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Ian Mackenzie
10-13-2003, 05:56 AM
I thought is appropriate to start a new thread to illustrate and document the progress on building this monitor, or more correctly adapting my existing JBL boxes to the 4345 spec.

As the title of the thread suggests, Bo the damm Yankee from parts unknown is the catalyst for the idea, having published the dimensions in the 4345 plans thread elsewhere.

So where am I up to? Don't ask me, not exactly sure, but my back aches and I need an assistant.

O'kay here are some of the tasks: The 39 Steps

1. Sketch & sign off drawings for baffle cut-outs (done)
2. Purchase Jasper Jig and 1/4 in router bit (done)
3. Purchase 18mm Mdf materials (done)
4. Plan sequence of baffle fabrication and overall project
assembly (done)
Make jig frame for holding baffles (done)
Cut baffle circles (top layer then bottom layer - done)
Drill driver mounting holes (done)
Cut 18 mm MDF for Dog boxes (done)
Screw & glue dog boxes to 2nd MDF layer (done)
Laminate top and bottom MDF layer with PVA glue using a
dozen or house bricks for a press (done 1 baffle)
Clean, trim and sand & apply undercoat to finished baffles

5. Amend height of existing cabinet & volume by 6 inches (done)
6. Cut out existing baffles & make rear access opening
Drill screw holes for baffle mounting
Re paint cabinets with 2 pack Dulux effects paint finish (Arab
Sand effects paint)
7. Clean & vacum cabinets and fit new 3/4 inch fibre glass fill

8. Wire and fit crossover
Purchase 6 new x 100 watt faders (done)
Purchase Holvand capacitors for all horn filters (done ouch)
Assemble crossovers
Wire and calibrate faders with std JBL test jig
Fit crossovers in sealed sub enclosures

9. Fit new baffles, glue and scew
10. Fill screw holes, clean and paint baffles
11. Fit drivers

12. Check for air leaks & vibrations using low frequency sine
wave tones via Phase Linear 700.
13 Test, measure and evaluate new boxes (pray)

The list is my no means complete, with special jigs and processes being thought out as each step is taken.

Obviously this is not a weekend project, I'm down to task 5 or thereabouts, and there are plenty of new and sometimes daring challenges along the way. Photos are being taken as the project creeps forward.

So far touch wood, there have been no major issues, although cutting the top of the existing boxes was a painful, in more ways than one...:banghead: Muhahahahahaha

The stouter boxes are more waf friendly I have to report and perfect elbow height for a beer tasting says I.

More news shortly...here is an early version of the baffle drawing:

Ian

:smthsail:

Ian Mackenzie
10-13-2003, 06:05 AM
The earlier cabinets:

Ian

Ian Mackenzie
10-13-2003, 06:09 AM
The 4345 cabinets we are now so familar with:

Ian

boputnam
10-13-2003, 10:44 AM
Man, you are goofy to attribute any credit in this to me! You're the 4345 Clone Slave - not me! I'm mighty glad to be able to help-out with a few measly measurements. But even in that, it took me an extra week to get a dang metric tape! :rotfl:

I can tell you, there's been more than once I wanted to remove all them transducers and get some real answers for you. If you'd have come across, we coulda done just that, over a few bottles of Shiraz Blend... Your plan looks real good - and I now the actual one is precise.

Here's what's on my list:

1) Get home during the day to drag the 4301B's to the paint store and model that JBL Blue for your baffles.

I think we'd all be interested in what the total materials cost, is pard', when you're done. Might help relieve some eBay hubris, and get people to buy the cabinets they long for! IMHO... ;)

Keep your ear muffs on, hey?

4313B
10-13-2003, 10:49 AM
"Get home during the day to drag the 4301B's to the paint store and model that JBL Blue for your baffles."

'bout time! :D

I need twenty or thirty gallons of the stuff to paint my house with :)

Ian Mackenzie
10-13-2003, 01:36 PM
Cheers Bo,

"I can tell you, there's been more than once I wanted to remove all them transducers and get some real answers for you. If you'd have come across, we coulda done just that, over a few bottles of Shiraz Blend... Your plan looks real good - and I now the actual one is precise."

Don't worry there will a few bottles of red drunk when this job is done.. and when I rock over your way a few more....muhahaha.

As for materials to construct the baffles and make alterations its run up to AUS $150.00 incl safety goggles. Setup cost for Jigs and router bits etc about AUS $140.00.

I esimate the cost of the crossovers (using Hovlands, AEON & 100 watt faders) is about $400 in parts, the drivers, well we can all guess that one...muhahahahah

To make the boxes with 1 inch MBF for the cabinet walls is about $30 a metre here so I would guess 6 metres or another $180. Plus 10 metres of F17 hardwood for bracing., scews glue etc, sweezers for splinters etc about $50.00

The means or tools of trade which are precison like the (USA) Jet Table Saw and Porter Cable Router are another matter. Plus the experience on hand from one who knows is hard to come by.

My previous two attempts on the baffle color have failed, thougth I was in the Greek Islands with the last effort. Whats is the colour called ..JBL blue

Ian

Ian Mackenzie
10-19-2003, 02:38 AM
A short update.

Nearly completed the both the baffles today.

Just need to fix the hardwood frame edging around the baffle and taper with the router.

Its looks very good and no mishaps thus far (touch wood)
Taken 18 photos (sorry only normal Nikon) and will arrange work in progress photos in a day or two.

Querry: The little plastic adjustment (tweekers) on the JBL level pads. Does anyone know the JBL part number or have any spare they don't need??

regards

Ian:smthsail:

4313B
10-19-2003, 07:08 AM
"Querry: The little plastic adjustment (tweekers) on the JBL level pads. Does anyone know the JBL part number or have any spare they don't need??"

52192

From the latest Pro miscellaneous parts list -

52192 - KNOB BLK DPTTED *52191 $2.40 USD EA

boputnam
10-19-2003, 08:23 AM
Originally posted by Ian Mackenzie
Just need to fix the hardwood frame edging around the baffle and taper with the router. That is something Widget and I worked on to get close-as-possible to original. I don't know if you're trying to do the same, but if so, here a crude image I worked=up in Paint for Widget (he's yet to come down to collect his own measurements... ;) ).

And, er, uh, it's Imperial. :)

Ian Mackenzie
10-19-2003, 01:15 PM
Thankyou (both),

Like the drawing Bo,

This is the sort the thing I am looking at, it will be very similar if not identical..

Here's an interesting statistic from the project: 6 buckets of saw dust.


Ian:smthsail:

Ian Mackenzie
10-25-2003, 11:49 PM
Cut out around the old baffles yesterday,

Two inches of mdf was a bit of an ask the the junior power saw. Will have to hand saw through the remaining hard wood bracing which is over 4 inches deep from the surface on some areas.

Will post some pics shortly.

Ian:smthsail:

4313B
10-26-2003, 06:57 AM
Originally posted by Ian Mackenzie
Just need to fix the hardwood frame edging around the baffle and taper with the router.
Have you considered abandoning recessed baffles and going with flush, rounded baffle edges such as used on the 240Ti or 250Ti?

Ian Mackenzie
10-26-2003, 01:25 PM
Yep,

I know the implications, l'm just following tradtion at the moment.


Its only a 10 mm recess in this insance and I intend to make some grill cover later( but can always plane down the recess)

Ian

Ian Mackenzie
10-27-2003, 02:44 AM
Here is a series of photos ..work in progress.

The first shot shows the Porter Cable router with Jasper jig attached, and the baffles mounted in a Frame Jig ensuring alignment of the centre holes.

The Frame jig was made of spare particle board and enabled precison and consistency during the complete circle cutting and laminating process. (Dad's idea...what are dads for.....)

Ian:smthsail:

Ian Mackenzie
10-27-2003, 02:55 AM
Next, nearing completion of the first of four baffle cuts and still gaining experience with the Jasper Circle Jig.

Ian:smthsail:

Ian Mackenzie
10-27-2003, 03:05 AM
Here the Dog box is being fastened securely to the rear baffle layer with PVA glue and 8 gauge screws. (the front layer will hide these fixing screws).

When I started measuring up and positioning the physical location of the Dog box on the baffle after cutting all the holes (7 of them)I realised how little real estate there was left on the baffle.

The Dog Box fits snuggly in a strategic location on the baffle and provides significant strength once fixed to the structure.

Ian:smthsail:

Ian Mackenzie
10-27-2003, 03:11 AM
Here, a shot of the reverse side of the baffle after laminating with the inset holes for the horn and slot flanges clearly visible.

The complexity of the baffles and the mirror image sets made organising the cutting mandatory to avoid costly and time consuming errors.

Ian:smthsail:

Ian Mackenzie
10-27-2003, 03:16 AM
Here is a view of the general work area.

An excellent well equiped workshop, clean with strong and spacious benches, great lighting and quality tools.

Ian:smthsail:

Ian Mackenzie
10-27-2003, 03:21 AM
The nearly finished baffle, waiting the hardwood frame and holes for the attenuators.

More pictures to follow,

Ian

:smthsail:

Ian Mackenzie
10-27-2003, 03:46 AM
Not quite the image in the 4343 brochure but tasty non the less.

Anyone for dinner? Anchors away.


Ian

:smthsail:

boputnam
10-28-2003, 11:21 AM
Beauty, step-by-step, dude. Very meticulous work! Lucky (or careful planning...) that MF doghouse cleared the baffle-cuts for the HF and UHF. I've had similar headaches in lesser projects - and truly, there is very little spare space on most baffles, at least on the backside!

Anxious...

Ken Pachkowsky
10-28-2003, 11:52 AM
I suspect these are going to look great Ian.

Nice Shop!

Are you using 2123H's?

Ken

Ian Mackenzie
10-28-2003, 12:46 PM
Bo the intent was not to make it look over the top....far from it.

But moreover appreciate what's involved in the assembly of the dang thing so anyone else contemplating the same can pickup a few clues.

Without a very good drawing (the plan) you would be stuffed with a job like this.

Ken, I'm using the infamous 2122H. The story behind this is a bit like Jules Verne's Nautilus, the parts have come from all over the world and are assembled by some mad man, but in this case its hardly a secret.:D

Ian

Ken Pachkowsky
10-28-2003, 01:48 PM
You were very lucky to find a pair of those. I suspect they are very difficult to find and would fetch a small fortune on ebay. Are the recone kits still available for the 2122H?

Ken

Ian Mackenzie
10-28-2003, 02:14 PM
Ken,

Yes these are lovely black Crabs....fit for any audio feast,

I actually found them on The JBL Pro Tent Sale a while back and have no intention of trading these. (shipped courtesy of Rob my good friend in NY....how are you Rob?)

The recone kits, to the best of my knowledge are still available.

There are other places to look for parts like Reconers classifieds. I've seen the odd familiar name from Lansing herritage over there.

Giskard as 4 2122H on the shelf...send him a PM.

Ian:)

Audiobeer
10-28-2003, 08:17 PM
Outstanding work! Tools make the difference don't they! What will the cost be to St. louis from your Island my friend?

Ian Mackenzie
10-29-2003, 01:08 AM
The tools are important, but also how to use them.

I spent 3 weekends practising with the plunge router and then several test cuts before starting the actual baffles.

Also pays to not rush this sort of job, one boo boo and your buggered.

I will have to count out the foot paces from here to St Louis and work it out;

http://www.explorestlouis.com/visitors/mileage.asp

Looking at this link its a bit of a hike, I mean to Bo the Yankees Palace of JBL (San Francisco, CA...) its 2,159 dang miles Man plus crossing the Pacific Ocean......A man could get up a fair thirst on a journey like that...better pack some home brew...(Thunder ale might even assist with a tail wind).

And I would have to think of my creature comforts, that means packing the Blonde for the journey...I mean imagine the excess baggage (worse than a pair of 4355's)

Ian:eek:

boputnam
10-29-2003, 11:57 AM
Originally posted by Ian Mackenzie
Looking at this link its a bit of a hike, I mean to Bo the Yankees Palace of JBL (San Francisco, CA...) its 2,159 dang miles Man plus crossing the Pacific Ocean......

And I would have to think of my creature comforts, that means packing the Blonde for the journey...I mean imagine the excess baggage (worse than a pair of 4355's)

Ian:eek: Yea, but me and the Widget could sure have some good fun on your visit! :yes:

Ian Mackenzie
10-30-2003, 02:14 AM
O'Kay,

Just as well we're flying to California first, I'm sure she will blend in quite nicely. (know one will even notice the speaker)

Ian:cool: :cool: :cool:

Ian Mackenzie
10-30-2003, 03:08 AM
Some late breaking News,

These just turned up in the mail from 9457S University Blvd #411, Highlands Ranch, Co USA 80126.

Guess the supplier and I'll email a life size image of the Blonde to the first correct answer. Muhahahahaahah.

Out with the Welbourne solder on the weekend.

Quantity two each of 3.0 uf @$15.00, 6.0 uf @$21.00, 5.0uf @$30.00 less a 10% discount (the 5.0uf were not on special). I also have some other Hovlands to complete network.

Ian:smthsail:

Robh3606
10-30-2003, 05:46 AM
Hello Ian

Now if the blonde showed up in the box with the caps!!:D That would be news! I would also be placing an order:yes: Nice caps the whole project looks like its gonna be a stunner. Keep the pictures comming!

Regards Rob:)

Ian Mackenzie
10-30-2003, 06:00 AM
Rob,

Well I already had 2 pair of Hovlands left overs from the 2344 crossovers so it seemed logical to complete the job here.

As the Black soldier in the movie Pretator said,

"I'm gonna have me some fun, I'm gonna have be some fun".....

Here is the link to those switches you very kindly sent over:

http://www.passdiy.com/gallery/bosoz-p1.htm

If you are looking for a top flight preamp....I am happy to assist
(it runs balanced and unablanced inputs and outputs..all highly bias @ 40ma in class A)

Hey, I'm trying to keep my eyes of all the nice JBL Goodies on E bay at the moment, Le10H, 2245s and the 4315's wooooee.

Ian:eek:

Robh3606
10-30-2003, 08:48 AM
Wow!!:eek: Ian you do some nice work! Lot's of good stuff up. Just got a pair of 2123H's to try out. Can't wait to get them. Without the passive crossover in the 4345/4344 you get a rissing response from about 800hz and up. For biamping with steep filters at 1.2K I have to notch it out. So I am hoping the 2123 will be "flat" in that region so I don't have to EQ them in the midrange like that. Let you know how it goes.

Rob:)

Ian Mackenzie
11-01-2003, 04:46 PM
Completed one baffle yesterday.

Looks good.

The frame around the baffle really finishes the job off nicely!

Its not exactly the same as the drawing posted by Bo, but none the less conveys the same impression.

We used scrap 46 x 90 mm hardwood and ripped it down to 46 x 25mm lengths. Mitre joints were not necessary (and a bastard to fit), we used butt joints as I will be painting the exterior (shock horror I know.....may even consider veneer at some stage...very expensive though).

So the frame sits about 10mm proud of the baffle, that's about 3/8's for you Yankees Boooooys. (If I make some frames later on, I'll fit foam inserts around the edges to soften any diffraction effects)

The frame was fitted after clamping, gluing and pre drilling with two inch nails (punched in). I then used the plunge router with a 45 degree bit and roller bearing. It was a bit of trial and error on a scrape length of timber to gauge the right depth.

I opted for about 16 mm depth in the end, that gives an obvious visible angle and still leaves some meat on the bone. I think cutting it almost to the inner edge like JBL did is a risk and would be prone to chipping and damage.

Unless anyone can tell more about the blue baffles I'll be painting them in the Dulux effects two colour finish (arab sand) with a sea sponge.

Ian:smthsail:

Ian Mackenzie
11-01-2003, 04:58 PM
This blue colour JBL use looks to have a ting of red in it.

I wonder is Giskard can tell us what's on the side of his paint can or what's in the mix. Hopefully its not a trade secret like Coca Cola.

Ian:)

(I realise this is not world best practice for colour matching...I'm just looking for ideas and feedback)

boputnam
11-01-2003, 05:48 PM
Doh! :banghead:

I'm having trouble getting to the paint store - the only qualified tech works weekdays only, and I can't get there in-time! Ugh! If you're pressed, I'll make some arrangements this week.

Sorry, JBL Blue Fans... :(

Ian Mackenzie
11-01-2003, 06:04 PM
Dude,

Painting will be a few Moons off yet, so don't race on nmy account.

I think we should just shirt front JBL and askem.

Any one know any one in The JBL Northridge paint shop.

It would certainly help a few of us out around here...is the paint lsited in the parts list...muhahahahaha

Ian:smthsail:

scott fitlin
11-01-2003, 06:06 PM
You might just call them up and ask em! They might tell you! tell em you want to paint your listening room JBL Blue.

Ian Mackenzie
11-01-2003, 06:35 PM
Why do they use blue baffles?


Ian

scott fitlin
11-01-2003, 06:44 PM
Someone must have thought it looked good!

Daniel B
11-01-2003, 07:10 PM
Ian,

Are you going to try and color match the grills too?

dB

http://www.studionoumena.com/clients/NewWork/usaf/images/BlueLine_detail.jpg

Ian Mackenzie
11-01-2003, 09:06 PM
Probably not,

But if anyone can point to a source of supply I will investigate further

In the mean time I will continue with my dream of using the Blonde's cheese cloth underwear...that should be very acoustically transparent...Muhahahahaha..ha ha.

Ian:smthsail: :p

Ian Mackenzie
11-25-2003, 01:25 AM
Sorry about the lack of progress updates but I have had a recent back injury which I have now full recovered so now back on the case.

Both baffles are virtually complete, made the rear horn driver supports last weekend.

Also in todays mail a nice surprise, some L pad knobs care of our resident JBL guru Giskard..thankyou so much for your assistance.

More progress updates shortly..

Ian:cool:

Ian Mackenzie
12-12-2003, 09:24 PM
Okay, some news

Today I am back on the job...too many projects not enough time.....so whats new.

Well, I have allocated today for heavy duty mods to the existing boxes.

The front panels are now out and in process of tidying up the innards.

If all goes according to plan both new baffles will be installed this time next weekend ready for finishing

Ian
Ian;)

Ian Mackenzie
12-18-2003, 12:42 PM
The original boxes are now been completely gutted awaiting installation of new bracing and batting.

This was necessary to accommodate the side ports and make provision for the rear access panel.

The more I prepare the cabinets the more I admire the way the original 4345 enclosures were designed, the whole is great than the sum of the parts.

The manner in which the internals are arranged forms a matrix of surprising rigidity.

Below is my best attempt at simulating (BassBox) the tuning of the enclosure/tuning (incl virtual volume) combination based on actual port dimensions and empirical data advised by GT.




Ian


:cool:

Ian Mackenzie
12-19-2003, 08:38 PM
Has anyone done any listening tests for crossovers in or out of the Box?

I read in the recent JBL brochures they isolate the crossover from the chambers.

But does this really matter? Are capacitor or chokes more prone to vibration interference?

To isolate the large iron laminate core chokes from each other and still have them in a small inner compartment is not practical so I may mount the parts in a section of MDF and scew down on the rear panel like previously

Any ideas?

Ian

Robh3606
12-19-2003, 08:43 PM
Hello Ian

Why not just put them outside?? That's where mine are L pads and all. They are not attached to the cabinets at all. They are wired into panel connectors on the back of the cabinets. I don't know if they are microphonic or not but outside it sure is easier to tweek them.

Rob:)

Ian Mackenzie
12-28-2003, 02:50 AM
More progress,

Today I put the 1st undercoat on the new baffles following a quite chat with our resident JBL paint expert Bo Putman.

The project is coming together nicely, the new stiffeners have been installed on one enclosure and I am pleased to say its rock steady.

My next task is to arrange the rear access panel.

For the sake of completeness, I have decided to mount the crossover in the original location (with the LF inductor mounted remote to the main crossover board). I may mount the smaller elements in a sealed 5mm clear perspex enclosure if removal of the board external to the box offers a subjective improvement

I have posted this image just to put these monitors in perspective, even along side the might 4355, it's still one kick arse loudspeaker don't you reckon. By the way that smaller box atop the 4355 is a 4312, not the 4311 so no rants please.

Ian:cool:

boputnam
12-28-2003, 02:52 PM
Originally posted by Ian Mackenzie
...I have posted this image just to put these monitors in perspective, even along side the might 4355, it's still one kick arse loudspeaker don't you reckon. By the way that smaller box atop the 4355 is a 4312, not the 4311 so no rants please. And, atop the 4345 is the meritorious 4301B, my favorite tyke of the 43xx series... :yes:

Ian Mackenzie
12-31-2003, 01:56 PM
Here are some low res snappy from the Pc Cam, no santa did not bring a new digital camera.

The baffles have been stopped up and undercoated ready for mounting in the main enclosures.

Today I plan to finish the wood work on the main cabinets and then start fitting the baffles.

Ian

Ian Mackenzie
12-31-2003, 01:57 PM
The front of the baffles....

Ian Mackenzie
12-31-2003, 02:11 PM
I have already starting thinking about grill covers and other projects like amps for the new boxes....(all we need is the fabric)

I was thinking about an X 350 or 600 for the woofers and X 200 for the mids, but that would be about 1000 watts class A dissipation per channel.......may have to install water cooling and a Zen fountain for a primary cooling tower (only joking)

Although I will actually build a X 600 this year as I am a firm believer in dynamic headroom, and to celebrate my visit to Passlabs in Northern Califorina around May 2004.

Ian :smthsail:

Ian Mackenzie
12-31-2003, 02:13 PM
Massive isn't it, they weigh 150 Ib each

Ian:p

jtgyn
12-31-2003, 09:08 PM
G'Day Ian,
Nice cabinet work!
From your photo it looks like you have sealed the back of the baffle with clear lacquer. Is there a reason for this?

Regards Scott

Ian Mackenzie
12-31-2003, 11:41 PM
Scott,

That is just effects of lighting and surplus dust from the spackle sanding, no lacquer here.

I propose not to paint the interior at all, but chalk all the seams and joints to ensure an absolute air tight enclosure.

In fact discarding the effects of the 3/4 inch fibreglass lining, I'm hoping for low box ( QL=7) losses, as the enclosure is very rigid ad made as per the original design to the letter.

The net effect will be minimal colouration from box resonance and maximum perceived LF extension. I recall from the previous system prior to pulling it down, the bass was tuneful, tight and extended with an effortless quality unlike no other.

Only time will tell...

Ian

Here is a pic of the old box, and the proposed new look..

Ian Mackenzie
12-31-2003, 11:48 PM
The final anticipated image (courtesy of Bo Putman)

Ian

4313B
12-31-2003, 11:49 PM
The better JBL enclosures measure a QL of roughly 10 to 12. The last 3.4 cubic footer I built for an LE14H-1 came in just above 14. A QL of 7 is pretty typical for mass produced stuff. A QL around 3 is considered worthless junk.

Ian Mackenzie
01-01-2004, 06:11 AM
Giskard,

A while ago I did the manual measurements for the 2245h in the existing enclosure albert 10.30 cubic feet at the time.

It was a very tedious measurement following the prescribed method by Dr Bullock as the actual RE of the system is difficult to determine when the woofer is one huge microphone.

I recall vaguely its was about QL=11 but can't find the paper work paperwork, so all things being equal the result should be similar.


Ian

Ian Mackenzie
01-03-2004, 05:03 AM
Here's a good question

To Bolt or Not to Bolt?

I am deliberating over how to attach the front panel/baffle to the box proper.

Scews are easy enough to install and hide with counter sink and filler, however it is one way trip usually and I always find regardless of how well you will fill those scew holes they always show through the damm paint. (Also One box caused me grief with screws that broke when I tried to undo them removing the old baffles)

That said I would like the option of baffle removal at least initially in case anything is overlooked or needs changing. So I started looking at bolt on options.

The most elegant solution so far appears to be these Screw-In insert nuts with self tapping body and connector bolt with allen key fitting.

I tested to idea today on a mockup peice of hardwood and MDF board using a trip of soft cell 4 mm foam rubber for the gasket and it worked well.

Any thoughts / ideas are much appreciated.

Ian

Ps I was thinking of covering the bolts witb velcro strips for the grill covers.

Robh3606
01-03-2004, 09:16 AM
Even when predrilled I have had screw heads shear right off using my deck gun to assemble things. What a PITA that is. The only issue with either is without glue you need many as the glue is what really hold things tightly together and does the real work. I will be facing the same issue when I make my new cabinets with removable baffle plates. I was thinking a screw/bolt every 4-6 inches. They look like an atractive solution and bolts with a suitable anchor can be torque with greater force without stripping like a scew will do. I for one don't mind seeing hardware as long as it is nicely spaced and not all chewed up. Hiding them under velcro is a good idea.

Rob :)

boputnam
01-03-2004, 09:46 AM
Originally posted by Ian Mackenzie
That said I would like the option of baffle removal at least initially in case anything is overlooked or needs changing. :scold: Won't work, IMHO. I've struggled with this in the modified L65's I finishing, and simply cannot get the box airtight. Real bugger. What I have done, but don't take the listening as "final", is hold the baffle on with massive wood clamps, but it ain't sightly. :biting:

maxwedge
01-03-2004, 10:14 AM
Those screws look a little weak. I think you're better off with some longer bolts, with tappered heads, going through the bracing to T-nuts. If it's temp then I would skip the tappered heads and use a large washer under the bolt head to try and hold it together. I think we'd be talking about 3" bolts depending on the bracing.

Scott :)

Robh3606
01-03-2004, 11:37 AM
Didn't the 4343 or 4344 have a rotateable baffle panel?? Anyone know what JBL used. Hey Mike Baker those 3115 have a rotateable baffle what do they use there??

Rob:)

Ian Mackenzie
01-03-2004, 01:16 PM
Thanks everyone.

I'm not alone here.....

I thought about bolting right through...100 mm bolts with T nuts.

I'm using these for the *mid cone and woofers. (*JBL supplied the former)

I think the down side for the baffle is getting the long hole plum and finding a suitable bolt head...flush/counter sink...would grind into the soft MBF and make a messy finish of my paint

Regards the hardware in the pic, they appear quite strong, the bolts are M6 threaded with 4mm hex drive, the larger diameter head ensures excellent joint strength according to the packaging

On the packaged of the Scew insert nut they quote postive locking and strong pullout resistance due to torsion or vibration.

I figured 6- 8 inch spacing would be plenty and once I am cool about it all I can go permanent or glue. The soft cell foam rubber has an adhesive backing and sufficient give for an air tight seal under pressure.

Ian

Ps like my new avatar...muhahahah:coolness:

Ken Pachkowsky
01-03-2004, 09:17 PM
Hi Ian

Just wanted to drop a line and deliver some well deserved compliments on your project. Fine job your doing!!

Happy New year.

Ken

Ian Mackenzie
01-04-2004, 02:01 AM
Thanks Ken,

Well we are keeping this in the family after all..............

It rained continuously all day here so I enjoyed the solitude of working on the project while playing all my Pink Floyd albums in the background.

Today I designed and built the rear loading dock (removable rear access panel) . Quite an intersting challenge actually to maintain the integrity of the enclosure while also providing a removable sealed panel.

Its quite neat, the lower horizontal flange interlocks with the rear vertical bracing forming a double T section stiffener. The flange is made from two peices of F17 hardwood glued and screwed to the fixed section of the rear MDF panel. The side and top flanges will mount against the existing frame.

This graphic in Paint highlights the bracing (air brushed ) within the overall structure.

Ian Mackenzie
01-04-2004, 02:12 AM
Here's a sneak view from the 4345 Live Cam (low res)

Ian:cool:

Ian Mackenzie
01-04-2004, 02:18 AM
Closer

Ian:cool:

boputnam
01-04-2004, 06:02 PM
Very cool, Ian - great job...

I am goofed on seeing my 4345's as your avatar! That is stunner! Flattered... :o

I wish I had the skillset you have, and ability to fabricate some new passive crossovers for these. I'm sure they'd benefit from renewing some of the components...

Ian Mackenzie
01-05-2004, 04:27 AM
"I wish I had the skillset you have, and ability to fabricate some new passive crossovers for these. I'm sure they'd benefit from renewing some of the components..."

What, You started all this with your imperial tape measure.

Bo, your speakers are operating in bi amp mode. This overcomes the primary source of passive crossover limitation in this design, the smaller value capacitors for the horn and slot are less likely to be an issue.

My view is the existing active crossover you are using is the limiting factor here.

I will devise an exotic discrete active crossover for the 4345 monitor as soon as time permits.

As the first recipient of this new active crossover and I am sure your expectations of the 4345 will elevate to a new level.

And then perhaps little while later a very substantial cast aluminium heat exchanger will arrive on your door step to finish the job.

Ian


:coolness:

Ian Mackenzie
01-11-2004, 04:53 AM
Some pictures to follow shortly,

Both cabinets are now nearly complete, only mounting of the baffles, drivers and crossovers remaain.

At the moment I am stopping up all the screw holes in preparation for finishing.

I acquired new fibreglass batts yesterday (at no charge) from the local hardware and enough of those bolt fasterners to build the QE2.

I have decided to make the baffle permanent following a dry fit up. The main reason is maximum bond strength with the enclosure and baffle, in fact I purchased hi grade PVA glue for the job.

I am very pleased with the way the boxes are turning out and with the rear access panel a removeable front baffle seems redundant.

With any luck I will be posting hi resolution images by next weekend. I trust there will be some similarity with the original design.

Ian

jandregg
01-11-2004, 10:49 AM
Ian, in 1974 I built two 6 cu boxes. I framed the front baffle opening with 2 x 2, and used cloth felt ( .1 inch thick) as a gasket. These are still my main speakers after four cross county moves and a fair number of years.

John

Daniel B
01-11-2004, 05:05 PM
Originally posted by Ian Mackenzie
I am very pleased with the way the boxes are turning out and with the rear access panel a removeable front baffle seems redundant.

Only until the day after the glue has dried.

dB

Ian Mackenzie
01-11-2004, 05:28 PM
Your right,

The dry fit will be the clincher and will pay to be maticulous with the fitting up, no second chances here.

Regardless I will be squirting a bead of liquid nails or Bostick sealer around all the inside surface joints.

As it is I have had to block and plug the previous 3 side vent holes like a wine maker re sealing the bottle.

Damm shame really about those side ports, good bye to Harley and Charlie....:scoot:

As you can see here I have about 2 1/2 inches of mating surface to contact with and plan on being liberal with the glue...alas I plan on having a helper with all that white sticke stuff, drying time is only 30 minutes

Ian

Ian Mackenzie
01-25-2004, 10:57 PM
Finally this afternoon I did the 1st successful dry fit of the baffles.

Not an easy job on an enclosure of this scale, damm heavy too.

They must have taken a long time to make in the factory.....that would be an interesting topic to research.

Both baffles now glued and fixed with 16 bolts to the enclosure.

The boxes is now particularly heavy and solid.

The next step will be to sand down and re finish the enclosures.



Ian


:eek:

Ian Mackenzie
01-27-2004, 03:45 AM
Here are some quick 4345 web Cam view until I access the real digital Still.

If you are into serious big speaker projects this is the real thing, and recipients make sure you understand just HOW big they are before placing the final order for the timber....muhahahahah.

Its hard work, definately not a 1 weekend project and takes serious planning but the results and satisfaction are very worthwhile.

Start your routers and tables saws Boys, here's a quick tour.

The boot as Bo says:

The driver support here fastened to the back of the Dog box. The rear rebated baffle openings, precision cut with the Porter Cable router and Jasper circle Jig. Impossible without the jig.

Ian Mackenzie
01-27-2004, 03:49 AM
Looking down the interior there are the ports, the front openings are rebated in like the real vintage

Also the side bracing shown here which had to be carefully spaced so as to allow free access for the ports. Your drawings have to be spot on, mistakes can't happen.

All bracing is F17 builders grade hardwood, glued with PVA and screwed. The exterior walls are 1 inch MBF, the front baffles are laminate 2 x 3/4 inch (1 1/2 inch thick) MBF and Dog box 3/4 inch MBF.

Ian

Ian Mackenzie
01-27-2004, 03:58 AM
This is looking straight up;

The rear bracing partially visible. Some patching on the side walls from the previous side ports seen



Ian

Ian Mackenzie
01-27-2004, 04:02 AM
When the real still is here I will shoot full frontal. The front to rear struts are yet to be fitted.......Oh my back aches...all the bending over!

They are virtual dead weight now.

Ian

boputnam
01-27-2004, 08:22 AM
:shock:

Man, you have done a terrific job. Looking under the hood is identical the the interior of the 4345's. Wow...

Ian Mackenzie
02-01-2004, 04:55 AM
Yeah,

I know where are those pics.......not far away.

Today all fabricarion activities including the kick base have been completed.

But the purpose of this post is one of opinion.

I have thought about inserting a smoked glass top a bit like the Jubal.

Has any one gone this route? Problems/Pitfalls?

My thinking is it will look cosmetically nice (future waf factor) and be durable as drink glasses, ornaments etc tend to spoil the wood finish. ( I have the odd loud party!)

I also plan to veneer the sides but have never tackled a veneer finish on this scale?

Any ideas would be much appreciated

Ian

Mike C
02-01-2004, 05:10 AM
Hi Ian I think the glass while not been authentic is a great idea. I had a pair of L-300s and the glass tops made them. I replaced the original glass with some almost black stuff and they looked great. I would do as the L-300's and have some felt cut to the same shape and place the felt between the glass and the enclosures this looks great as well as stablizes the glass. Experiment with different colours of felt for the right look.
Mike.C

Ian Mackenzie
02-01-2004, 06:24 AM
Mike,

Thanks for your ideas,

I like the idea of using the felt.

Ian

Hofmannhp
02-01-2004, 11:35 AM
Originally posted by Ian Mackenzie
Mike,

Thanks for your ideas,

I like the idea of using the felt.

Ian

Hi Ian,

the idea with the glas on top is great. I thought about the same on my 4435 in cause of drink glass ring prints (I love parties). But its to late ...the rings are there sh.....

My favorit for a material between the glas and the cabinet was a 2 or 3 mm black foam rubber (like Armstrong) I think the glas is more adhesive on this foam rubber.
It looks fine when you use colored glass (maybe grey).

HP

boputnam
02-01-2004, 12:48 PM
Originally posted by Ian Mackenzie
I have thought about inserting a smoked glass top a bit like the Jubal. I'm not typically outspoken, but think this a bad idea. The top of the 4345's is such a vast expanse of beautiful walnut, it would be a shame to have it covered. No-one looks at that as a shelf or table-top, believe me - plus they're too tall for most folks, anyway... :rotfl:

Ian Mackenzie
02-01-2004, 12:58 PM
Okay,

We have disagreement from the originator.......

While not of scientific value I stood beside my monoliths this morning and they are almost perfect bar drinking height.

To clear up the disagreement Bo would you mind parking your butt beside your 4345s so wifey can post a mug shot for our verification......muhahahahahaha

Thanks everyone

Ian:confused:

Ps I bet ya he chickens out....Damm Yankee

Hofmannhp
02-01-2004, 04:08 PM
Originally posted by Ian Mackenzie
Okay,

.......I stood beside my monoliths this morning and they are almost perfect bar drinking height.

To clear up the disagreement Bo would you mind parking your butt beside your 4345s so wifey can post a mug shot for our verification......muhahahahahaha

Ps I bet ya he chickens out....Damm Yankee

Woowh,

Bo whats up .......I thought you might be minimium 6 ft high.....
must be enough for a 4345 with a laszive position....:D

HP

boputnam
02-01-2004, 04:32 PM
Originally posted by Ian Mackenzie
While not of scientific value I stood beside my monoliths this morning and they are almost perfect bar drinking height. No, no, no... Can't be - why would you stand AT your 4345's when partying, dood! Are you building some sorta Bose4345 look-alike? Up close, that's how'll they'll image (oh no... :banghead: Now I've awoken the masses of Boseheads... :slink: )

For the record, I am 2 m tall. But, being of my sort, my image cannot be captured on film...

Ian Mackenzie
02-01-2004, 05:09 PM
Okay you are just too modest.....Euk.

Me a Bose mackination...are you kidding,...Damm Yankee

When the 4345s are running at cruising speed the air vibrations from the 18 inch 2245's are a real turnon for the babs...didn't you know they just ove rubbing up against big JBL's....just ask wifey.

Muhahahaha

Ian:eek:

boputnam
02-01-2004, 05:13 PM
:rotfl:

So that's what goes on in the afternoons 'round here... No wonder she's taken a real interest in cooking dinner at home, lately... ;)

boputnam
02-01-2004, 05:40 PM
Originally posted by Ian Mackenzie
Ps I bet ya he chickens out....Damm Yankee OK, OK...

DanielB pm'd this, from a recent confab we were having. Giskard forgot his green team blazer... Wish I had his knees!

Ian Mackenzie
02-02-2004, 02:37 AM
Okay,

Just add a bit of imagination Bo.......muhahhah

Cheers

Ian

Ian Mackenzie
02-02-2004, 02:48 AM
Forgive my humour,

Nothing at all to do with being an Aussie....there is a fine line b/n genius and total stupidity...:o

Here is a nice shot looking up the inner cavity..

The whole thing is a neat bit of box design on JBL's part being very rigid and functional. Those rear struts from the rear panel to the back of dog box make a noticable difference to the resonant quality of the front baffle...already well damped.

Ian

boputnam
02-02-2004, 09:08 AM
Wow, dood! Nice job. 'cept you're building them upside down (for your perspective...) ;)

Ian Mackenzie
02-13-2004, 04:38 AM
Heres a sneek preview of the mid/hf/uhf elements of the 4345 crossover under construction

Ian

Ian Mackenzie
02-13-2004, 04:47 AM
The 100 watt faders loomed and ready for installation

Ian

boputnam
02-13-2004, 06:52 PM
Hey, Ian...

Just listening to the 4345's and thinking of you, and your project. You will be so very pleased with those 2245H's in that cabinet. It will move you - and as Giskard says - give it one watt, you will get one watt. Such great performance...

It takes a stack of pro PA gear and racks of amps to replicate this... :yes:

Ian Mackenzie
02-13-2004, 07:03 PM
Yes,

The 2245H can move Heaven and Earth with amazing linearity.

I hope to be listening to them later today and into the early hours.

Pink Floyd's "Dark Side of the Moon" with be the premier event!


Ian:eek:

boputnam
02-13-2004, 09:01 PM
Originally posted by Ian Mackenzie
The 2245H can move Heaven and Earth with amazing linearity.
Yea, sorry - it was a weak moment. I walked into the house after a really involved week (3 live gigs...) and XM Radio was playing "Real Love" by David Gray. Even at low gain, these boys are really good... :p

4313B
02-13-2004, 09:54 PM
Originally posted by boputnam
Even at low gain, these boys are really good... :p That's a fact :yes:

Ian Mackenzie
02-14-2004, 06:09 AM
Unfortunately a local 42 C heat wave prevented completion of the project today.....Pink Floyd will have to wait another day.

This is one of the completed passive mid/hf/uhf boards, the large 4.8 hm open E core is not shown...

The Mid passband caps are Axon 250 volt metalised polypropolyene bypassed with 0.1 Axon Tin Foils polypropolyene. The rest of the caps are Hovlands film/Foil exclusively, unbypassed and un biased. Mills resisters are used in the series elements of the fixed mid pad. All the air core inductors are hand wound, coated with resin and calibrated with a LCR meter

It looks a bit messy but that's the price we audiophile types pay for point to point wiring..LOL.

Ian:o

boputnam
02-14-2004, 07:27 PM
Snatched this today, for your consideration.

SmaartLIVE on RTA mode, on laptop.

Blue is pink noise (reference), with gain reduced here for perspective.

Green is ambient, using Earthworks Audio M30BX.

Reference signal is input into preamp, and then pre-amp output split pre-EQ, going into the EQ and into the laptop. Sure it's pretty darn flat, but it sounds great too. :rotfl:

Keep the lamps trimmed and burning, Ian - you'll get there... ;)

Ian Mackenzie
02-14-2004, 08:17 PM
Thanks Bo,

I actually loaded the demo Friday night and just checked the 4345 network, all is correct we are ready for lift off Houston.

This was the reading for the midrange, exactly -11 db (+20 as reference level) as per calibration.

Ian:cool:

Ian Mackenzie
02-14-2004, 08:32 PM
Here is the sheet , simple enough but very useful

Passed the QA with flying colours, many thanks to Giskard for the TechBot support on the rework of the schematic,

Ian

Ian Mackenzie
02-15-2004, 02:05 AM
Yeah,

I still building crossovers, there they are...not a bad days work (more like a whole weekend)

Point to point wiring takes a lot longer than a PCB.

For those interested the overall cost of the crossovers is in a vacinity of $800.00 for the pair, a bit over half that is in the capactors.



Ian:eek:

boputnam
02-15-2004, 02:29 PM
Man, we are gonna have to all chip-in and get you a proper camera! What are you using, your mobile phone...? :confused: Hard to see the results of your hard work!

Ian Mackenzie
02-16-2004, 12:53 AM
Don't worry,

My Nikon with ED Zoom is taking the real evidence as I progress and these cam shots were to stop you falling alseep while you wait patiently for the end result. LOL.

Its just that I hate throwing a whole roll of film away for two or three shots. On that point IMHO I still regard any digital camera I can reasonable afford as a gimmick.

I planned to have the project completed much earlier and hi resolution pics posted here already however as you maybe aware there have been far more pressing commitments which as a matter of necessity have taken precedence and I don't mind that.

All will be seen soon enough...all great things take time.:)

Ian

Ian Mackenzie
02-19-2004, 02:02 PM
Okay,

They are finished and have take 24 shots with some Nikon Ed glass......looks great, will scan and post tonight.

Ian:)

boputnam
02-19-2004, 02:46 PM
OK, so nice furniture.

How's the sound, dood? Or, not quite there yet... :(

Ken Pachkowsky
02-19-2004, 03:10 PM
Some of us have been quietly awaiting the debut!

Yo Bo!

Ken

Ken Pachkowsky
02-19-2004, 03:35 PM
Originally posted by boputnam
Hey, you! Howzit? Whar ya been?

I have been keeping a low profile. My folks just left today after visiting for three weeks. Been selling a wack of stuff on Ebay though. Sold one of the pairs of 375's that I have for 1350.00 BIN to a guy in Japan yesterday. Damned things sold in less than an hour. I have accumulated 3 sets of Diaphragms for them as well and sold a set of those yesterday for 425.00 BIN to a guy in Taiwan.

Hey, help me out here. Some guys I noticed don't accept paypal from asian countries? Can you explain why? Also, do you know the best way to ship to Japan and Taiwan with tracking that does not cost a small fortune?

I got a deadbeat bidder the other day on those 4313's, will have to relist.

How are you and Susan? (Julie just said hi)

Ken

Mr. Widget
02-19-2004, 03:49 PM
Hey Ken,

Whaddya think this is a social forum?:D

You should send JBLDog a PM he is Mr. eBay.

Widget

Ken Pachkowsky
02-19-2004, 03:53 PM
Originally posted by Mr. Widget
Hey Ken,

Whaddya think this is a social forum?:D

Widget


Good point Widget! Post was slightly off topic!!!

Thanks for the tip Widget...will pm him.

Later guys.

boputnam
02-19-2004, 04:33 PM
Originally posted by Mr. Widget
Whaddya think this is a social forum?:D Yea, I already blowed my OT posts away. Weren't worth the bytes, anyway... :biting:

Ian Mackenzie
02-19-2004, 05:13 PM
I'm at work so can't upload for the moment.

They are finished, too late in the evening for a trial run last night, but tapped the woofers with the finger test and nearly popped the front windows of the living room out, so I figure the tuning is about right

Have some great pics all angles and close ups, incl a shot of the L100's atop one of the big boys...wow.

The slant plate lense and spacing of the drivers on the baffle is damn sexy, not to mention the 2245..the mother of all woofers.

Plan to play some Pink Floyd tonight over a pint of Guinness. ..Dark Side of the Moon and Welome to the Machine

Talk to you all later

Ian:cheers:

boputnam
02-19-2004, 07:33 PM
Originally posted by Ian Mackenzie
...tapped the woofers with the finger test and nearly popped the front windows of the living room out Too bad, for you... :scold:

That particular "test" is a rather well-recognized myth, and actually ruins the 2245H's and the cabinets. Sorry. The other components seem to suffer peripheral damage, as well. So, you're hosed.

I'll arrange for shipping those poor ruint things here, to the States. Since you've been so good to the Forum, I'll pay all the costs, of course... :nutz:

Oh, but before you ship them, you might test Acoustic Alchemy's "Positive Thinking". Phenomenal exhibit of what that cabinet can do. If you've not a copy, there will be one here waiting for your visit... :yes:

Ian Mackenzie
02-19-2004, 08:00 PM
I'm more interested in the Bar Test,

Damn Yankee

maxwedge
02-19-2004, 08:18 PM
Originally posted by boputnam
That particular "test" is a rather well-recognized myth, and actually ruins the 2245H's and the cabinets. Sorry. The other components seem to suffer peripheral damage, as well. So, you're hosed.
:rotfl: LOL, thats a good one. Pic's, pic's, pic's....their lookin really nice.:)

Ian Mackenzie
02-20-2004, 03:24 AM
So here you are Boys:


The images here of the JBL 4345 project are some quick scans, the contrast ratio of the baffles made lighting difficult but you will get some idea.

Some comments are in order, the baffles are yet to get the final paint coat once I have tweaked out any bugs, this should lighten the colour tone. When I have aligned and calibrated the level pads, the foilcal will be ordered, what you see is an art paper rendition, still its sets the mood.

This first image is full frontal.....the baffle layout conveys precison and impact, both visually and acoustically


Ian:thmbsup:

Ian Mackenzie
02-20-2004, 03:36 AM
Here a sense of scale,

The L100 sits atop the big boy

Ian

Ian Mackenzie
02-20-2004, 03:50 AM
The crossover network pre installation

Ian

Ian Mackenzie
02-20-2004, 04:45 AM
The 2122H, 2307/2308 horn lense assembly and 2405 Alnico Slot Radiator.

As you can see, keeping finger marks off the baffle (visitors) is going to be a problem.

Ian:(

Ian Mackenzie
02-20-2004, 04:53 AM
The MID/ HF and UHF crossover mounted as per the vintage design, just to the right is the LF crossover.

Ian:cool:

Ian Mackenzie
02-20-2004, 04:56 AM
One Dog Box

Ian

Ian Mackenzie
02-20-2004, 05:02 AM
My Girl watching of the big Boy

Ian

Hofmannhp
02-20-2004, 05:34 AM
Originally posted by Ian Mackenzie
My Girl watching of the big Boy

Ian

Hi Ian,

they look great.....do you let them black on the front.........
not "Bo-blue"?

HP

boputnam
02-20-2004, 07:44 AM
Yea, that Blue ain't right! Gol darnit! Never occurred to me the one paint shop that batches this would get it wrong! :banghead: I will get another done post-haste and post, haste! Sheeeit...

There was one other qt done in this batch - Giskard, have you checked yours? :(

*****

But besides that obvious damned yankee paint batch quality issue, those are some incredible cabinets, dude. I reckon they are identical to the original.

VERY NICE JOB!

4313B
02-20-2004, 07:48 AM
No. Haven't opened the can yet. Would I have been surprised? Is it really pink or something?

boputnam
02-20-2004, 07:49 AM
Dunno. It is not easy to tell "in the can". Need to test a few wood strips... Lemme know what you find. That REALLY pisses me off... :bomb:

*****

Is it pink or something?

I caught that after-market edit!! Hell - it just might be... :(

Ian Mackenzie
02-20-2004, 09:16 AM
Bo never mind, save for when I arrive!
Now The Sound,

Well I have to say I'm really not sure about this, that's a tough one.....

I would have to say it sounds very Greg Timbers, come to think of it very JBL actually.

The sound is quite unremarkable......they don't sound like loudspeakers at all. A sense of complete inertness with total silence between the notes, with transients that snap like fresh shortbread and a velvet smoothness which I have only ever heard with the Quad's.

This is a very good sign at this early stage and I have only just set the levels by ear (well a damn good set of ears) my God.

To sum up I would have to say they are pretty well the bees knees and if you are looking for a project to build up the 4345 deserves very serious consideration.

Ian

That's definitely bar height




:cheers:

Robh3606
02-20-2004, 10:05 AM
Very Nice Ian!!!:cheers:

"The sound is quite unremarkable......they don't sound like loudspeakers at all. A sense of complete inertness with total silence between the notes, with transients that snap like fresh shortbread and a velvet smoothness which I have only ever heard with the Quad's."

Gives me something to look forward too when I build up a pair of 4344's this summer!

Rob :)

Ian Mackenzie
02-20-2004, 10:13 AM
Exactly Robert,

Take your time with it, the results will be very worth while.

Ian

boputnam
02-20-2004, 06:48 PM
I'm baffled (er, make that miffed... :rotfl: ) about that blue!!! Damit!

Same-same batch instructions as that on this build of mine. :wtf:

Ian, I am terribly sorry - I was so busy securing that paint tin for overseas post that I never swatched any from that tin. Dumbest thing I've done...

Help is on the way... :scoot:

maxwedge
02-20-2004, 06:55 PM
awesome job Ian, have a few on me!:cheers:

Audiobeer
02-20-2004, 09:24 PM
That is absolutely Beautiful Ian! What a sense of satisfaction you must have! :smthsail:

Ian Mackenzie
02-20-2004, 10:38 PM
Thanks everyone,

Yeah, I feel pleased about this project and the performance is far beyond my expectations.

Its surprising what you can do if really try .

But is was the journey, the discovery of the raw engineering behind the system and the new friendships forged along the way that made this project special.

In particularly, my contact with Greg Timbers and the support of Robert and Bo, two of our most cherished Lansing Heritage Forum members.

On this note I would ask that all of you who are involved in the "Lansing Heritage Project Teams" get right behind the Project May.

There will be something in it for everyone and plenty of opportunities to meet new people, pickup new skills and just have great fun.

As they say in the Nike advert Just Do It..........

Ian Mackenzie

:dancin:

speakerdave
02-20-2004, 11:21 PM
Yeah, that's a very nice job of work, Ian. Inspires us others to clear off the table saw.
Congratulations!

David

Ian Mackenzie
02-21-2004, 04:18 PM
This is a straight frequency response at 1.5 metre in the room on axis with the HF horn.

The response is un treated with no smoothing. Impressive for a room mreasurement.

With equipment used was the Panasonic mic insert with custom preamp feeding Winairr software via the PC sound card.

Ian

Ian Mackenzie
02-21-2004, 04:30 PM
The 30 degree of axis response. Not a lot to get exited about

Ian

Ian Mackenzie
02-21-2004, 04:36 PM
The 30 degress vertical off axis response. Again nothing to write home to Momma about.

Ian:cool:

Ian Mackenzie
02-21-2004, 04:54 PM
If there is sufficient interest, and a few Pms suggest this maybe the case I will prepare blue prints of the JBL 4345.

Also if there is interest I will document in a new thread Building the 4345/4344 and a how to guide for construction covering the baffle fabrication, box construction, tuning and crossover design and construction.

Ian

speakerdave
02-21-2004, 06:31 PM
Originally posted by Ian Mackenzie


Also if there is interest I will document in a new thread Building the 4345/4344 and a how to guide for construction covering the baffle fabrication, box construction, tuning and crossover design and construction.

Ian

Hello, Ian,

I would be an attentive reader of that thread and would probably raise my hand to ask a few questions.

David

Ian Mackenzie
02-22-2004, 12:43 AM
Well,

The response has been surprising, go here for more details:

http://audioheritage.csdco.com/vbulletin/showthread.php?s=&threadid=1812.

Ian:nutz:

Ian Mackenzie
02-23-2004, 05:25 AM
Following my earlier summation of the subjective performance I thought it appropriate to follow-up with commentary on some specific aspects.

The bass appears highly tuned, the distinction between bass heard and felt is profound, the lack of distortion immediately obvious. Extension into the sub audible regions has a musical quality, the overtones and timing in the upper bass is perfect.

Playing a range of sources suggests very low mid band colouration. Accuracy exists in a crisp but natural way that renders each recording a new experience, there is no discomfort even after long periods.

I was quite surprised by the upper midrange, expecting the much mooted sea shell artefacts from the horn but seriously I cannot hear it. I liken it to the better electrostatics and ribbons.

I suspect the manner of application has a hand in this; the precision JBL crossover and use of the Hovlands appears to be worth every penny, liquid and expressive of the finest details without any signs of glare; the solid clamping of the horn and support assembly sinks any resonances; careful adjustment of the levels; there is tendency for riding the mid, horn and slot too hard when the application is at fault.

The highs are silky smooth, no drilling out or spiting obvious, in fact the integration is seamless. Once the enclosures were arranged in perfect symmetry within the room, the imaging and sound stage is realistic and precise.

Overall, it makes you look up at them in awe but does not demand it. There is nothing obvious that stands out, they do eveything very very well.

I suspect my appreciation will continue to grow over time.

Ian Mackenzie

boputnam
02-23-2004, 08:38 AM
That, is a perfect description of the 4345, IMO.

Welcome to my world, dood. Ain't it sweet?

Your description of the 2245H in that cabinet differs from how Widget voiced the same impression only in how you articulated it. Truly remarkable performance. Interesting description of the 2307 and the 2421B. I think somewhere that got a bad "rap" - perhaps from fatigued, 20-yr old diaphragms. Easily enough remedied... :yes:

I lust after your passive networks - but only for an A/B comparison to evaluate any degredation over time in these stock issue. But, I am disinclined to tear into them...

I'm thinkin' okumokum is sittin' happily on his 14-pair of these - he knows better than to part with them... :rotfl:

I'm working on that damned JBL Blue, now that the workweek has started and the sole trusted Paint Tech is back on-deck! :mad:

John Nebel
02-23-2004, 10:10 AM
Bo,

Greetings!

Has anyone that you know of figured out how to duplicate the grille cloth?

John

boputnam
02-23-2004, 11:01 AM
Hey, John! Good to hear from you - and thanks (again...) for the generous hosting of this Forum! :yes: :thmbsup:

On the grill cloth, either Widget +/- Giskard was trying to source some of that. I think Widget. He took a postage-sized (it is rare, you know... :rotfl:) sample to a resource, but we haven't heared anything lately.

Ian Mackenzie
02-23-2004, 11:28 AM
Welcome to my world, dood. Ain't it sweet?

And a few others no doubt...Right Ken


Bo,

So you thought my Stereophile Review was good...rant ..rant

The sound of that horn also depends if you are cloth eared or not from too many loud Gigs using clipped Amcrons and Ev's..LOL

I was thinking the Paint shop must have forgot part of the formulae, if I added in the 5th Element..hey presto?.

Some JBL grill cloth would finish it off nicely.

Ian;)

boputnam
02-23-2004, 11:31 AM
Originally posted by Ian Mackenzie
I was thinking the Paint shop must have forgot part of the formulae, if I added in the 5th Element..hey presto?. Hey, man...

I don't know. My first thought was likewise - the white was omitted. :wtf: I instructed wifey to only get it from "The Dude" - maybe they convinced her it was a straight-ahead enough formula. Doh! Checking, today, and will get another qt made for you.

4313B
02-23-2004, 03:48 PM
Originally posted by boputnam
He took a postage-sized (it is rare, you know... :rotfl:) sample to a resource, but we haven't heared anything lately. Good grief! It was bigger than a postage stamp! More like the size of a square Zee table napkin! I sent one to Widget and one to Oldmics.

Mr. Widget
02-23-2004, 04:01 PM
My source bombed! She gave the sample back to me. She said she would be going to a trade show in Los Angeles late Spring early Summer and would take the sample with her then.

Giskard, isn't JBL using this same fabric for the 4344 MkII and others in Japan? Couldn't we try to source it through JBL Consumer?

Widget

4313B
02-23-2004, 04:44 PM
Ooops, I forgot to check :rotfl:

Ian Mackenzie
02-29-2004, 01:51 AM
Had a friend over for tea on Friday night and gave the system a stretch.

He played the Car mix version of a Sade album, well to cut a long story short I think I redefined the meaning of Slam.

It reminded me of Bulldog Brower the then strongest the westler in the world picking up Haystack Kalhoon all of 35 stone plus- the then heaviest wrestler in the world.

Not only did Bulldog Brower fully slam Haystacks Kalhoon he also caved in the whole ring and snapped it in half!!!!! Needless too say Haystacks did'nt get up..he was completely %^&*($.

That was a first.....and all recall Jack Little the comentator saying "Thats it folks, thats all there is, there is no more....LOL"

And so it is with the 4345's, be afraid, be very afraid.....

Ian

4313B
02-29-2004, 07:57 AM
Well Ian you obviously built them right because if you got on here posting how awful they were after you finished them then I would know immediately that catastrophic "user error" was involved :rotfl:

Excellent job :thmbsup:

Ian Mackenzie
02-29-2004, 01:19 PM
Na Na,

The only user error is on the knob on the Phase Linear 700B Series 2 when wound fully clockwise...the fine print says your f&^%$n "broken" mate.

Ian

Ian Mackenzie
03-04-2004, 11:54 AM
Here is a new digital file a bit like one of the 4345 promotional 2 colour images....black..blue it does not matter.

Some trivia, I heard an odd resonance from the left channel the other night and was convinced the woofer was odd.

After changing out the driver and re foaming it I realised I have two room mode resonances at 40 and 50 hertz during a sweep tone test.....how unlucky and you be... well you live and learn.

Will need to hunt down a graphic or parametric EQ, moving the enclosures does not seem to help.

Ian

Robh3606
03-04-2004, 01:26 PM
Hello Ian

Sheet rock vibration or molding on the rattle?? I have a similar problem on my right side. In my case it was molding at the ceiling that had worked its way loose. Drove me nuts from my seat it sounded like it was inside my cabinet. Took a while to find it. 40 and 50 Hz are close how bad are the peaks??

Rob:)

boputnam
03-04-2004, 01:35 PM
Originally posted by Ian Mackenzie
Will need to hunt down a graphic or parametric EQ, moving the enclosures does not seem to help. Well now, that's what you get for using a crummy old 2245H woofer! I hear the entire city would resonate where it a SUB1500!! :rotfl:

You should have an EQ anyway, dood. Will really smarten-up the acoustic response. Nothing else quite like it. I'm running the dbx1231 - clean, flexible, parallel in and outs, both balanced and unbalanced. Full +/- 6dB (or 15dB switchable) of cut or boost. All I do is notch-out the badly behaved portions... :scold:

Are you sure it's the room, and not the cabinet? Hoping...

Ian Mackenzie
03-04-2004, 02:01 PM
The room is rendering on brick but the left wall is some other construction like hard plaster board.

I am sure its not the box, and it can't be my clacka..that resonates a 17 cycles..square wave!

I swapped L/R last night, the left side of the room is odd, the right side is minor resonances .

I will exlpore this more over the long weekend and play with the oscillator and virtual ears to work out best enclosure placement.

Oh well another JBL weekend.

Ian:)

JuniorJBL
03-04-2004, 02:24 PM
Originally posted by Ian Mackenzie



Oh well another JBL weekend.

Ian:)
My wife hates it when I say that!
:shock:
But thats not a bad thing!:yes:

Ian Mackenzie
03-08-2004, 01:18 AM
Well we all make Bloopers every now and then...this is mine.

Earlier I reported a strange resonance on the LHS of the room but could not figure it out properly.

Previously this baffled me......for fff'n days and nights...why did the RHS channel sound good...the LHS chesty and muffled?.....buggered if I knew and this was given me the willys

It sounded great the first few days....then hello what's that?

Well I left it alone and did the Formula One thing here a bit and came back to this issue arvo...and just decided to play some Madonna because I know the bass lines very well...and put my hand gently on the 2122 LHS cone while I was tweaking the Pad.

Hello.......why was it vibrating.......at low volume...that's strange.
So I changed out the woofer and checked the crossover.

There it was...a crocodile clip shunted across the 60 uf High Pass midrange filter.......SHIT.

The explanation.....
The other day I after the initial trials I did some phase tests just to be sure all 4 drivers were wired correctly...with 4 its easy to get it wrong.

Anyway to test the 2122 absolute phase I had to temporarily bypass the 60uf series HP capacitor and remove the 4.8 hm choke.....the driver was in correct phase so I then did the other channel.

The lighting was not the best and I re wired the choke ...but forgot to remove the crocodile jumper shorting the 60 uf mid filter on the left channel.

So there you have it....a JBL Blooper.....we all havem.

Back to researching the 4344 drawings....Ian

:nutz:

Ian Mackenzie
03-21-2004, 06:55 AM
This post possibly belongs in a tweak thread.

I recently played around with decoupling the 4345 cabinets from the floor to see what the effect was.

The cabinets sit atop a 2 inch kick base which is in direct contact with the floor. In my case this is carpet/underlay on 6 inches of conrete (reinforced I hope).

You would think concrete is dead and not prone to vibration..WONG. Its actually quite easy to get LF resonances with a slab.

At the time I was also considering various cabinet locations so I hit on the idea is using some 2 inch heavy duty castors and installed them on the inside perimeter of the kick base. The kick base now just clears the floor enough to enable the cabinets to be rolled around without to much effort.

The improvement in bass clarity is quite noticable on certain program material and this effect extends well into the midrange.

On recordings like The Eagles "Hell Fleezes Over" one of my favourite albums, the system appears more dynamic as there is more or less silence between the heavy bass transients, no overhang there at all now.

Considering the improvement I thought I would pass this tweek on. No doubt those Hi End tip toes or cones would also decouple the cabinets, but they are not very convenient if your WIFEY likes to vacum behind your second wife.

Being in a playful mood I also hooked up one of my diy baby class A amps. This one is rated about 35 watts 8 ohms and double again into 4 ohms. It cruises with a total of 9 amps bias current and and pair idle at about 300 watts....a small hair dryer tell the wifey.

"Hell Fleezes Over" never sounded so good..

Ian





:rockon1:

JuniorJBL
03-24-2004, 10:16 PM
Very nice DIY Ian!!
:cheers:


Shane

Ian Mackenzie
04-22-2004, 05:38 AM
Okay,

Here are some images of my 4345 cabinets with the authentic JBL Blue baffles.

Special thanks to Bo for so kindly assisting with the sourcing and colour matching, a difficult job and a fantastic result.

If we had an award for the most well liked and most generous Lansing Heritage Forum member, Bo would be the recipent.

The look in reality is quite impressive and I am sure they sound even sweeter. (no kidding).

Ian

ps A little touching up to be done in the ports , but is not obvious with normal lighting.

Ian Mackenzie
04-22-2004, 05:47 AM
Another angle

Ian

Robh3606
04-22-2004, 05:55 AM
Wow Ian

Those came out nice!! Good color match Bo! Bet they sound great.

Rob:)

Ian Mackenzie
04-22-2004, 05:57 AM
The mid / high array close in.

Ian

Ian Mackenzie
04-22-2004, 06:08 AM
Yes,

I get more excited about playing them now.

They have broken in a bit now and with the X Aleph (class A) driving them the presentation is utterly transparent.


Ian

Ian Mackenzie
04-22-2004, 06:15 AM
For those die hard fans of the 43XX vintage monitors, the 2307/2308 and 2405 slot have not gone out of fashion...very sexy according to girlie.

Ian

Ian Mackenzie
04-22-2004, 06:25 AM
Hard to pick the blue here, but in ambient light the varying color tones add a nice mood.

Ian

boputnam
04-22-2004, 08:42 AM
Originally posted by Ian Mackenzie
If we had an award for the most well liked and most generous Lansing Heritage Forum member, Bo would be the recipent. You, sir, are drunk.

I too have had fits of ectasy stting in front of my 4345's, and have also said some curious things, but nothing as outlandish as that!! :rotfl: We're all participating here, sharing what we can. I certainly deserve nothing such as this! I'm no electrical engineer :shock: and can't touch half of what y'all go on about here - hell, I can't even get the dang paint right! ;)

boputnam
04-22-2004, 08:43 AM
Originally posted by Robh3606
Good color match Bo! What a hassle - I now know what it takes to get men into space...

Spent another few hours with the Paint Guy yesterday afternoon, and either he'd been on a bender the night before, or, he's one o' them daily liver testers. His breath was inflammable... :flamed:

Anyway, we went back to the first batch - the best match yet and the one he omitted an ingredient from - and rebuilt. It is now perfect. Touch-ups are indiscernible on vintage baffles. Most importantly, HE WROTE DOWN THE FORMULA CORRECTLY!!

So, Ian, there will be a tin to take home with you. It is a slight shade / colour tone improvement - subtle, but for those DIY'ers nothing but perfection...

Giskard, there'll be a tin headed your way next week, and to any others pm me...

Ian Mackenzie
04-22-2004, 01:15 PM
Actually I had just one beer,

But who else would mail a 3rd can of paint 1/2 way round the world?:hmm:

See you soon.

Ian

Ian Mackenzie
10-15-2006, 06:42 AM
News:

http://www.audioheritage.org/vbulletin/showpost.php?p=129259&postcount=194

macaroonie
10-18-2006, 06:53 PM
Does anyone have the Pantone reference for the color that JBL use.
Do they Have it on file anywhere ? Has anyone asked them ( JBL ) ?

hjames
10-18-2006, 07:53 PM
Does anyone have the Pantone reference for the color that JBL use.
Do they Have it on file anywhere ? Has anyone asked them ( JBL ) ?

Would this thread help??

http://www.audioheritage.org/vbulletin/showthread.php?t=1910

JBL 4645
08-31-2007, 07:24 PM
Didn't the 4343 or 4344 have a rotateable baffle panel?? Anyone know what JBL used. Hey Mike Baker those 3115 have a rotateable baffle what do they use there??

Rob:)


They use the same technique on there LSR 32 studio monitor.
http://www.sonsetbeach.com/PICTURES/STUIO%20Equipment/JBLlsr32.jpg