JBL E140 modification question
This is a simple one, but I wanted to be sure before implementing.
I have a pair of JBL E140-8A's that I don't need the aluminum dust cap in the application I have in mind. I want to use in a front loaded horn system from 150hz up to 800hz.
I want to know if I could put a paper dustcap over the aluminum one, or if I need to remove the aluminum to install the paper dust cap.
I am looking at using the 140's due to their extremely low Qes which I believe makes them a good candidate for horn use.
I will be using less than 10 watts in their intended mode. The only thing that might screw things up is the "bump" in response due to design that I read about. Other than that, I figure the dust cap needs to be subdued(aluminum).
Any and all comments welcome on this. The horn is a older Edgar tractix 150hz front loaded which I will use up to 800hz where a GP 399 driver on Edgar 500hz round horn will be used.
Ron
Speakers are not for re-sale
Earl,
Thanks for reply. I just don't know if the aluminum dustcap will spray HF I don't need into the horn. If I could just use it the way it is, then I will leave it alone.
I see the E140 as a great horn driver from the low "Q" specs, basically the reason I picked them up for.
Ron
Earl, What would you paint over with?
My concern with applied coating to the dustcap is I don't want to "mass-load" the driver and change the specs as I would imagine it would increase Qts by adding weight to the cone/dustcap.
Ron
Sounds about right to me.
I have heard from those using Bruce Edgar's midbass horns with D130's and complaining about hearing the HF spray(even with using a crossover which is 1st order). So I will go to my speaker repairman and see if he has the time to perform the operation.
I have 2 left thumbs and won't take a chance at screwing up a pair of good drivers!
Ron
Materials to coat the dustcap with
If it did not add too much mass to the cone, I would think rubber cement would be a good thing to apply to the dustcap. But I think that would add more mass than would be a good thing.
So far the best solution seems to be removing the aluminum dustcap and replacing with a paper dustcap.
Thanks to all for the replies!
Ron