Midtop plans:
Shoutbox - Chat
Ohm's Law
http://en.wikipedia.org/wiki/Ohm's_law
Thiele Small
The EV PA Bible!
http://www.electrovoice.com/tech-library.php?pt=general
http://www.mrdos.com/PABible.htm
Designs
http://www.geocities.com/loudspeakerguru
Interesting designs,completely crazy web page layout
All sorts of great articles
Horns
Important horn info 'dinsdale files' and the essential edgar midhorn and basshorns designs from SB.
http://db.audioasylum.com/cgi/search.mpl?searchtext=horn&b=AND&topic=&topics_only=N&author=tomservo&date1=&date2=&slowmessage=&sort=score&sortOrder=DESC&forum=hugForum Search Tomservo, Tom danley, DJK,str8ro
Thoughts on line arrays
http://www.burton-manor.co.uk/Audio/Audio.htm
Factors Affecting Sonic Quality of Mid & HF Horns & Waveguides
http://www.audioheritage.org/vbulletin/showthread.php?t=12967
DBkeele.com
http://www.DBkeele.com
The HF horn + 15" business.
http://www.harman.com/about_harman/technology_leadership.aspx
Whitepapers applicable to Prosound also
http://www.jblpro.com
technical papers
http://www.prosoundweb.com has alot -but the navigation sucks...Topics like horn clusters and power alley.
Design
Hifi but applicable to prosound
http://www.linkwitzlab.com/x-sb80-3wy.htm
http://www.audioheritage.org/vbulletin/showthread.php?t=12967
Id save it as a word document
Crossovers
http://www.trueaudio.com/st_index.htm
http://www.lenardaudio.com/education/06_x-over.html
http://www.passivecrossovers.com/
http://www.bcae1.com/
Car audio but decent basic Xover info
http://sound.westhost.com
Varied site with xover and amplifier plans/buy something.Decent info analogue electronics
http://www.passivecrossovers.com/
http://www.lenardaudio.com/education/06_x-over.html
Horn design
http://www.audioheritage.org/vbulletin/showthread.php?t=12967
Douglas Self's Amplifier Institute:
http://www.dself.dsl.pipex.com/ampins/ampins.htm
(A very interesting website, with a quirky interface, lots about amplifier distortion and design. Schematics as well, though mostly for hifi use)
Rane Notes:
http://www.rane.com/library.html
(A library of application notes and very useful spreadsheets, presentations, tutorials, an excellent resource overall)
Rane Names:
http://www.rane.com/pronames.html
(Pretty much every initials/names of any company in pro audio)
Rane Books:
http://www.rane.com/digi-dic.html
(One of the most complete book references on pro audio, from Leo Beranerk's Acoustics to psychoacoustics)
Rane Directory:
http://www.rane.com/digi-dic.html
(The Hitchiker's guide to Pro Audio, covers James Bullough Lansing to zero-based mixing)
Audio Engineering Society:
http://www.aes.org/
(Need I say more?)
Digital Room Correction:
http://www.duffroomcorrection.com/wiki/Main_Page
(Information and techniques on applying DRC to a system. Includes software download links)
Sound and hearing:
http://hyperphysics.phy-astr.gsu.edu/Hbase/sound/soucon.html
Piston Excursion calculator