The TW (Tall & Wide) surround design involves an important trade-off. Its larger surround geometry allows the cone to achieve greater excursion while maintaining better mechanical control and reducing the risk of surround deformation. However, a wider surround also reduces the effective radiating cone area (Sd).

A larger cone area can move more air with less excursion, while a smaller cone with greater excursion can achieve a similar displacement volume. The key is achieving the right balance between effective cone area, linear excursion, motor strength and suspension linearity.

However, the additional mass of the larger surround also affects the driver’s T/S parameters, particularly Mms and Fs. To compensate for the increased moving mass, we utilize carbon fiber components, which offer a high stiffness-to-weight ratio while keeping the moving assembly lightweight.

The result is an Mms comparable to the original design, while Fs is reduced by 7 Hz, with sensitivity remaining within 1 dB of the original.