I ordered the Intact Audio speaker autoformer with a -6dB to -15.5 dB/0.5dB attenuation range based on the fact that my Altec 802 drivers are about 12dB more sensitive than my 99 dB/1W/1M Altec 414A woofers. Other than that, I went into this project hoping that Google would be my friend, only to find out it wasn't!π
Since I use external crossovers for my Altec 753C, disconnecting (and reconnecting for comparison purposes) the Altec 32C/802 horn/compression driver is a breeze. The 753C-style cabinets essentially serve as bass bins in which the 414A woofers operating in wide range mode (unfiltered) + the 20275 diaphragmed 802 compression drivers mounted on the Lycan3R WP12024 horns are perched on top!