The loudspeaker units for the Q113 will be produced at Scan Speak A/S in Videbæk. But what can the West Jutlanders do that a clever businessman has not long since moved to China? I'm looking at the construction of the special speakers.
Trial workshop at Scan Speak. The parts for the Q113 loudspeaker are ready to be assembled and tested.
N.C. Madsen founded the company known today as Scan Speak A/S in 1933. Two of Madsen's values were enterprise and creativity, and in this section I will tell how the spirit of the founder still runs through the factory.
Without bragging. The Q113 Revolution bass speaker looks like other speakers until you look closely.
Q113 uses specially designed loudspeaker units
From the beginning of the project, the readers of the Engineer have helped to specify the loudspeaker units to be used in the Q113 loudspeakers. The work has consisted of a series of calculations and simulations based on the framework of the project, and there has been a lively debate about the importance of the different characteristics of the speaker units.
The level of ambition is high and now we have some insane speakers built to Scan Speak's standards with modifications added, from the application of an absorbent substance to the diaphragm, to specially manufactured parts and right up to the very limit, our tweeter for the Revolution models, developed from scratch.
It's worth mentioning the passive devices here, which even the sharpest experts can't predict how work. Indeed, there is no reliable calculation tool that can do the job. Conversely, it is entirely in the spirit of the project to let the Revolution speakers step out of the safe confines and go to the edge of engineers' knowledge, in an attempt to push a boundary. Maybe.
All this talk of world-class and lofty ambitions seems oddly meaningless if it's not offset by talk of the ordinary. Things need to be seen side by side. So I'll show you an ordinary good bass speaker, to put it in perspective for the extraordinary. Because sometimes people ask: is there even a difference?
Separate. A regular, good 5 inch woofer, as they look in many compact speakers the size of the Q113.
Common sense prevails in the ordinary loudspeaker
A good and common loudspeaker unit is designed with affordability, ease of production and reliability in mind. This recipe has produced many successful loudspeakers in this world, and with a certain amount of ingenuity one can even build a production plant that can almost automatically build the loudspeaker units from start to finish. From many points of view, this is almost on the first page of the book of success.
A look at the construction of the standard woofer shows a motor system based on a 72 mm ferrite magnet, a 25 mm diameter voice coil wound on an aluminium coil former. The whole thing is built in a pressed steel basket and the sound-absorbing diaphragm is made of a relatively soft type of cardboard which, with its inherent damping, prevents violent colouration of the sound.
The example shown is a loudspeaker which is no longer on the market, but many other loudspeakers are produced today which are basically built in much the same way.
Wildness. The Q113 Revolution woofer is one of the heaviest 5½-inch woofers ever made.
The extraordinary beats reason
I find it incredibly interesting to see how Scan Speak's product compares to something as rational as a good speaker. The exceptional speaker in the example is the bass unit for the Q113 Revolution.
The magnet in the motor system of our woofer is made of neodymium, the strongest and most expensive material available for magnets in loudspeakers. The voice coil, which controls the movement of the diaphragm, has a diameter of 42 mm. It is wound on a titanium form and has a stroke length of an insane +/- 9 mm! There is probably no other 5½ inch woofer capable of this.
This is actually a 5½ inch woofer that on paper is capable of moving air like a regular 8-10 inch woofer. One could stop the comparison there, for the answer to the question "Is there any difference at all?" is self-evident. There are big differences! But there's more.
Only exotic solutions
As far back as 1933, the factory's founder was struggling with how to create a speaker that could find its way into Danish televisions, which were then being produced on a large scale within the country.
The solution came through creativity and ingenuity, and today you can still see that creativity unfolding in the form of a host of design details intended to deliver audio experiences in a way that ordinary speaker units are unable to. The following text refers to the image above.
White arrows. Here you can see how the speaker's diaphragm actually consists of two thin membranes glued together by hand.
Red arrow. The two membranes are not the same. For example, the outer one has a small edge into which a vibration-damping bead is placed.
Blue arrow. The neodymium magnet, which would have been prohibitively large if made of ferrite.
Grey arrow. The construction is open and shaped to allow air to pass unhindered around the speaker's parts.
Light blue arrow. Both diaphragms have an embossed pattern that creates a defined gap in which a vibration-damping substance is placed between the diaphragms.
Yellow arrow. The voice coil form is made of titanium, which is strong like steel but 40% lighter. Titanium cannot be induced in a magnetic field, and therefore will not act as a brake on the movement of the diaphragm, as aluminium does.
Green arrow. The waves in the centering disk get progressively larger, which should make the resistance to movement more uniform.
Black arrow. A construction without cavities, where air would otherwise be compressed and limit the dynamics of the sound.
The speaker taken to the next level
Where the Revolution embraces bold solutions, Evolution refines the existing and builds on ideas that are proven to work.
The Q113 Evolution bass speaker borrows both the ferrite magnet and its tall overhung voice coil from the so-called "common and sensible speaker", but then the similarities end.
The magnet is 110mm and the diaphragm is driven by a 38mm diameter voice coil and the excursion is +/- 6.5mm, more than twice that of a conventional speaker. But it's the creative engineering that really gives the ambition wings. Check out the neat details referenced in the image above.
Red arrow. The diaphragm has slits placed in a special pattern.
Green arrow. The material is wood fibre, made up of five types of wood and a binder.
Light blue willow. The slits are filled by hand with a vibration-damping substance.
Purple willow. Different types of damping compound are applied to the slots.
Light grey willow. Membranes for drying after treatment.
White willow. The large voice coil is now mounted. It is wound on fibreglass.
Yellow arrows. The outer edge of the diaphragm gets an additional coating to trim the sound.
The evolutionary tweeter
The main requirement for the Q113 Evolution tweeter is that it manages to operate at a high level of quality in a two-way loudspeaker, where the crossover frequency is relatively low and where the edge reflections that we measured on the project's predecessor, the SA2K loudspeaker, must not occur.
The solution is to use the same tweeter as the SA2K, but to use a type with a waveguide that directs the sound away from the edges of the cabinet. This glorious piece of precision engineering gets competent and careful treatment in Videbæk. The text below refers to the picture above.
Blue arrow. The membrane of almost transparent textile is manufactured for Scan Speak by a specialist in Germany.
Yellow arrow. In a spinning round, coating is applied to the membrane.
Red arrow. A small felt block almost "floats" just below the membrane and helps to regulate the acoustics in the tweeter's own small cabinet.
Green arrow. Star-shaped cut-out acts as a housing for the diaphragm's suspension.
Black arrow. Diaphragm with voice coil is fitted.
Purple arrow. This tweeter has a magnet motor larger than many woofers!
White arrow. The cast aluminium waveguide is fitted and the bolts tightened diagonally so that the voice coil is optimally seated in the magnet fork.
The speaker that couldn't be done
Nobody really believed that this speaker device was possible. Well, apart from the guy who holds the patent that makes it possible! And, of course, the engineers who went through fire and water to make it a reality.
The challenge, in short, was to revolutionise tweeters, to use a big word. It's well known that a waveguide can control the radiation of sound, but it's equally well known that tweeters benefit from greater sound radiation at higher frequencies. The solution is the patented DXT acoustic lens, provided free of charge to the Q113 loudspeaker, and developed in a special version for our purposes.
By the way, there is the small curiosity that the acoustic lens, after several experiments, proved to work best with Scan Speak's patented ring beam diaphragm. The principle was patented by Scan Speak in the mid-90s, after 20 years in the making.
Yellow arrow. The tweeter's own cabinet (rear chamber).
Red arrows. The four different types of damping material placed in the rear chamber.
Green arrow. Neodymium magnet with hole for the rear chamber.
Light grey arrows. Three different decoupling rings placed between the speaker parts.
Blue arrow. The special ring-beam membrane.
Purple arrow. The almost unnoticeable phase plug that, after 20 years of experimentation, made the ring beam possible.
White arrow. The cast aluminium DXT lens.
The rescue, when all else was impossible
The Q113 Revolution had only been in the air for a few months when the high level of ambition drove the project into the ditch. The engineers' calculations showed that we could create a compact speaker with remarkable bass response. That is, if we could find room for a bass reflex tube in the speaker with a diameter of 60 mm and a length of 42-48 cm! A physically impossible task when the speaker has to be small and compact.
The clever solution came in the form of passive devices that work by using the pressure changes in the air inside the speaker. The only unknown factor is that even the industry's best simulation equipment can't predict exactly how the passive devices work. We don't know if they contribute enough to bass reproduction. But we can always rebuild them if that's what it takes.
That's why we're still holding our breath, and looking forward to experiencing the Q113 Revolution with sound.
Creativity goes on the road to China
After visiting Scan Speak, it is clear that the company's secret weapon is its dedication to delivering solutions that often go the long way to get there. It's no obstacle if a design detail requires painstaking handwork to be executed correctly. Even if it costs. Back in 1933, when the company was founded, it was the ability and courage to invent the original that put it on the map. It's clear that spirit still runs through the factory.
From a wider perspective, where many Danish business leaders ask themselves "What can we do in Denmark that can't be done in China?", the story of Scan Speak is a good one to have. Not least because the West Jutlanders are successful and experience demand from all over the world.
It is very fascinating to see the units for Speaker Q113 being built. In my last post about the factory in Videbæk, I wrote that innovative companies have a short distance between the thinking and the creating employee. At Scan Speak this means that the development manager can do an experiment in the lab and 1½ minutes later instruct a production employee.
It's the personal involvement that goes down the road to China. It's not that there's anything wrong with the ordinary and sensible. It's just so damn common ....
