035Ti Tweeter Repair

[Wagner]

So someone please educate me. Are both metal plates magnets? Is there any special orientation to "aligning" the two other than getting the gap even? There are the holes for the screws but I cant tell if they are supposed to line up with anything.

[spirou38]

The "damping foam" is there to stop spurious sounds from being created by the titanium dome .As such, it needs to lightly touch the dome ( from inside the dome ) .The foam deteriorates with age & turns into a crumbly mess / eventually pulling away from the dome ( & no longer fulfilling its original design function ).- The foam "crumble" can also get into the voice-coil gap, causing ugly distortion type problems .The ( now ) under damped titanium will become brighter, a bit louder ( if the foams not in the gap ) & a bit more brittle sounding ( to those with well developed listening powers ) .You need to remove the diaphragm ( try googling for directions ) , & then remove all traces of the foam ( including any bits found within the magnetic gap ), & then fit the unit with a new piece of acoustic foam ( use some glue to hold the foam plug in place / it goes without saying , you'll need to find some foam glue / 3M stuff works well ) . Here's a thread that you need to read .

Hi Earl K,Do you know the thickness of the soft open cell foam sheet I should use for restoring 035Ti and 2420 ?Pascal

[Earl K]

Hi Earl K,Do you know the thickness of the soft open cell foam sheet I should use for restoring 035Ti and 2420 ?
Pascal

Simple Answer; Sorry, but I don't .

- Some DIY explorations ( for you to pursure ) :

2420 :

- I would simply buy some 10-12mm thick boot-felt ( winter boot liners ) & cut it into a circle that is sized, to fully fill ( the full diameter of ) the back-cap ( of the 2420 ).

035ti :

- The ( touching ) foam performs a mechanical damping on the dome ( from the inside ) .
- This damping concept is similar to the function of the "damping pedal" on a piano ( which uses felt applied against the ringing strings ) .
- FWIW, a person can also use their finger to modify the ringing of the 035 dome or piano string ( or guitar string ) .

- My advice ( for the 035 ), buy some moderately spongy foam that crushes down by only a few millimeters ( when measured against the "inside curvature" of the 035 dome .

[spirou38]

Simple Answer; Sorry, but I don't .

- Some DIY explorations ( for you to pursure ) :

2420 :

- I would simply buy some 10-12mm thick boot-felt ( winter boot liners ) & cut it into a circle that is sized, to fully fill ( the full diameter of ) the back-cap ( of the 2420 ).

035ti :

- The ( touching ) foam performs a mechanical damping on the dome ( from the inside ) .
- This damping concept is similar to the function of the "damping pedal" on a piano ( which uses felt applied against the ringing strings ) .
- FWIW, a person can also use their finger to modify the ringing of the 035 dome or piano string ( or guitar string ) .

- My advice ( for the 035 ), buy some moderately spongy foam that crushes down by only a few millimeters ( when measured against the "inside curvature" of the 035 dome .

Thanks Earl K !!!

[trueview]

not mine...http://orangecounty.craigslist.org/ele/5091024792.html

[spirou38]

Simple Answer; Sorry, but I don't .

- Some DIY explorations ( for you to pursure ) :

2420 :

- I would simply buy some 10-12mm thick boot-felt ( winter boot liners ) & cut it into a circle that is sized, to fully fill ( the full diameter of ) the back-cap ( of the 2420 ).

035ti :

- The ( touching ) foam performs a mechanical damping on the dome ( from the inside ) .
- This damping concept is similar to the function of the "damping pedal" on a piano ( which uses felt applied against the ringing strings ) .
- FWIW, a person can also use their finger to modify the ringing of the 035 dome or piano string ( or guitar string ) .

- My advice ( for the 035 ), buy some moderately spongy foam that crushes down by only a few millimeters ( when measured against the "inside curvature" of the 035 dome .

Hi Earl K,

I have 2 spare 035Ti JBL genuine diaphragm kits and I found a small piece of foam in each. Before, I didn't know what for it was, but now, I know .

Those small foam parts are about 10 x 10 mm and 3.5 mm thick.

Pascal

[Earl K]

Ah, it's good to know the original size ( ie; 10mm x 10mm x 3.5mm high )

Thank-you ! Pascal for those measurements .

[grumpy]

10mm (diameter?) x 3.5mm doesn't quite sound right in either dimension...
(pardon my reuse of this pic) perhaps 2x in both?:

[spirou38]

10mm (diameter?) x 3.5mm doesn't quite sound right in either dimension...
(pardon my reuse of this pic) perhaps 2x in both?:

Hi Grumpy,

Sorry for the bad information , when I first had a look at one of my 35Ti diaphragm kit it was in the half darkness of a room.

I just had a check and in fact I saw that in the middle of the square 10 mm x 10 mm black foam part there is a circular cut that makes a small cylinder like on your pic. That cylinder is about 5 mm diameter and exactly 3.5 mm thick.
But I didn't find the big cylinder like the one of your pic .

So I decided to open the second ( and never opened ) repair kit and it's the same than the first one : no big foam cylinder .

Pascal

[grumpy]

Thanks for checking ... No idea what the smaller piece is for,
and have no official instruction sheet.