Crossover for Altec 416-8B , 806-8A , 811B

You will need at least a 12DB slope crossover. The 800 Hz is in my opinion a little low for the 811 horn. I would try 1200 Hz @ 12 DB. That would require a cap and coil for each driver. There are calculators on the internet that can get you in the ball park and you may/will need a resistor in the tweeter circuit to balance the sound level as the horn will sound too loud in relation to the woofer. A large quage coil for the woofer circuit will increase the woofer output which is helpfull if using a single ended or low power amp. The cap for the tweeter and the coil for the woofer is where I would spend the most money. The higher crossover frequency will also help protect the horn driver to survive with out incident.

You need to join the Lansing Heritage site dedicated to Altec/JBL diy. Full of ex JBL engineers waiting to help.

Thanks for the input!

Tubeking,

You are correct, if u could provide exac