JBL K9800 /Be project

[cooky1257]

Over the next month I'll post photos of this new JBL driver project I'm in over my head on.
150L dual ported, fully active, 15" ME150H Bass, 1.5" 2452/4" Be comp on H9800 horn

 

[Space is the Place]

What happened to the Array replicas?

 

[cooky1257]

The Array clones returned to full JBL driver compliment(2235/2435be) are shrinking down to a 100L IB to fit in the TV/cinema room.
The Precision Devices15" drivers are now for sale-the JBL ME150 is a monster of a bass/mid and out performs the PD(though at 3x the price.)

 

[cooky1257]

 

[martin clark]

Good heavens; that's fabulous. I would really like a listen!

 

[cooky1257]

Anytime you are on the Wirral, you are welcome Martin.

 

[Mr_Sukebe]

Are they now finished? If so, they look stunning. Heard a pair of the real ones last year in Thailand. Awesome would be a reasonable description.

 

[cooky1257]

Some minor cosmetic finishing to be done but they are finished and sound fabulous.
Better than the Array clones in the bass and low mids, the ME150S driver is incredibly articulate, mid /tops sound very similar with the vertical SAM 1 horns giving slightly better(?) stereo imaging.

 

[Paul R]

I don't know what I'm looking at, but it looks good.

Paul

 

[cooky1257]

It's a loudspeaker Paul.

Loosely based on the JBL K2 9800. it is an active 2 way, 15 inch JBL ME150H bass/mid crossed(for now) @800hz 24LR to a JBL 2452H compression driver with Truextent 4" Beryllium diaphragm on a Birch ply/mdf reproduction h9800 horn.

Sensitivity is 97dB/w, the curved sided enclosure is mostly 25mm mdf extensively braced, has a 60mm front baffle, rear ported, 150L tuned to 30 hz.
The horn throat was modelled in SolidWorks then cnc milled, the rest of the horn was constructed from layered birch ply planed and sanded to a template. Front and top are finished in leather, side panels are American walnut.

 

[Paul R]

I wasn't sure whether there was something clever going on on the top.

Anyway a proper project properly executed. If PFM had a kudos button I'd be pressing it.

Paul

 

[cooky1257]

I wasn't sure whether there was something clever going on on the top.

Anyway a proper project properly executed. If PFM had a kudos button I'd be pressing it.

Paul

Thank you.
The curvy top is mainly for looks but the front slope could accommodate a super tweeter later....

 

[amdismal]

That's a beautiful look you have there, really well finished.

How are the 2452s higher up? I have a general rule of thumb not to expect too much accuracy from a 1" compression driver above 10k, but JBL claim 20k. Do they sound OK up there?

 

[cooky1257]

That's a beautiful look you have there, really well finished.

How are the 2452s higher up? I have a general rule of thumb not to expect too much accuracy from a 1" compression driver above 10k, but JBL claim 20k. Do they sound OK up there?

Thanks,
They are 1.5" optimised aperture (no throat), the first break up of the 4" Be dia is at 26k, they start to roll off at about 18k but I roll them off at around 16k in any case-sweet as anything if you don't push them. The DD6600 runs the 476Be all the way out to 20k.

 

[Dev]

Good job Frank.

 

[cooky1257]

Thanks Dev,
I'll post a step by step soon.
How are yours coming along?

 

[Dev]

I haven't even started Frank. Every weekend the boss seems to find things for me to do. . Hopefully soon.

 

[cooky1257]

I haven't even started Frank. Every weekend the boss seems to find things for me to do. . Hopefully soon.

Ho ho, my 'boss' was in Florida for 4 weeks while I destroyed the dining room.....soon then eh?.

 

[RobsterD]

great stuff Frank,shame I'm too far away would love a listen.

 

[cooky1257]

great stuff Frank,shame I'm too far away would love a listen.

Cheers Rob, I'll put up more pics if there's enough interest.
They are sounding pretty darn good(thank god!).