Some weeks ago I bought a pair of vintage Philips AD12100/W4 from another DIY/er who needed to clear his huge collection. I intended to give these a try in a TL of some sort. To my surprise he sent me 4pc ... so the plan changed to an OB with 2 of these per side, with the lower of the 2 only used for the lower frequencies.
I had suitable piece of wood laying around (an old table), so I cut that in half, made the holes with my router, added triangles on the side zo it would a) be able to stand up and b) create a sort of U-frame for the lower driver to have a bit more bass:
After having this one completed, I hooked it up to my Marantz 2230, adjusted bass and high a bit with the tone controls and played some music...
which was a positive surprise, this already sounded rather nice, especially voices. and that in mono...
After that I fired up my microphone and did some measurements:
purple curve is lower driver (measured off axis), beige curve is upper driver (on axis, 1m)
I loaded the measurements into LspCAD to do some filter simulations. The lower speaker I just add a 15mH coil, the upper got 2 corrections for baffle step & dipole loss compensation (and in the process, the highs got a boost as well):
Looks promising... now just need to build the 2nd speaker and solder the filters and then have a proper listen. I hope to have time for that in about a week...
I had suitable piece of wood laying around (an old table), so I cut that in half, made the holes with my router, added triangles on the side zo it would a) be able to stand up and b) create a sort of U-frame for the lower driver to have a bit more bass:
After having this one completed, I hooked it up to my Marantz 2230, adjusted bass and high a bit with the tone controls and played some music...
which was a positive surprise, this already sounded rather nice, especially voices. and that in mono...
After that I fired up my microphone and did some measurements:
purple curve is lower driver (measured off axis), beige curve is upper driver (on axis, 1m)
I loaded the measurements into LspCAD to do some filter simulations. The lower speaker I just add a 15mH coil, the upper got 2 corrections for baffle step & dipole loss compensation (and in the process, the highs got a boost as well):
Looks promising... now just need to build the 2nd speaker and solder the filters and then have a proper listen. I hope to have time for that in about a week...