New DIY MTM Towers designed by Dennis Murphy and Paul Kittinger

[KenM10759]

I'm well aware that many magnets are brittle and being a machinist by trade, I'm pretty good at sizing things.

In reading some of the comments/reviews on the product pages and knowing a little about magnet poles, I guess you have to orient them to each other or they could repel. I checked my KEF speakers and it's definitely magnets both sides. The ones on the grills are those weak, soft stick-on type like you see with so many "refrigerator magnet" products. I have no clue what lies beneath the veneer on the speakers. I just wouldn't want anything loose in the speaker cabinet that could rattle when the grills aren't on.

 

[highfigh]

I'm well aware that many magnets are brittle and being a machinist by trade, I'm pretty good at sizing things.

In reading some of the comments/reviews on the product pages and knowing a little about magnet poles, I guess you have to orient them to each other or they could repel. I checked my KEF speakers and it's definitely magnets both sides. The ones on the grills are those weak, soft stick-on type like you see with so many "refrigerator magnet" products. I have no clue what lies beneath the veneer on the speakers. I just wouldn't want anything loose in the speaker cabinet that could rattle when the grills aren't on.

Most of the ones I have seen were mounted with epoxy.

 

[KenM10759]

The soft magnets on the grills for my KEF speakers are glued or epoxied to the plastic frames. There's 8 of them per grill!

I can't imagine there would be any production time used to orient the "poles" of them, so I'm thinking use the kit's neodymium magnets in the cabinets and some similar soft magnets on whatever grills I make. It's bound to work fine.

 

[AuralFission]

Ok guys, I finished my build in September of 2016 after starting January 2016. Haven't taken the time to upload, but here it is. I built both the towers and center. I took a lot of pictures, so the pages are kinda data heavy.

The box:

The inside of the box:

Everything taken out:

Stuffing and speaker grille cloth:

 

[AuralFission]

Next, the speaker components:

Tweeters:

The Woofers:

Crossover Stuff:

 

[AuralFission]

Internal Braces:

That oblong looking thing on the left is a circle cutting jib I made. The router bolts to the wide end with the cutting bit going through the hole. There's an adjustable pin that goes into the hole's center. I like it because it's infinitely adjustable.

For the bottom brace, I drilled holes to accomodate threaded inserts which would screw into the base. I wanted the base to be removal should I ever need to get into the crossover.

I made a little jig to help with inserting the threaded inserts:

And the finished product:

Heres the bottom of the base where the screws thread into the bottom brace:

 

[AuralFission]

Construction of the towers:

Cutting the dados into the sides of the towers. I clamped both sides at the same time make sure they would get the same cut. I used the exact brace that would go into the slot to account for variations in thickness. It was a lot of eyeballing and careful clamping to make sure the guide pieces lined up. I don't have a picture of it, but I used a flush trim bit to cut the dados. I cut about 1/8" each pass. I like it tight!

 

[AuralFission]

More tower construction:

All wood is 3/4" Baltic Birch. The good stuff. I measured wrong and cut a dado in the wrong spot. Here's me clamping up the "plug" for the screw up.

Nice and tight:

Rough fit up:

The bottoms (these will be flushed trimmed later):

 

[AuralFission]

Tower glue up:

This was stressful. I had to glue and clamp up all the braces at one time. Worked out though.

Inside of the bottom. This is where I did the alignment between the bottom brace and the base.

All glued up:

The port section. Rough fit up of the port and speaker terminals:

 

[AuralFission]

Stuffing the towers:

 

[AuralFission]

Gluing up the Fronts:

Cutting the Chamfer:

View from the Bottom:

After Clamp-Up:

 

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Making the Baffles:

 

[AuralFission]

Gluing the Veneer:

What you see is African Sapele:

4' x 8' Sheet:

Backside of the Veneer Sheet:

Glue and Application Method (I stopped using the tray after awhile. It was faster squirting straight from the bottle and saved glue). Just drizzle on the glue to both the venner and the opposing surface and roll flat with the roller. Bring the two pieces together and clamp up. It was hot at the time, so dry time wasn't that long.

Gluing the Sides:

I made sure to leave overhang so I could flush trim the veneer later.

Taped up the veneer before I flushed trimmed to prevent the router from damaging the surface.

 

[AuralFission]

More Veneer Work:

Gluing the Top (I didn't have a long enough piece at the time, so I spliced a smaller piece):

 

[AuralFission]

Making the Speaker Grilles:

I don't have a lot of pictures of this process, but I basically clamped the front baffle to another piece of wood to get the profile I wanted and used a flush trim router bit to match the profile. I used Super 77 contact adhesive to attach the grille cloth.

I inset magnets into the frame:

Here's the front baffles with the magnets in place. I used two part epoxy to fill in the holes and sanded flush.

 

[AuralFission]

Gluing the Front Baffles/Prepping the Base:

Taped around the veneered portion to keep glue away:

Since I like making things harder for myself, I also used threaded inserts to attached the woofers and tweeters to the baffles. Note the holes in the baffle and the tower. I didn't use the supplied wood screws. I like machine screws, it looks better to me.

Making the Base:

 

[AuralFission]

Prep work for Painting:

Back of the Speaker:

Some the materials I used for prep:

 

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After applying the basecoat:

 

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Making the Crossovers:

 

[AuralFission]

Applying the Stain:

I used Watco Danish Oil, Red Mahogany.

With the base and grille: