JBL 435(X) Tower Speakers

[brucewood]

I have recently completed the build of some new speakers based on the 4355 system but I have made some significant changes as can be seen. Due to space limitations I decided to configure the system as a "Tower".

Before starting this project I have read hundreds if not thousands of pages of threads from the Lansing Heritage site and wish to thank the many, many individuals who have contributed their expertise and knowledge. Without that help I would never have been able to tackle this project.
I have used the same speakers as in the original 4355 (2x 2235H, 2202H, 2441, and 2405H). I used a 2397 replica horn which is made from solid black walnut. I had made a previous set of these horns and really like the sound quality. The 2405 front end has been replaced with a Kenrick polished bronze unit.
I am currently using a Accuphase F-15 Electronic crossover with a 290Hz and 2 way card installed and a JBL N1200 and N8000 units for the upper passive crossovers. This is only temporary while a charge coupled set of crossovers are being completed. I am very pleased with the sound quality.
Disclaimer: Any similarity to Westlake tower speakers is purely intentional.

[CowFish]

Wow, stunning!
Got more pics?

[SteveJewels]

Beautiful!!!!!!

[rusty jefferson]

Snap! Nicely done, congratulations. A build thread with pictures would be great.

[brucewood]

Snap! Nicely done, congratulations. A build thread with pictures would be great.

I do have more than 100 photos that I took during the construction of these speakers and also more the making of the Smith horns - that is a project in itself. Anything in particular that anyone would like to see?

I constructed the speaker cabinets of 3/4" baltic birch plywood and walnut veneer. No MDF used-I hate working with that stuff. Once you have some MDF dust powder in your shop you will never get rid of it! Not good to breathe either.

[srm51555]

Nice work!

[martin_wu99]

I have recently completed the build of some new speakers based on the 4355 system but I have made some significant changes as can be seen. Due to space limitations I decided to configure the system as a "Tower".

Before starting this project I have read hundreds if not thousands of pages of threads from the Lansing Heritage site and wish to thank the many, many individuals who have contributed their expertise and knowledge. Without that help I would never have been able to tackle this project.
I have used the same speakers as in the original 4355 (2x 2235H, 2202H, 2441, and 2405H). I used a 2397 replica horn which is made from solid black walnut. I had made a previous set of these horns and really like the sound quality. The 2405 front end has been replaced with a Kenrick polished bronze unit.
I am currently using a Accuphase F-15 Electronic crossover with a 290Hz and 2 way card installed and a JBL N1200 and N8000 units for the upper passive crossovers. This is only temporary while a charge coupled set of crossovers are being completed. I am very pleased with the sound quality.
Disclaimer: Any similarity to Westlake tower speakers is purely intentional.
Great job!
But i think it is more like a Westlake:D

[rusty jefferson]

I do have more than 100 photos that I took during the construction of these speakers and also more the making of the Smith horns - that is a project in itself. Anything in particular that anyone would like to see?....
If you have the time, a construction thread with commentary and photos would be great for posterity, including the eventual building of the cc crossovers. Folks around here love that sort of thing, and will probably ask a lot of questions about the build. For people like me, without creativity skills, it's great to see what people accomplish when they have them.

[brucewood]

Great job!
But i think it is more like a Westlake:D

Did you notice my disclaimer in the original post? I was definitely influenced by the Westlake design.

[speakerdave]

Did you notice my disclaimer in the original post? I was definitely influenced by the Westlake design.

Cultural divide, I think. Possibly Martin did not pick up on your irony.

[brucewood]

Since I didn't have any plans to go by, I had to design the cabinet on paper first. I had a few considerations: 1. the interior width of the cabinet was dictated by the width of the Smith horn which is just over 26". 2. The cabinet had to have casters on the bottom for easy movement over hard floors as well as carpets. 3. The cabinet's height had to be less than 80" so that they would fit upright through normal doorways. 4. I need to make the 2235 and 2202 speaker enclosures the same volumes as the original 4355.

I drew some full size plans for the front of the cabinet and started from there. I was able to get very close to the requirements. The final dimensions: Height including base and top 73 1/2", Width 27 3/4", Depth 24". The top has an additional overhang of 2 3/4" and the Smith horn protrudes 8" from the baffle. I had decided to make rectangular port tubes and had to calculate their length as appropriate for the 2235 speakers mounted in individual chambers.

I am fortunate in having a 1200 sq ft woodworking shop for such a large project. When I started the building I had decided to build both cabinets at the same time step by step so that my table saw settings didn't have to be changed. I also used a number of spacers that were used for both cabinets so that everything would be identical.

The attached photos are of the rear of the cabinet and as you can see they are fully finished as well. The center portion of the back is removable to gain access to the 2241 driver, 2328 horn adapter and horn. There is also a recessed panel for the banana jack connectors. The top of the cabinet had not yet been attached.

[martin_wu99]

Did you notice my disclaimer in the original post? I was definitely influenced by the Westlake design.
Sorry for my don't noticing your disclaimer,anyway,it is a perfect DIY:D

[brucewood]

Here are a couple of photos of the beginning of the assembly. The panels for the bottom, 3 internal cross pieces and the top (not yet attached) are connected to the side panels with pocket screws and glue. In one photo you can also see the smaller chamber that will enclose the 2202 speaker.

[Dr.db]

Wow, these are some serious speakers for shure!!
You have some great woodworking skills and I like your design a lot.

How far is the 2202 and the 2405 apart from the 2397 horn?
How did you come up with this baffle-layout?

[Woody Banks]

Beautiful! I particularly like the fact that they require a lot less real estate than the original design. Great job. :applaud:

[brucewood]

Wow, these are some serious speakers for shure!!
You have some great woodworking skills and I like your design a lot.

How far is the 2202 and the 2405 apart from the 2397 horn?
How did you come up with this baffle-layout?

The center of the 2405 is 6" above the top surface of the 2397 horn. The positioning of the individual speakers just kind of evolved. I had read that 2 identical speakers should normally be placed as close to each other as possible. However this requirement is not as critical for low frequencies. Separating the 2235 speakers to the top and bottom positions allowed me to place the 2397 horn at optimal ear level (42 1/2"), Westlake tower speakers frequently place the UHF driver below their midrange horn however I just didn't like that look and felt that would place the UHF too low. The chamber for the 2202 has the exact dimensions of the original 4355 cabinet, and the volume requirements for the 2235 speakers (about 5 cu ft/speaker) mandated the height of that section of the cabinet. The 2441 driver is also mounted in a wood cradle that raises it about 1" off of the partition that it rests on. I have included a photo of the mount before cutting it from the plywood stock.

[brucewood]

After completing the basic cabinet (sides, top, bottom and 3 internal horizontal partitions) it was time to start with the front baffle. My previous post describes how the design came about. I made 2 templates, upper and lower, for the baffle from ¼” MDF. I marked the position of the internal partitions as well as the actual positions of each speaker and ports. I left the space between the upper and lower portions about 3/8” greater than the height of the horn. This gave me some “wiggle” room for positioning the horn. In the actual build I built added a 2 layer of ¾” plywood on the inside of the lower baffle then placed a ¼” thick rubber pad for protection of the bottom of the horn. This filled in the extra part of the gap.


I drilled holes in the baffle templates for center location for each speaker. The 4 port openings and the opening that would contain the 2405 were marked on the templates, I then made a routing template for the ports and one for the 2405 panel. These templates were attached to the actual plywood baffle with 2 sided tape the the router was used to route out the area. Using this template ensured that all 8 port openings would be identical in size. The speaker openings were cut using a router and a Jasper circle jig.
The port tubes are constructed with ¼” walnut veneer plywood. The ports are 3”x4” rectangular. Since the 2235 speakers are in separate compartments and I was using a rectangular port tube it was necessary to calculate the length of the tubes. I used the same frequency (32 Hz) as the original. I checked the calculations on several different website to make sure they agreed. The ports are about 10”, sorry can’t remember the exact length. The ¼” plywood pieces for the sides of the tubes were cut an inch longer. The plywood was stained and finished on the insides before being glued together. I used the same template for the glue up as I did in cutting the openings in the baffle. I would have a glove fit when attaching the tubes to the baffle. After all the tubes were glued up they were cut to exact length. The finished port tubes were attached to the baffle prior to the baffle being attached to the cabinet.


In the attached photo you can see the stack of port tubes along with the frames that will be attached to the front of the baffle which will cover the ¼ raw edges of the port tubes. In the upper left corner of the photo is the template used to cutout the opening in the baffle as well as in the glueup of the port tubes.

[Don C]

I really like the finishing details on these. They remind me of high end Tannoys.

[brucewood]

I really like the finishing details on these. They remind me of high end Tannoys.


Stay Tuned! Don't touch that dial! More to follow.

[Dr.db]

Thanks for the info ;)

[brucewood]

As I was working in this phase of the project I realized that there would be no way to run the internal wiring for the bottom 2235 after the baffle and back panels were glued in place. I decided to run a pipe from the lower chamber up to the upper middle chamber that would contain the 2441 and horn where the input jacks would be located. See photo for the 1/2 “ copper pipe.

By this time I had applied the walnut veneer to the sides, front baffle and rear panels. The speaker openings and ports would be cut after the panels cut to size. I had marked and cut the templates earlier that I would use to mark the cutouts on the walnut veneer plywood panels. I also stained the front baffle and rear panels prior to gluing to the cabinet.
I had added ¾” square strips to the interior of the cabinet on both the front and rear to provide backing for all for edges of the front and rear panels. Some interior bracing was also added. Since I had plenty of scrap pieces of the ¾ birch plywood, I made some bracing out of 3 layers of the plywood glue together to make it 2 ¼ “ thick and cut to appropriate length and width.
I Added 1” thick fiberglass insulation to the interior of the 3 speaker chambers prior to gluing the back panels and front baffle into place.

[Woody Banks]

Great job! You have inspired me to do two things. #1 Clean up my shop. #2 Build something.
I used to pass through Placerville to get to my home in Somerset years ago.;)