Model T Speakers

[jmw31]

Originally Posted by John49

Why is this Model T speakers thread full of posts about all sorts of other Bryston products? Just my OCD 2c...

I had the same question. I keep coming to this thread to see more on the Model T and there is never anything pertaining to that model.

[James Tanner - Bryston]

Yes - maybe I will ask Ivan to change it to Bryston Speakers.

james

[hooknosed]

does anyone have experience Bi-Amping the model T passives with A pair of Bryston 4B-SST2's?

[James Tanner - Bryston]

MEMO: To All Bryston Customers
SUBJECT: Sneak Peak – Bryston Surround System Review

Sneak Peak !

Doug Blackburn from Widescreen Review Magazine has done a very extensive review of a Bryston Surround System which will be published in their February 2016 addition.

Favourite Quotes:

The Bryston A2s don’t editorialize the sound in any way I can identify. They don’t sound fast/slow or bright/dark or etched/rounded. They just sound normal/natural and un-gimmicked. This is the kind of sound few people dream of, but most people should want the natural sound of loudspeakers like the A2s.

Bryston did exactly the right thing with the design of the AC-1 Mini. It’s the sort of center channel I would consider owning if my setup allowed for the fairly large size of the AC-1 Mini.

Music listening on the Bryston Mini A speakers was surprisingly satisfying. I easily got drawn in during several listening sessions that were supposed to be brief examinations. Each session turned into a few hours of listening to both new and old favorite tracks.

The quality of the Bryston Model A Sub’s bass is excellent overall. It’s as good as any subwoofer I’ve heard down to its limit.

Bryston has delivered the sort of loudspeakers you might expect from a well-respected electronic components manufacturer. Serious performers, no baloney design, no silly/snake-oil explanations about how the loudspeakers work, no outrageous claims. Just solid engineering, purposeful design, engineered for reliability and performance.

[mindu]

Hi James just wondering would it be possible for you to post or give a link to some rear and side close up photos of your drivers from the T series and possibly one of the crossovers as the model T is on my short list as a replacement speaker and modern Driver design with the latest materials is key for me as I have had some bad luck in the past with drivers made up of materials that were sold in premium speakers.

I have been looking online for quite some time and cant locate such photos

Thanks

[James Tanner - Bryston]

Originally Posted by mindu

Hi James just wondering would it be possible for you to post or give a link to some rear and side close up photos of your drivers from the T series and possibly one of the crossovers as the model T is on my short list as a replacement speaker and modern Driver design with the latest materials is key for me as I have had some bad luck in the past with drivers made up of materials that were sold in premium speakers.

I have been looking online for quite some time and cant locate such photos

Thanks

Hi Mindu

I have not figured out how to post pictures in AA so please email me at jamestanner@bryston.com and I will see what I can find.

We design and manufacture all our drivers in house so I can assure you they are of top quality and we could not approach a 20 year warranty on the speakers if they we not

james

[James Tanner - Bryston]

Hi again Mindu - some info on drivers for you:

Drivers and the Myth of Tweeter Materials

Modern Marvel

All of us take for granted lots of modern marvels, but it nevertheless still impressed me in that instant that a tiny reciprocating electro-mechanical motor— the voice coil of the Bryston Model T tweeter—moves a titanium dome back and forth 10,000 times per second to precisely reproduce that convincing hi frequency sounds of a triangle in an orchestra. (The triangle is an instrument of indefinite pitch but the bulk of its output is centered around 10,000 Hz.)

Think about it for a moment: the audio voltage, an AC signal representing the triangle’s complex acoustic spectrum zips out of the output transistors along the speaker cables reaching the tweeter’s voice-coil and magnet structure. In the second or so that the triangle sound resonates and decays, the voice-coil moves a few millimeters back and forth 10,000 times, and so does the tweeter’s titanium dome, compressing and rarefying the air molecules at the same rate (10 kHz). These rapid pressure waves travel across the room and reach your ears 10 milliseconds later (sound travels about 1 foot per millisecond—my couch is about 10 feet from my speakers).

Eyes closed, the better to imagine the orchestra spread across the front of my living room, I react by thinking, gee, now that sounds real. It’s just as amazing that my eardrum also vibrates at the same rate and my brain interprets that signal as “triangle”! But that is a subject for the future; for now we’ll stay with drivers.

Silk Domes vs. Polypropylene vs. Titanium/Aluminum

Why utilize titanium in the Bryston speakers and not silk or cloth for the tweeter dome, you might wonder? Isn’t cloth or silk inherently softer than metal, hence better suited to reproduce music? This touches on a common misunderstanding of loudspeaker design, especially of tweeters, by some professional reviewers and lots of enthusiasts. They believe that a hard dome material imparts a “hard” or harsh quality to the sound, or conversely, a “soft-dome” tweeter made of cloth or silk will yield “soft” or “silken” traits to strings and other sounds. This is incorrect, and is based on la lack of understanding of how a tweeter dome operates.

It is not the material the dome is made of that imparts so-called musical qualities to loudspeaker sound reproduction; it is the ‘linearity or accuracy’ at which the dome precisely vibrates, without distortion, for example - to recreate the waveform of the triangle that convinces us of a triangle’s sound. The lighter the dome is, the less energy it takes for the voice coil to easily move it back and forth, stopping and starting its travel as the voltage moves between positive and negative cycles. Ideally, a tweeter dome should exhibit a perfect piston like motion during its rapid back-and-forth excursions. The dome must be rigid and not change shape during these rapid fluctuations. Titanium is ideal – light yet rigid—and functions as a heat sink to drain heat away from the tweeter voice coil during loud dynamic swings in the music. If cloth or silk doped with a stiffener were used to shape it into a dome (still used on many speakers) or polypropylene (plastic) material, it might be less rigid and could change shape, especially from overheating, which would alter the accuracy of the reproduced waveform just a little, perhaps enough that the triangle sound might not have that lovely ring. Just because the tweeter utilizes a cloth-dome design does not guarantee a smooth non-fatiguing sound.

In fact, it is the ‘unbalanced frequency response’ of a speaker that makes it sound shrill, not the cone or dome materials. Over many years of double-blind listening tests at the National Research Council in Ottawa, as well as the many systems I have had at home I’ve heard speakers that used a variety of different materials for the tweeter dome. Some cloth or silk dome tweeters exhibited edgy aggressive highs, but when the tests were over, you could quickly spot the jagged, unbalanced treble frequency response in the measured curves that was responsible. Similarly, I’ve praised some speakers that used aluminum and metal-dome tweeters or ribbons very highly and downgraded others. It’s all about smooth balanced frequency response free of jagged nasty resonances, not about the driver dome or cone materials.

Getting Loud

What happens inside a tweeter when the music gets loud? When a big cymbal crash comes along, a bigger voltage hits the voice coil and it momentarily heats up, but the Bryston titanium dome helps conduct heat away from the voice coil. Moreover, the voice coil is immersed in a bath of magnetic ferrofluid to help move heat away from the vibrating voice coil (ferrofluid has the ability to increase heat transfer from seven to ten times that of air). This is one reason why Bryston tweeters can cleanly reproduce very high-volume sound and cleanly handle dynamic peaks without compression.

For its woofers and midrange cone drivers Bryston utilizes aluminum because it, like titanium, is lightweight and rigid, so the voice coils can easily move the cone using fewer watts, hence gaining sensitivity and efficiency. Like the tweeter, the midrange and woofer voice coils on our speakers are connected to the aluminum cone, so again the cone works as a heat sink, cooling the voice coil and enabling it to accept higher power levels and play cleanly and dynamically without problems. The rigid nature of aluminum also helps keep the cone moving as a perfect piston without changing shape, ensuring that the acoustic waveforms of sounds are accurately reproduced.

How It Works

You may be curious about why the voice coil/magnet assembly is termed the “motor” of a loudspeaker. It’s called that because a finely wound coil of wire (the voice coil) surrounds a permanent magnet pole piece but it is separated by a tiny gap. It becomes an electro-magnetic motor when an electrical signal is applied to the voice coil. As the varying audio voltage surges through it moving between positive and negative swings of the waveform, the magnetic properties of the voice coil change and interact with the surrounding permanent magnetic field, causing the voice coil to move back and forth with the varying audio voltage. The voice coil drives the cone or dome to which it’s connected (hence the term “driver”) which moves along with the voice coil, compressing or rarefying the air molecules in front of the dome or cone. And when those pressure waves hit our eardrums, presto, sound!

Woofers

Midrange cone drivers and especially woofers must use much larger magnets, voice coils and cones because they have to move a lot more air to reproduce lower frequencies than tweeters. Bass instruments have long wavelengths; hence the reciprocating woofer cone must generate lots of big pressure waves. That’s also why the woofers consume much of the power (watts) because the large motor assembly needs lots of watts to move the big cone back and forth. This introduces problems of excursion—the distance the voice coil and cone must move to produce loud deep bass. If the voice coil moves too far, it may move out of the magnetic field of the speaker magnet. When that happens, the cone movement becomes non-linear, so it distorts or doesn’t accurately reproduce the audio waveform. A 15% movement of the voice coil outside the magnetic field is equivalent to about 3% distortion.

To ensure accurate translation of the audio electrical signal into deep bass sound waves at higher volume levels, the voice coil can sometimes be made longer so the cone travel (excursion) can be increased, hence the cone can move a greater distance without moving the voice coil outside of the magnetic field. Long excursion woofers may be equipped with dual voice coils, as they are in all of Bryston’s subwoofers. Wired in parallel, these dual voice coils present a lower impedance to the amplifier, letting the amplifier deliver more current and power to the woofer.

There’s much more to good loudspeaker design than covered here, but hopefully the above will help you appreciate the amazing accuracy and operation of the quality loudspeaker drivers used in all Bryston loudspeakers.

[James Tanner - Bryston]

Some more for you:

BRYSTON SPEAKERS:
CABINET AND DRIVER DEVELOPMENT

Question:

James what part did loudspeaker drivers and cabinet design play in the development of the Bryston speakers?

Answer:

I guess the best way to explain the Bryston Model T speaker is we did not really start with a specific driver design in mind. We started with the Bryston reference speaker concept and the speaker concept determined what type of cabinet and what kind of drivers were needed.

The above is the main motivation for why I went to a specialized company driver and cabinet manufacturer in the first place as I knew needed someone with the qualifications and capabilities to design and manufacture a speaker from the ground up - (anechoic chamber, sophisticated test gear, excellent engineering talent, 30 years of experience in speaker design, ability to design and build custom drivers etc.)

So once I decided I wanted a full-range speaker with extremely low distortion, wide power response, wide listening window with high power handling and no dynamic compression the project moved in that direction. So the Model T cabinet was designed and the compliment of drivers and cabinets we went through involved about 5 different aberrations from (single woofer – single mid – single tweeter) to what you see now – (Triple Woofers, Dual Midranges and Dual Tweeters).

All our goals were met with the driver and cabinet compliment you see now in the Model T and the cabinet bracing and driver design is a function of what it took to reach that goal. With the additions of the other Bryston Speaker models - (mini t, Middle T, Center channel, Subwoofer, On-Walls and In-Walls etc.) different drivers with different characteristics and parameters (voice coil type, magnetic structure, suspension system, compliance etc.) were developed to optimize their performance in each specific cabinet.

Hope this helps

James
Bryston

[mindu]

Thanks very much James

[James Tanner - Bryston]

Originally Posted by James Tanner - Bryston

Hi Mindu

I have not figured out how to post pictures in AA so please email me at jamestanner@bryston.com and I will see what I can find.

We design and manufacture all our drivers in house so I can assure you they are of top quality and we could not approach a 20 year warranty on the speakers if they we not

james

Hi Mindo

Pictures sent.

james