John Sheerin
08-21-2007, 07:34 PM
http://ldsg.snippets.org/HORNS/070819_sc/driver2_1.jpg
I'm continuing in the clean out of my basement, and since I had luck selling a woofer here, I thought I'd give these a try. It's a pair of Stromberg Carlson compression drivers. They're permanent magnet - I assume Alnico but I don't know for sure. The diaphragm is phenolic, and the shape is the same as the Western Electric 555, but with a multi-roll surround instead of the tangential corrugations. The phase plug is also the same as the 555 (visually - I don't know the exact sizes). It's a single slot phase plug. I bought these off ebay about 2 years ago, cleaned them up (cleaned the gaps), and that was it. I decided to sell them the other day, so I took impedance and response curves and listened to both for a minute - they sound fine. The DCR's are basically identical at about 12 ohms from my measurements, but the resonance is different. I'd speculate that one has more phenolic on the diaphragm than the other. Looking at the response curves, you can see the results - the one with the lower resonance has lower sensitivity and extends lower in frequency. I would use active eq to correct for the difference between them, but you could take any number of other approaches. These response measurements were made in identical conditions, but where taken with the mic just sitting above the driver's exit. No horn was attached. It is only to show to what degree they are matched. I'd say they could be used between 500hz and 5khz for home use when mated to a suitable horn, but you'd have to confirm that. The exit diameter of the drivers is 0.709 inches. The thread size looks like 1-7/16 - 16 (OD of threads is 1.430", 16 threads per inch).
I also have the pair of metal re-entrant horns these were mated to. They're painted the same color, are round, and roughly 15" diameter by 15" depth just from memory. I don't have pictures of these, but can take some if people are interested. Sorry, I'm being lazy. I would (was planning on) use the horns as shop decoration as I imagine they'd ring like crazy and use the drivers as midranges in a horn system.
Pictures and measurements are here:
http://ldsg.snippets.org/HORNS/070819_sc/
Price is $260 plus shipping. Due to their age, I'm selling these as-is.
Thanks,
John
I'm continuing in the clean out of my basement, and since I had luck selling a woofer here, I thought I'd give these a try. It's a pair of Stromberg Carlson compression drivers. They're permanent magnet - I assume Alnico but I don't know for sure. The diaphragm is phenolic, and the shape is the same as the Western Electric 555, but with a multi-roll surround instead of the tangential corrugations. The phase plug is also the same as the 555 (visually - I don't know the exact sizes). It's a single slot phase plug. I bought these off ebay about 2 years ago, cleaned them up (cleaned the gaps), and that was it. I decided to sell them the other day, so I took impedance and response curves and listened to both for a minute - they sound fine. The DCR's are basically identical at about 12 ohms from my measurements, but the resonance is different. I'd speculate that one has more phenolic on the diaphragm than the other. Looking at the response curves, you can see the results - the one with the lower resonance has lower sensitivity and extends lower in frequency. I would use active eq to correct for the difference between them, but you could take any number of other approaches. These response measurements were made in identical conditions, but where taken with the mic just sitting above the driver's exit. No horn was attached. It is only to show to what degree they are matched. I'd say they could be used between 500hz and 5khz for home use when mated to a suitable horn, but you'd have to confirm that. The exit diameter of the drivers is 0.709 inches. The thread size looks like 1-7/16 - 16 (OD of threads is 1.430", 16 threads per inch).
I also have the pair of metal re-entrant horns these were mated to. They're painted the same color, are round, and roughly 15" diameter by 15" depth just from memory. I don't have pictures of these, but can take some if people are interested. Sorry, I'm being lazy. I would (was planning on) use the horns as shop decoration as I imagine they'd ring like crazy and use the drivers as midranges in a horn system.
Pictures and measurements are here:
http://ldsg.snippets.org/HORNS/070819_sc/
Price is $260 plus shipping. Due to their age, I'm selling these as-is.
Thanks,
John