UNPRECEDENTED DYNAMICS
1 1/4” (32mm) tweeter
A revolution in in-car audio, the FRAK tweeter is a Focal exclusive. With a unique frequency response, it has an ‘M’-profile aluminium/magnesium cone and incorporates patented technologies to give your system unprecedented dynamics. Aluminium makes it possible to obtain a rigid cone for good frequency lowering, while magnesium provides superb damping and, by its lightness, allows the tweeter to perform brilliantly in the extreme treble. The Frak tweeter is a perfect pairing with the other products from the K2 Power M range, delivering pure, hi-fi, in-car sound.
With these active K2 Power M products, you can build your own “à la carte” audio system, to create the system you really want. These powerful products are also ultra compact for easy installation into all cabins.
KEY POINTS:
STRIKING REALISM
3 1/8” (80mm) midrange speaker driver
Like all the speaker drivers in the K2 Power M range, 3 KM is fitted with Focal's iconic aramid fibre K2 sandwich cone. And for an even bigger performance, Focal's engineers have combined it with their famous ‘M’-profile. This shape of cone offers better frequency response and better sound dispersion, and reduces speaker driver depth. Attributes that go hand-in-hand with the power and dynamics delivered by the K2 cone. Thanks to this 3 inch (80mm) speaker driver, your system delivers faultless musical and pure, high-fidelity sound to provide the ultimate listening pleasure.
With these active K2 Power M products, you can build your own “à la carte” audio system, to create the system you really want. These powerful products are also ultra compact for easy installation into all cabins.
THE K2 SOUND SIGNATURE
6 1/2” (165mm) woofer
Like all the speaker drivers in the K2 Power M range, 6.5 KM is fitted with Focal's iconic aramid fibre K2 sandwich cone. And for an even bigger performance, Focal's engineers have combined it with their famous ‘M’-profile. This shape of cone offers better frequency response and better sound dispersion, and reduces speaker driver depth. Attributes that go hand-in-hand with the power and dynamics delivered by the K2 cone. Thanks to this 6 1/2” (165mm) speaker driver, your system delivers faultless music and pure, high-fidelity sound to provide the ultimate in driving and listening pleasure.
With these active K2 Power M products, you can build your own “à la carte” audio system, to create the system you really want. These powerful products are also ultra compact for easy installation into all cabins.
K2 SANDWIcH CONE
The K2 sandwich cone comprises an ultralight foam core, sandwiched between a layer of aramid fibres and a layer of glass fibres. Iconic for its extraordinary performance and recognisable by all for its yellow colour, this cone ensures great purity and precision, all without colouration. It combines 3 key success factors: rigidity / lightness / damping. It offers high quality sound reproduction whatever the style of music.
The innovative ‘M’-profile, made from a single piece (with no dust cap), means it is incredibly rigid. The result? An extremely linear frequency response, a low distortion rate and better sound dispersion.
The many advantages of the ‘M’ profile:
K2 POWER M FRAK
A true revolution in Car Audio, the FRAK tweeter is a Focal exclusive. Unique in terms of its frequency response, it features an Aluminium/Magnesium M-profile cone and incorporates various patented technologies that bring unprecedented dynamics to your installation. It combines perfectly with the other products in the K2 Power M range for pure hi-fi sound, signature of Focal. Available “à la carte”, the K2 Power M products enable you to create the active audio system of your choice for a bespoke installation
The perfect harmony between aluminium and magnesium
A veritable revolution in Car Audio, FRAK is a tweeter designed by Focal. With an ‘M’-profile, FRAK is a tweeter equipped with a cone that perfectly combines aluminium and magnesium. Aluminium makes it possible to obtain a rigid cone for good frequency lowering, while magnesium provides superb damping and, by its lightness, allows the tweeter to perform brilliantly in the extreme treble.
This new Focal tweeter has the structure of a loudspeaker: TMD surround, progressive profile spider, etc. This architecture makes it unique for its frequency handling. Wide band, its remarkable versatility allows it to reproduce the highs with perfection and deliver the midrange with clarity. FRAK brings unprecedented dynamics to an in-car audio system, providing a unique sound experience, signed by Focal.
TMD - Tuned mass damper
The obsession with the midrange
The midrange register is no doubt the most complicated to control in a sound system. On one hand, there must be a smooth transition with the bass. On the other hand, it must be tuned to the tweeter in terms of dispersion and acceleration. This determines the homogeneity of the timbre and spatialisation.
For the past 20 years, we have been working on mastering the "break up" (the frequency at which the cone becomes deformed, leading to distortion) of our 3rd generation "W" cones and on drastically reducing the resonance of the tweeter with the IAL 2. Today, thanks to the power of finite element analysis, our teams have developed simulation software to visualise the dynamic behaviour of the suspension which connects the cone to the basket, thus revealing the performance issues requiring attention.
Tuned mass damper
Following the discovering of these issues, we had to conceive the equipment to solve them. The solutions already known for increasing the damping properties of the suspension all result in an increase of the mass which consequently alters definition. The answer came from a technology used in earthquake-resistant skyscrapers and which is also used for the suspension on racing cars! This technology is called a "Tuned Mass Damper": an additional mass oscillate in opposition to the resonance frequency to control it.
Applied to the speaker driver, the solution consists in simply two tubular rings on the suspension whose dimensions and position have been judiciously determined. They form our Tuned Mass Damper (TMD) and they stabilise the dynamic behaviour of the surround according to resonance, thus avoiding deformation of the cone without afflicting the dynamics. This innovation is patented.
Visual analogy of the surrounds
Our Tuned Mass Damper (TMD) consists of two tubular rings moulded onto the surround. On the left the default suspension, on the right, the TMD suspension. This simple solution, perfected thanks to our new software, stabilises the dynamic behaviour of the surround according to resonance, thus avoiding deformation of the cone without afflicting the dynamics.
Principle of the Tuned Mass Damper
The principle of the tuned harmonic damper (TMD): The graph on the left demonstrates the principle of the tuned mass damper. In red, an m1/k1 system with very pronounced resonance. By adding a mass/spring system m2/k2 (upper section of the diagram), there will be two resonance peaks, as represented by the blue curve. The drop or anti-resonance being previously based on the resonance of the main system, we get the green curve. Finally, by judiciously adding a damper, we obtain the purple curve. The resonance has almost disappeared!
With Sopra hi-fi speakers, we opted for exponentially shaped cones in order to increase frequency response, and consequently impulse response. Another reason for increasing definition.
Measurement and analysis
Improved response linearity between 1 and 2kHz and the frequency extension provided by the exponential cone profile..
Frequency response of our latest midrange driver (blue trace) compared to the previous-generation W-cone midrange, representing prior state-of-the art performance (red trace). Improvements to the magnetic circuit also contribute (see next section). NB: The dip at 3kHz in the blue trace is due to the tested driver not being fitted with a dust cap.
Effect of the harmonic damper on linearizing the frequency response between 1.5 and 2kHz (blue trace with TMD, red trace without).
Effect of the harmonic damper on nonlinear distortion, which is halved between 1.5 and 2kHz (blue trace with TMD, red trace without).
| Type | Tweeter |
| Woofer | 1-1/4″ (32mm) |
| Depth | 3/4″ (19.5mm) |
| Cone | Aluminum, M-shaped |
| Maximum power | 150W |
| Nominal power | 25W RMS |
| Sensitivity (2.83V/1m). | 91dB |
| Frequency response | 600Hz- 32kHz |
| Impedance | 4Ώ |
| Magnet | Neodymium |
| Voice-coil diameter | 1″ (25mm) |
| Suspension | TMD® |
| Type | Woofer |
| Woofer | 3″ (80mm) |
| Depth | 1-1/8″ (27.3mm) |
| Cone | K2 Sandwich, M-shaped |
| Maximum power | 120W |
| Nominal power | 60W RMS |
| Sensitivity (2.83V/1m). | 89dB |
| Frequency response | 200Hz- 9kHz |
| Impedance | 4Ώ |
| Magnet | Neodymium |
| Voice-coil diameter | 1-3/8″ (35mm) |
| Suspension | TMD® |
| Type | Woofer |
| Woofer | 6-1/2″ (165mm) |
| Depth | 21/8″ (54mm) |
| Cone | K2 Sandwich, M-shaped |
| Maximum power | 240W |
| Nominal power | 120W RMS |
| Sensitivity (2.83V/1m). | 92.5dB |
| Frequency response | 50Hz- 5kHz |
| Impedance | 4Ώ |
| Magnet | Ferrite |
| Voice-coil diameter | 23/8″ (60mm) |
| Suspension | TMD® |
