replace Focal 8" woofer?

dreamer · 5th September 2004, 08:25 AM

I got a pair of Hales Concept Three, the woofer's rubber
surround start to crack now. I checked it is made by Focal
and it's model no. is 8KN515JHDG. It may similar to Focal model
8K515. I planned to replace the woofer.
I found 8K516 and 8N515 in Hong Kong. Anyone know what's
the different? anyone got their datasheet?
Besides, I may try to replace it with current focal model 8W5411.
Will it be better? Anything modification to the crossover required?

Any suggestions are welcome

Thank you!

here attached the crossover for the woofer.

inertial · 5th September 2004, 02:52 PM

Hi dreamer, ( excuse for my english)
If you change woofer you must adjust the RLC trap . First you measure the impedance curve of the new woofer in the box , then you must calibrate the exact inverse resonant frequency and the Q of the "notch"to obtain a flat impedance module (instead of the peak ).
This is the standard mode, perhaps the RLC is a bit elaborate so is possible that designer appositely detuned it to obtain his particular target .
Maybe Mr. Hales could be more exaustive !

8 K = Kewlar cone
8 N = old neoflex
8 KN = ?????? maybe kewlar black painted ??

I have a pair of 8K 515 on my speaker , it is very good for 3 way,
IMO 8W have too much different T/S parameter and neoflex
is obsolete technology.
Original spare parts?

Hi all

dreamer · 6th September 2004, 05:38 PM

oh, thank you for your comment.

would you mind to make a copy of the 8k515 specification and
email to me?

johninCR · 6th September 2004, 06:22 PM

It would be a lot easier and cheaper to get the surrounds replaced. If you are "handy", then just get a surround kit and do it yourself.

dreamer · 6th September 2004, 08:09 PM

hello john,
I hope that I can just replace the surrounds of it, it will save lot of money and no need to modify anything.

But the problem is......I can get the orginal or good quality rubber surrounds here.

I got another pair of speaker before, after I replaced their surrounds(not the orginal one), the sound change alot and finally
I sold them out!

If you know any good source of surrounds, please let me know and I will make a try!

Thank's!

6th September 2004, 06:22 PM	#4
johninCR diyAudio Member Join Date: Apr 2004 Location: Costa Rica	It would be a lot easier and cheaper to get the surrounds replaced. If you are "handy", then just get a surround kit and do it yourself. __________________ Everyone has a photographic memory. It's just that most are out of film.

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5th September 2004, 02:52 PM	#2
inertial diyAudio Member Join Date: Aug 2004 Location: Italy	Hi dreamer, ( excuse for my english) If you change woofer you must adjust the RLC trap . First you measure the impedance curve of the new woofer in the box , then you must calibrate the exact inverse resonant frequency and the Q of the "notch"to obtain a flat impedance module (instead of the peak ). This is the standard mode, perhaps the RLC is a bit elaborate so is possible that designer appositely detuned it to obtain his particular target . Maybe Mr. Hales could be more exaustive ! 8 K = Kewlar cone 8 N = old neoflex 8 KN = ?????? maybe kewlar black painted ?? I have a pair of 8K 515 on my speaker , it is very good for 3 way, IMO 8W have too much different T/S parameter and neoflex is obsolete technology. Original spare parts? Hi all

6th September 2004, 05:38 PM	#3
dreamer diyAudio Member Join Date: Feb 2004 Location: Hong Kong	oh, thank you for your comment. would you mind to make a copy of the 8k515 specification and email to me?

6th September 2004, 08:09 PM	#5
dreamer diyAudio Member Join Date: Feb 2004 Location: Hong Kong	hello john, I hope that I can just replace the surrounds of it, it will save lot of money and no need to modify anything. But the problem is......I can get the orginal or good quality rubber surrounds here. I got another pair of speaker before, after I replaced their surrounds(not the orginal one), the sound change alot and finally I sold them out! If you know any good source of surrounds, please let me know and I will make a try! Thank's!

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