Magnesium possesses great damping qualities, Aluminum great rigidity and the two in alloy can greatly reduce distortion. This unique marriage of metals offers several advantages. The impulse response is incredibly rapid yet benefits from a very short settlement time and excellent damping. This enables the tweeter to extend its frequency response beyond 28kHz (-3dB)…
This configuration produces a precise, analytical sound and an extremely deep soundstage. The frequency response curve linearity is also remarkable in that it ensures perfect neutrality. When listening, the treble frequencies are dynamic and detailed. The Aluminum/Magnesium inverted dome tweeter then combines perfectly with the Polyglass woofer in a perfect tone synergy.
Inverted Dome Tweeter
The particular advantage of the inverted dome tweeter of our Studio Monitors is the optimization of the mechanical coupling between the voice coil and the dome. The voice coil is fixed at mid-height on the dome and uniformly moves the cone entire surface. The positive dome is only joined at its edge, causing it to be inactive beyond 16kHz for a flexible surface. The inverted dome directly radiates into the air, with maximum efficiency, which is translated by an extremely precise soundstage. The dome’s response curve is clearly more linear than that of any positive dome. It provides better space dispersion and very low directivity, contrary to ribbon tweeters. The inverted dome tweeter offers unequalled dynamics, enabling sound engineers to very precisely control compression.
The image precision (height, width and depth) is outstanding and makes the positioning of each element very easy, as well as allows one to exactly assess the reverb tails.
Focal, after two years of research and development, produced a world first: a pure Beryllium inverted dome, able to cover more than five octaves (1000Hz – 40kHz). You may ask yourself why do we strive for an extended response at 40kHz, if the human ear can only hear up to 20kHz? If you can extend frequency response, you will improve the perception of transients and other micro details. As well, the linearity of the speaker’s response curve is mainly a function of three opposite parameters: lightness, rigidity and damping.
To this day, only one material permits a joining of these parameters: Beryllium. For domes with identical masses, Beryllium is seven times more rigid than Titanium or Aluminum, the latter two well known for their rigidity. This results in a sound wave propagation three times faster than Titanium and two and a half times faster than Aluminum. In the end, the linearity of the frequency response curve, the acoustic transparency and the impulse response of the Beryllium tweeter are maximized and offer near-perfect sound.
The TNF Tweeter
Focal brand’s signature product, the inverted dome tweeter has been continually developed ever since it was created. It bears repeating that its main advantage, apart from its very low directivity, lies in its use of a coil of small diameter (hence very light and better accelerating) directly fixed to the rigid dome. Just as with the cones of its bass and midrange speaker drivers, what makes Focal unique is working directly on the sound output and, therefore, on the mechanical characteristics of materials. When we introduced the pure Beryllium inverted dome tweeter ten or so years ago, we clearly demonstrated the decisive advantage of this exclusive technology. For the TNF tweeter, we have brought two major evolutions to our aluminium/magnesium tweeter. The suspension between the dome and its bracket uses Poron, a material with shape memory. This suspension method is directly derived from the famous Utopia Beryllium tweeter, making it possible to reduce distortion by a factor of three in the 2-3 kHz range, where the human ear has very great sensitivity.
The inverted dome’s spatial characteristics and very low directivity already make it greatly superior to the conventional domes used by our competitors and to further improve this a wave guide has been developed. In a horizontal plane, its frequency response has a variance of +/- 0.5 dB. This performance guarantees an incredibly stable sound stage which makes the listening position much less critical.
It is due to more than twenty years dogged work on our manufacturing processes that it is possible to achieve such precision in a component as delicate as a tweeter.
Control over production is the one and only solution for continued innovation when it comes to loudspeakers…
Cross-section of the TNF tweeter
Poron’s physical properties provide improved control over the mobile assembly in the magnetic parts.
Distortion levels directly affect sound quality
The use of Poron has reduced the distortion by half in the tweeter’s. Bandwidth between 2–4 kHz: an area where the sensibility of the ear is very high.