Matrix Revolution build

4thtry

After hearing Scott's Matrix speakers in Iowa, I decided to build a pair.  Mine will be a slightly modified version because I already have a pair of used NEO3W's and NEO8 PDR's that I would like to substitute.  Scott used the NEO3 (PDR) and NEO8 (non-PDR) versions.

Here is a link to Scott's threads:  http://techtalk.parts-express.com/forum/speaker-project-gallery/1359902-matrix-revolution

There are slight differences in driver sensitivities and FR curves, but I should be able to compensate for this by taking some measurements and doing a little tweaking.

I ordered a quad set of ND-140-8's from PE and picked up the lumber last week. I will be building my pair out of solid 1" thick knotty pine stair treads!   Should be interesting!

Bill S.

4thtry

4thtry

4thtry

4thtry

I have the wood stacked & separated by 1x1 stakes with a large box fan set to a low speed which lightly blows fresh air through the stack.  I am not trying to "Kiln" or "Air" dry the wood.  I am only attempting to acclimate the wood to my local indoor temperature and humidity conditions before I do the glue up.

PWRRYD

Any idea how you're going to finish the pine wood Bill?  It looks like it has some interesting patern to it.  Maybe just some clear lacquer like old Wisconsin cabin furniture?  BTW I am surrounded by that stuff right now...  we're at the Wilderness Resort at the Wisconsin Dells 

4thtry

I created a full scale baffle board layout in Photoshop and then printed it out on several sheets of 8.5x11 paper.  I then transferred this layout to a set of four 8.5x11 transparencies that can be run through a standard photo copy machine.  I then taped the transparencies together to make a full-scale "see-through" baffle board layout sheet.   In this way, I can lay the transparency on top of my solid pine baffle boards to avoid knots and other defects.  Below would be an example of a bad layout, with a huge knot along a projected Neo8 driver hole cutout: 

 

4thtry

PWRRYD said:

Any idea how you're going to finish the pine wood Bill?  It looks like it has some interesting patern to it.  Maybe just some clear lacquer like old Wisconsin cabin furniture?  BTW I am surrounded by that stuff right now...  we're at the Wilderness Resort at the Wisconsin Dells 

Just a few rough ideas right now.  As you are probably aware, pine is a very difficult wood to finish or stain.  It can get very "blotchy" with some areas getting very dark and other areas staying very light.  It probably needs some type of "pre-stain" or "pre-finish" applied to it to avoid problems.  In gluing up the box, I will have to be very careful to keep glue from getting onto the surface of the wood or soaking into the wood, as this can create a real mess.

When done with glue up, I will have a large pile of scrap pine to experiment with.  Hopefully, I will be able to "stumble" onto a nice looking finish.  I will certainly try the clear lacquer idea to see how it goes.  Thanks for the tip.

Wolf

Torch it! Pine looks awesome when you use a steady hand and torch the surface lightly. Use a damp cloth afterwards to rehydrate the wood a bit and remove the excess ash in the surface. Then you can use maybe a light coat of paint as a stain or a stain alone, just lay on and wipe off, and then top-coat with polyurethane. My 3CR-Ti were done with red paint, but otherwise same process.

rjj45

I haven't used pine, but I've seen it used to demonstrate the importance of pre-stain conditioners. I grew up surrounded by yellow knotty pine, so I'm now a fan of a clear finish, but it's your design and build.
Good idea to acclimate the wood. You never know what's it's been through at the big stores.

How are you going to mount your B&G Neos?  
I'm finishing a build now with a Neo3 and I'm going to use the Meniscus flat plates.
I've also got a pair of Neo8s I'll probably team up with Rival 179 woofers.

4thtry

Wolf said:

Torch it! Pine looks awesome when you use a steady hand and torch the surface lightly. Use a damp cloth afterwards to rehydrate the wood a bit and remove the excess ash in the surface. Then you can use maybe a light coat of paint as a stain or a stain alone, just lay on and wipe off, and then top-coat with polyurethane. My 3CR-Ti were done with red paint, but otherwise same process.

This sounds interesting.   Will definitely give this a try, outside and in a safe location, once it warms up a little.  Thanks for the tip.

4thtry

rjj45 said:

I haven't used pine, but I've seen it used to demonstrate the importance of pre-stain conditioners. I grew up surrounded by yellow knotty pine, so I'm now a fan of a clear finish, but it's your design and build.
Good idea to acclimate the wood. You never know what's it's been through at the big stores.

How are you going to mount your B&G Neos?  
I'm finishing a build now with a Neo3 and I'm going to use the Meniscus flat plates.
I've also got a pair of Neo8s I'll probably team up with Rival 179 woofers.

I will not be using the custom flange plates for either the Neo3W or Neo8 PDR.  My plan is to recess mount them about 1/4" deep into my 2" thick double thickness baffle board.  The recessed area with the mounting bolts and pop rivets will be covered up by a custom gasket made from sheets of 1/8" thick foam rubber.  This will hide the mounting bolts and rivets and, if I take my time and do it right, will provide a very flat mounting surface for both drivers. 

Wolf

4thtry 

This sounds interesting.   Will definitely give this a try, outside and in a safe location, once it warms up a little.  Thanks

It does take a bit of practice, and just a standard butane torch is fine. You'll be surprised how easy the process is. Just keep moving, or the entire board will be black, or at best, spotty looking. I find the best grain styles to be fairly closely striped initially. Wide swirls really won't show the best results.

Wolf

The baffle you have drawn in the thread looks like it would be a good candidate, btw.

4thtry

Wolf said:

4thtry 

This sounds interesting.   Will definitely give this a try, outside and in a safe location, once it warms up a little.  Thanks

It does take a bit of practice, and just a standard butane torch is fine. You'll be surprised how easy the process is. Just keep moving, or the entire board will be black, or at best, spotty looking. I find the best grain styles to be fairly closely striped initially. Wide swirls really won't show the best results.

Thanks.  I will keep this in mind, when I test this out on leftover boards.  Sounds like what you are trying to do is simply darken the wood a little bit, giving it a deeper and richer looking yellow tonal quality.  

rjj45

4thtry said:

rjj45 said:

I haven't used pine, but I've seen it used to demonstrate the importance of pre-stain conditioners. I grew up surrounded by yellow knotty pine, so I'm now a fan of a clear finish, but it's your design and build.
Good idea to acclimate the wood. You never know what's it's been through at the big stores.

How are you going to mount your B&G Neos?  
I'm finishing a build now with a Neo3 and I'm going to use the Meniscus flat plates.
I've also got a pair of Neo8s I'll probably team up with Rival 179 woofers.

I will not be using the custom flange plates for either the Neo3W or Neo8 PDR.  My plan is to recess mount them about 1/4" deep into my 2" thick double thickness baffle board.  The recessed area with the mounting bolts and pop rivets will be covered up by a custom gasket made from sheets of 1/8" thick foam rubber.  This will hide the mounting bolts and rivets and, if I take my time and do it right, will provide a very flat mounting surface for both drivers. 
 

I thought about rear mounting the Neo3, but decided that my wood chops were not good enough.  Looking forward to a demonstration of how to do it!

I

rjj45

4thtry said:

rjj45 said:

I haven't used pine, but I've seen it used to demonstrate the importance of pre-stain conditioners. I grew up surrounded by yellow knotty pine, so I'm now a fan of a clear finish, but it's your design and build.
Good idea to acclimate the wood. You never know what's it's been through at the big stores.

How are you going to mount your B&G Neos?  
I'm finishing a build now with a Neo3 and I'm going to use the Meniscus flat plates.
I've also got a pair of Neo8s I'll probably team up with Rival 179 woofers.

I will not be using the custom flange plates for either the Neo3W or Neo8 PDR.  My plan is to recess mount them about 1/4" deep into my 2" thick double thickness baffle board.  The recessed area with the mounting bolts and pop rivets will be covered up by a custom gasket made from sheets of 1/8" thick foam rubber.  This will hide the mounting bolts and rivets and, if I take my time and do it right, will provide a very flat mounting surface for both drivers. 
 

I thought about rear mounting the Neo3, but decided that my wood chops were not good enough.  Looking forward to a demonstration of how to do it right!

4thtry

rjj45 said:

4thtry said:

rjj45 said:

I haven't used pine, but I've seen it used to demonstrate the importance of pre-stain conditioners. I grew up surrounded by yellow knotty pine, so I'm now a fan of a clear finish, but it's your design and build.
Good idea to acclimate the wood. You never know what's it's been through at the big stores.

How are you going to mount your B&G Neos?  
I'm finishing a build now with a Neo3 and I'm going to use the Meniscus flat plates.
I've also got a pair of Neo8s I'll probably team up with Rival 179 woofers.

I will not be using the custom flange plates for either the Neo3W or Neo8 PDR.  My plan is to recess mount them about 1/4" deep into my 2" thick double thickness baffle board.  The recessed area with the mounting bolts and pop rivets will be covered up by a custom gasket made from sheets of 1/8" thick foam rubber.  This will hide the mounting bolts and rivets and, if I take my time and do it right, will provide a very flat mounting surface for both drivers. 
 

I thought about rear mounting the Neo3, but decided that my wood chops were not good enough.  Looking forward to a demonstration of how to do it!

I

I thought about rear mounting too, but decided against it because that would have created too much of a horn loading effect.  My plan is keep the surface plane of the Neo3W and Neo8PDR exactly the same as the surface plane of the baffle board.   The depressed area with the pop rivets and mounting bolts will be filled in completely with a custom black foam gasket.  I will post detailed pics when I start the mounting process. 

rjj45

Cool!

Wolf

Basically, the dark spots get a lot darker toward black, and it may yellow the wood a touch. There is someone on the internet that does the Lichtenberg burning process, and he recommends using wood bleach after the burn to lighten the lighter wood back to where it was. That is also an option.

4thtry

 
No build thread would be complete without a few "glue up" pics.  As I went along, the knotty pine fought me at every step, constantly twisting and bending as I tightened the clamps. As you can see, I had to clamp several "stop boards" along the gluing path in an effort to force the slightly warped boards into a straight line.  

 

4thtry

After the glue set, I flush trimmed the enclosures and then sanded everything smooth with 100 grit.  I will sand them again with 150 and 220 grit before applying finish.  Once I hit these with finish, all the strange looking knots, interesting grain patterns, greenish accent colors, and other "imperfections" should really pop.

4thtry

 
I built separate internal enclosures for the Neo3W and Neo8 PDR drivers.  The Neo3W already has a small, thin-walled plastic enclosure, but I will be giving it an additional 3/4" thick internal enclosure.  This internal enclosure is quite small, only 0.25 liters, but I plan to stuff it lightly with poly fill.  This should help dampen the thin-walled plastic enclosure a bit and provide better isolation.

The Neo8 PDR will be getting a 2 liter internal enclosure.  This internal enclosure will expand to a wider cross sectional area for each one inch of depth.  I am not sure of the exact size of internal enclosure that Scott used, but from his description I am guessing that it was 1.5" deep by 2 3/4" by 7.5".   My enclosure will be a total of 3 inches deep with the first 1 inch of depth measuring 2 3/4" by 7.5".  My 2nd inch of depth will measure 4.5" by 9.75".  My 3rd inch of depth will measure 5.5" by 9.75".  The idea here is to create an expanding type shape in an effort to spread out any internal resonances.  I will be stuffing each layer with 1 inch thick UltraSonic Acoustic Panels, cut to exact size for each layer.  I bought a six-pack of these 12x12x1" UltraSonic Acoustic Panels a few years ago at Menards and I still have enough left to complete this project!   
 

jhollander

So what are the finish plans?  Shellac would be traditional. Might look good with shellac plus wax for a lower sheen?

4thtry

jhollander said:

So what are the finish plans?  Shellac would be traditional. Might look good with shellac plus wax for a lower sheen?

Thanks for the suggestion, John.  I'm currently testing several options on leftover 3" x 13" knotty pine boards.  I'll add shellac plus wax to my list and test it as well.  Will post comparison pics when done.

Other options on deck:

1) Wolf's torch suggestion.  I was going to test this but discovered that my small propane torch was empty.  Have to stop at the hardware store for a new tank.

2) Craig's clear lacquer suggestion.  I have a test board sanded 100/150/220, tacked, no stain, then 5 thin coats of rattle can semi-gloss lacquer applied with 2 hours between each coat.  This looks really good.  The lacquer soaks in just a little and darkens the wood, then builds to a nice smooth finish after about 5 coats. 

3) Min-wax wipe on poly (my idea).   I have another test board sanded 100/150/200, tacked, no stain, then 5 coats of Min-wax wipe on poly.  The poly soaks in quite a bit and does not build to a very smooth finish.  Because the poly soaks in, it deepens the yellow color of the pine more than the lacquor does. 

PWRRYD

The only down side to lacquer that I've found thus far is the stank when spraying it.

I also love the look that clear shellac gives, but that stuff is difficult to apply because it dries so stinkin fast.

Wipe on poly is super duper easy to apply but I find its look less "rich" compared to lacquer and shellac.

You can always apply a wiping oil that has varnish like Watco Danish oil or Waterlox which will make the grain look pop and provide some protection.

jhollander

With Bill's new spray gun he could spray a few coats of seal coat on those massive cabs in no time.

Speaking of torch, I did a power washer blast-then burn, on some long leaf pine.  The power washer basically ate away the soft pine creating grooves, the torch cleaned up the wood fuzz.  Really a cool technique, very similar to sand blasted pine.  I never built anything with it.

ani_101

if you are trying stuff, try the danish oil, rub on, three coats should be real nice, not much cheen or shine, and looks very natural, might darken a bit.

BTW my pine had shellac and wax. Will get a pic tonight....

4thtry

Thanks for all the great finishing tips.  When the temperature gets above 50F, I'll be moving out to my garage, both doors wide open for a nice cross breeze, and firing up my compressor.  Think I will try out my new detailing sprayer with the 1.0mm tip to see how it sprays sealcoat, lacquer, and shellac. 

I have 3 quart cans of the rub-on type Watco Danish oil, natural, light walnut, and dark walnut.  The only problem that I have had so far with the Danish oil is that you need to let it dry for a least a week before spraying any finish on top of it.  Otherwise the oil will chemically react with the lacquer and cause bubbles to form in the finish.

Ani,  please post your pine with shellac & wax photo.  I'd like to see it.

Bill

4thtry

A little progress:

The baffle board will be double thickness, approximately 2 inches.   I therefore cut the driver holes slightly oversized on the inner baffles to eliminate a long 2 inch "tunnel" behind the drivers. 

Also, I wanted to use long 2 inch sheet metal screws to mount the ND140's, so I  scalloped the ND140 woofer holes on the inner baffle, leaving enough baffle material for the screws.  Pine is very soft, so I have to be careful about stripping out mounting screws.

Once I have both baffles glued in place, I will cut another set of holes in the outer baffle to flush mount the drivers.   Slowly but surely, I'm getting there.

PWRRYD

I have found that having a box fan or two blowing directly on the work pieces cuts the oil's dry time in half, at least.  I also turn the work pieces every few hours.  I was able to topcoat some hickory with lacquer only 3 days after applying the last coat of boiled linseed oil.