Lab Sub wall thickness question

[toshiba_nz]

I have the plans (dimensions for all the pieces of wood) for .75" or 19mm wall thickness Lab Sub Build. I can only get 24mm wall material. How do I compensate the dimensions to stay true to all the internal volumes? Add 10mm to everything?

[GM]

Greets!

No, you'll have to redesign the entire horn to preserve its per unit area expansion.

That said, I've never paid much attention to this horn, but I re-calc'd a sim of a similar bulk horn and the minor increase in CR and reduced cab Vb, mouth area simmed a barely measurable and completely inaudible difference, so if I were in your situation I'd center the internal baffles to split the difference, but as always YMMV, caveat emptor, etc..

Might want to ask here just to be sure though if it's a prosound app: http://www.danleysoundlabs.com/forum/category-view.asp

GM

[Brett]

Originally posted by toshiba_nz
I can only get 24mm wall material.

Search harder. 18mm is fairly generic and is one of the most common sizes.

It's a difficult build, so plan a lot of time and space to do it.

[toshiba_nz]

Greets GM
http://www.geocities.com/hulkss/page3.html has the cad files in a Model Press Myriad format, but the free Myriad reader wont let you change the dimms.
I may just go with your sugestion

Hey Brett, I can get 18mm ply, in a low quality pine. Still not the 19.05mm high quality material thickness used in the plans. I thought about using a thicker ply to compensate for the inferior material. do you have/build the lab sub? Do you play bass thru it? What do you use for tops? What amps and what do you cross the lab sub over @? What wood did you make it from?

[Samuel Jayaraj]

Where do you plan to use the LabSub? A single cab will not get you down in frequency and these were designed by Tom Danley to be used as a set of 6 cabs to get down to 27Hz.

However, you could build an extended adaptor to correct the LF response for even a single cab.

[Brett]

Originally posted by toshiba_nz
Hey Brett, I can get 18mm ply, in a low quality pine. Still not the 19.05mm high quality material thickness used in the plans. I thought about using a thicker ply to compensate for the inferior material. do you have/build the lab sub? Do you play bass thru it? What do you use for tops? What amps and what do you cross the lab sub over @? What wood did you make it from?

I made mine from an 18mm set of plans. I may still have a copy here somewhere.

Also, if this is for domestic use, some of the Tapped horn designs are fantastic.
I'm going to use Don Bunce's LAB12 design (as I have 4 NIB drivers spare), and then there's Erik (Volvotreter's) 3015LF based design, post 666 in the TH thread. MUCH, MUCH, MUCH, MUCH easier build. Hint: try these first; easier to mod to the wood you have available.

[toshiba_nz]

Hi Samuel.. my living room. Its pretty small 4m x 5m. I want to try the version 3 Lab sub. I also had in mind to incorperate them into some bass guitar rig

[toshiba_nz]

Hi Brett,

Don Bunce's says he prefers the Lab12 folded TH, but he only gives plans for the straight TH with few details on the construction of the folded version.
He mentions something about cutting the straight one in half, and gluing/screwing it to the side of the other one...
Do you have these plans, or can you get them? Cheers

[Brett]

Originally posted by toshiba_nz
Hi Samuel.. my living room. Its pretty small 4m x 5m. I want to try the version 3 Lab sub. I also had in mind to incorperate them into some bass guitar rig

I wouldn't bother with a LAB for a BG rig. Doesn't go low enough in single units, is too big and heavy. A single Eminence 3015LF in 120L will give more than adequate SPL and LF extension. Add something else above it if you like full range. Anything more than this and you sould be through the PA.

[Brett]

Originally posted by toshiba_nz
Hi Brett,

Don Bunce's says he prefers the Lab12 folded TH, but he only gives plans for the straight TH with few details on the construction of the folded version.
He mentions something about cutting the straight one in half, and gluing/screwing it to the side of the other one...
Do you have these plans, or can you get them? Cheers

No. Tall and skinny works best for my room.