Isophon Orchester (pre - 2000)

[Cristobal]

Hi everybody,

I recently bought two Isophon Orchester speakers. These are 30 cm coaxials, built in February 1968 (that’s printed on the chassis), serial numbers are 5444 and 5447.

They are mint, in the original cardboard box, with the leaflet. This leaflet says that for a lower limit of 25 c/s, enclosure volume should be 240 litres and the balancing ports should be 360 cm2. Does that mean a bass reflex enclosure with a 360 cm2 rectangular port? Or would a transmission line enclosure be better?

What is the Qts of these speakers, their sensitivity (…/w/m) and their power handling?

Any other advice for the best sound with these speakers would be appreciated.

Thank you in advance.