I just discovered this site today, thanks to a link posted on the Sound Practices discussion group (joelist) in which I have been a participant for perhaps five years. Perhaps there are some joelist participants here. Anyway, I am a retired EE with audio as a hobby, off and on, for the past 50 years. My interests lie mainly in power amps (tube amps for the past several years, SE and PP, but mainly SE) and speakers. I have bought and sold quite an appreciable number of speakers over the last few years, ranging from TAD HF drivers to Tannoy Golds ((which I used as my primary speakers for some 30 years) to quite a few larger JBLs, Altecs and Peaveys to several of the more rare and exotic full range speakers, on down to whatever. It would take far too long to go into detail.

Anyway, my interest here is learning about the π speaker designs. I perused the various designs and noted something that was somewhat troubling. Perhaps someone can comment further. e.g., the delta 15 states a Qts of something like 1.61, as I recall. It is common knowledge that this to far too high a value to work properly in any kind of conventional enclosure, either sealed, ported, or horn. So, how does the π design differ from other designs with regard to allowing the use of such a high value of Qts. My intuition (and TS simulation) tells me that the bass response of such a speaker should sound entirely wretched. Some of the horn designs look to be little different than a common duct loaded speaker facing into the corner. Anyway, it escapes me how acceptable performance can be expected from a speaker with such a high Qts.

I have a pair of 18 inch peavey speakers that might be suitable for one of these designs. Are the plans available separately? They are currently listed on eBay with no bids, so if they do not sell I would like to explore using them in one of the π designs. If anyone has direct experience with this speaker (Black Widow 1808-8) in any of the &pi designs, I would welcome their comments.

Dan Marshal