Apparantly the stupid dealer doesn't have JBL 2235H recones anymore, so thats pretty annoying. Considering that a month ago they had them but not anymore! He said he has to talk with his dealer in Asia or something.

That brings me to another point - how good are these aftermarket/non genuine JBL recones? I read a very interesting and somewhat funny thread on the High Efficinecy forum regarding chinese recones, and apparantly there was a mixed response. Some said they were fine, others said they were cheap, and I think that included Wayne too! Are these chinese recones "crap"?

I was notified that although I can recone a 2225 basket to a 2235, a person on high eff forum said that the real 2235 basket has whats called a "mass loading ring" or something that accounts for 33% of its cone mass. I found this rather weird cuz the basket isn't the cone and only the cone makes the cone mass - duh :P But I dont know what JBL's done. Can anyone comment on this? Will the cone mass be ~33% lighter thus higher Fs, eff, etc if I recone the 2225 basket to a 2235?

Today I came accross another deal. A pair of ORIGINAL JBL 2225H's in perfect condition. 600 bux australian dollars the pair. Very good price actually. If I reconed the baskets with chinese 2225 recones it would cost 30 bux more. So the originals would be the way to go in this case. If I reconed with the 2235 recones which are actually the ones I wanted (but may not be able to get ANYMORE) it would cost more, but it would be the one I wanted. It would also be a chinese recone though so it might be crap.

I wonder which is the best way to go! The 2225's will work just the same for my application anyway, but they wont go 40Hz -3db point, only 65Hz. But at least they are original and not chinese, and also I have a sub anyway. How bad are the chinese recones? Also, whats the mass loading ring thing and will be T/S parameters be shifted if I put a 2235 recone in a 2225 basket which has no mass loading ring?

Thanks for any help whatsoever! I think I'm gonna just give up speakers and start a stamp collection or something, this stuff has got my brain racing at ten thousand kilmeters per hour since I started this idea. So if you dont wanna see me start a stamp collection, then please give me some help, otherwise I'll be posting pictures of stamps on this forum and not speakers, haha.

Adrian

• http://www.speakerrepair.com/

Can anybody give me any advice on that mass loading ring though - and if it does affect driver parameters in the way described in my last post. Any tips on the quality of chinese recones also welcome/wanted!

:-)

The explanation on the mass loading ring thing, in part stolen from memory from Martin Colloms "High Performance Loudspeakers":

Suppose you have developed a diaphragm which shows a given, wanted behavior over it's frequency area - we are here talking drivers used pretty high up in frequency their size taken into consideration, large bass/ midrange drivers really. And suppose you want to increase the drivers moving mass (for example, to make it able to work lower in frequency in a given box volume).

Now, just adding mass to the diaphragm as a whole will alter it's HF behavior, which we already have 'in place'. So instead, you increase the moving mass by attaching a ring (with the wanted mass increase) to the diaphragm, usually at the 'neck', where voice coil former & diaphragm is attached to each other. Placed here, the ring will have as little influence on the diaphragms behaviour as a whole as possible. This way, you alter the units low frequency characteristics without destroying it's good behaviour in it's HF range.

In some cases, manufacturers have made additional use of the mass ring by placing it strategically on the diaphragm &/or gluing it with a 'soft' glue, thereby controlling unwanted resonances/standing wave modes. I don't think that's the case with JBL, though.

If the manufacturer does nothing with the suspension after adding the mass control ring, only two T/S parameters are changed; The Fs, which will go down, & the Qt, which will go up - the Vas should stay the same. Hope this helps, Adrian - I'm sorry I can't help you with the rest of your questions :-(

Thanks for the reply. I think I understand it - the mass ring is placed in the neck of the diaphram, so that LF gets deeper and HF isn't sacrified. Is this it?

Is these rings placed inside the neck, or could I say its like being placed in the voice coil former? If so, then its not a part of the basket, and that would mean the 2225 and 2235 baskets are exactly the same, because the mass ring is placed on the diaphram. So if I buy a 2235 recone kit, it should have these mass loading rings? Or at least have the mass increased in a simlar way?

Thanks!
Adrian

The ring is usually placed on the diaphragm (at the backside, I think) right where it's attached to the voicecoil former. That's where it can be placed with the least possible influence on the HF response. And no, it's NOT part of the basket, it's a part of the moving system.

But remember, this will change the units HF behaviour - the gluing solution I mean! But as far as I recall, you cross-over pretty low, so I doubt it will be a problem - but you do need to know how much mass is needed. And don't forget, the overall efficiency of the driver will be reduced - the usual battle between LF extension & efficiency.

Having not tried the trick with gluing added mass to the centerdome myself, I hope somebody else will chime in about experiences in this regard. Oh & I need to remind you, gluing things to the drivers centerdome will increase it's moving mass, but NOT it's re-sale value ;-)

• http://www.aftermarketdiaphragms.com/jblafreckit.html

I found a place which has genuine recones here in Australia, but they are $395 each and the non-genuine is just $200 each. Almost double the price. So I think its wise if I just go for the pair of 2225's all assembled which I luckily found, and they use original cones.

Thanks again!
Adrian

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