Hi And thanks for reading this post.
I have taken out two blown tweeters from my speakers and replaced them with two jbl2447j compression horn drivers.
I need to find a small screw on horn to fit onto the jbl's as i am limited by cabinet space, but i am having difficulty finding small enough horns.
As a compromise, could i take the horn from a tweeter and fix it onto the jbl's. I am not sure if it will work. I noticed horn tweeter on ebay with removable horn, item number 151914558336
Could this work? Can i remove the horn attachment from the ebay tweeter and fix it onto the jbl's and still get good sound and dispersion.
Many thanks in advance. John.
I have taken out two blown tweeters from my speakers and replaced them with two jbl2447j compression horn drivers.
I need to find a small screw on horn to fit onto the jbl's as i am limited by cabinet space, but i am having difficulty finding small enough horns.
As a compromise, could i take the horn from a tweeter and fix it onto the jbl's. I am not sure if it will work. I noticed horn tweeter on ebay with removable horn, item number 151914558336
Could this work? Can i remove the horn attachment from the ebay tweeter and fix it onto the jbl's and still get good sound and dispersion.
Many thanks in advance. John.
Take a look at DIY Sound Group web site. The have various sized waveguides / horns. You can turn up some interesting horns on ebay from time to time. Depending on your work skills, you can make a horn out of built up pieces of plywood / MD, wood etc. It is also possible to cast a small horn out of resin using model clay as a mold if you need something special to your needs. Good luck.
Hi. Thanks for the replies, much appreciated.
I think the ebay horn is slightly too large for the jbl 2447j's, but i am desperate and am willing to try anything.
What if i used jb weld ( a strong adhesive ) to fix the ebay horns onto the jbl compression drivers.
Then use some kind of filler, to fill up the few millimeters of space between the makeshift horns and the jbl's exit.
q1. The ebay horn is four inch diameter, do small horns like this bring out the high frequencies more, is that a general rule, what kind of frequencies are we talking about.
q2. The neck of the ebay horn is only one inch, will this be a problem, should i extend the horn to have a longer neck, how will this affect the sound.
Many thanks in advance. John.
I think the ebay horn is slightly too large for the jbl 2447j's, but i am desperate and am willing to try anything.
What if i used jb weld ( a strong adhesive ) to fix the ebay horns onto the jbl compression drivers.
Then use some kind of filler, to fill up the few millimeters of space between the makeshift horns and the jbl's exit.
q1. The ebay horn is four inch diameter, do small horns like this bring out the high frequencies more, is that a general rule, what kind of frequencies are we talking about.
q2. The neck of the ebay horn is only one inch, will this be a problem, should i extend the horn to have a longer neck, how will this affect the sound.
Many thanks in advance. John.
goodguys,
You need to provide more info on your speaker. The word "tweeter" covers a lot of ground, what frequency do you need on the low end ? You are definitely going to have do some crossover modifications or bi /tri amp your system. It may be easier to mount a proper horn on a baffle on top of your speaker box if possible. It sounds like you are opening a rather large can of worms !!!
You need to provide more info on your speaker. The word "tweeter" covers a lot of ground, what frequency do you need on the low end ? You are definitely going to have do some crossover modifications or bi /tri amp your system. It may be easier to mount a proper horn on a baffle on top of your speaker box if possible. It sounds like you are opening a rather large can of worms !!!
Hi. Thanks for the replies.
@TopShelf. I don't know what to do. I can't find a horn that will fit so am being forced to cannablize the ebay horn.
@Hottatto. I am trying to use the jbl's as tweeters from 9khz upwards.
The system is biamped. I have a polk audio active sub with a crossover frequency of 100hz @ 12db/octave roll off. This consists of 2 X 8-inch drivers in a 2 cubic foot enclosure.
Upwards from that i have a quad 405-2 power amp which is being fed 120hz signals and upwards from an active crossover.
I am going to hook up a 1uf capacitor to the jbl's, then connect that to the quad amp.
The problem is the jbl's are replacements for a pair of b&c tweeters which blew, and the b&c's took up less space so were able to fit into the speaker enclosure without any problem.
The replacement jbl's are massive in comparison. If i shove the jbl's to the very back of the speaker enclosure, i have 4 inches of space from the front baffle board. I need a 1.5" screw on horn, no bigger than 8" in diameter, and with a length of no more than 4 inches.
Preferably i would like a small horn because of the 9khz crossover frequency.
Many thanks.
@TopShelf. I don't know what to do. I can't find a horn that will fit so am being forced to cannablize the ebay horn.
@Hottatto. I am trying to use the jbl's as tweeters from 9khz upwards.
The system is biamped. I have a polk audio active sub with a crossover frequency of 100hz @ 12db/octave roll off. This consists of 2 X 8-inch drivers in a 2 cubic foot enclosure.
Upwards from that i have a quad 405-2 power amp which is being fed 120hz signals and upwards from an active crossover.
I am going to hook up a 1uf capacitor to the jbl's, then connect that to the quad amp.
The problem is the jbl's are replacements for a pair of b&c tweeters which blew, and the b&c's took up less space so were able to fit into the speaker enclosure without any problem.
The replacement jbl's are massive in comparison. If i shove the jbl's to the very back of the speaker enclosure, i have 4 inches of space from the front baffle board. I need a 1.5" screw on horn, no bigger than 8" in diameter, and with a length of no more than 4 inches.
Preferably i would like a small horn because of the 9khz crossover frequency.
Many thanks.
Thing is, the 2447 really isn't the driver you want, in form or function, for your application. Sell them, buy something suitable. I'm 99% sure that there are no screw on horns that will fit a 2447, I don't think I've ever seen an adapter even.
Look at the frequency plots, that were taken on a compatible horn and plane wave tube:
http://www.jblpro.com/pub/components/2447.pdf
Look at it below 9kHz, and above 9kHz. These drivers usually get passed off to a tweeter right about where you are wanting it to come in.
There are literally dozens of drivers out there that will suit your application so much better, without having to resort to extreme measures.
Look at the frequency plots, that were taken on a compatible horn and plane wave tube:
http://www.jblpro.com/pub/components/2447.pdf
Look at it below 9kHz, and above 9kHz. These drivers usually get passed off to a tweeter right about where you are wanting it to come in.
There are literally dozens of drivers out there that will suit your application so much better, without having to resort to extreme measures.
Just out of curiosity, which B&C drivers did you have in the speakers? I haven't seen a B&C with a screw on mount before. The ones I've seen are all bolt on flange mount types (but I'm no expert).
Also, the JBL 2447J are 16 ohm, 4 bolt flange mount drivers with a 1.5" exit and are over $800 each new. Is that what you have now? Certainly not a kludge driver if that's the case.
Also, the JBL 2447J are 16 ohm, 4 bolt flange mount drivers with a 1.5" exit and are over $800 each new. Is that what you have now? Certainly not a kludge driver if that's the case.
Last edited:
Hi. Thanks for the question.
Sorry for being vague. The blown b&c's were tweeters not compression horn drivers, they were 4 inches in diameter, the de35's.
The jbl's are as you state, a good driver costing a lot of money, that's why i wanted to use them rather than buying more drivers.
I actually have two boxes full of drivers, and am finding difficulty justfiying additional expenditure to the wife. She is looking over my shoulder as i type this.
Many thanks.
Sorry for being vague. The blown b&c's were tweeters not compression horn drivers, they were 4 inches in diameter, the de35's.
The jbl's are as you state, a good driver costing a lot of money, that's why i wanted to use them rather than buying more drivers.
I actually have two boxes full of drivers, and am finding difficulty justfiying additional expenditure to the wife. She is looking over my shoulder as i type this.
Many thanks.
Attachments
Hello Mrs. Goodguys.
Mr Goodguys, I think you'll have a very difficult time integrating the JBL driver with your existing box. The previous B&C dome has a fraction of the efficiency and the crossover would need much work.
If you have 2 boxes full of drivers why not sell a bunch of them and either buy or make some thing that you can actually use? The JBL will be worthless if you epoxy a mismatched horn to it.
Just a thought.
Mr Goodguys, I think you'll have a very difficult time integrating the JBL driver with your existing box. The previous B&C dome has a fraction of the efficiency and the crossover would need much work.
If you have 2 boxes full of drivers why not sell a bunch of them and either buy or make some thing that you can actually use? The JBL will be worthless if you epoxy a mismatched horn to it.
Just a thought.
Goodguys,
You could remove the back cover of the 2447J, stuff a sock in the horn exit, and use it backwards as a 4" dome tweeter.
Better to sell them and get the proper replacement de35, as anything else will require crossover modification to sound right.
Have fun,
Good Luck!
Art
How do i sell them, i put the jbl's on ebay, which cost me £600 each plus another hundred for the horn, and i started the bidding at £100 and i didn't get a single bid. At the same time I put up a pair of morel cdm54 mids which cost me £330 and i started the bidding at £100 and again i didn't get a single bid. Why is stuff so difficult to sell, is it the recession
Commercial Sector
Swap Meet
Sell your stuff here, who knows, some other fanatic might be interested!
Swap Meet - diyAudio
Swap Meet
Sell your stuff here, who knows, some other fanatic might be interested!
Swap Meet - diyAudio
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.