I understand Tom Danley once proposed some mods to the A7 which are supposed to improve the sound greatly, especially the phase response. I couldn't find anything on the net, and paging Tom on AA brought no result.
Anybody happen to know where I could find further info?
As per the Danley "white paper":
A-7 mods
Replace stock drivers with JBL-2226 and BMS 4550.
Replace lower vent panel with one having 4 , 4 inch dia ports, 5 inches long.
Pic #60
Reinforce 15? horn flares, glued in with construction adhesive not wood glue or epoxy.
I used boards which were 5 ? inches by 12 inches with one side cut to a 20 degree angle to better mate with the horn flare.. These are way too live.
Shown in pic # 62
Before and after is shown in measurement, gets rid of a few dips.
Optional, it wouldn?t hurt to put a 2X2 diagonally on the lower cavity side walls with a 2X2 added to tie the sides (from one side to the other) together.
I would use construction glue to adhere the 2X2?s to the walls and when dry, use screws to attach the cross brace.
Apply damping to the under side of the final bell of the 511 (not visible).
Mount the horn on the rear side of the wood, setting it back from stock.
Mount the 15?s with an extra front gasket for clearance at Xmax.
Use foam tape to seal all removable panels and replace the wood screws with 1 5/8 drywall screws.
Drizzle some extra glue at the front edge of the flare on the interior (the glue joint at the front where the bent plywood attaches. Use that gorilla glue (polyurethane) for this as it fills gaps. On this one there was a gap in the wood (on the inside).
Remove and remount the horn mounting board, remount 2 ? inches rearward and use the foam tape under it (which dampens the box top panel).
Not all vegetables make good leaders.
Thanks very much for that. Do you have a link for the white paper? Does he say anything about the crossover?
Sadly, i cannot find my file of the original, i just copied this from an old post here on the board.
Not all vegetables make good leaders.
Thanks. Anybody else happen to have the complete paper?
So in other words, totally change it into something other than an A7.... no thanks.Originally Posted by bowtie427ss
Audio_by_Goodwill
Michigan, USA
get rid of the altec woofs?! and the drivers?!! never, no way,not gonna happen. something along the lines of..'pry my cold dead hands off it'
"those sounds to which no definite pitch can be assigned are usually classified as noise"<br />harvey fletcher-1928
IIRC I have heard that JBL-2226 in the A7 and it was pretty good. But so are the Altec drivers.
"When EF Hutton talks, people listen" never meant squat to me, but I'll listen to pretty much anything TD has to say about speakers.
Everything has to be taken in context though. TD is a pro sound guy. His mods make perfect sense for that app; bump up the ultimate output while giving up as little as possible.
Comparing the 2226 to a 515 yields several similarities, but a higher Qes. The big difference is Vd (almost double, hence the extra gasket) with the electrical ability to handle it.
The polyester BMS is pretty smooth too. Again, the kicker is ultimate output.
Does the TD version sound better full tilt than stock? I dunno.
Would I give it a try if I had empty A7s and some gigs to play? You betcha.
"[I]We're going all the way, till the wheels fall off and burn[/I]!"
Bob Dylan, from [I]Brownsville Girl[/I]
[I]"Time wounds all heels"[/I]
John Lennon, referring to the Nixon/Hoover deportation fiasco.
This isn't exactly what you are looking for.....you could take a look.
Boston University School of Theology Archives
Once you get to the link.....go down to notes: #36....and there is an some info.
Let us know how your project works out.
I am looking for a single.....Altec 805 horn.
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