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Niklas Nord
04-26-2003, 07:44 AM
Today i recieved two 2235H 15inch drivers in excelent
condition. One of them was black painted, and the other
is gray on the basket.

wery interesting.

Is the massring UNDER the dustcap ?

Niklas Nord
04-26-2003, 09:33 AM
yes that would be great!
pictures that is

Niklas Nord
04-26-2003, 03:55 PM
GREAT!!

Itīs not big, but it makes a difference though!

Niklas Nord
04-26-2003, 04:10 PM
You mean 30 grams i presume

Niklas Nord
04-26-2003, 04:13 PM
I thought you ment the massring, was it not 30 grams?

if you take the massring away, is it a 2234 then ?

Earl K
04-26-2003, 06:09 PM
Hi Rob

I have TAD cut sheets that suggest that the weight of the moving parts won't necessarily equal Mms. TAD actually used to give a Mms spec & a Mmo spec. The Mmo spec was the weight/mass of the diaphragm assembly on it's own while Mms additionally included a projected weight of the air load.

How many different mass rings does JBL now offer ? Are there 3" versions available ?

A buddy of mine wants to turn his 2204 woofers into more of a HiFi variant . If I can delaminate the whole assembly from the basket I may suggest he fudge up a pair of 2203s' by adding mass rings with a high compliance surround . Would be a real shame to toast the original voice coil ( also .75" deep ) and a perfectly good cone that can, if necessary , be surface treated to raise stiffness.

regards <. Earl K :)

sa660
04-28-2003, 05:59 AM
Earl,

I am reading your reply with the 2204 change into a 2203.
I was looking at the specification of both 2204 and 2203. But could not see enought information to see if both magnet assemblies are identical. I then looked at the JBL website to see the cost of new 2203 cone to see a whapping $250 each.
I was looking at buying 6 2204 and change 4 of them into 2203.
It will be easier to use 2235.

What are the pros and cone between 2203 and 2235 apart from power and efficiency?

Let me know what you think please?

Thanks,

Earl K
04-28-2003, 03:14 PM
Hi Richard

I don't recommend buying 2204 woofers to turn into 2203s ( unless they are virtually free ). As you just pointed out, the recone kit plus labor costs make it really prohibitive. The present cost of 2235 cone kits make it a much better candidate for reconing surplus baskets into useful subwoofers .


Re; the 2204-3. My friend already has his 2204 woofs. My musings are to try to help him turn them into a usable HiFi woofer. The existing stiff compliance and light Mms ( 57 gram ) combine to give a pretty high Fs ( 45 hz ). Our goal is to lower Fs some buy adding mass & maybe loosening up the compliance. This is a very long term project and the "water into wine" approach may not work out He's on the road now and only mentions salvaging these things for HiFi use after he's listened to my le14/le10 combo.

Havng said that, Giskard is the expert on the 2203 . He has in past forums quite eloquently framed his criteria for choosing a woofer based on the realities of ones' available real-estate or floor space . Maybe he'll repeat that for you. My memory isn't great on this, but I believe Rob G also stated he wouldn't use a 2203 up to the typical croosover point of a horn driver ( ie something about the 4315 - best used either as a sub for below 100 hz or maximized for above 100 hz - ) .

Do you have any Prediction Software for tuning enclosures ? If you don't , you should get some. In mine ( MacSpeakerZ ) , the extremely low Qts of the stock 2203 gives some pretty odd looking curves in the pass-band area when it's tuned for LF extension. Those curves in themselves may turn you towards using 2235s as subs below your E145 speakers. The 2235 always tunes quite nicely and does have decent midrange quality and linearity in the pass band ( if you want to retire the 145s for a while ) . One can always add an 8" or 10" to also improve the 2235s' midband.


What is the nature of your proposed project ? Was it to be a fudged "Twin Vertical" type a la the K2 S5500 or 5800 ? ( with the horn in the middle ) If it is, then read the info posted in the Lansing Library for the K2 S5500 (http://www.lansingheritage.org/html/jbl/specs/home-speakers/1993-k2-s5500.htm) . You'll notice the voice coil sizes are 3" for both the le125s ( S5500 ) & the Fe1200 ( S5800 ) with deep top plates /gaps for extra motional control. JBL moved away from 4" voice coils for these smaller K2 speakers ( probably to raise Qts ). It looks to me the motors for these 3" coil K2s are directly related to JBLs' 2000 series of transducers. Check out the cut sheet for the 2020 12" . That's one impressively powerful motor - but , for HiFi use needs an appropriately weighted cone / with high compliance surround for LF extension and midband linearity .


If it was me, I'd just add 2235 subwoofs below the components you already have. That satifies another important criteria ( EOE ). That's "economy of effort" to get to good listening .

best regards <> Earl K