JBLPRO
04-07-2022, 06:57 AM
Hello All....
I am super excited to share some vintage JBL info with you. I spent some time with an engineer friend of mine and we came up with a 99 % perfect affordable replacement horn throat sleeve( JBL part #21251) for the 2” vintage compression driver family. The models that use this part include- 375, 2482 and 2440/2441. JBL discontinued these many years ago. They are manufactured from black Delrin ® and are NOT 3 D printed! They are SUPER strong and are VERY high quality! Precisely manufactured to replace the original JBL factory part.
As many of you are already aware the original old aging JBL throat sleeves(most were bakelite material) have become brittle and crack easily when the drivers are packaged/shipped improperly. On top of that many of these drivers have lost their spec’d gauss making the magnet more prone to movement with impact thus intern cracking the aging brittle factory original throats. I see it all the time when these drivers are shipped! Compression driver value also decreases significantly with damaged throats. There is now a solution to have them repaired with a new sleeve. This is not really a DIY replacement as to do the repair properly the drivers need to be demagnetized/magnetized. I seen it done as a DIY but its not recommend as the unit will loose some charge when opened. There are other techniques of removing the throat without the need to open the driver but I do not have experience with this method.
It's interesting that when JBL shipped these heavy 2” compression drivers way back in the 70’s and 80’s there was not much of an issue with magnet shifting. The original packaging was conservative not very big and, utilized a styrofoam partial clam shell. They were freshly charged tested, in spec and all was good to go!
Please let me know if anyone is interested in seeing samples or pics.
mk
I am super excited to share some vintage JBL info with you. I spent some time with an engineer friend of mine and we came up with a 99 % perfect affordable replacement horn throat sleeve( JBL part #21251) for the 2” vintage compression driver family. The models that use this part include- 375, 2482 and 2440/2441. JBL discontinued these many years ago. They are manufactured from black Delrin ® and are NOT 3 D printed! They are SUPER strong and are VERY high quality! Precisely manufactured to replace the original JBL factory part.
As many of you are already aware the original old aging JBL throat sleeves(most were bakelite material) have become brittle and crack easily when the drivers are packaged/shipped improperly. On top of that many of these drivers have lost their spec’d gauss making the magnet more prone to movement with impact thus intern cracking the aging brittle factory original throats. I see it all the time when these drivers are shipped! Compression driver value also decreases significantly with damaged throats. There is now a solution to have them repaired with a new sleeve. This is not really a DIY replacement as to do the repair properly the drivers need to be demagnetized/magnetized. I seen it done as a DIY but its not recommend as the unit will loose some charge when opened. There are other techniques of removing the throat without the need to open the driver but I do not have experience with this method.
It's interesting that when JBL shipped these heavy 2” compression drivers way back in the 70’s and 80’s there was not much of an issue with magnet shifting. The original packaging was conservative not very big and, utilized a styrofoam partial clam shell. They were freshly charged tested, in spec and all was good to go!
Please let me know if anyone is interested in seeing samples or pics.
mk