2225, 2235 mass control ring?

[jbl]

hi,
this is my first post. does any one out there know if the 2225h/j woofer use the mass control ring? the jbl lit i have makes a big deal about it in some of their lit, in others , they don't mention it.
i have seen this in the 2235. when they do mention it, they state that it offers better control at about 1k. what advantage/disadvantage is there?
in my system (4671) the 2225 (8 ohms) goes up to 800hz where it is crossed over to the 2425 using a 3110a crossover. the 4430 (2235) goes up to appx. 1k, then to the 2426. in my system the crossover is seamless. when i heard the 4430 there was a boom around the crossover frequency.
any one out there noticed this?

thanks

[Tom Loizeaux]

I don't know anything about the 2225, but there have been a large number of posts about the 2235 and mass rings (the 2234 is the 2235 w/out mass ring). Others on this forum are more informed than I, but my understanding is that mass rings slightly weight the cone causing a very slight reduction in output, slightly reduced higher frequency response, but smoother lower mids and improved bass response over the same driver without mass rings. JBL says the mass rings make the drivers more linear.
Hope this helps.

Tom

[Guido]

Tom is right!

The massring does not improve high end but low end. E.g. the 2225 cone weighs 105 gram, the 2235H cone weighs 155g. Equal to 50 grams massring.
I can't confirm any hump in the response of the 4430 around 1 kHz. Are you shure with that? Was the 4430 all original?
Which jbl lit do you mean?:confused:

[4313B]

List of JBL transducers that employ a mass controlling ring.

[GordonW]

Huh, the 122A shows a mass ring? I guess I wasn't so far off, making up a 10 gram mass ring, to go on the 128H kit I used to recone the last 122A I just did! Though, there wasn't a ring on the original 122A cone- just an EXTREMELY THICK layer of Aquaplas... maybe that was a production "alternative" JBL used?

I'm postulating, that the factory mass ring on the 122A is probably about 10 grams... that seems to be the difference between that cone, and the 129H, 128H and 128H1 cones...

Regards,
Gordon.

[sa660]

JBL,

If you are used to listen to the 2225 you may be used to hear a drop in response around that frequncy point.
I would beleive that the 4430 are more linear than the 4671.

Regards,

[jbl]

hi guido
i will check the code on the back side of the jbl product lit. that code states the production year. as i have stated, some spec sheets mention the mass control ring, while others do not.

[jbl]

hi sa660
there really is no drop in response or output (that i can hear) at or around the crossover frequency. that would really depend more on the room than the 3110a. on the other hand you may be correct in your assessment. the 3110a has a three position switch for the mids and a three position switch for the highs. i use both on the center setting. this applies a slight boost at these settings. i never tryed the other settings or combinations.

jbl