Re: Foster 5.25 inch driver
Pete,
Based on the basket, i'd peg those as Coral OEMs (and with a good chance the marketer was Radio Shack). Look like nice drivers.
daPS: to get past the search thing, just check the box that says you searched (whether you did or not)
Pete,
Based on the basket, i'd peg those as Coral OEMs (and with a good chance the marketer was Radio Shack). Look like nice drivers.
daPS: to get past the search thing, just check the box that says you searched (whether you did or not)
Hi Dave,
Thanks for the thoughts on the drivers - there are no markings on them at all. I was thinking about phase plugs - looks like the 1354 plugs might fit.
I tried to check the box, but it kept coming up. Probably a work computer problem!
Pete
Thanks for the thoughts on the drivers - there are no markings on them at all. I was thinking about phase plugs - looks like the 1354 plugs might fit.
I tried to check the box, but it kept coming up. Probably a work computer problem!
Pete
Bluebeard, Thats a good q about the cloth surrounds. My modified Wharfedales were treated with a bituminous coating over 25 years ago. They still sound fantastic.
I have had success with old and new cones with PVA. It doesn't seem to dissolve the adhesive used on VCs and dust caps. Also PEP aircraft gasket cement is good for stiffening cones. I gave the modded wharfies that treatment, and they haven't faded.
I don't know what material was used in the cloth surrounds, but it has stood the test of time. My unmodified Wharfedales show no sign of deterioration in the surrounds, yet the cones are many shades lighter.
I guess the manufactures don't want there products to last.
Geoff
I have had success with old and new cones with PVA. It doesn't seem to dissolve the adhesive used on VCs and dust caps. Also PEP aircraft gasket cement is good for stiffening cones. I gave the modded wharfies that treatment, and they haven't faded.
I don't know what material was used in the cloth surrounds, but it has stood the test of time. My unmodified Wharfedales show no sign of deterioration in the surrounds, yet the cones are many shades lighter.
I guess the manufactures don't want there products to last.
Geoff
Here are my so called Heppner drivers. 12" woofer and 1" horn.
Supposed to be from an RCA console, but the horns says Magnavox. Also supposed to be Alnico, but I don't know.
Maybe Panet10 the dirver spotter knows what these are.
The horns first. Cast into the metal horn it says "JAPAN"
Supposed to be from an RCA console, but the horns says Magnavox. Also supposed to be Alnico, but I don't know.
Maybe Panet10 the dirver spotter knows what these are.
The horns first. Cast into the metal horn it says "JAPAN"
Attachments
They look a bit like the horns Radio Shack were selling in the late 70s. I" phenolic dome, plastic rear cover. Went to about 17K.
Geoff.
Edit: I have seen bass drivers like that, no mounting holes, use L shaped clamps. They are alnico. Don't recall the brand. Peerless?
Geoff.
Edit: I have seen bass drivers like that, no mounting holes, use L shaped clamps. They are alnico. Don't recall the brand. Peerless?
panomaniac said:
If they are Heppner they will have a 575 on them (like the 137 on the woofers -- 137 is CTS (Chicago Telephone Supply))
The horns are Magnavox (found in magnavox speakers & consoles & RCA consoles), but were OEMed by a number of people including Jensen (the original designer), Heppner, & Foster (if it says made in Japan it is a Foster). They are alnico. They have a lot of resonances that need taming.
Here http://www.planet10-hifi.com/EIA-SpeakerCodes.html you can see how to interperet the codes (mostly US manufacturers)
dave
panomaniac said:
Should work fine like that.
Looks like you have removed the dust covers -- some packing tape to keep the dust out of the VC.
dave
Thanks Dave!
I had not seen your speaker code page. What a great resource.
So it seems my drivers are CTS woofer from early 1970, Foster tweeters from late 1969. Cool. And Alnico.
Woofer magnet dust covers were removed for photos only.
Your right about the horn resonances, the plastic dust cap is awful. Tap on the back and you can hear it from the horn loud and clear. A little rope caulk helps a lot.
The divers where originally in a sealed styrofoam box lined with fiberglass. Pointed about 45 degs. from each other. The Alnico must be doing its thing , they get loud without much power.
I had not seen your speaker code page. What a great resource.
So it seems my drivers are CTS woofer from early 1970, Foster tweeters from late 1969. Cool. And Alnico.
Woofer magnet dust covers were removed for photos only.
Your right about the horn resonances, the plastic dust cap is awful. Tap on the back and you can hear it from the horn loud and clear. A little rope caulk helps a lot.
The divers where originally in a sealed styrofoam box lined with fiberglass. Pointed about 45 degs. from each other. The Alnico must be doing its thing , they get loud without much power.
If those horns need a bit more surgery, I glued a disk of masonite in the back of the cover, cut a cardboard tube to fit inside the cover, filled the gap with epoxy resin, lined the inside of the tube with felt, and placed the horn back on the cover. With the right amount of epoxy in there you'll never get it apart again. It probably pushed the fr up a bit, but these weren't needed under 5 Khz. May have upset the ratio of the chambers, if it was designed into them. I didn't know about the relationship between the rear and front chamber/throat size in those days.
The horn flare itself gets a bit exited. Wrap it in cotton wool and bind with a gauze bandage. That's only first aid, there's probably a better fix for it.
Geoff
The horn flare itself gets a bit exited. Wrap it in cotton wool and bind with a gauze bandage. That's only first aid, there's probably a better fix for it.
Geoff
Hi Bob, are you trying to get in trouble with the cook again?
Are these going on another OB?
Cheers,
Geoff.
Are these going on another OB?
Cheers,
Geoff.
Nah, Geoff. At $6 for the pair, I am well within my "allowance"! I am thinking of trying a small box design that is high in WAF. Dave put me on to one design. I am always looking for others as well.
I gotta put the wings on that bigger OB and get a report for you.
I gotta put the wings on that bigger OB and get a report for you.
That'd be right. 6 bucks for speakers for the good lady. What have you in mind for St Valentines Day, Pizza to go?
For your wings, I spotted a pic using piano hinges. I would have thought they'd rattle. This one had a B200 on it, if they were going to rattle, they would in this case. Scottmoose is planning to use hinges on a pair. Worth looking at.
Cheers,
Geoff.
For your wings, I spotted a pic using piano hinges. I would have thought they'd rattle. This one had a B200 on it, if they were going to rattle, they would in this case. Scottmoose is planning to use hinges on a pair. Worth looking at.
Cheers,
Geoff.
I picked up some podge and will try that in a light coat on the cones first. Taking the dust cone out will be a real treat!! I have a pair of Z-horns here that I can place these in with no mods.
Piano hinges for the big un? Now that would solve tight space storage and allow subtle adjustments. Thanks Geoff.
Piano hinges for the big un? Now that would solve tight space storage and allow subtle adjustments. Thanks Geoff.
I'm pretty sure those are Atomix.
$15 is a very good price. How are the surrounds?
They will benefit cosmetically & sonically from a bit of puzzlecoat.
XO them low to a 3" mid-tweeter, or high (6-8k) to a tweeter (horn probably best)
Notice the tab for grounding the basket?
dave
$15 is a very good price. How are the surrounds?
They will benefit cosmetically & sonically from a bit of puzzlecoat.
XO them low to a 3" mid-tweeter, or high (6-8k) to a tweeter (horn probably best)
Notice the tab for grounding the basket?
dave
Is it better to "flower petal" the center cap for removal or cut neatly around the edges? I may have to practice on a set of Radio Shacks first.
I'd just excise the cap completely. You do need to fill the resulting hole with some sort of phase plugs to finish the job thou.
dave
dave
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