JBL 4345 CNC'd new build

[atilsley]

Pristine components, making this new large build.

Euro birch, with Oak finish (not yet stained).

Kenrick Sound style stands in matching Oak.

JBL blue is a challenge....this client wished for a brighter blue, Dulux Wingman Blue.

Many many hours of work.

Massive 3 way xover, with DSP active bass.

Andrew

[atilsley]

Additional pics with xover. DSP used for bass (Bryston amps).

The pic with stands had the white ports before painting.

Needing to do final sanding then "ye olde" bees wax finish.

Andrew

(PS, these available in CAD/CNC files, flat pack kits...world wide shipping.)

[Ian Mackenzie]

Nice work

[atilsley]

Nice work Thanks Ian, a fun journey. I did not have all the gear to run multiple amps....but I did test the rig...wow, great output, lovely clean/tight sound.

[just4kinks]

Please tell us more about your CNC setup. You stick plywood in one end and speakers pop out the other?

[atilsley]

Please tell us more about your CNC setup. You stick plywood in one end and speakers pop out the other?

Hi, I'm a little unsure of your comment, kindly.

I used the JBL dims to CNC the original 19mm ply baffle. Then I added a further 3mm MDF baffle, which was glued onto the original ply baffle.

I then "adjusted" the rear of the rear of the baffle by routering to ensure accurate depth of mounting the horns.

Ideally, this should have been completed with the original ply baffle (which was painted in expensive two pack poly), but I made a mistake in mounting the tweeter. As such, the "original" baffle had four incorrect holes drilled. The client, naturally, was not happy.

As such, I CNC'd a new front "skin" in 3mm MDF, then repainted in same two pack poly blue.

All good.

Does this answer your inquiry?

Kindly

Andrew

(PS, with CNC, I now can offer all of the famous JBL monitors in CAD/CNC file, or kit form, or fully built.)

[DES-1]

Nice work!

I don't understand the need to add a 3mm MDF front to the baffle, when a 19mm baltic birch (3/4") is the spec.

[atilsley]

Nice work!

I don't understand the need to add a 3mm MDF front to the baffle, when a 19mm baltic birch (3/4") is the spec.

Des, as I wrote below -

".....but I made a mistake in mounting the tweeter. As such, the "original" baffle had four incorrect holes drilled. The client, naturally, was not happy." Quite a lot of work to correct 4 small holes, but worth it in the long run.

See the pic below with the speakers on the stands...look closely at the tweeters...the square bracket is incorrectly placed on the front of the baffle, not the rear...hence the additional screw holes in error.

One good thing came of this, I drilled 4 magnets into the "original" baffle to support the grill frame (also with magnets). The 3mm MDF new skin then covered the hidden magnets....and is thin enough for them to work equally as strong.

[DES-1]

Ah, OK, thanks for the explanation. Many would have just filled the holes filled the holes and adjusted cosmetics until undetectable. Your fix looks great though :thmbsup:

[gdmoore28]

Brilliant work, Atilsley! Those look great.

GeeDeeEmm

[Ricpan]

Brilliant work, Atilsley! Those look great.

GeeDeeEmm
Great Job, I would like to know more about the crossover.

[atilsley]

Bees wax added, grill frames built...hidden magnets (behind 3mm "front" baffle). I like the Oak veneer.

[atilsley]

Pair polished.

[DES-1]

That's a nice look, squared front and flush grill :thmbsup:

[atilsley]

That's a nice look, squared front and flush grill :thmbsup: Thanks for your kind remarks.

The front is not really 'square,'....the Oak trim is angled....but the photo doesn't show it up very well.

I wasn't sure why the original grills needed to protrude so much...hence flush.

[atilsley]

Great Job, I would like to know more about the crossover.

I'll need to inquire from the client...I wasn't sure if followed the original schematic, or started with something new.

Certainly the big difference is it is passive for top three channels only...with DEX active for bass.

I've listened to the bass with my crappy amp....fantastic output.

[Dr.db]

Very clean finish!

[BMWCCA]

I wasn't sure why the original grills needed to protrude so much...hence flush.

Umm, for the defraction lens? What lens are you using?

Nice work!

[atilsley]

Umm, for the defraction lens? What lens are you using?

Nice work!Um, I don't think the client is intending on using a separate lens. Certainly, the speakers were sounding pretty good when I was testing them....

[DES-1]

Owner's choices are interesting and to my limited knowledge seem reversed ... Bass active yet upper frequencies passive, and no lens. But I have no doubt they play magnificently and based on the quality of design and execution, would wager they are sonically every bit as good as OEM or Kenrick.

[BMWCCA]

Um, I don't think the client is intending on using a separate lens. Certainly, the speakers were sounding pretty good when I was testing them....
Maybe you could continue testing them in the new owner's home and maybe try an A—B with and without a lens and let us know what you think?

Again, beautiful workmanship. :applaud:

[Ian Mackenzie]

Hi Andrew,

Don’t feel obligated.

There has been curious and at times robust discussions in another thread on the lens on lens off situation.

[BMWCCA]

Don’t feel obligated.
I wasn't implying or suggesting an obligation. I was simply replying to the Original Poster's statement:
"I wasn't sure why the original grills needed to protrude so much...hence flush."
:thmbsup:

[hjames]

They are a gorgeous pair of monitors!
Really great work

[DogBox]

Hi Andrew,

Really nice work on those 4345's! :applaud:

Just wondering if you had thought about "other" models like the 4343? The 4344 is the same size physically but

has a different front baffle layout and other slight differences. A Full Design working set of drawings and assembly help

was done by another member which is 24 pages long (24.9 MB) http://www.audioheritage.org/vbulletin/showthread.php?13237-4344-Production-Plans/page2 and

hopefully that link will give you the page to download that file. Hope it still works! :blink:

See what you make of it...

Kind Regards,
DogBox
[Steve]

[DogBox]

Thanks for your kind remarks.

....the Oak trim is angled....but the photo doesn't show it up very well.

...the original grills needed to protrude so much...hence flush.

Hi Andrew,

Do you have the 4343 or 4343B on CNC file ready to cut? How much does a Flat-Pack of a Stereo Pair work out to be? I am VERY interested!

I didn't know the Tasmanian Oak did mouldings "like" that front edge..?? Isn't that cool!

The JBL 2308 Lens is the better way to go unless you want to get "radiated" by the high frequency that comes out of that Horn! The lens tame's it down nicely. "So"

you need the front Grill to be that deep. I think they also add a sense of "what's under there??"

Look forward to your reply

Steve

[atilsley]

American Walnut over birch ply.

[Mr. Widget]

Looking great... I rotated your images. They look even better that way! :D
Look forward to seeing them with a finish on them and populated with their drivers.


Widget

[Ian Mackenzie]

Excellent

[atilsley]

Pic of one cabinet polished with wax then buffed.

[grumpy]

Very nice. Inspirational, in fact.

I -really- need to make working space in the garage and get going before George comes and kicks my butt!

[carpediem]

Wow, they're pretty. The sounds probably as good as the look,

[Kay Pirinha]

How did JBL fasten these tweeters in the 4345's? Did they drill blind holes into the baffle's back and use propel nuts?

Btw, splendid craftmanship, to both :applaud:!

Best regards!

[DogBox]

How did JBL fasten these tweeters in the 4345's?
Best regards!

Hi Kay,

The 2405 UHF driver, http://www.jblpro.com/pub/obsolete/2405.pdf [sorry, wanted to use a picture but it's the next best thing :o:] was put into the cabinet

from the inside and the four mounting screws inserted from the front to screw into the square mount plate. The ones you can see in/near the rounded corner

plate. The HF Horn's were mounted in a similar fashion. Hope this helps.

Kind Regards,
DogBox [steve]

[Kay Pirinha]

Of course it does, Steve ;)!

Then the wrong holes (by atisley) might be interpreted as too large in diameter or in the wrong places, I assume?

Best regards!

[mortron]

I love seeing all these 4345 builds. I'm curious as I've seen a few mentions of them... Are there a set of CAD drawings or files for CNC available online? Or are all of these CNC builds from one off sets of plans?

EDIT: found them. Apologies.

Great build. Love the veneer you folks are getting too. Great grain and figure.