You wrote:

>> 1. Is it possible to make the 3.5X6.5X10 port a slot, instead?
>> Say, 10WX3.5HX6.5D?

Yes, that will work. You can change port shape slightly and expect it to act pretty similar to another having the same cross-section area and length.

>> 2. I have 2 sets of 1.6k Eminence crossovers, one stock for the
>> PSD-2002's and the other with the 10uF removed for the JBL
>> 2226J/3677s combo. Do I have the parts I need to make an
>> 800Hz X-over?

No. You'll need to get parts to make an 800Hz crossover, because values for the 1600Hz filter are different.

>> Is there a Pi schematic for an 800 Hz X-over?

Yes, and I'll send it to you right now.

>> Should I just get the Altec X-over on E-bay?

It is an option, sure.

>> 3. I saw somewhere that the Altec horns were designed to be in
>> free air,not in the box. True? Is it okay to have it in a three-sided
>> box as long as it's not the same box as the woofer? I'm thinking
>> of the way LaScala's are built with the horn and crossover open
>> to the back and separate from the bass reflex boss.

Actually, most horns are improved by mounting on a baffle, because they are then radiating into halfspace instead of freespace. I think that the Altec's probably don't need baffle mounting, certainly not if crossed over high. That makes horn placement a matter of aesthetics, really. But I wouldn't hesitate to baffle mount or to put the horns in a cabinet.

Take care!

Wayne

You may be surprised at the response curves given when a filter is in the presence of reactive loads. A purely resistive load will provide damping for the filter to provide the smooth rolloff you expect. But a complex load having both resistive and reactive components will modify the filter pretty substantially. And the loudspeaker itself is a complex load, which the compensation circuit modifies. The bottom line is that the loudspeaker is an integral part of the filter circuit, and all components are inter-related. So you'll need to analyze the circuit in more detail to know its response.

"since a 8 ohm 1.6khz crossover should equal a 800 hz crossover for 16 ohms (and it should), "

Not quite. Using 2nd order BW's for example, the 1.6kHz/8 ohm xover requires 8.8uF and a 1.12mH choke. An 800Hz/16 ohm xover requires 8.8uF cap, YES, BUT the choke needed is 4.5mH...

A google search for "crossover calculator" will turn up the web site for "Select Products" on-line applet. Sam

The same can be said of crossover technologies. There are pros and cons of most any solution, but it's all just different ways of doing the same stuff. There are definite benefits of running active crossovers and bi-amping. But not everyone can use this solution. As long as the filters are well-formed and use good parts, you can expect performance of the system to be good, either way.