Bass enclosure for 3 way

[Dr.EM]

Ok, well I just hope I won't need to adjust it much once installed. Making a removable panel sounds a bit tricky at this stage

Some more progress anyhow. Angled deflector has been installed now. It's 9mm ply but well supported by large pine blocks. I used allen head screws as clamps were tricky to mount the board to the blocks, they were temporary though, it's just the glue holding it now so I have a flat area to fix foam to.




The blocks are a bit rough as all I had to cut them was my jigsaw! Tried to router them from a template but it wasn't stable enough. Seems mostly in contact though, I used more angled blocks to clamp these blocks on initially, giving me flat surfaces to clamp against temporarily. It feels pretty solid to knock on.

I've just been preparing the 100mm studio foam. I know I wanted some behind the driver so that has been cut, admittedly crudely with straight edges and a kitchen knife, but acceptable! The angled deflector, if nothing else, has allowed more foam area to be installed behind the driver.

I have more foam left though, what is your advice for where in the cab to install it? I was thinking at the bottom, but am not certain. Mabye on one side will be better?

[Andersonix]

Originally Posted by Dr.EM

I have more foam left though, what is your advice for where in the cab to install it? I was thinking at the bottom, but am not certain. Mabye on one side will be better?

I would continue lining the surfaces closest to the back of the woofer, so the sides and top, and maybe even the rear of the baffle itself if it was easy enough. It's looking really good so far...

Have you thought about any provisions for feet or outriggers? Such as threaded inserts or something?

[Dr.EM]

Ok, that sounds like a plan, the side walls are rather close to the driver so I suppose I ought to line them! I might have to cut the foam down a bit though to fit it in.

I am having some special feet made for this and similar smaller ones to go on the top section. Here's what they should be like, solid aluminium:



Allows the spikes to be beyond the bounds of the cabinet base for more stability, and I think they will look nicer . The nature of the part tends to keep it in place under the cabinet weight, but each will have a wood screw holding it. Expensive stuff, but hopefully worth it; these little details make a big difference imo

Big issue is "veneer". The top front baffle part is real wood, but the rest basically has to be a "fablon" type material, and with the dark one no longer available I still can't decide on what I want

This is looking the best so far, and I might be able to get 900mm wide material which will wrap right round

[Andersonix]

Regarding your feet: I feel you should mount them to the cabinets better than just one wood screw, as just simply tipping or moving the cabinet can put large sideways forces on one foot. Maybe also put a screw horizontally through the upright part to keep the foot from rocking or twisting and a gap appearing? Or redesign it to make it mounted to the cabinet better (like threading holes in it and screwing it on from the inside).

Also give yourself the option of using several types of feet: spikes (or cones), 'gliders,' and rubber feet, so you can explore the differences and compensate for different types of floors and building construction. Spikes aren't automatically better...

[Dr.EM]

Thanks for your input! The parts are being made undrilled, so I can drill what I need to mount them. Perhaps 2 woodscrew holes (long allen head types as seen mounting the plywood deflector), or a machine thread and fixture from the inside (but I suspect the overlap is still mostly over the cabinet walls). It shouldn't come away from the cabinet side as the weight pushes it against it with a levering effect, or so a wooden mock up I made did. I will try to avoid moving these with spikes installed.

I plan spikes in the bottom ones which I will buy after and just fix to an M6 thread I will create in the aluminium. Since these will be on carpet this seems best? The top section ones will use adhesive rubber feet though, I'd actually like some clear ones like those which come with hammond enclosures. Ideally a bit more jelly than hard rubber too.

At the moment it's seeming like these cabinets won't be all that heavy anyhow, which is strangely dissapointing! There is a sand filled section of the front baffle planned though (the lower front baffle) though it will only be 18mm sand fill depth

[MJL21193]

Heavy is overrated

Looking good Dr.!


I like those feet! (and I feel certain that one screw will hold them just fine).

[Dr.EM]

Thanks for the comments!

Bit more progress. Side panel is glued on. Not as well as I'd have liked, I figured I could do with about 6 more clamps to get really good contact at all points, but it is on nevertheless. I also prepared some more foam, tricky cutting it accross it's thickness but I managed to do it roughly to make these side absorbers (not glued in yet!):



There's a partial block under the top brace too not really seen here. I also have a bit left still which I will find locations for

After this photo I routered off the excess 9mm ply from all round. Now I shall be adding in the ribs on the other side panel and mabye adding struts tying some pairs together. Internal volume is rather dimimshed, probably around 30L only now! Don't know if the foam adds or takes away effective volume, lightweight BAF supposedly adds it by slowing the movement of air.

Already not looking forward to having to build another cabinet from scratch

[Dr.EM]

Been a while! A few updates are in order

I am now (nearly) seeing double!



Unlike the top sections, I didn't build these alongside each other, so most my time has gone into building the second one you see on the right. It needs a few internal beams, the little ply braces as you see on the left one (felt they might be of some use), and to router off the excess ply.

Also, the metal feet are ready! I picked them up some weeks ago and drilled them myself:




There are 8 like this and 6 mini ones for the top sections. Feel very sturdy, at least in side to side motion when fixed (or actually just resting on) the bottom of the cabs:



Next is to make the front baffles, for which I will need real wood in some places. Plan is 9mm base, then top has 27mm real wood and lower part has 18mm MDF+9mm MDF. The slight thickness of the fablon material on the bottom might upset the theoretical match here though, will have to see how close tolerance the real wood is. I will also need to purchase a 1/2" roundover bit which I have planned

[Dr.EM]

Not any progress to show unfortunately, I'm stuck a bit at the moment, need to figure out exactly what I must do next.

I have a concern however. These cabinets are sitting out in our unheated garage. We are having frosts overnight sometimes now so I'm concerned this might take it's toll on the glue joints? I have always used this glue:

Adhesives and Sealants for the DIY, Trade & Stationery Markets

The bottle says "for use from 5-30 celsius". Obviously, it'll be getting below 5c now, but do you think that's just the temperate it can dry at? Apparently it's PVA based but incorporates resin too. It hasn't shattered apart or anything and feels solid, but I am concerned it may be weakening it

[MJL21193]

Originally Posted by Dr.EM

The bottle says "for use from 5-30 celsius". Obviously, it'll be getting below 5c now, but do you think that's just the temperate it can dry at? Apparently it's PVA based but incorporates resin too. It hasn't shattered apart or anything and feels solid, but I am concerned it may be weakening it

Hi, Good progress!
That's the temperature you need to use the glue in, once it's dry it will be unaffected by cold. Keep the glue from freezing in the bottle also by storing it in a heated place.