I was looking in the window of a local electronics repair shop on the weekend and noticed a whole bunch of solid looking dome midranges. I'd say the size would be more than 2 inches (they show about 2 and a half) and they have a bit of horn loading (about one inch).
I tried trolling the web, but could not find a picture that looked anything like these (sorry, I don't have a digital camera), but they have a square front plate (about 5") with rounded corners and a dedicated rear chamber.
So, I went in and had a look and the only marks on them are:
ITT (in quite large letters)
27 44
49133
60100
None of these helped me in any way. but the speakers were fairly solid - which seems to indicate a fair sized magnet. The only reason I'm hanging off grabbing them is their price of $40AUS - which could be steep (and I don't get paid until next Thursday).
The owner knows no more about them than I do, except that they came from a bankrupt business which he managed to get some 'mint' 70's amplifiers and receivers from, which were still in their original packaging.
Does anyone have any idea what I have stumbled across?
I tried trolling the web, but could not find a picture that looked anything like these (sorry, I don't have a digital camera), but they have a square front plate (about 5") with rounded corners and a dedicated rear chamber.
So, I went in and had a look and the only marks on them are:
ITT (in quite large letters)
27 44
49133
60100
None of these helped me in any way. but the speakers were fairly solid - which seems to indicate a fair sized magnet. The only reason I'm hanging off grabbing them is their price of $40AUS - which could be steep (and I don't get paid until next Thursday).
The owner knows no more about them than I do, except that they came from a bankrupt business which he managed to get some 'mint' 70's amplifiers and receivers from, which were still in their original packaging.
Does anyone have any idea what I have stumbled across?
Bill,
Unfortunately my description wasn't the best.
The speaker has the same horn-loading style, but the faceplate around the 'horn' is larger and not smooth. Also, the rear, while about the same depth, is not nearly as smooth as the Morels. Come to think of it, it looked like it had room for screw paths on the back (ie. so the rear chamber could be removed). I'll have to look at them again.
I've had word that these may be pictured in one of Martin Colloms books "High Performance Speakers", so I'm going to check it out in the library after work...
Unfortunately my description wasn't the best.
The speaker has the same horn-loading style, but the faceplate around the 'horn' is larger and not smooth. Also, the rear, while about the same depth, is not nearly as smooth as the Morels. Come to think of it, it looked like it had room for screw paths on the back (ie. so the rear chamber could be removed). I'll have to look at them again.
I've had word that these may be pictured in one of Martin Colloms books "High Performance Speakers", so I'm going to check it out in the library after work...
Hi Cloth Ears,
here's some picture from the ITT Midrange.
I bought mine in 1979 (about 35$ CAN ).
Those midrange has been used in B & O loudspeaker and maybe in some 3 way Revox Studio Monitor (I'm not totally sure)
Even today they sound fine.
I don't have the spec anymore.
But they should cover from 2Khz to 5Khz.
here's some picture from the ITT Midrange.
I bought mine in 1979 (about 35$ CAN ).
Those midrange has been used in B & O loudspeaker and maybe in some 3 way Revox Studio Monitor (I'm not totally sure)
Even today they sound fine.
I don't have the spec anymore.
But they should cover from 2Khz to 5Khz.
OK. I checked out the speakers and Martin Colloms book and they're definitely the same speaker. A 50mm fabric dome "double suspension" midrange (courtesy "SEL/ITT"). From the back of other ITT cone midranges and tweeters in the same shop (there's quite a few of them), they were manufactured in West Germany - and they have only the "ITT" on the back with no mention of SEL. They are a closed chamber design (I'd guess about .4-.6litre), but the chamber is held on by 4 bolts that you undo through the faceplate.
Michelf, do you know the designation of the speakers that you have? And I could not see the picture that you posted - any chance of posting it again?
Christopher - thanks, you picked it in one (being the driver in Colloms book - page 188 in the 4th edition).
Does anyone know where old spec sheets go to when they die?
Michelf, do you know the designation of the speakers that you have? And I could not see the picture that you posted - any chance of posting it again?
Christopher - thanks, you picked it in one (being the driver in Colloms book - page 188 in the 4th edition).
Does anyone know where old spec sheets go to when they die?
Check this link
http://www.caninialtoparlanti.it/images/mid-ITT.jpg
This ITT Midrange was the replacement of the ITT midrange pictures that I posted.
The parameters may not be the same but they probably close.
http://www.caninialtoparlanti.it/images/mid-ITT.jpg
This ITT Midrange was the replacement of the ITT midrange pictures that I posted.
The parameters may not be the same but they probably close.
I didn't get back to you last year, michelf, but this is exactly the speaker I have and the specifications were exactly what I needed. I didn't want to start designing with them without first knowing the original specs and ratings (it's all very well measuring the the output response - but if they're only rated for 10 W and you want them for 100W... you get the picture
So, it might be late, but thank you, merci beaucoup!
So, it might be late, but thank you, merci beaucoup!
These is an old ITT model .If i remember it has a resonance frequency 220 hz and was perhaps the best mid in 70s.The later model was with double ferrite magnet.Attention it must be used with cross between 400 to 2000 hz because of the low frequency resonance.It was used by many constructors as Audiolab ,saba,in england by stuart engineer,and in other companies in nord Europe.
Fantastic unit. Recommend 4th order @ 500 hz accoustic high pass.
3rd harmonics somewhere at -70dB iirc. Could measure again if anybody is interested.
Salvaged mine from Beovox M70, M100 and a single unit from a Saba Professional 1300.
These things can play 'loud' for a 2" dome. And they do it without the typical dome waggle.
Dome is coated in Kurt Muller dope.
Consistency is still good after all those years too.
3rd harmonics somewhere at -70dB iirc. Could measure again if anybody is interested.
Salvaged mine from Beovox M70, M100 and a single unit from a Saba Professional 1300.
These things can play 'loud' for a 2" dome. And they do it without the typical dome waggle.
Dome is coated in Kurt Muller dope.
Consistency is still good after all those years too.
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