couple bhox questions


2001-08-16 10:25 pm
I am building a three-way with my woofer in one chamber and my mid/tweet in another. the bottom chamber has a height of 30" without the spikes, and the top chamber will probably end up being about 8" by 7" by 7" (* tall). I was wondering what the rule of thumb is for how far back from the edge of the baffle of the bottom box should the top box baffle be mounted? Would it be advantageous to slope the baffle of the top box in any way? and What is the best way to attach the two boxes for ultimate strength and rigidity (I can't help bu tthink that just the screws and liquid nails will give me the bond I really want with such a small syrface area). Thanks a lot!
As a general rule, you'll want to line up the voice coils of the individual drivers, one above the other. This applies to all drivers in the speaker. You'll have to determine that by physical inspection of your drivers. The fly in the ointment is that the crossover will introduce phase delay at the crossover point (excepting first order crossovers, but I'm probably the only fella around here crazy enough to use those...). The phase delay can wreak havoc on your careful physical alignment. That's when you go for either *very* detailed modelling or impulse testing to fine tune the positioning.
Screws and/or glue will do just fine for the physical mounting. Screws have the added benefit that you can reset them if you decide that you need to re-align the drivers.