New BassChat 8"Cab design

[tauzero]

2 minutes ago, Phil Starr said:

Here you go two of the fane's in a 40l cab will do this with a fully rated amp driving 450W into the cab. That's a couple of db louder than most 12's. What it will need is a decent sized port as the amount of air that port will be moving at full power will be considerable. I've looked at using a 110mm soil pipe inside diameter 108mm 11.15mm longas a decent compromise. I'd be rear mounting the port so as not to weaken the front baffle too much.

 

 

If the port is 11.15mm long, surely that means it will be shorter than the thickness of the cab (assuming 12mm ply).

[rwillett]

I see that many people round the edges of the cab.

 

Is there a good reason for this please? Perhaps for the mottled finish or because the plastic corners assume so?

 

If so what's the recommended radii? 5mm?  12mm? Or just to take edge off?

 

Thanks. 

 

 

[Pea Turgh]

1 hour ago, rwillett said:

I see that many people round the edges of the cab.

 

Is there a good reason for this please? Perhaps for the mottled finish or because the plastic corners assume so?

 

If so what's the recommended radii? 5mm?  12mm? Or just to take edge off?

 

Thanks. 

 

 

I assume it’s to lessen the impact to your fingers when you walk in to some immovable object loading in.  I’ve got a hell of a lump on my little finger where I bashed it on a hand rail carrying a tumble dryer - if only it had rounded edges…

[Stub Mandrel]

2 hours ago, rwillett said:

I see that many people round the edges of the cab.

 

Is there a good reason for this please? Perhaps for the mottled finish or because the plastic corners assume so?

 

If so what's the recommended radii? 5mm?  12mm? Or just to take edge off?

 

Thanks. 

 

 

 

To stop chipping and make it more pleasant to handle. Very easy with a router.

 

Also paint won't take well on sharp corners. 

 

12mm is good.

Edited Friday at 09:45 by Stub Mandrel

[rwillett]

1 minute ago, Stub Mandrel said:

 

To stop chipping and make it more pleasant to handle. Very easy with a router.

Fair enough...

[nekomatic]

Also because the plastic corners do need a rounded edge, or at least the ones I’ve used did. 

[rwillett]

1 minute ago, nekomatic said:

Also because the plastic corners do need a rounded edge, or at least the ones I’ve used did. 

I've printed mine and they assume a square edge. I think I'll do some rounding on the dges and do a redesign of them

Rob

[Obrienp]

10 hours ago, tauzero said:

 

If the port is 11.15mm long, surely that means it will be shorter than the thickness of the cab (assuming 12mm ply).

I have no expertise at all but I have the feeling it was a typo and @Phil Starr missed out a zero: 110.15?

[Chienmortbb]

3 hours ago, Obrienp said:

I have no expertise at all but I have the feeling it was a typo and @Phil Starr missed out a zero: 110.15?

That is about the length on the prototype. 

[RhythmJunky]

18 hours ago, Phil Starr said:

 

Edited Friday at 18:18 by RhythmJunky
Realised it'd been asked before. I hadn't refreshed the page...

[Mottlefeeder]

13 hours ago, rwillett said:

I've printed mine and they assume a square edge. I think I'll do some rounding on the dges and do a redesign of them

Rob

Bear in mind that wood with a paint finish will have a different overall radius to wood with a rat-fur finish.

 

I'd start with the corner radius and work out the wood edge radius to suit.

 

David

[Phil Starr]

23 hours ago, tauzero said:

 

If the port is 11.15mm long, surely that means it will be shorter than the thickness of the cab (assuming 12mm ply).

Cm 🥹😅

[rwillett]

9 hours ago, Mottlefeeder said:

Bear in mind that wood with a paint finish will have a different overall radius to wood with a rat-fur finish.

 

I'd start with the corner radius and work out the wood edge radius to suit.

 

David

Thanks for this. I've got some router bits with a decent curve 6mm and 12mm from memory. [Nope 3mm and 6mm after checking]

 

I've also got my identically sized spray booth to practise on so I'll see which size works best. 

 

I'll probably round the plywood, put the Armacab on and then design new 3d printed corners to fit. 

 

Redesign should be relatively easy. 

 

The only area I'm slightly puzzling over is the front as it's just 12mm of ply sticking out. Will look at what other people have done here. 

Edited Saturday at 09:48 by rwillett

[tauzero]

15 hours ago, Phil Starr said:

Cm 🥹😅

 

Damn confusing metric units. Far simpler to use imperial: 0.00055426 furlongs.

[tauzero]

6 hours ago, rwillett said:

The only area I'm slightly puzzling over is the front as it's just 12mm of ply sticking out. Will look at what other people have done here. 

 

On the ones I've made (BC 112, BC 6" micro, my own Plenty), I've rounded the outer edge with about 12mm radius and left the inner edge as is. The micro cab (leatherette covered) has a cheapo round speaker-sized grille, the BC 112 (Tuffcabbed) and Plenty (leatherette) have metal grilles, and I've got a piece of aluminium grille for the 8" cab. https://www.ebay.co.uk/itm/362491694497?var=631653707862

Edited Saturday at 16:05 by tauzero

[tauzero]

 

 

 

 

[Chienmortbb]

53 minutes ago, tauzero said:

 

 

 

 

Can you get longwave on those?

[tauzero]

2 hours ago, Chienmortbb said:

Can you get longwave on those?

 

I don't bother since Test Match Special ended.

[rwillett]

Do people mask off the area for handles or simply roller [Tuffcab|Armacab|Wernex] over them?

 

I've drilled holes for the speaker, the port and the rear panel. I've also put M3 or M4 pronged t-nuts behind the holes so that's all done. Should I mask the area off or not?  

 

Not yet done holes for the handle or amp mount so checking now. 

 

I think I should mask off but not sure.  

 

Thanks

 

Rob

[Chienmortbb]

On the prototype, I put the handle on after applying Tuffcab. The advantage of masking is that it guarantees that the handle will sit flush but at the handle dimensions are variable (on most strap handles). 

 

If you are not going for a full-on Artex type of finish, then the handle will be secure and in my case is sat well on top of the Tuffcab. 

[rwillett]

Thanks.

 

Did you mask off the area where the speaker meets the front baffle? I would have thought that should be done, to ensure a tight fit, but happy to be advised otherwise. 

 

Rob

Edited 6 hours ago by rwillett

[Chienmortbb]

42 minutes ago, rwillett said:

Thanks.

 

Did you mask off the area where the speaker meets the front baffle? I would have thought that should be done, to ensure a tight fit, but happy to be advised otherwise. 

 

Rob

I painted the baffle Matt Black as Tuffcab is not a good idea in a baffle. I stopped the Tuffcab at the inside edge and started the Matt Black from there.

[rwillett]

Ah! Didn't realise that. 

 

That makes sense now. I was going to put a grill on as well. So matt black(or red Hammerite) is fine on the baffle. 

[basstone]

2 hours ago, Chienmortbb said:

I painted the baffle Matt Black as Tuffcab is not a good idea in a baffle. I stopped the Tuffcab at the inside edge and started the Matt Black from there.

Is it not a good idea only from the perspective of getting a good seal on the drivers or is there another reason?

[tauzero]

1 hour ago, basstone said:

Is it not a good idea only from the perspective of getting a good seal on the drivers or is there another reason?

 

The battens around the front edge and the holes for the port and the speaker mean it's not that easy to apply the Tuffcab. Painting it black (I used rattle can matt black on the ones I built) is much easier, and if you're putting a grille on, you can't really see the texture anyway.