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View Full Version : JBL 4333's or 4355's? Or??...



Challenger604
04-12-2016, 06:36 AM
Hi all!

Because it will be very quiet for me this summer again, I will have a lot of time to kill!

For this reason, I would like to know if anyone would be interested in 4333's or 4355's that I can build for.
Only the cabinets!!

This proposition is for North America only! Except if serious deal with Europe.
For the US, shipping would be made from the US.

If SERIOUSLY interested, please PM me.

Christophe

PS: If you read "SERIOUSLY" and you are not SERIOUS! Please, don't insult me! I don't work for free!

Don C
04-12-2016, 12:06 PM
If you want to be really busy, maybe you could offer to build M2 clones.

Challenger604
04-12-2016, 12:47 PM
If you want to be really busy, maybe you could offer to build M2 clones.
That is a pretty good idea!!!
Thanks!
C

hsosdrum
04-12-2016, 05:11 PM
If you do build M2 clones, I strongly urge you to not delete the front baffle step between the woofer mounting area and the lower baffle (where the ports are located). The step is NOT a cosmetic treatment—it was added to the baffle by Alan Devantier (the engineer responsible for the M2 cabinet design and the M2's over all system integration) during testing to deal with response anomalies in the 500Hz region (revealed in Harmans "spin-a-rama" anechoic testing) that Devantier determined were caused by reflections on the (originally flat) cabinet face. Adding the step eliminated the reflections and improved response in the 500Hz region. It made the cabinet (and the final M2 speaker) more expensive, but was necessary to achieve JBL's desired performance goals.

BMWCCA
04-12-2016, 05:19 PM
If you do build M2 clones, I strongly urge you to not delete the front baffle step between the woofer mounting area and the lower baffle (where the ports are located).
Are you referring to the recessed woofer baffle? The bottom (port baffle) and the top (wave guide) seem pushed out just to make the grille fit flush. Was the wave-guide originally stepped-out, too, or was it done for an acoustic reason or to match the port baffle? :dont-know:

hsosdrum
04-12-2016, 06:40 PM
Early in the M2's development the portion of the baffle where the 2216nd mounted was flat all the way to the bottom of the baffle panel (the waveguide was always proud of the woofer baffle). After uncovering the response anomalies and determining their cause, Devantier re-designed the woofer baffle with the lower baffle area proud of the woofer mounting area, which eliminated the anomalies. I know this because after seeing the initial prototypes with the flush baffle, Alan showed me a later version with the step. I asked him why he added it, since to my mind the step would cause diffraction, and he explained that the stepped baffle actually eliminated response anomalies in the 500Hz region without causing any audible or measurable diffraction effects. (Which in hindsight makes sense, since the wavelengths at the top of the 2216nd's operating range in the M2 are around a foot long, too large to be affected by the baffle step.)

So if it's a true M2 clone you're after, you need to include this stepped baffle—it's there for performance reasons.

BMWCCA
04-13-2016, 10:40 PM
Thanks!

grumpy
04-14-2016, 07:57 AM
So nice to see a useful/helpful post. Thanks hsosdrum.

hsosdrum
04-15-2016, 04:12 PM
So nice to see a useful/helpful post. Thanks hsosdrum.

You're most welcome. The M2 is one of the few JBL speakers that I feel qualified to offer insight on. When I worked at Harman I was one of many who took part in listening evaluations of the M2, so I was able to hear it evolve into what I consider the most accurate speaker available today. I also wrote the M2 user manual, although I did that as an independent contractor (Harman had axed my department a couple of months prior). And while Charles Sprinkle was developing the Image Control Waveguide he and I engaged in dozens of discussions about what he was doing and why he was doing it. Jerry Morro and Greg Timbers also explained to me the performance benefits of the aluminum VC wire in the 2216nd, but I didn't take notes (I figured I could always get back to them with questions), so I'm not as sure of those specifics as I need to be to speak authoritatively on it.

One thing I am sure of is just how neutral the M2 sounds to me. In all my 39 years in the audio business (including 30 years making my own recordings) this is the only speaker that has ever made me feel like I was hearing exactly what is on the recording, with the speaker taking away nothing and adding nothing of its own. The first extra 20 grand I get, a pair of them and a couple of Crown amps will be in my studio. (Of course, the operative word here is "extra"...)