For the high-end TIW 250 XS 8 Ohm woofer we recommend one of two cabinet sizes: either a small, space saving version with a net volume of 30 litres ( SUB T-25.30 ) or a somewhat larger version with 50 litres net volume and a lower tuning ( SUB T-25.50 ).

As one would expect, the SUB T-25.50 provides warmer, deeper bass, and the lower limiting frequency is 25 Hz, considerably lower than for the SUB T-25.30 . But it is particularly in smaller rooms that the 30 litre version comes into its own. The missing low-bass (approx. 3 dB at 35 Hz) can easily be compensated for by applying a little electronic bass boost. Of course, the maximum volume level will be slightly lower as a result.
Extract from Hobby HiFi 6/04 (TIW 250 XS)

With its TIW 250 XS, Visaton has launched the successor of the TIW 250, which has proved extremely successful for well over a decade. As regards the Thiele-Small parameters and all the acoustic ratings, it follows very closely in its predecessor's footsteps, which means it can be used without any alterations to the crossover and cabinet in applications originally designed for the TIW 250. As regards high-level signal behaviour, it even exceeds its predecessor: the length of the voice coil has remained the same, but the broad elastic cone displacement enables far greater room for the diaphragm to move. This driver responds to moderate clipping in a very well-natured manner: The distortion only increases very gradually in the limit zone. Carefully positioned holes and perforations in the basket ensure optimum air flow and minimise physical losses. The capton voice coil carrier makes an additional contribution