Bad 2235H?

[Rolf]

I am talking 700W (8ohm) to each woofer. 800W to four is only about 100W a woofer in 8ohm. Not much.

The Crown K2 pushing a 4ohm load is 800w to four 2235's

[rusty jefferson]

I'm not so sure it's just the watts per woofer, but the quality. The bridged Hafler I described earlier was outputting about 750 watts, but didn't have the headroom [?] of the Parasound [630 watts] or the Crest [only 500 watts]

[Loren42]

I am talking 700W (8ohm) to each woofer. 800W to four is only about 100W a woofer in 8ohm. Not much.

That would depend on how the drivers are wired, but generally, solid state amps put greater power out as the impedance drops.

[4313B]

It is quite easy to hit the mass ring in a 2235H with an improperly built enclosure. The problem arises when DIY folks use the 2235H improperly.

In the JBL B380 enclosure the BX63 "protects" the 2235H below enclosure resonance with its 25 Hz high pass filter. In the JBL Studio Monitors with the 2231H and 2235H, JBL always advocated using a 30 Hz high pass filter and the 5234/5235 had one. In both cases, mass ring issues were minimized as much as possible.

JBL frowns upon the mass ring these days. It is quite unpopular. It was used in the 121, 124, 2203, 136, 2231, and 2235. It is on the same plane as the spider so if one is hitting the mass ring they are also hitting the spider and mechanical failure is imminent.

Like I've said a hundred or more times, the 2235H likes a 4.5 to 5.0 cubic foot box tuned to 30 Hz. Anything bigger and/or tuned lower (especially without a high pass filter) invariably ends in compromised performance.

[spkrman57]

Without the mass rings I believe the 2234 would be more suitable for some higher level applications with very little LF loss compared to the 2235 is the design is done properly.

Ron

[rusty jefferson]

.
In the JBL B380 enclosure the BX63 "protects" the 2235H below enclosure resonance with its 25 Hz high pass filter. In the JBL Studio Monitors with the 2231H and 2235H, JBL always advocated using a 30 Hz high pass filter and the 5234/5235 had one. In both cases, mass ring issues were minimized as much as possible.

Do you think my original [Hafler] amplifier wasn't actually the culprit with my B-380/bx63-a ? I have always assumed that even though it had plenty of power [700 +watts] it couldn't control the driver during those demanding peaks. Again, once I changed to a more modern high current amplifier,[500-600 watts] the spl increased and the speaker never "popped" again.

[4313B]

Do you think my original [Hafler] amplifier wasn't actually the culprit with my B-380/bx63-a ? I have always assumed that even though it had plenty of power [700 +watts] it couldn't control the driver during those demanding peaks. Again, once I changed to a more modern high current amplifier,[500-600 watts] the spl increased and the speaker never "popped" again.

Amps that can't control four-inch voice coils are definitely a problem. We've talked about this quite a bit too.

[Loren42]

It is quite easy to hit the mass ring in a 2235H with an improperly built enclosure. The problem arises when DIY folks use the 2235H improperly.

...

JBL frowns upon the mass ring these days. It is quite unpopular. It was used in the 121, 124, 2203, 136, 2231, and 2235. It is on the same plane as the spider so if one is hitting the mass ring they are also hitting the spider and mechanical failure is imminent.

Like I've said a hundred or more times, the 2235H likes a 4.5 to 5.0 cubic foot box tuned to 30 Hz. Anything bigger and/or tuned lower (especially without a high pass filter) invariably ends in compromised performance.

The big difference between the 2234H and 2235H (besides cone mass) is the 2235H gives you an audio warning when Xmech is reached, whereas the 2234H does not annunciate that it is about to self destruct.

[Russellc]

If you don't play your system at very loud levels with subsonic bass, you can get away without a filter. I have a 15 Hz filter on my Marantz 3650 which should protect my 2235.

I play it plenty loud. When listening in the garage. (several rooms away)
it will be hitting over 100 db and louder, no problems.

russellc

[Russellc]

Like I've said a hundred or more times, the 2235H likes a 4.5 to 5.0 cubic foot box tuned to 30 Hz. Anything bigger and/or tuned lower (especially without a high pass filter) invariably ends in compromised performance.

This is the recipe I have, JBL 4507/4647 box, between 4.5 and 5 cu ft, with either one (34 hz ) or two (30 hz) of the four vents plugged. Plays loud, nothing hits the pole piece, even when flat Jamming!

russellc