaker cabinet.

Loudspeaker Cabinet Bracing: A Detailed Look on Do's and Dont's | Audioholics

Your comment makes no sense, Gene, in the context of a full-range loudspeaker. (For subwoofers, an analysis bandwidth-limited to ~700Hz does show that lots of bracing can push resonances outside the unit's passband, but for mains the analysis is basically useless.) Thin wall (especially with CLD panels) is generally more expensive than elaborate bracing, because it's a more time-consuming and labor-intensive means of construction. Panels have to be assembled, lossy adhesives take time to set before additional work can be done, etc. Speakers that actually implement the damping-first approach to their cabinets (the aforementioned Snell XA Reference and Harbeth, Geddes' speakers, Spendor, etc.) are certainly not cheap. Furthermore, while a skyscraper may be more complex than a loudspeaker cabinet, it's worth noting that modern skyscrapers are all designed with quite a bit of damping, not just stiffness. Otherwise they would shake themselves to pieces!

It's also worth noting that FEA of a whole cabinet rather than just panels led KEF to a BBC-hybrid approach on their LS50, with thicker (but being MDF, well-damped) walls, a dissimilar material for the baffle to get the "cracked bell" effect without Alan Shaw's unsightly screws, and bracing not rigidly attached to the cabinet but instead floating on a mastic. From their techno-propaganda, with emph. added:

A pair of braces, crossing behind the driver, were added to the model in an attempt to prevent the lowest enclosure resonance. However, while the resonance was raised to a higher frequency, its amplitude was not reduced relative to the driver. Indeed the frequency is raised towards the ear's most sensitive region. *** It was found that adding material with high mechanical resistance and low stiffness between the walls, baffle, driver and brace results in extremely effective suppression of the resonances. This arrangement proved highly effective at damping the wall resonances ***. As with the BBC approach, using thick damping pads, the frequency of box resonances is not increased. ***

So basically, like many of the "technical" articles here, that one advances an agenda more than it engages the relevant science. An article on loudspeaker cabinets that does not engage the Harwood and Mathews BBC paper, the seminal paper in the field, is simply not a well-researched piece, no matter what degrees the author holds.

 

[gene]

Your comment makes no sense, Gene, in the context of a full-range loudspeaker. (For subwoofers, an analysis bandwidth-limited to ~700Hz does show that lots of bracing can push resonances outside the unit's passband, but for mains the analysis is basically useless.) Thin wall (especially with CLD panels) is generally more expensive than elaborate bracing, because it's a more time-consuming and labor-intensive means of construction. Panels have to be assembled, lossy adhesives take time to set before additional work can be done, etc. Speakers that actually implement the damping-first approach to their cabinets (the aforementioned Snell XA Reference and Harbeth, Geddes' speakers, Spendor, etc.) are certainly not cheap. Furthermore, while a skyscraper may be more complex than a loudspeaker cabinet, it's worth noting that modern skyscrapers are all designed with quite a bit of damping, not just stiffness. Otherwise they would shake themselves to pieces!

It's also worth noting that FEA of a whole cabinet rather than just panels led KEF to a BBC-hybrid approach on their LS50, with thicker (but being MDF, well-damped) walls, a dissimilar material for the baffle to get the "cracked bell" effect without Alan Shaw's unsightly screws, and bracing not rigidly attached to the cabinet but instead floating on a mastic. From their techno-propaganda, with emph. added:

You have a talent for misapplying and misunderstanding research. Recall when Dr. Floyd Toole had to come here and correct you for your misunderstandings of his research that you kept quoting.

Nobody is saying to brace and cabinet and use no damping. The proper balance of both must be used to get the best results.

Thin walls are CHEAPER to product then thick panels with ample bracing. There is merit in both approaches but there is NO downside to a thick wall cabinet properly braced and dampened. If you bothered to read the article I linked previously you would see how that plays into effect.

from this page:
Loudspeaker Cabinet Bracing: Finite Element Analysis - Part III | Audioholics
Observe the Displacement, sub-panel center, for various numbers of braces graph. Reviewing the results in the plot, the general trends of increased cabinet frequency and suppressed resonant displacement is clear.

The "agenda" of our article is to provide informed information on the relationship of the effects of rigidity and dampening to cabinet structure. This is a subject often misunderstood by loudspeaker manufacturers that produce products, many times b/c they lack the sufficient analysis tools or comprehensive skills to analyze. We are fortunate to have someone with such skills writing articles on this subject matter and I learned a lot from this process myself.

 

[DavidW]

Furthermore, while a skyscraper may be more complex than a loudspeaker cabinet, it's worth noting that modern skyscrapers are all designed with quite a bit of damping, not just stiffness. Otherwise they would shake themselves to pieces!

Actually, most buildings have very little damping, usually about 1%-2% of critical damping at service load levels, depending on the material used, and only goes up to 2%-5% under extreme conditions such as earthquake loading where the structure is actually taking damage that creates the extra damping. Stiffness is the driving factor in design and additional damping, which is expensive to implement, is only used for the most severe cases where dynamics issues cannot be solved with additional stiffness due to escalating costs.

Incidentally, additional damping only helps at or near the resonant frequency and actually hurts for frequencies above resonance as can be seen from a typical plot of Transmissibility:

​

Since it is unlikely that any cabinet could be designed with the fundamental resonant mode high enough above the upper bound of the audio band at 20 kHz, this is a real concern.

Also, other than being exactly at critical damping for a given system, too much damping, over damping, of the resonant response of a system is worse than too little damping:

​

Note where zero is on the y axis for each of the plots above.

Generalizations aside, for any structure, and by that I mean any physical object with the ability to maintain its own shape, engineering design for dynamic loading should be based on studying the dynamic response and selecting the best combination of dynamic characteristics given the physical constraints of the problem by using the equations of motion:

​

This can be done either as a differential equation solved in closed form for simple systems or through the use of discretization methods such as finite element analysis for more complex systems.

Proper engineering requires careful consideration of physical behavior along with the design goals.

David

 

[Chu Gai]

 

[Nuance AH]

Your Science statement reminded me of this (what a great show):

 

[biggarthomas]

Just two days ago, Bryston announced another line of speakers the Model A line. Indeed, the Model A1 looks quite like Axiom's M100. Since companies are in business to produce profits I guess, despite the naysayers, the alliance is bearing fruit.

 

[gtpsuper24]

Just two days ago, Bryston announced another line of speakers the Model A line. Indeed, the Model A1 looks quite like Axiom's M100. Since companies are in business to produce profits I guess, despite the naysayers, the alliance is bearing fruit.

30 years of Engineering Excellence and all they (Axiom) can do is just recycle the same old designs. The best they can do is just add another woofer and make it 3 instead of 2. The M100 is a pointless model and must have been made to use excess panels already cut for the LFR model.

Profits is what Axiom is best at and then marketing and then speaker design a distance 3rd.

 

[biggarthomas]

Bach's French Suites played by Glenn Gould have never sounded sweeter than on the M100s - I'm listening to them right now. Those French Suites are just the sort of music that is supposed to sound horrid on Axiom speakers. I've a friend who hosted classical music shows for the CBC coming over to listen to my speakers in a few days time - I'll let you know what he says! Incidentally, to respond to the issue of Axiom putting out the same stuff for years. There are several companies in the audio field that pretty much just tweak their products every few years, Quad comes to mind, (I started out with 303 current dumping amps, moved to 306s and now own two 909s all based on the same design that was crafted 40 years ago). As you probably know, Quad Electroacoustic speakers have changed little over the past 30 to 40 years. Others that come to mind are Harbeth and other producers of the LS3/5A and LS5/8 series. How long have they been in production now - 50 years and still going strong. Not so incidentally, I own and daily use, a pair of Rogers LS3/5As. I find that the Rogers and M100s handily compliment each other. There is little or no need for radical change if people appreciate your gear. Like it or not, Axiom audio equipment sells - people like it - hell, it was a serious audiophile who drew my attention to Axiom in the first place. I've only been an owner for the past year.

Almost finally, I thought that profit was what most companies are in business to make. If Axiom is succeeding in this - more power to them. Looks like they are making their payroll despite the naysayers.

As to the issue of just adding a third woofer, I should mention that the woofers in the M100 are newly designed and produced, there is an interesting video on the Axiom site about their design. In addition, as I understand it, the tweeters and mids in the M100 have been modded and the crossover is a redesign.

If you have any personal history with Axiom products and you do not like them, that's fair enough. On the other hand, if your opinion about Axiom products are crafted from those of others. . .

 

[Socketman]

All loudspeakers are still designed on the basic principles of a design patented in 1898 by oliver lodge. An electromechanical transducer. With every speaker manufacturer working with the same basic design principle there really is only so much any one of them can do. Perhaps GT has some input that thiele or paradigm or quad etc could benefit from since he seems to be a speaker expert , though I have not heard of him short of his complaints about axiom.

 

[biggarthomas]

Let's not forget that all of our iPods, iPads, iMacs and iPhones are made by the same cheap incompetent Chinese labour. Oh by the way, so is the excellent Shanling built Music Hall mmf CD25 that I bought 10 years ago. The mere juxtaposition of negative language next to the word "Chinese" fails to, as it used to do, bring to mind shoddy workmanship. In addition, and I'm not sure whether you know this or not but Axiom stopped sourcing produces from China on an OEM basis some time ago. They have a wholly owned factory called Axiom Audio Shanghai - there is a video about it on the Axiom website - check it out!

 

[biggarthomas]

Even though I'm just a forum troll, begging for attention, I agree with you Socketman.

 

[Irvrobinson]

All loudspeakers are still designed on the basic principles of a design patented in 1898 by oliver lodge. An electromechanical transducer. With every speaker manufacturer working with the same basic design principle there really is only so much any one of them can do. Perhaps GT has some input that thiele or paradigm or quad etc could benefit from since he seems to be a speaker expert , though I have not heard of him short of his complaints about axiom.

You might consider getting your facts straight. Lodge patented a cone loudspeaker, but it was some Bell Labs guys that did a moving coil version of a cone speaker. Furthermore, electrostatics, ribbons, planars, and the AMT designs are completely different, so your statement about "all" loudspeakers descending from Lodge's concept is just plain incorrect.

 

[Socketman]

Who developed it first is up for debate but it doesn't change the timeline much. Since Axiom doesn't build any of those high frequency designs and it is axiom that is being attacked here I fail to see the relevance of your statement other than to start yet another flame fest . Furthermore I see no need for you to use that condescending tone. This from Wikipedia since I wasn't born yet "In 1898, Lodge gained a patent on the moving-coil loudspeaker, utilizing a coil connected to a diaphragm, suspended in a strong magnetic field". "The modern design of moving-coil (also called dynamic) drivers was established by Oliver Lodge in 1898 " In retrospect I should have said Moving coil . The statement was to make a point not to provide a history lesson.

 

[fuzz092888]

If your point was valid, the same could be said of the internal combustion engine. Same basic principle and there are so many things you can do with it however, I don't think anybody is going to compare a Bugatti or Ferrari engine to early combustion engines.

Who developed it first is up for debate but it doesn't change the timeline much. Since Axiom doesn't build any of those high frequency designs and it is axiom that is being attacked here I fail to see the relevance of your statement other than to start yet another flame fest . Furthermore I see no need for you to use that condescending tone. This from Wikipedia since I wasn't born yet "In 1898, Lodge gained a patent on the moving-coil loudspeaker, utilizing a coil connected to a diaphragm, suspended in a strong magnetic field". "The modern design of moving-coil (also called dynamic) drivers was established by Oliver Lodge in 1898 " In retrospect I should have said Moving coil . The statement was to make a point not to provide a history lesson.

 

[Grador]

You might consider getting your facts straight. Lodge patented a cone loudspeaker, but it was some Bell Labs guys that did a moving coil version of a cone speaker. Furthermore, electrostatics, ribbons, planars, and the AMT designs are completely different, so your statement about "all" loudspeakers descending from Lodge's concept is just plain incorrect.

Furthermore it's like saying that all automobiles are designed on the same principle that they have for over 100 years. Yes, they've got an engine, four wheels, and brakes but you're not going to see me driving a model T to work any time soon.

EDIT: Looks like fuzz beat me to the exact same point. DARN YOU