Lots of different theories & opinions about speaker & crossover designs.
I think you may enjoy this link
http://www.audioholics.com/loudspeaker-design/most-influential-speakers
And this..
http://www.classicspeakerpages.net/IP.Board/index.php?/topic/5624-matching-up-advents-for-stacking/
I believe that the old rule-of-thumb on stacking like-model speakers is to put the tweeters close together in the vertical-stacking arrangement. On the other hand, if the woofers are together -- with the tweeters at the top and bottom -- a phenomenon known as "mutual-radiation" causes the bass response (below the frequency of ultimate-radiation impedance) to rise about 3 dB all the way down to resonance. This is akin to placing single left- and right-channel speakers in the corners. Unfortunately, this rise in this overall low-frequency output does not give added bass extension; the resonance stays the same, but the output (relative to the midrange/treble) gets "heavier" and "punchier" as a result. With the tweeters at the top and bottom, other odd diffraction effects can occur. Using unlike models of a speaker, as in different vintages of the Large Advent, the only real issue might be efficiency, with one set getting more of the amplifier's output than the other set, but otherwise it should work fine.
Stacking mainly gives a system increased power-handling capability and greater "impact," it might also give the sense of a larger sound source with increased spaciousness.
I suggest that you ask detailed questions about your OLA speakers in the speaker forum …Dollars & Sense is really a value forum and the only place that value & money discussions are allowed on AK.
If you post your questions in the speaker forum..
http://www.audiokarma.org/forums/index.php?forums/speakers.27/
You will get much better info from folks who are very knowledgeable about speakers & the science behind different drivers, crossover & speaker designs.
Also try using the search box in the upper right hand corner before you post a question.
Very often you will find multiple threads about the subject that you are wanting learn about.
Welcome to AK!
PQ
PS may I suggest that if you are finding AK informative & helpful consider becoming a subscriber & help support this site.
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