Introducing the SSA-WG

[sdl2112]

Thanks Jim...That's about what I'm shooting for. I just won't have the extended low end you have.

[jim1961]

Thanks Jim...That's about what I'm shooting for. I just won't have the extended low end you have.

Thats what subwoofers are for :B

On the other hand, you should be able to get a F3 around 30hz if you end up in the ported version. Much depends on how much bass reinforcement your room provides. Knowing your room, and having the back wall only a few feet behind the speaker might be helping a lot.

If you want to take this idea further, you could pull up the simulation on your current speaker, and then do a in room measurement, and compare the difference. It might provide a more accurate picture to how much bass reinforcement to expect.

FYI, I took my sub a few months ago and progressively moved it away from the back wall. The difference between 1' and 5' from the back wall was 6-8db at 25-30hz!

[sdl2112]

Front baffles

The top I made earlier defined the baffle width....next was the front baffles. I drilled the center pin of the two layers together and used a wooden dowel to keep them aligned. Here is the baffle progress...

Clamping both baffles at once Pic 1


Pic2


Pic3


Finished and glued


Detail of the midrange chamfer

[jim1961]

Those look awesome Scott.

[sdl2112]

Thanks Jim!...the builds of your Troels Jenzen and my Modula MT-XE are really paying off a lot to be learned with practice :T

[sdl2112]

Must have tool

One of my favorite tools to help with woodworking is a 12" digital caliper. It really helps making accurate mistake free cuts. Great for transferring measurements to a combination square.

I got mine at Harbor Freight but here's one on Amazon for under $40.

[jim1961]

Scott, we were talking about acoustic curves the other day. Here is my woofer/subs curve (blue) vs my mid/tweet curve (orange). The green curve is everything driven (not summed curves). All measurements at the listening position.

Despite the LR2 XO, the acoustic curves more resemble a 1st order network than a 2nd order.

Just thought you might gain something from the illustration.

[sdl2112]

Continuing with cabinet updates. I wasn't sure how I was going to line up the cabinet panels...dado's, biscuits, butt joints etc. I elected primarily dado's. I had concerns lining up multiple pieces for the shelf but routing them together guarantees alignment.

First though is the view of the C173 mid from behind. Plenty of ventilation :T. People familiar with the C173-6-090 will notice this is the new motor structure. There is no center pole piece ventilation. They added holes in the VC former and to the back plate gap. I have mixed opinions on this. I see a little more wiggle in the 1kHz region than older ones I've seen on the net. Could there be a cavity resonance? I'll assume they know what they are doing. The funny thing is that when I bought these from Madisound back in ~2010 I received the old version...since the new ones were in production they agreed to an exchange. Luckily I got these before the price went up to $900!

Those interested...here's a PDF of their new motor info.


C173 rear view


Here I lined up the baffle and sides for the dado cut...thus when folded up it should align perfect for the shelves.


Back dado.


Making more holes.


Got to love carbide router bits. I cleaned it once through this and still appears to cut well. Side note...I couldn't image doing all this in MDF even though I have pretty good dust collection.

[jim1961]

Lots of nice looking coasters there

[sdl2112]

Yep...or wheels for pinewood derby cars...:B

[TEK]

Great info here and butiful work.
Thanks for the idea of lining up the sides before cuttibg the dados - had not thought about that, will probably do that on ny next build!

[5th element]

Nice work, I usually keep a few of those 'coasters' around for using. I find them quite useful when building stuff. Either as spacers, supports, something to place behind something else that I am drilling through etc :P Or if I need to test a rebate size for a smaller driver, the centre pivot is already drilled etc.

It will be interesting to see some distortion measurements of the C173 at some point if you can, just to see how this new motor performs.

Pole vents are a cause of resonances, but then again so is almost anything within a loudspeakers construction

[sdl2112]

Thanks guys!...I think I do have some measurements from a while back. I'll take more later too. I'll try to post tomorrow...now I'm headed out to a Halloween costume partyarty:

[sdl2112]

Here's a harmonic sweep of the C173 at 4 inches at 1V. We would really need to compare the new and old with the same setup to see the differences.

[sdl2112]

A few updates...

I did a quick dry fit of the panels and so far so good :T. After the initial fit I added a small brace between the mid and tweeter. I didn't want to add another shelf as I think it would confine the mid too much. I then made a window shelf for the bottom. This will serve as the platform to connect the removable base and internal access to the crossovers.

Next will be applying internal damping material to the panels before assembly and base construction. I expect this to take some time...a lot of details.

Panel fitment.


The new Mid - Tweeter brace


Brace installed


Window brace construction


View from the bottom

[jim1961]

I think you could drive your car onto them if you wanted

Those are deeper cabs than I thought. What are the finished dimensions to be?

[sdl2112]

Yes...quite sturdy :T. They will be 46-47"H x 11.7"W x 17" deep. 43" high w/o the base.

[BobEllis]

Not much bigger than the Ardents but looks a lot bigger.

[jim1961]

Yes...quite sturdy :T. They will be 46-47"H x 11.7"W x 17" deep. 43" high w/o the base.

Are you trying to get the mid to ear level? What height will that be?

[Steve Manning]

Looking good Scott ....... I've been thinking about going the dado route instead of biscuits next time around. Is that bamboo ply actually 3/4" or is like typical plywood and is an oddball size?

[BobEllis]

If it's 18mm like Baltic Birch, a 23/32 bit works great.

[sdl2112]

Are you trying to get the mid to ear level? What height will that be?

The design listening axis is between the mid and tweeter which is about 38" high. See the vertical polar plot I showed earlier.

[sdl2112]

Looking good Scott ....... I've been thinking about going the dado route instead of biscuits next time around. Is that bamboo ply actually 3/4" or is like typical plywood and is an oddball size?

Thanks Steve,

The bamboo ply is 1" and measures about 0.99". The Baltic birch is 18mm and yes I used a 23/32" down shear bit. It fits nice and snug. I considered biscuits but the few times I used them I had trouble lining them up. The dado's have worked great so far.

[sdl2112]

Not much bigger than the Ardents but looks a lot bigger.

It's funny...I showed a few people a picture on my cell phone and they had the same reaction...those are big!...for some reason I guess they look bigger in the pic.

[Steve Manning]

Thanks Steve,

The bamboo ply is 1" and measures about 0.99". The Baltic birch is 18mm and yes I used a 23/32" down shear bit. It fits nice and snug. I considered biscuits but the few times I used them I had trouble lining them up. The dado's have worked great so far.

Thanks Scott ..... what bit do you use?

[TEK]

It's funny...I showed a few people a picture on my cell phone and they had the same reaction...those are big!...for some reason I guess they look bigger in the pic.

I can't quite agree about that.
SSA-WG: 46-47"H x 11.7"W x 17"D
Ardent: 42-43"H x 11"W x 16"D
So they are quite a bit taller, a bit higher and a bit deeper.
I think that he facet look of the Ardent make the baffel look both slimmer and lower than it actually is. I assume that when you combine the actual size different and the effect of the Ardent baffle you are likely to get a feeling that the Ardent's is quite a bit smaller than the SSA-WG.
But so what, I think the SSA-WG looks great anyway.

What finish are you planning for these? Natural bamboo look as Jon's Isiris?

[sdl2112]

Thanks Scott ..... what bit do you use?

I'm using the Eagle America bit P/N 102-1195.

[sdl2112]

I can't quite agree about that.
SSA-WG: 46-47"H x 11.7"W x 17"D
Ardent: 42-43"H x 11"W x 16"D
So they are quite a bit taller, a bit higher and a bit deeper.
I think that he facet look of the Ardent make the baffel look both slimmer and lower than it actually is. I assume that when you combine the actual size different and the effect of the Ardent baffle you are likely to get a feeling that the Ardent's is quite a bit smaller than the SSA-WG.
But so what, I think the SSA-WG looks great anyway.

What finish are you planning for these? Natural bamboo look as Jon's Isiris?

Thanks TEK! I think they will look great too. A big butcher block quality to them . My favorite is the slanted faceted look like the Ardents but that is not appropriate here with the waveguide.

Yes I plan on a natural bamboo look. I will likely use General Finishes Seal-A-Cell and Arm-R-Seal. This is what I used on the Modula MT-XEs I built.

[dar47]

Ah my second fav speak, I think that's the first time you have shown these I like the contrast. I made grill frames for mine but never finished them, how are these attached, magnet's?

[TEK]

Those aremjust wonderful - great work!

[sdl2112]

Ah my second fav speak, I think that's the first time you have shown these I like the contrast. I made grill frames for mine but never finished them, how are these attached, magnet's?

Thanks! Yes I added magnets to the baffle along with the magnets already in the Parts Express grill. I did a build thread here if interested.

[sdl2112]

Those aremjust wonderful - great work!

Thank you!

[dar47]

Scott, gees I'm losing it I posted in your thread,haha.

[sdl2112]

Construction updates...

My goal is to make a very inert cabinet. I used lead sheet on the walls of my Modula MT-XE and feel it is the best bang for the buck to damping the panels. The price to pay is weight. For the SSA-WG I'm using 1/16" lead sheet. Just to get an idea of densities....lead is about 16 times more dense than bamboo ply so 1/16" lead sheet is equal to about 1" of bamboo ply....pretty neat . I need to use it sparingly or else the weight will get out of hand....I'm already worried as my initial estimates are higher than I would like 8O.

Here's rolling out the lead to cut to size.


Next I was thinking how to make the base. I initially was gong to use 1" bamboo ply but decided not to "waste" the material and save it for a later project. I have a 12mm Baltic birch 5'x5' sheet...so I could stack layers for thickness...

Now, I always thought how to design a vibration absorbing base...how about BB, lead layered base...done. That's my approach :B.

Here's lead sheet cut and flattened to the size of the base.


Next layering up the base materials with BB, lead and construction adhesive.


Clamping the assembly.... I used thickness blocks at each end and in the middle to achieve consistent thickness for the layer stack. Good thing I did as the middle didn't want to compress the same as the ends. It took all the clamps I could find to compress the middle.


Edge view

[sdl2112]

Here is the edge view of the inner base stack cut to size. This will be covered by a MDF skirt painted black...details to come.


Another view...


To help with alignment I made a drilling template for the base. This allowed me to transfer dimensions between the various assemblies.


Inserting 1/4-20 wood inserts in the the bottom window brace.


Bottom brace view.

[sdl2112]

Early X-mas present

Kind of spur of the moment purchase...:E

The most used power tool is probably my sander so...time for a new addition. My Dewalt DW421 has and is still great but for larger surfaces it will be nice for an upgrade. I just got it tonight but the reviews look awesome. It should serve me for a long time...Festool ETS EC 150/3 EQ Brushless Sander.

Sander


...and accessories

[jim1961]

Sure your not secretly building a fusion reactor :P

I assume those pics of the cabinets are glued now? Looks like your project is really coming along. Xmas may not be a stretch for completion after all.

[sdl2112]

Not glued yet, just held together with clamps. I need to line the cabinets with damping material...mainly where I won't have access once assembled. I also need to add rails to mount the crossovers. Devil is in the details...just taking it one step at a time.

[5th element]

Looking good there! And power sanders are one of my favourite tools in that they save you so much time and effort.

[Steve Manning]

Nice xmas toy there Scott, brush-less is nice ...... make sure you run that dust collector if you get it around that lead, mdf and other wood dust is bad enough for your lungs.

[sdl2112]

Yes!...I certainly plan too. It can even be configured to only operate if the dust collection hose is connected. I'm out of town now but I hope to play with it later this weekend.

[sdl2112]

Base construction update

I think I'm making these bases more complicated then necessary but oh well...they will be one of a kind :B. The base will very inert with the layering of BB and lead. I am including a port option, the shape and close proximity to the floor make the base part of the port loading. Testing showed it lowers the port tuning by about 2Hz.

I elected to make a cosmetic floating skirt around the base. This will not interfere with the base damping and allow me to finish the parts separately. It also allows me to remove and repair if damaged...a real concern moving these as heavy as they are becoming.

Preparing to glue the legs and base


MDF skirt ready for flush trimming with router


Other side


Done

[TEK]

I think I'm making these bases more complicated then necessary

:a> YES, this is totally overkill.

And I LOVE IT. They look smashing good!:dancenana:
And isn't that the whole point of DIY - to be able to just go totally overboard and make it they way YOU want it to be, without having to think about any commercial stuff! arty:

[sdl2112]

Base update #2

Here's a few more photos.

View of the base and skirt


Another view with the floor slider...should work on carpet or tile/wood floors


Here I show felt sliders for the skirt. When making the skirt I used shims to give a small gap between the skirt and base. The felt disc will compress to fill the gap.


Applying SealCoat

[5th element]

Nothing in this design is being overlooked or skimped over imo!