This is from the spec sheet for the kappas.Notice the allowable input of 300w.That doesn't mean minimum input.
Rating of a mode
Scheme 4 ways, 4 loudspeaker bass-reflex scheme, and a floor type
Using unit For low-pass: 30cm cone type
For inside low-pass: 16cm cone type
For mid-high ranges: 7.6cm dome shape
For high regions: Planar type
Frequency characteristic 32Hz-35kHz}2dB
Input impedance 6ohms
Output sound pressure level 89dB/2.8Vrms
Allowable input 300W
Cross over frequency 180Hz, 700Hz, 4.7kHz
Dimensions Width 415x height 1200x depth of 300mm
Weight 36.5kg
Adjunct Spike
Rating of a mode
Scheme 4 ways, 4 loudspeaker bass-reflex scheme, and a floor type
Using unit For low-pass: 30cm cone type
For inside low-pass: 16cm cone type
For mid-high ranges: 7.6cm dome shape
For high regions: Planar type
Frequency characteristic 32Hz-35kHz}2dB
Input impedance 6ohms
Output sound pressure level 89dB/2.8Vrms
Allowable input 300W
Cross over frequency 180Hz, 700Hz, 4.7kHz
Dimensions Width 415x height 1200x depth of 300mm
Weight 36.5kg
Adjunct Spike