Threads for 2402H

[JCC1]

I am attempting to mount a pair of 2402H tweeters on the back of a 1.5 inch thick baffle board. I routed out the baffle surface to coincide with the angle of the horn launch. Getting inside of this enclosure to mount a different type of screw from behind is a non starter. (The enclosures are already built sanded and the back is sealed, it is tight in there)

I guess the best way to do this is to form a template so i know exactly where to drill the holes for the 2 inch long machine screws. Now, the 10 cent question:

What is the size and pitch of the threads on the mounting flange of the 2402H's? Everything i tried at the hardware store would go in about 1.5 turns and then become locked. I don't want to "bugger up" the threads nor drill and retap.

What the devil are they?

Thank you so very much in advance for the workable answer.

Sidebar:

Short of taking the actual driver in to the hardware stores, I went to Lowes and purchased 16 different machine screws. No one there that i talked to knew the difference between a machine screw, a wood screw a cap screw, bolt or self tapping. I was amused when i was shown sheetrock screws after I explained exactly what I was trying to accomplish!

[mech986]

Hi, take a look at this pdf detailed drawing of the 2402H driver from JBLPro site.

http://www.jblproservice.com/pdf/Discrete%20Sales%20Models/2402H.pdf

If you have the square mounting flange, it should be a standard 8-32 THD type screw that goes through the flange. However, if you don't have the flange, then you are trying to mount with the screw holes that hold the flange on.

I can't find a reference to the flange mounting screw 803-11110-12, JBL doesn't list it in their Misc. Parts list. However I looked up the same type of flange screw from the 2405 model, uses the same flange and that was listed as #61871


61871 SCREW 8-32X1 1/4 FLH $ 0.85 USD EA Sounds like it should be 1.25" long flat head machine screw. This assumes that the horn has not rotated around its mount and the screws can go all the way down. Sounds pretty long though. Best to take the driver with you and check right there

Hope this helps.

Bart

[JCC1]

Thank you so much for the info. I suppose the paint was keeping the screw from fully interjecting the threads. I purchased some high spec cap screws based on the info and will proceed to make a template to accomodate the mounting. So sorry it took many days to get back to this post but web forums are pretty low on my list of priorities unfortunantly. As with many of us 50 somethings, we stay mired down with numerous projects eating away at time and resources.

This is a very fine forum and I hope to have more time to read through some of the communication here. Just for reference; my first (bought new) JBL's were that of the 4311WX and beginning with the l-200, (used) some le14/mashers and several other older lansing speakers, the quality of the machine work and the tighter tolerences PLUS that 'locked in sensitivity" originally drew me to the products. It is sad for me to see all the stamped steel china products badged as JBL (in original logo mind you) thaty are on the market being proudly displayed as higher quality goods. A consumer has their work cut out for them these days with separating the high profit posing products from those of really higher quality. Sites like this help to spread the proper words to enlighten those who need enlightening!

Cheers mates and good day,

J-

[mech986]

You're very welcome and Welcome to the LH site. With your background, you are already certifiably JBL-centric!

Send us a pic of the completed set up once you have it done. Remember to keep pic size below 800 x 600 for best results.

Again, Welcome!

Regards,

Bart
La Habra, California USA

[JCC1]

Thank you!

I am using some "victor' components from Japan in the set-up as well. These will be 'hanging speakers' for mid field studio use for those who want the 'ooomph' displayed in the mid 110dB levels. I would not consider them a thing of 'beauty' but they will be very fuctional. 12 woofer with fs of 22Hz, mid horn multicellular that will arrive on the scene at about 900Hz and the 2402H arriving at full amplitude..very high. The acoustic crossover of the baffle mount will support down to 3K but needless to say.. I don't want it to go down there. I am extrapolating with about an 11K crossover to actually be down less than 6dB at 4500 so the situation should be pretty fun. once mounted..then on to the crossover voicing duties and mainly done by ears but using good starting places for driver protection purposes (and ear protection purposes).

If I wind up with a +/-3dB system from 32 to 14K I will be pleased.