Another DIY cab thread. Loud, Small, and Cheap. 22 pounds that pounds.

[Rick Auricchio]

The other would be a light stain and poly seal.

The only issue is whether the birch ply is nice enough to stain. The sheets I got were very good, but in some cases there were blemishes that might not look pretty.

(Although I am having irrational premonitions of slicing off my fingers with the circular saw.)

My table saw is too small to cut 15x15 panels, so I built a circular saw "sled" as documented by Bill Fitzmaurice. Clamp the sled into position, think carefully about where your hands are, and cut. It helps to clamp the workpiece down so it doesn't move; if it were to move you might try to grab it, and that's where an accident could happen.

I will post the instructions for the saw sled, used without permission. I'll hope he considers this a public service announcement!

 

[Rick Auricchio]

Reprinted from Bill Fitzmaurice's Omni-10 plans, without permission:

"Another handy tool is a circular saw sled. To make one cut two pieces of half-inch plywood, one about six inches wide, the other about two inches wide, both about three feet long. Screw the two pieces together as shown here, so that when you set the saw shoe against the upper piece there's about a quarter-inch of material remaining to the outside of the blade."

See the attached photo from Bill's document. I added the "cut line" indication.

"Run the saw the length of the sled, the shoe tight to the stop piece, cutting off the excess from the lower piece. Now you have a zero-clearance cutting jig. Place the sled edge at the cut line and the saw will cut exactly along that line."

I marked the sled in several places saying "good piece on this side of the sled" so I'd never put the sled on backwards. One time I had it the wrong way round, then I caught the error before cutting.

You clamp the sled into position and run the saw along it. As always, be very careful.

 

[FerruleCat]

BUILD UPDATE:

I have the wood for two cabs and will start my cuts this afternoon.

In other news, I've ordered the amp. I won't give that away until the final rig reveal, but it's neither a MarkBass nor an Aggie (although I would like to add a TH 500 down the line.)

I probably won't report back until I have the boxes built, at least.

Thanks again to Lowactnsatsfctn for engineering such an efficient cab, and to Rick for the excellent build detail and advice.

 

[Scottkarch]

Hi there. I'm thinking of building something similar. If I keep the same internal volume can I make the cab taller and shallower?

 

[Rick Auricchio]

You should be able to adjust dimensions as long as the internal volume is the same. I'll let Lowactnsatsfctn run the numbers. I could calculate it but it seems faster to just have the computer do it.

I suspect the change might be an inch or two shallower and taller. With a taller cab I'd move the driver upward to put it farther from the port.

The weight probably won't change, of course, because you'd still be using the same amount of wood.

EDIT: My quick calculation says this. If you move the back (14x16) in one inch, that reduces volume by 224 cubic inches. Adding 1-1/4" of height gains back 227 cu.in. which is close enough. Total height would be 18-1/4 rather than 17 inches.

Port dimensions wouldn't change.

I don't know if the modeling would allow two inches shallower; at some point I'd expect that to be crowding the driver, or reducing the effectiveness of the port. If you can go two inches shallower, you get close with 2-1/2" of additional height. That makes the cabinet 19.5" tall.

Any shallower/taller and they may be a little wobbly when stacked, unless your amp head is very light.

Disclaimer: Let's wait for the real answer from Lowactnsatsfctn.

 

[will33]

Natural wood finishes can be really pretty...and susceptible to nicks/scratches etc. if you do a lot of hauling and gigging.

I've considered going that route on a couple rig builds, using colored stain like a dark green or cranberry red, so it's colored but still has all the visible wood grain. In this case, the color doesn't really matter, it's a personal preference, it's the clear coat I'm getting at.

One thing I'm considering for these that you may want to, is using a tough, oil-based clear coat like we use on hardwood floors. Yes, it's stinkier than water-based stuff...needs a couple days to gas out and cure, but is really tough (think women in heels walking on wood). I'm think the durability is worth the initial stink. And, can always roll on a fresh coat if it does get too beat up and it comes out looking new again. You'd just likely have a lot longer use time in use between the future "freshen up" top coats. Stuff takes wetsanding & buffing really well too if you want a really rich finish. Can use the same process as you would a car finish.

 

[FerruleCat]

Thanks for the great tip, will33, but my plywood selection has ruled out a natural finish -- too many surface fill patches. I'll just stick with the minimalist black duratex look, which will be sleek... WITH MY NEW TONEHAMMER. Sweetwater has just sprung a one-week, 36-months, no-interest deal that covers Aguilar, so I jumped on it.

In other news, I made a circular saw cutting sled last night, but somehow my entry and exit were bad, so I wound up with a freaking arc in the edge of my sled. How you cut a freaking arc with a circular saw using a guide rail over a mere 36 inch span, I have no earthly idea. But I did it. The good news is that I check these kinds of things before ruining a bunch of plywood. I did, however, hang everything up for the night after that -- too much bad juju.

And in still other news, I saved $2 by buying two 2x2 3/4" baffle sheets instead of one 2x4 baffle sheet. That's good, because now I need to buy more wood for sled attempt #2.

 

[will33]

Use the edge of a precut panel as your straightedge for the saw foot to run against. I also check them with a 4ft. level (straightedge).

Be surprised how many things that are supposed to be straight are in fact not.

Don't push/force the saw too much, that makes curves. Make sure things are clamped/screwed down tight and focus on keeping the foot butted up against the straight edge the whole way.

 

[will33]

Also never use the marks on any saw as an accurate measure of angles. Even a little kids gradeschool protractor is more accurate than those. Always use a protractor to set the blade to 90 degrees (or 45 or whatever). Something simple and cheap is ok.

 

[will33]

I use one like that I got at Harbor Freight for $5. It's way more accurate than the markings on even an expensive saw.

Of course, the wonders of PL Premium glue makes all this a bit academic. It's probably more important to get the angle right on the saw sled than it is on the cab with that stuff.

Also make sure your blade is straight and sharp, or buy a new one just to make sure. A lot of even so-called high-quality tools nowdays are just cheap chinese stuff with a brand name. Get your blade a little too hot one time and it will warp and cut curves, even if you can't visually see it as being warped.

My circular saw is ancient, and has an old titanium blade in it from back when things were made to last. I've never had to change it. It'll still slice through nails and screws while cutting so straight you could make arrows with it.

They don't make them like that anymore. I got the whole thing, saw with the blade in it, at a pawnshop for $12 many years ago.

Point is, double-check your tools themselves. Sometimes it's really not operator error.....that is unless you figure the operator should be able to reverse-engineer and compensate for tool deficiencies on the first cut.

 

[Lowactnsatsfctn]

Hi there. I'm thinking of building something similar. If I keep the same internal volume can I make the cab taller and shallower?

You can do what ever your heart desires. However, I will say that straying too far in either direction as far as box volume goes, either lessens power handling greatly, or brings in a mid bass hump that creates "boom".

How much taller and thinner were your thinking? (think women in heels) haha


Rick, thanks for keeping the thread going, the detailed directions and cut list. That's just what some people need to take a project on. I think yours look better than mine haha. The duratex is a nicer finish than the spray on bed liner I used IMO, but they are both better than..... carpet.....


I used a drywall T square or 4' level clamped to the wood as a guide for years before I got a table saw.

 

[Scottkarch]

Thanks for the answers. I'll mock something up with cardboard to get an idea of sizes. I guess I was thinking can I before I figures what sizes I'd like. Thanks for the thread. It's great.

 

[will33]

The duratex is a nicer finish than the spray on bed liner I used IMO, but they are both better than..... carpet.....

Depends on who you ask.

 

[Rick Auricchio]

Scott, as long as you try to match the existing internal volume of the cabinet you should be good. If you steal an inch from one dimension, figure out how many cubic inches that takes out. Restore those cubic inches (or as close as possible) by increasing another dimension.

Remember that the back of the cabinet is still 14w x 16h in its original size, which is 224 sq inches. (You have to include the port opening as part of the back even though it's a port.)

 

[FerruleCat]

I've been wondering about internal cab volume and all the things we do to reduce it, including bracing, recessed handle cups, and batting. I've seen some images of fEARful builds that were extremely aggressive with egg crate padding, and I have to wonder how much of the target volume was actually left.

In practice, it looks like builders don't sweat those details, though.

I know I'd feel more confident if I would add full-length 1/2 inch cleats to the edges of the panels -- and I just might. It would double my gluing surface area and would surely reduce the likelihood of any air leaks. The total volume lost would probably approximate a recessed handle cup, which could be recouped if needed by using an externally mounted strap handle.

 

[CL400Peavey]

I've been wondering about internal cab volume and all the things we do to reduce it, including bracing, recessed handle cups, and batting. I've seen some images of fEARful builds that were extremely aggressive with egg crate padding, and I have to wonder how much of the target volume was actually left.

In practice, it looks like builders don't sweat those details, though.

I know I'd feel more confident if I would add full-length 1/2 inch cleats to the edges of the panels -- and I just might. It would double my gluing surface area and would surely reduce the likelihood of any air leaks. The total volume lost would probably approximate a recessed handle cup, which could be recouped if needed by using an externally mounted strap handle.

Per the batting: That generally isnt seen as reducing your internal volume. You can over or under stuff, but that will effect your mids.

Cleats: If you are using something like PL Premium, the joints will end up stronger than the panels. No reason to use the cleats.

 

[will33]

For true net volume you subtract for anything taking up space in there, yes....But....when it gets down to differences of only a few cubic inches, like a corner cleat or handle cup, the differences in the end result are getting so miniscule as to be considered inaudible, especially playing with a band.

Get as close as you can, yes, but don't agonize over a few cubic inches here or there. Don't use some type of handle you don't like as much, etc., thinking those 4 cubic inches are so crucial they'll make or break the design...they won't.

 

[FerruleCat]

I don't know, man. I really find that ABS handle cups add a certain pleasing resonance.

I'll just forge ahead without cleats. Once I break my "traditional adhesive" mindset, I'm sure I'll get it. Of course, now my expectations are high.

Thanks, all! (Good to see you, Peavey.)

 

[Scottkarch]

Cool. OK I have to admit, I'm going to keep coming up with ideas and changing my mind until it's built. I am thinking that 1x112 will be plenty for a small practice space... especially because we're also using our IEMs to get used to the IEM mixing ( new Mackie DL1608 ). So with only one cab, I will come up with plans/dimensions for a kickback cab. I'll draw it up and post in case anyone wants to review. Thanks guys



As far as tone on this speaker. For years I used a Peavey 115 Black Widow. No tweeter.. just single 15. Always liked the tone. Should I expect this tweeterless 112 to be similar? At least closer to a 115 without a tweeter vs my TC cab with a tweeter in it.

 

[will33]

Cool. OK I have to admit, I'm going to keep coming up with ideas and changing my mind until it's built. I am thinking that 1x112 will be plenty for a small practice space... especially because we're also using our IEMs to get used to the IEM mixing ( new Mackie DL1608 ). So with only one cab, I will come up with plans/dimensions for a kickback cab. I'll draw it up and post in case anyone wants to review. Thanks guys



As far as tone on this speaker. For years I used a Peavey 115 Black Widow. No tweeter.. just single 15. Always liked the tone. Should I expect this tweeterless 112 to be similar? At least closer to a 115 without a tweeter vs my TC cab with a tweeter in it.

Which model of Widow?

Compared to a 1502, this cab should be clearer/cleaner/more "focused", and less of the really aggresive grind those give when you dump power into them.

Compared to a 1505, might be a little more familiar in that it'll hold together under power. Likely different "character" to the mids but the biggest difference being a lack of that body-vibrating depth the 1505 can give.

Just going by "spec sheet stuff" here. Obviously the OP would be better able to describe the nuances of his cab.

I am pretty familiar with Widows though, with the 1505 being one of my favorite one-way "one speaker plays it all" bass guitar speakers there is.