What do you mean by 'vintage drivers'? Without being a little more specific, it's almost impossible to say. Some examples perhaps?
First up, for the love of Heaven, if you buy some, make sure you have their T/S parameters, or can measure them, or they are easily available elsewhere, or we'll just be reduced to a very simple ROT from the 1940s, and a lot of pure guesswork & cut & shut experimentation.
Assuming you do, make sure the Qt is moderate -preferably no more than about 0.45; same goes for Vas -preferably no more than about 45 litres, unless you want, and can live with, absolutely vast (and I don't mean just 'large') cabinets.
The usual checks apply of course -keep a sharp eye on the condition of the cone, the motor, and particularly the surround. Difficult just in a few pictures, but important. Don't go for too large a driver either, again unless you want a monster cabinet. 6 1/2in is the sweet-spot IMO, at least in terms of keeping size down to vaguely sensible levels. Personally I'd love a pair of 30in deep, 90in tall, 18in wide monsters with 12in drive units, but they wouldn't fit through the door for a start, and once in, would look a trifle overpowering, even if I took a sledgehammer to my dividing wall & knocked two rooms into one, making a much larger floorplan.
Personally, I'd look for a second hand pair of top of the range Fostex drivers -the defunct FE168Sigma or FE208Sigma perhaps. Not vintage, but their reputation preceeds them.
First up, for the love of Heaven, if you buy some, make sure you have their T/S parameters, or can measure them, or they are easily available elsewhere, or we'll just be reduced to a very simple ROT from the 1940s, and a lot of pure guesswork & cut & shut experimentation.
Assuming you do, make sure the Qt is moderate -preferably no more than about 0.45; same goes for Vas -preferably no more than about 45 litres, unless you want, and can live with, absolutely vast (and I don't mean just 'large') cabinets.
The usual checks apply of course -keep a sharp eye on the condition of the cone, the motor, and particularly the surround. Difficult just in a few pictures, but important. Don't go for too large a driver either, again unless you want a monster cabinet. 6 1/2in is the sweet-spot IMO, at least in terms of keeping size down to vaguely sensible levels. Personally I'd love a pair of 30in deep, 90in tall, 18in wide monsters with 12in drive units, but they wouldn't fit through the door for a start, and once in, would look a trifle overpowering, even if I took a sledgehammer to my dividing wall & knocked two rooms into one, making a much larger floorplan.
Personally, I'd look for a second hand pair of top of the range Fostex drivers -the defunct FE168Sigma or FE208Sigma perhaps. Not vintage, but their reputation preceeds them.
The Philps AD 9710/ M - if you happen to find a pair at a reasonable price?
Thousands of these were sold, and often used in Voight pipes a few decades ago. Where are they all stashed away ?
Diameter: 8.5", 20.3 cm
Efficiency: 97 dB SPL @1m, 2.83v, 8R
Re: 5.2R
Z: 7R
Fs: 46 Hz
Qms: 2.28
Qts: .63
Qts: .49
Vas: 3.55 ft^3, 100 l
Pe: 15W
Xmax: +- .7mm
SveinB
Edit: Looking more closely at the T/S, maybe this would be better in OB?
Thousands of these were sold, and often used in Voight pipes a few decades ago. Where are they all stashed away ?
Diameter: 8.5", 20.3 cm
Efficiency: 97 dB SPL @1m, 2.83v, 8R
Re: 5.2R
Z: 7R
Fs: 46 Hz
Qms: 2.28
Qts: .63
Qts: .49
Vas: 3.55 ft^3, 100 l
Pe: 15W
Xmax: +- .7mm
SveinB
Edit: Looking more closely at the T/S, maybe this would be better in OB?
There are probably a lot of diamonds in the rough among the "no-name" vintage drivers you see there, but once word gets out on a specific model, prices go high. (Priced Diatones lately?)
I think a lot of them come out of consoles/TVs/juke boxes/etc, so they are basically geared toward "infinite baffle", i.e. high Q.
One potential path is to build a simple open baffle (a la JE Labs) with easily interchangeable drivers, and just try out a bunch.
I think a lot of them come out of consoles/TVs/juke boxes/etc, so they are basically geared toward "infinite baffle", i.e. high Q.
One potential path is to build a simple open baffle (a la JE Labs) with easily interchangeable drivers, and just try out a bunch.
Hi, The Altec designed cabinet for the 755 was 1.5 cu ft. sealed. 11.25x11.25x23.5" Mated with a 2000B cone tweeter or a 3000B horn.
The next model up used 2 755s and the 3000B in 2.7 cub ft. 14x14x26"
the 402 was a very similar driver. More info at:
www.lansingheritage.org/images/altec/catalogs/1971-home/page24.jpg
The next model up used 2 755s and the 3000B in 2.7 cub ft. 14x14x26"
the 402 was a very similar driver. More info at:
www.lansingheritage.org/images/altec/catalogs/1971-home/page24.jpg
Geoff H, do you have any specific info on the Altec 402C? Years ago I picked up a pair of Altec cabs with a 755C and a 402C in each. I believe the 402 was used to extend the bass. I have been using the 755's in open baffles, but haven't figured out what to do with the 402's.
They are 16 ohm units with alnico magnets and a stamped basket. Although they seem to be good quality, I don't think they can compete on their own with the 755.
-- Dave
They are 16 ohm units with alnico magnets and a stamped basket. Although they seem to be good quality, I don't think they can compete on their own with the 755.
-- Dave
Hi Dave, The only info I have on the 402s is that the designs I have call for a 402 or the 755. From what I can tell, the 755 is the ceramic magnet replacement for the 402. They should sound similar.
I would guess your 755s replaced 402s at some stage. Especially if the
755s are 8 ohm.
The 433 is another similar unit. Ceramic, 8 ohms, 58Hz in 1 cub ft.
If you haven't done this yet, these respond well to cone treatment. 2 light coats of PVA on the cone and dome. Not on the surround though!
What to do with yours? You could send them here. LOL. They are very versatile. 1 cub ft sealed, full sized BR, 5.2 cub ft and 28 sq in port. 1/4 size A7.....
I think they're candidates for TLs. My 433s could be my next TL project.
Did your cabinets have the 3000 horn tweeter?
I would guess your 755s replaced 402s at some stage. Especially if the
755s are 8 ohm.
The 433 is another similar unit. Ceramic, 8 ohms, 58Hz in 1 cub ft.
If you haven't done this yet, these respond well to cone treatment. 2 light coats of PVA on the cone and dome. Not on the surround though!
What to do with yours? You could send them here. LOL. They are very versatile. 1 cub ft sealed, full sized BR, 5.2 cub ft and 28 sq in port. 1/4 size A7.....
I think they're candidates for TLs. My 433s could be my next TL project.
Did your cabinets have the 3000 horn tweeter?
I'm sure that Altec intended to put two different drivers in the cab. The 755 was connected directly to the terminals in the back while the 402 was connected in parallel, but with a choke in series. There was even a little circuit diagram glued inside the cab with 755C, 402C and the choke clearly labeled. I saved the diagram, but who knows where it is now...
The 402's do not look anything like the 755's. JE Labs has a web page with photos of the entire 755 series showing the unique shape of the cone itself as well as the gooey stuff on the surrounds. Notice that the cone resembles a horn more than a cone with the outer edge becoming nearly flat. (I don't meant to imply that this makes it a 'horn' speaker; that just happens to be the shape of the cone.) Also notice the ripples about half way out from the center. Clearly the cone was intended to operate in two sections much like the biflex drivers that Altec marketed around the same time. In contrast, the 402's have very conventionally shaped cones with untreated cloth surrounds.
-- Dave
The 402's do not look anything like the 755's. JE Labs has a web page with photos of the entire 755 series showing the unique shape of the cone itself as well as the gooey stuff on the surrounds. Notice that the cone resembles a horn more than a cone with the outer edge becoming nearly flat. (I don't meant to imply that this makes it a 'horn' speaker; that just happens to be the shape of the cone.) Also notice the ripples about half way out from the center. Clearly the cone was intended to operate in two sections much like the biflex drivers that Altec marketed around the same time. In contrast, the 402's have very conventionally shaped cones with untreated cloth surrounds.
-- Dave
Hi Dave, The cone you describe is known as a "curvilinear". The 433 has a similar cone, with corrugated surround. Much smaller magnet.
What I have found on the 402, they were used in columbs for theatre use, (to fill areas where VOTTs were used up front) Info from the Altec /JBL Heritage site. 1975, prof series. There are a few errors - omitions on the index page. There is more to be found if you view www.lansingheritage.org/html/altec/catalogs/ Dig into that, you may find the full specs.
Interesting comments on your originals. I used to do a trick like that on columbs with 4 drivers. The middle 2 had dual cones. With 4, the vertical spread gets too narrow.
Geoff.
PS. Interesting link for JEL. Thanks
What I have found on the 402, they were used in columbs for theatre use, (to fill areas where VOTTs were used up front) Info from the Altec /JBL Heritage site. 1975, prof series. There are a few errors - omitions on the index page. There is more to be found if you view www.lansingheritage.org/html/altec/catalogs/ Dig into that, you may find the full specs.
Interesting comments on your originals. I used to do a trick like that on columbs with 4 drivers. The middle 2 had dual cones. With 4, the vertical spread gets too narrow.
Geoff.
PS. Interesting link for JEL. Thanks
Hi!
I do not intend to sound like an expert here BUT I wonder if the Monacor SPH60X really measure QTS 0.43. Scott, have you or someone else, dmason for example, seen measurments on these?
What I have seen is the SPH155X which claims 0.5 QTS. Measured 0.8 in reality!! Question arise then, how much difference will it make when listening, not looking at a graph?
I realize I'm sticking my head into a killer-bee hive, but I must say after all fuzz I've seen about sizes and ratios I decided to build a Monacor BIB with the right ratio as shown on Zilla's page.
There is difference between my oversized (1:2 ratio) than the normal(1:41...) The oversized have more bass for sure, but the issue about more ripples in oversized enclosures... well I can't hear it.
If I can't hear it, I don't want to measure them to realize that I've got really lousy speakers
Cheers
Peter
I do not intend to sound like an expert here BUT I wonder if the Monacor SPH60X really measure QTS 0.43. Scott, have you or someone else, dmason for example, seen measurments on these?
What I have seen is the SPH155X which claims 0.5 QTS. Measured 0.8 in reality!! Question arise then, how much difference will it make when listening, not looking at a graph?
I realize I'm sticking my head into a killer-bee hive, but I must say after all fuzz I've seen about sizes and ratios I decided to build a Monacor BIB with the right ratio as shown on Zilla's page.
There is difference between my oversized (1:2 ratio) than the normal(1:41...) The oversized have more bass for sure, but the issue about more ripples in oversized enclosures... well I can't hear it.
If I can't hear it, I don't want to measure them to realize that I've got really lousy speakers
Cheers
Peter
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