Early Altec/Simplex with tar filled 804
From Williamsburg Theatre renovation:
"Simplex/Altec Voice of the Theatre speakers behind the screen, circa March 1998, before the (inferior) rolling screen was installed. This is the original curved screen frame installed for CinemaScope in 1954, though the screen itself was replaced in 1982. We were replacing the horn diaphragm in the left-channel speaker when this picture was taken."
GM
From Williamsburg Theatre renovation:
"Simplex/Altec Voice of the Theatre speakers behind the screen, circa March 1998, before the (inferior) rolling screen was installed. This is the original curved screen frame installed for CinemaScope in 1954, though the screen itself was replaced in 1982. We were replacing the horn diaphragm in the left-channel speaker when this picture was taken."
GM
Attachments
Altec 421 A's
Hello;
New here and I really know almost nothing about speakers and cabinets. I picked up two homemade speakers last Sept at an auction. Didn't pay much attention to them as I only paid $5 for them. Finally got around to opening them up and found that the 15" speakers were a pair of Altec Lansing 421A's. They sound really good and seem to have a wide range. I was going to use them in a Bass Cabinet for guitar but have decided I would rather use them for my stereo. They have a 5" realistic speaker used as a tweeter, no crossover. I'm hoping someone can give me some advice on various options. I would like to get rid of the realistic, install a crossover and either a better speaker or ideally a driver/horn setup. I'm open to either one that I can install in the box or something I could mount outside. I've attached a photo of the speaker box, sorry my flash didn't work so quality isn't so good. Thanks in advance for any sugestions
Hello;
New here and I really know almost nothing about speakers and cabinets. I picked up two homemade speakers last Sept at an auction. Didn't pay much attention to them as I only paid $5 for them. Finally got around to opening them up and found that the 15" speakers were a pair of Altec Lansing 421A's. They sound really good and seem to have a wide range. I was going to use them in a Bass Cabinet for guitar but have decided I would rather use them for my stereo. They have a 5" realistic speaker used as a tweeter, no crossover. I'm hoping someone can give me some advice on various options. I would like to get rid of the realistic, install a crossover and either a better speaker or ideally a driver/horn setup. I'm open to either one that I can install in the box or something I could mount outside. I've attached a photo of the speaker box, sorry my flash didn't work so quality isn't so good. Thanks in advance for any sugestions
Attachments
Greets!
The 421A is a '60s-'70s era musical instrument (MI) driver: 421A
As such, it's very Xmax limited, so it naturally has a lead guitar's highly colorful sound to it and especially bass guitar 'tone' if driven with much power down low, so best not to tune it below ~40 Hz for HIFI apps unless either driven with a high output impedance amp and/or used in a prosound mid-bass alignment to raise its F3.
They were used with both 500 and 800 Hz compression horns/1" exit drivers, so much better options to the RS unit. Note that there's better XO options than the stock Altec 500/800 Hz units, though with some passive or active EQ can be made to work fine. The later 1200 Hz XO with either horn is a popular choice also.
Anyway, lots of info to browse:
ALTEC LIBRARY
Altec User's Board - Hostboard
Lansing Heritage Forums
GM
The 421A is a '60s-'70s era musical instrument (MI) driver: 421A
As such, it's very Xmax limited, so it naturally has a lead guitar's highly colorful sound to it and especially bass guitar 'tone' if driven with much power down low, so best not to tune it below ~40 Hz for HIFI apps unless either driven with a high output impedance amp and/or used in a prosound mid-bass alignment to raise its F3.
They were used with both 500 and 800 Hz compression horns/1" exit drivers, so much better options to the RS unit. Note that there's better XO options than the stock Altec 500/800 Hz units, though with some passive or active EQ can be made to work fine. The later 1200 Hz XO with either horn is a popular choice also.
Anyway, lots of info to browse:
ALTEC LIBRARY
Altec User's Board - Hostboard
Lansing Heritage Forums
GM
Your project might be a good candidate for eWaveguide-ing, see perhaps:
AK Design Collaborative - Econo-Waveguide Speaker - AudioKarma.org Home Audio Stereo Discussion Forums
AK Design Collaborative - Econo-Waveguide Speaker - AudioKarma.org Home Audio Stereo Discussion Forums
What, you can't look through 800+ pages of posts to find the plots??
Guess that is a bit much. The "Flex your PCD Mettle" thread at TechTalk is a little more concise, might be better off there for finding polar data. Here is the page for a particularly nice one (using the QSC waveguide):
Flex Your PCD Mettle: - Page 23 - Techtalk Speaker Building, Audio, Video, and Electronics Customer Discussion Forum From Parts-Express.com
Scan through and look for the multicolored red-in-the-middle polar maps. I wish these were all collected in one place by them selves...
edit: there's an index to a bunch of designs (crossovers, but polar plots are often given) at
http://techtalk.parts-express.com/showthread.php?t=215536
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Newbie A7 Owner
Hi Guys would like to introduce my A7's I picked up recently for a steal
... All the A7's I have seen have the horn on top mine are on the inside, They have the 416 8A drivers and 806 8A drivers for the horns witha b 811 lens and N801 -8A crossovers, one driver is blown but the other works great along with both horns, right now I have a replacement beyma 15 in the one and even tho it is 98 db the altec is considerably deeper sounding and more musical as well!.I have a ART 31 band EQ and it seems they really come on around 50-80 hz? Really nothng lower that I can hear when i eg? also have a audio control ten for final eqing if need be to increase or decrease anywhere. I had to boost some in the 125-250 range too, So I have a curve starting at 40 and increasing a little til i come back down around 125 i think, but they really thump well, using a old project one mark 1500 receiver putting out 160+ watts into 8 ohms and 300 into 4 ohms!. I would like pictures of what you guys have done to brace the flares and cabs in general, they seem to rattle pretty well when turned up loud. Right now I just shoved a bunch of real dense foam we have at work in behind the flares on the beyma one, and also some 1" dense foam on all cab sides above the horn and down in the reflex area as well.Have made some braces to brace flares ,but haven't added them yet. so show me what ya got! ....
Hi Guys would like to introduce my A7's I picked up recently for a steal
... All the A7's I have seen have the horn on top mine are on the inside, They have the 416 8A drivers and 806 8A drivers for the horns witha b 811 lens and N801 -8A crossovers, one driver is blown but the other works great along with both horns, right now I have a replacement beyma 15 in the one and even tho it is 98 db the altec is considerably deeper sounding and more musical as well!.I have a ART 31 band EQ and it seems they really come on around 50-80 hz? Really nothng lower that I can hear when i eg? also have a audio control ten for final eqing if need be to increase or decrease anywhere. I had to boost some in the 125-250 range too, So I have a curve starting at 40 and increasing a little til i come back down around 125 i think, but they really thump well, using a old project one mark 1500 receiver putting out 160+ watts into 8 ohms and 300 into 4 ohms!. I would like pictures of what you guys have done to brace the flares and cabs in general, they seem to rattle pretty well when turned up loud. Right now I just shoved a bunch of real dense foam we have at work in behind the flares on the beyma one, and also some 1" dense foam on all cab sides above the horn and down in the reflex area as well.Have made some braces to brace flares ,but haven't added them yet. so show me what ya got! ....Attachments
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Hi Grandville - you got the upside down ones. They were done that way to be more compact. You can always flip them over and put the horns on top if you want.
Yeah, 50-60 Hz is all you're going to get with the big port like that. Even with the horn blocking part of the port. Closing them a good bit will give you more bass extension. EQ just won't get it until you report them.
The flares rattle, for sure. I braced mine with curved braces and painted the backs with asphalt paint mixed with sand. Better, but still not perfect. I've found some water based caulk made by DAP that I'm going to spread in a thick layer back there to damp them more.
Bracing helps too. Side to side, front to back. I stapled a big piece of fiberglass in the wall behind the woofer. It presses on the woofer when the back wall is screwed in and braces it.
These can be great Hi-Fi speakers with some work. Congratualtion!
They were done that way to be more compact. You can always flip them over and put the horns on top if you want.Yeah, 50-60 Hz is all you're going to get with the big port like that. Even with the horn blocking part of the port. Closing them a good bit will give you more bass extension. EQ just won't get it until you report them.
The flares rattle, for sure. I braced mine with curved braces and painted the backs with asphalt paint mixed with sand. Better, but still not perfect. I've found some water based caulk made by DAP that I'm going to spread in a thick layer back there to damp them more.
Bracing helps too. Side to side, front to back. I stapled a big piece of fiberglass in the wall behind the woofer. It presses on the woofer when the back wall is screwed in and braces it.
These can be great Hi-Fi speakers with some work. Congratualtion!
They seem to work nice if you put the horn on top and use a filler board that leaves about 75-90 sq. inch port.
Greets!
They're tuned around 65 Hz, so yeah, ~50 Hz is where they start loading and why EQing any lower just results in more driver 'flapping' which increases VC heating and maybe even burnout, so if you're going to EQ it to 40 Hz, then the cab needs to be tuned to at least 40 Hz and preferably to around 32 Hz.
Yeah, the horn starts unloading around 175 Hz, so the cab has a strong step response if not driven with the matching impedance it was designed for.
Typically the horn cavities are filled to both brace and damp them. Some have used sand, others with expanding foam (careful you don't blow them out) while I used kitty litter/oil dry. For an 825 cab like yours, it's necessary to add side block off plates. Folks typically drill fill holes in the top plate, but I prefer to drill them in the block off plates.
I've no pictures of my own and these are the only ones I saved links to:
building my Altec A7 -like Speakers
Vintage Altec
The back plates need significant bracing, so typically are done ~like the later cabs: http://www.lansingheritage.org/images/altec/plans/1970's-lf-plans/enclosures11.jpg
Side, bottom plates need either a second layer of void free plywood laminated to them or nominally 1x3 planks or 3/4" plywood ribs glued on edge. The horn plate can either be braced with a laminated plate or mount the HF horn on it and use its mounting to brace it. Adding ribs to the vent baffle board(s) is a good plan too.
If mounting the horn on top, best to scrap the two piece baffle and make one big one, so that the vent is at the extreme bottom.
For HIFI/HT apps, I recommend lining both sides, back and top above the driver and underside of the horn with 1" acoustic fiberglass insulation.
GM
Thanks for the Welcome Guys!... I will take pics of what i am doing and the foam I have and u can tell me if I am headed in the right direction ... also To Tune it lower just add another baffle board on top of the one their? so i would be closer to the bottom of the HF horn then? I cut a couple of boards to try that I will take pics of those too..The foam we have at work is the polyuerthane type foam like used in carpet pad etc.When u fill up that cavity in the flare do u take away from the space for the driver or no? GM I am guessing u mean i need a board to cover up that area between wall and baffle board? so it is one solid piece? I really want to send that other 8A in and get done by GPA, I noticed last night the other one the suspension is very loose feeling compared to my beyma, is that normal for the altecs? I really like the way the new ones are built with the horn section and all that bracing!.Was watching Basic last night and just love how these sound for movies!! After all they are movie theater speakers .I was lucky enough to pick these up for $50
... also To Tune it lower just add another baffle board on top of the one their? so i would be closer to the bottom of the HF horn then? I cut a couple of boards to try that I will take pics of those too..The foam we have at work is the polyuerthane type foam like used in carpet pad etc.When u fill up that cavity in the flare do u take away from the space for the driver or no? GM I am guessing u mean i need a board to cover up that area between wall and baffle board? so it is one solid piece? I really want to send that other 8A in and get done by GPA, I noticed last night the other one the suspension is very loose feeling compared to my beyma, is that normal for the altecs? I really like the way the new ones are built with the horn section and all that bracing!.Was watching Basic last night and just love how these sound for movies!! After all they are movie theater speakers .I was lucky enough to pick these up for $50
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50 bucks is a stupid good deal.
As said above, you will need to close down that port. And to do that you probably need to remove the horn. Tuning the box to 32 Hz would be a hole in the ply of about 14-15 sq in. (GM, can you check me on that?)
If you want to invest some $$$ in your "cheap speakers" then send all the drivers to GPA for a redo. Best to talk to them on the phone, email they are not good at. The 416 should not be loose, so there may be a problem. It's not a super stiff driver, but it doesn't flop, either.
As regards the flares, there were some built with the back of the flair open, like yours and mine. Bracing and damping done right can work wonders. Some had the flares sealed off, the woofer board went all the way across. Those can be filled with something as GM suggests.
Port it right and get rid of the rattles, and you'll have a wonderful speaker.
As said above, you will need to close down that port. And to do that you probably need to remove the horn. Tuning the box to 32 Hz would be a hole in the ply of about 14-15 sq in. (GM, can you check me on that?)
If you want to invest some $$$ in your "cheap speakers" then send all the drivers to GPA for a redo. Best to talk to them on the phone, email they are not good at. The 416 should not be loose, so there may be a problem. It's not a super stiff driver, but it doesn't flop, either.
As regards the flares, there were some built with the back of the flair open, like yours and mine. Bracing and damping done right can work wonders. Some had the flares sealed off, the woofer board went all the way across. Those can be filled with something as GM suggests.
Port it right and get rid of the rattles, and you'll have a wonderful speaker.
Yea I jumped on it when i seen it on craigslist! they were supposed to be both blown on the bottom,much to my surprise only the one is, and that one i think has been done already as it doesn't have the vented dust cap like the other one, I wouldn't say the driver flops it just is alot looser then the beyma one is all, easier to push may be a better word? I found this online, looks like the combo cabs may have been easier to reach a little further down? probably cause the horn blocks away some of that big port?
What part is the reflex portion?
>http://www.lansingheritage.org/images/altec/plans/1968-enclosure/page05.jpg
What part is the reflex portion?
>http://www.lansingheritage.org/images/altec/plans/1968-enclosure/page05.jpg
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