Passive-cone kit consisting of the basket and rubber surround of the model WS 13 BF. According to the article in the German magazine "Klang & Ton" a passive cone using a cardboard (e. g. beer-mat) can be constructed. The kit also includes a short instruction and a dimensioning table.
The VIB MIKRO AL is a small format shelf-mounted speaker with a passive radiator. In this 2-way combination, we have used a mid-bass AL 130 8 Ohm speaker with a G 25 FFL 8 Ohm tweeter. The speaker is characterised by well-balanced, clear sound output, good spatial separation and, for a shelf-mounted speaker, unbelievably low frequencyextremes. With a volume of only 9 litres, the VIB MIKRO AL can be found a place in even the most cramped of households. A particular feature of the VIB MIKRO AL is the passive radiator at the rear. But what is the advantage of a passive radiator? In principle, it has the same effect as a vent. However, it has been shown that, with small cabinets (i.e. the relationship between cabinet volume and cone area), tuning hardly produces any bass enhancement over an enclosed speaker. The passive radiator is completely different. Even if the relationship between conesurface area and net cabinet volume is unfavourable, the speaker is highly effective. The only drawback is that the maximum volume level in the low-frequency range is limited by the stroke of the radiator, making the VIB MIKRO AL speaker less suitable for disco or techno music at loud volumes. In order to achieve as linear a frequency response as possible, a special crossover unit was designed, which produces the required effect in conjunction with the passive radiator, tuned to 60 Hz.
