BC 8" cab

[rwillett]

23 minutes ago, stevie said:

If you buy white, you should be able to make whatever colour you want with some acrylic colourant. I've done this myself with colourant from Polyvine. I've never tried tinting white - so I've no idea how much you'd need. To get a good textured finish, you'll need the special foam rollers from Blue Aran. They're not the same as the ones you can buy in DIY stores - the foam is much coarser. You can buy them from Ali Express but I haven't seen them anywhere else. If anyone knows another source, that would be useful.

Blue Arran has no foam rollers in, I think their statement of "Huge Stocks" on their front page is not quite accurate TBH. I'll pass on the tinting at the moment. I'll never get it right. These rollers are exceptional value on eBay

https://www.ebay.co.uk/itm/325770386035.

 

31 minutes ago, stevie said:

If you can recess the input panel, you'll achieve a better seal - and it will also look better - but surface mounting works also. Don't for goodness sakes mess about with sealant. Use adhesive foam strip. 2mm thickness is about right.

Message understood on sealant  If the rain would stop,. I can test making a recess in some scrap wood. Already got the foam.

 

32 minutes ago, stevie said:

I'd use screws on the rear panel. Plenty of them. I'm assuming you're gluing the panel in, but do use foam gasket otherwise.

 

Not sure what you mean here, I'm expecting to glue the front panel in. I was also going to glue the rear panel in, but could use foam gasket as you suggest and screw that in. Is that what you meant? Glue the front panel, but screw the rear panel and use foam gasket. If I do that, I might have to recess a 20mm section on the rear panel as it'll stick out. Its flush fitting and anything would make it stick out. 

 

42 minutes ago, stevie said:

If the Fane is already gasketed (which is unusual), you won't need to add any more.

 

The Fane has two rounds of dense foam on top of the metal ring and underneath the metal ring. You can see the bits missing to allow screw access. Is this the gasket? or should I put adhesive foam between this and the wood baffle?

 

 

 

36 minutes ago, stevie said:

Fixing the speaker with T-nuts and bolts (likely M4 or 5) is the preferred method, but woodscrews should work on this size of speaker. If the Fane is already gasketed (which is unusual), you won't need to add any more.

 

I was going to say I have loads of t-nuts as I use them for aluminium extrusion, but I suspect you mean these

 

 rather than these  which are also called T-Nuts  Same name and different nuts, I'll check in the garage, but easy to get.

 

40 minutes ago, stevie said:

If you really need silicone sealant, you haven't built the cab properly. 

Well......

 

40 minutes ago, stevie said:

Unless you have a good (i.e. expensive) crimp tool and the correct crimps (there are different specifications), solder the terminals. It's fine.

 

I do have a decent crimp tool but I much prefer solder. 

 

41 minutes ago, stevie said:

Sealant has no place in a speaker cabinet!

 

Back to the bathroom it goes. 

 

Thanks for the comprehensive reply. Really helpful

 

Rob

 

[rwillett]

Apologies, just realised I've hi-jacked this thread. Sorry, I thought I was in the other thread. I'd repost but @stevie's response is very good. Let me see if I can move things around.

 

Rob

[tauzero]

That's OK.

 

I'd found the Penn Elconn website but the page I found had massive quantities for massive prices. That's a lot more like it, I'll get some black ordered.

 

In order to escape Antiques Roadshow, I did more cab building. Previously I'd got the battens on the side panels so now it was just a case of sticking the side panels onto the bottom, then putting on the top. Then see how well the front and rear panels fit.

 

I tried the rear panel first. It didn't fit in one way up, so I reversed it and it popped straight in. Slight gap but the rear panel is destined to be fixed in place so there will be some filler going in there.

 

 

Then the front panel - I think I'll be doing as Phil suggests and screwing this in place with 3mm thick neoprene adhesive strip 10mm wide round the joint. The fit was nice and snug.

 

 

Having done that, I went round the top and bottom panels putting the cross battens in place.

 

 

To do: cut hole for speaker, fix rear panel, make and fit cross brace, put wadding in, round over edges, fit front panel, paint, add corners, add handle, wire connectors, install speaker.

[tauzero]

Speaker paint ordered from Penn Elcomm, I should have some Blue Aran rollers knocking around as well as black spray paint.

[rwillett]

Looks good. My panels needed to fit in a certain orientation as well. 

 

I appear to have made the back panel flush so if I put any foam behind it, the panel would stick out so am contemplating what to do. I could route a 1.5mm ish recess around the back panel so I could put foam in. 

 

Not sure on foam stripes, wadding or cross brace. Advice seems varied on whether it will help. I suspect we both have the same offcuts so the cross braces seem easy to do though. 

 

Suspect the weather won't be good here so might be Saturday before I do anything else. 

 

Let's see how yours goes. 

 

Rob

[stevie]

21 hours ago, rwillett said:

Not sure what you mean here, I'm expecting to glue the front panel in. I was also going to glue the rear panel in, but could use foam gasket as you suggest and screw that in. Is that what you meant? Glue the front panel, but screw the rear panel and use foam gasket. If I do that, I might have to recess a 20mm section on the rear panel as it'll stick out. Its flush fitting and anything would make it stick out. 

 

I seem to have made things more complicated than necessary by mentioning using foam gasket to seal the back panel. Please ignore, and glue the back panel in. I'd still suggest using screws to ensure that the panel is firmly glued to the battens. If you drive the screws below the surface, you can fill the holes with wood filler and sand.

[stevie]

21 hours ago, rwillett said:

The Fane has two rounds of dense foam on top of the metal ring and underneath the metal ring. You can see the bits missing to allow screw access. Is this the gasket? or should I put adhesive foam between this and the wood baffle?

 

 

 

 

 

 

It looks like that driver comes with its own gasket already fitted. So, you won't need any foam. I wish other driver manufacturers would do this.

Edited Monday at 09:55 by stevie

[tauzero]

3 hours ago, stevie said:

 

I seem to have made things more complicated than necessary by mentioning using foam gasket to seal the back panel. Please ignore, and glue the back panel in. I'd still suggest using screws to ensure that the panel is firmly glued to the battens. If you drive the screws below the surface, you can fill the holes with wood filler and sand.

 

Alternatively, put the screws in from the inside. Also, fill gaps with wood filler to make the joint as airtight as possible.

[rwillett]

I have a lot of good clamps so it's not any issue to glue and clamp. Easier than screws, no work at the end with filling, though I will need to fill some of the areas.

 

Also just had a call from Penn Elcom apologising that the Armacab won't be here until Weds this week. Somewhat surprised as I wasn't expecting it until Friday anyway, so pleasantly surprised. 

 

Rob

[tauzero]

I got the same call - was just about to post here about it. Wasn't expecting that, I ordered it last night with the only delivery option being next day (which I assumed would be Tuesday). I'm not in any rush.

[rwillett]

My Armacab arrived Weds. Well packed, but still sitting in the box. Have you started yours yet? Was interested in what prep you are doing. 

 

My intention is to try it on some off cuts and see how it handles slight defects on the edges. Not sure if I need to have the surface piano grade smooth or the armacab will easily handle the small splinters on the edges. 

 

Also not sure if I want or need to round the edges. People seem to do it but I'm not sure why. 

 

My cab is basically done bar wiring and finish. Slightly nervous about the covering though. 

[Si600]

Stupid question, but could you make a cab out of perspex?  I'm thinking something like the appearance of a glass tower block where the plates are held with stainless buttons and the like?  Or maybe just face a plywood box with thin sheets to make it look like a glass cube.

 

Just wondering really, I'm not going to attempt it  

[rwillett]

Si

 

I've tried using perspex once and I'm not looking to do it again. It's a difficult material to work with and the use of power tools was really tricky. I gave up as things splintered and scratched.

 

However other people may be far better at it than me. 

Rob

[LawrenceH]

1 hour ago, Si600 said:

Stupid question, but could you make a cab out of perspex?

We've got quite a lot of strange perspex boxes made by our workshops (for laboratory experiments). It's heavy and prone to cracking, but you could certainly do it with the right cutting blades and drill bits.

But if you wanted it to sound good you'd need some kind of wadding inside which might spoil the look.