DIY - 212 cabinet - help with ports calculation

[agedhorse]

Is that a diffraction waveguide? You might check on the driver loading, polar pattern and sensitivity. Generally they are used with an additional flair.

 

[agedhorse]

IMO, Poplar is a good option, especially in that thickness.,

 

[KoziejMaclowski]

Plane wave guide, used also in lophat cabs

 

[Redbrangus]

IMO, Poplar is a good option, especially in that thickness.,

I'm not familiar with poplar plywood. If it's the same construction, there's no reason it wouldn't work about as well. I was concerned the OP had picked up on the guitar-cab quest for more 'resonance'. [Edit: using solid wood] Which I don't consider a desirable attribute for a bass cab. I should have been more specific.

 

[Roxbororob]

Just try to be sure to get ply with the most, thin layers possible. Also (if you can inspect before you buy) look closely at all the edges to see that there are no (or very few and small) voids.

 

[Bander]

I'm not familiar with poplar plywood. If it's the same construction, there's no reason it wouldn't work about as well. I was concerned the OP had picked up on the guitar-cab quest for more 'resonance'. [Edit: using solid wood] Which I don't consider a desirable attribute for a bass cab. I should have been more specific.

 

[agedhorse]

Just try to be sure to get ply with the most, thin layers possible. Also (if you can inspect before you buy) look closely at all the edges to see that there are no (or very few and small) voids.

The thickness of the plys (within reason) is not as important as the consistency of the ply material itself.

In general, the harder the wood, the thinner the plys need to be for (plywood) manufacturing reasons.

 

[KoziejMaclowski]

Just try to be sure to get ply with the most, thin layers possible. Also (if you can inspect before you buy) look closely at all the edges to see that there are no (or very few and small) voids.

Ok I found in my region nearby some plywood:
poplar plywood 18mm 9 layers (is that bad, should be realy 13 layers?), they have B/B or B/BB (not sure wich one yet thye have but not worse quality)
420 kg/m^3
elasticity N/mm^2 4000
flexural strength N/mm^2 36
what you guys think?
manufacture: Garnica, I think it's Spain plywood not Italnian

 

[agedhorse]

9 tubs fine

 

[Roxbororob]

The thickness of the plys (within reason) is not as important as the consistency of the ply material itself.
In general, the harder the wood, the thinner the plys need to be for (plywood) manufacturing reasons.

Edit: Yes.

 

[Downunderwonder]

Poplar is a little softer than pine and quite a bit softer than Baltic birch. Only important if you don't want dents. The stiffness doesn't much matter when it is braced.

 

[KoziejMaclowski]

Ok. So I will go for poplar. If I encounter any problems with vibrations, I would use some bitumen pads + felt. If no, then only Egg crate foam + maybe MDM3 for tuning

 

[Roxbororob]

Ok. So I will go for poplar. If I encounter any problems with vibrations, I would use some bitumen pads + felt. If no, then only Egg crate foam + maybe MDM3 for tuning

9 plies is fine, just check it before you buy. Look at all the edges, you dont want to see many voids. If there are several visible (10-20mm long gaps between the plies) you can be sure there are many that are hidden throughout the sheets. If they are there and you have no choice but to use that wood dont be shy with internal bracing (panel to panel braces dont need to be particularly wide). Use lots of polyurethane construction adhesive, wait until almost dry and easily clean up excess squeeze out with a sharp chisel.

Post photos!

 

[KoziejMaclowski]

 

[JimChjones]

Personally I'd have no concerns about that ply.

 

[KoziejMaclowski]

 

[Roxbororob]

Personally I'd have no concerns about that ply.

+1

 

[Downunderwonder]

That looks like a decorative veneer finish that may not be all that great in a butt joint.

 

[KoziejMaclowski]

That looks like a decorative veneer finish that may not be all that great in a butt joint.

There is no finish on that ply. Its raw. But i think I will try put first layer of lacquer beforce cutting ro avoid edge ripping or mask tape

 

[Downunderwonder]

There is no finish on that ply. Its raw. But i think I will try put first layer of lacquer beforce cutting ro avoid edge ripping or mask tape

I count 7 plys and two very much thinner veneers.