<font size="2" face="Verdana, Helvetica, sans-serif">They all (including Altec's) go back to Bell Labs/Fletcher's folded hornOriginally posted by valhallax:
are the el36's and b52's of today decendants..or revisions of an altec design?
and RCA/Olsen's Shearer folded horn
The 1215 horn isn't much longer than the 210 horn.
The 1215 is pretty good stacked in a 2x2 matrix, the mouth area get big enough for usable bass to 50-60 hz. Obsolete by modern standards- a Tuba 36 or EAW LA 400 will knock it dead.
If you look at the print Convergence posted, I think it is the Shearer horn- or a close derivative.
BTW 2 different 1215's- the "A" model fits the 16" frames. Have had no luck at prints.
these arent mine. i would like to audition them though. any speculations on this design? ive researched the archives and it seams there are no blueprints for them. looks like a great rig though.
are the el36's and b52's of today decendants..or revisions of an altec design?
Plans for large foded horn are not availabe. I found this which could work as well.
.....
I am new to forms and subs so forgive me...
I am a "band dad" with some woodworking and CAD skills and have a task at hand. We have come across a pair of Altec 421a's with one torn. I have reconed that one and want to put them into a pair of subwoofer cabinets for my son's PA system. They came out of an old home made bass cabinet that has a rattle when cranked up a bit (driven buy an old Custom tuck n roll head). Just ordered a second recone kit so speakers will be fresh.
I have glazed over with all the techno talk about subwoofer design. Does anyone have plans or pictures of what I should build? From what I read, folded horn for these speakers help. The dual folded one in this form is pretty tall - we are starting to provide sound for back yard gigs and are currently borrowing Mackie 15" powered subs that are approx 30" x 30"
Thanks
Chris
The 421 is not going to be much of a subwoofer no matter what you do. It never was a subwoofer, not even a woofer really.
Even less likely if you had it reconed anywhere but Great Plains.
Best bet is going to be a decent bass reflex box.
The 421a also has limited power handling by today's standards.
Honestly a folded horn won't help.
Better to assign the 421s to mid bass and build subs...even cheap modern speakers will make more bass.
Your neighbors called. They like your music.
i tried the 421's in a bf titan 48 cab..the 3156 woofer blew it away, and the 515g completely destroyed even the emminence definamax, the recommended speaker, in comparison. however..usable bass below 40hz..kinda.
"those sounds to which no definite pitch can be assigned are usually classified as noise"<br />harvey fletcher-1928
As previously mentioned, there may be better options out there.Originally Posted by cristo509
Prices on criagslist have dropped like a rock of late, so you should be able to get some good deals with a little hunting.
If (if) planning to build a folded horn for a woofer (note - I did not say 'subwoofer'), and if there is no specific design goal that leads you to a particular cabinet, I'd suggest instead to save the time and plywood money and put it towards gas and a pair of Peavey FH-1's. There are at least 3 pair (at last check) up here (PA) within driving distance of me. Nominally, we see them for ~300/pair. If you pick up 4, the usable LF range drops as you mutually couple them (place them next to ea. other). Efficiency is spec'd somewhere around 100db(+) 1/w 1/m, so you save yourself money on the amp end of things. (though they are going cheap as well these days).
Do a search for the FH-1 .pdf to check specs.
You'd probably want to cross @ 200-400hz or so... which makes the companion MB-2 (also seen along with them frequently) attractive. (search on 'peavey project one' perhaps)
Not trumpeting the FH-1 per se, but I've had them and they seemed to work well after reconditioning (check and clean the dry-rotted foam out of the woofer magnet/gap and re-seal the doghouse with fresh foam weather seal). Easier than the effort put into woodworking IMO.
If pursuing, I'd suggest removing the doghouse trap door, pulling the woofer to inspect, prior to purchase, jic.
Check to ensure the surround is good. The 1504 (?) Black Widow drivers are generally (all?) designed to allow for the basket (i.e frame, cone, voice coil, ...everything forward of the magnet) to be replaced, but I do not know if you can buy replacement baskets these days or not.
*... and you may not be able to cram any other woofer other than the 1504 (?) into them per the tight space of the 'doghouse'.
i cross out of my 'subwoofers' at 70 hz..no higher and give them 12 db's of boost below 40 hz... then pour judicios amounts of power to them, still cant keep up with 210's but an active crossover helps alot
"those sounds to which no definite pitch can be assigned are usually classified as noise"<br />harvey fletcher-1928
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