Stacking 511s

[Alien_Shore]

I'm using the speakers in my cabinet shop.
What am I trying to achieve? Trying to get the best sound, as determined by my tired old ears, that I can, over as much of the shop as I can. What I've read about stacking seemed pretty interesting, other than that the 511s shouldn't be splayed. This seemed like an interesting experiment that i could perforn with components I had on hand, or at least could round up pretty easily. I realize that stacking probably won't help with trying to get better sound to all corners of the shop, but "punchier" and "more high end" don't seem like bad things at all.

So, the questions are how do I hook it all up? Does "effectively lowering the xover point" mean I should be using xovers with a lower point (say 500) or does it take care of itself? Further, are my 1004s a reasonable substitute for 1005s, or does my search continue? If I go to 2 500 hz crossovers, do I wire them in parallel? If I go to 811/511, as per Cal, how do I cross them over as mids and tweeters?

I did much the same thing (goal-wise) in my garage. I wasn't trying to stack horns, but was trying to get the best sound out there with sub-optimal room treatments and speaker placement. It was a long process to get there, but what I wound up doing is using an active crossover to narrow down the XO points, XO slope, attenuation levels, etc. Then using what I learned with that, I built custom passive crossovers. I have old 416A (16-ohm) woofers in the 816 horns, and 802-8G drivers on 511B horns for the HF. Part of the challenge was getting a XO design that accounted for the different Z plots of the two drivers, and allowed some manual adjustment (via variable resistor in the HF notch filter). This is a parallel 2-way configuration. They sound amazing, considering that from a time-alignment perspective the positioning of the speakers is horrible.

If you are going to go with one woofer/two HF drivers per channel, a lot depends on your choice of amps as to how you wire everything up. You may want to bi-amp (woofers/HF) - probably a good way to go. Or, you can get creative in series/parallel wiring methods to manage the impedance profile of the load. For example, if you wire the two (8-ohm) horns up in series, the amp will see 16-ohms of impedance which will attenuate them down, which may be desirable if they are considerably more efficient that your woofer. If you put 16-ohm frams in the horns, you can wire them up in parallel, and the amp will see an 8-ohm load.

If you didn't want to Bi-amp, a series/parallel kind of thing could be done. Assuming all your drivers were 8-ohm nominal, you could series-wire the HF horns, then parallel wire those with the woofer, which would yield ~5.3 ohm load to the amp.

There's all kinds of things you can do here, and then adding in the crossovers, changes this around as well.