Two loudspeaker systems I made using a pair of Sony drivers I had lying around, and a pair of SEAS tweeters I bought for this system. (Click on image for large sized)

I bought this pair of German-made Isophon woofers (P30/37/10) and the tweeter-midrange array (DHB 6/2-10) for R200, since I need a pair of good vintage loudspeakers to match my older electronic components. They were originally sold built into open-backed cabinets of very soft particle board, the intention being that they should be installed in even larger DIY hardwood cabinets (left-most photo in the row below). The cabinets - whatever they were - had gone long before I acquired the drivers. The solder tags had also been ripped off off the bass drivers - very luckily not entirely destroying the flexible braided wires to the cone itself or the voice coil wire. The solder tag in the pic is my DIY one. By today's fashions, for 12-inch drivers, they have a fairly low power handling capacity, woofer 12W, tweeter array 15W, but I have no doubt they will sound wonderful at reasonable volumes.
		Left is a prospective cabinet design. I still have to measre the Thiele-Small parameters of the woofer before I can finalise the cabinet dimensions - but they will stand around 85cm high. I suspect that using the tweeter array 'horizontally' as originally intended, will give unpleasant phasing effects and a poor stereo image. Vertical orientation should improve this. Stereo was regarded differently in the 1950s, and precise placement of instruments was not a particularly important aspect, compared to showing a wide soundstage.

Some data of from Audio Asylum ; "...The T-S parameters for Isophon P30/37 are as follows: fs = 62 Hz, Qts = 0.29, Vas = 105 liters. This is a very light-cone driver with an Mms of only 22 grams.
I'm not sure this is correct - the Isophon datasheets give f_s as rather lower, so the other data may not be accurate.