nekomatic Posted January 23 Posted January 23 So the monthly jazz jam I go to has moved venue and whether it's because the 'stage' was on a hard floor and is now on carpet, or something else, I don't know, but I just can't hear myself through the house bassist's down-firing Acoustic Image combo any more. 'I know what' I said to myself, 'I'll bring my own rig next time, the compact transportable one, then I'll be in charge of my own sound. Job's a good 'un!' 'There's one problem,' I replied, 'you don't have a compact transportable rig.' 'Ah,' I said, 'fair point. Guess I'll have to get round to building that Basschat 1x8 then.' So then (and no more internal dialogue, I promise): driver and hardware obtained, timber supplies assessed, and a trip round the side of the house made to cut a bit off the length of spare drainpipe that's been lying around there ever since we moved in; deadline for completion, next jam on 13th Feb; let's go! I already had some bits of B&Q 12mm ply, and one of them was a strip I got cut 280 mm wide for some forgotten reason, so to save me a couple of cuts I've slightly adjusted the size to use a 280 mm wide baffle and back panel. Do not mix these two up Remaining cuts made with the handheld electric saw, using a batten or piece of board clamped to the workpiece as a guide, after careful adjustment (and checking the guide piece is actually straight). This could easily go wrong, but I seem to have got away with it. I cut the driver and port holes with the Dremel and circle attachment. This was very easy but in my excitement I forgot to properly allow for the cut thickness, so both holes have come out a couple of mm bigger than planned. Bit of a pain for the port, which will need packing out with something, but still plenty of wood left for the speaker to seal on as long as it stays properly centred in the aperture. To ensure that I cut some little pieces of a moulding I happened to have spare, and glued them to the insides of the cutout, and that seems to be just right to keep the speaker located. Now off to watch Phil's assembly video one more time… 7 Quote
Pea Turgh Posted January 23 Posted January 23 Oh I love a good cab build! Any thoughts on the finish? Natural wood? Tuffcab? 1 Quote
nekomatic Posted January 24 Author Posted January 24 On 23/01/2025 at 20:37, Pea Turgh said: Oh I love a good cab build! Any thoughts on the finish? Natural wood? Tuffcab? I’m keeping this simple, so it’ll be the same dark brown Tuffcab I used on my previous cab refurb. I’m still happy with how that one looks and it’ll be nice to have them match somewhat. Tonight I cut and drilled all the battens and started dry assembling them to the panels. A couple of errors: the verticals have come out a couple of mm too long (despite measuring against the panels 🤷♂️) so will need some sanding, and I failed to think through that only the rear verticals need holes in both directions, because the baffle will be screwed on from the front. Not fatal errors, I reckon. Some pics next post. 1 Quote
nekomatic Posted January 25 Author Posted January 25 The error I forgot to mention above is that the 25 mm screws I bought are a bit too short to bite in the panels without countersinking them into the battens, so I had to do that, which was a bit of time wasted, especially if you also do it for the holes you didn't actually need to drill in the first place (see picture). Anyway here it is fully dry assembled, apart from the baffle… …and with the baffle in place, which is a nice friction fit. Athough that probably means it'll be too tight after painting the recess. We'll cross that bridge when etc. It's beginning to look like a cab! The dry assembly was worth doing as it allowed me to check that everything fitted together (it did but only after sanding the too-long baffles short) and that all the screws bit and pulled in the panels properly (some of them didn't, so need a bit more countersinking). I found I preferred to use a hand screwdriver to do them up rather than the drill/driver - an elegant weapon for a more civilised age, or something. It's certainly not perfect but I'm fairly confident it is going to be airtight and robust and not wobbly. A little bit of sanding and filler and the wonders of Tuffcab will deal with the gaps and rough edges. It seems a shame when I've just put it together, but the next step is to take it all apart again and reassemble it with the glue. 2 Quote
Phil Starr Posted January 27 Posted January 27 (edited) Dry assembly is something I'd recommend for inexperienced builders and something I still do from time to time with my prototypes. I still get a little enjoyment from seeing it look like a cab early on and it's far better than finding a problem after you've let the glue set The battens are often a problem with a nominally inch square batten measuring anything from 25mm to 19mm. For those who have never built a cab you need the screw to go at least 5mm into the plywood and probably a bit more but it mustn't reach the outer ply so It can't be too long either. 25mm+12mm+37mm so a 35mm screw is probably right so long as you don't over tighten, 19+12 is 31mm so a 30mm screw is pushing up too tight and riscs coming out the other side of the ply or distorting the outer veneer. I use an electric driver but start off with it set to the lowest torque then finish off by hand except the last few screws that are inside the cab and difficlt to access. and lead to bruised knuckles with a hand driver It's coming along nicely though Edited January 27 by Phil Starr 1 Quote
nekomatic Posted January 29 Author Posted January 29 Glued. I thought I'd be clever and save myself further countersinking by digging some slightly longer screws out of the Box Of Random Screws and substituting those for the ones that failed to bite well. Not a bad idea in principle except that (a) some were too long and came out of the outside of the panel - not a problem after removing them again, any holes are tiny and will be easily sanded/filled - and (b) some were too thick, so they felt like they were doing up good and solid but left a gaping crack between the panels, because they weren't turning freely in the batten in order to pull in the panel. All rectified I think. Remaining minor imperfections and gaps due to short battens were filled with wood filler / wood glue mix, which I also ran a bead of along any inside joints that didn't obviously have surplus glue squeezing out. Now dried it feels sturdy and is square. A few places still need a touch of filler but I'm going to leave that until later as I still have a couple more holes to cut and sharp corners to round off, and anything might happen. Marked out the screw positions for the speaker. To me this looks a bit marginal for putting either T-nuts straight into the back of the baffle (one positioned for reference), or self-tapping screws into the baffle alone - what do the experts think? I can easily add a piece of batten behind each hole to give more wood for the fixing to get its teeth into. 3 Quote
nekomatic Posted January 30 Author Posted January 30 Drilled the holes for the screws that will fix the baffle to the front battens - taking care to miss both the screws that fix the battens to the top and sides, and the holes I incorrectly drilled front to back in the same battens - and very temporarily fixed the baffle to the cab and the speaker to the baffle, so that I could measure where the centre of mass sits, and put the handle there so the cab will hang nicely vertically from it. BUT THERE IS A PROBLEM. I wanted to use - and have bought - the round handle from Blue Aran, in sort of homage to the Basschat 112 design since I didn’t use that one in my own 112. However it’s too big to fit in the right position according to the balance point, because the cutout for it would need to come through the front batten and into the baffle. So it’s either fit this handle about 3 cm further back, which is basically in the centre of the top panel, or get a replacement which will have to be less pleasingly circular. 😭 Needless to say I put an order in to CPC earlier today for the last bits I thought I needed 😭😭 No updates for a few days now, we have guests over the weekend and I’ve had to tidy everything up as the kids will have to sleep in the spare room where I was working. Gives me some time to ponder the options… Quote
Phil Starr Posted February 4 Posted February 4 (edited) I've always used a simple strap handle on my smaller cabs, up to and including the BC110T, I have a Monza too as my 'posh' cab and like the look of the handle, which is great but it's a much more awkward carry than a simple strap, not least because the strap is on the side panel so the speakers don't bang on your lower leg. It's also along the COG line so the balance is good. Anything bigger and I put two handles, one on either side. Edited February 4 by Phil Starr 1 Quote
nekomatic Posted February 4 Author Posted February 4 I rejected a top mounted strap handle as an amp head wouldn't sit nicely on top of it, but have to admit I didn't think of side mounting. However I have found a better-suited bar handle from Terralec for six pounds forty delivered, which should do the job (as long as it turns up). After a quick test with an offcut of the ply I have concluded that I'm overthinking the speaker mounting issue and will just use self-tapping screws (with suitable washers) into the baffle. If they prove somehow unsatisfactory I can always upgrade this to some sort of T-nut arrangement. I am hatching a plot for a low cost grille which is either utter genius or utter folly. Stay tuned to find out which. Quote
Bassybert Posted February 4 Posted February 4 This is looking awesome @nekomatic well done! Really looking forward to seeing the finished cab it’s going to look 👌🏻 Quote
Chienmortbb Posted February 6 Posted February 6 On 04/02/2025 at 17:08, nekomatic said: After a quick test with an offcut of the ply I have concluded that I'm overthinking the speaker mounting issue and will just use self-tapping screws (with suitable washers) into the baffle. If they prove somehow unsatisfactory I can always upgrade this to some sort of T-nut arrangement. Many drivers have 8 mounting holes and using all of them with wood screws should be fine if you don’t have Ex-Yodal roadies moving your gear around. It may be worth gluing some wooden blocks behind the baffle to give the screws more to bite into though. 1 Quote
Phil Starr Posted February 6 Posted February 6 I confess I always use woodscrews on my prototypes with the intention of replacing them with T-nuts and rarely get round to doing it. After dozens of gigs with some of the prototypes none so far have ever had a problem, it just feels a bit shoddy I suppose 1 Quote
nekomatic Posted February 7 Author Posted February 7 Grilles. This is a speaker for taking out and about so I want a bit more protection than just some fabric. Custom made and painted speaker grilles aren't cheap, but I am. Well, I'm trying to keep the budget down for this project anyway. ESR do pre-painted speaker grille material which I could cut to size, but with postage that's still over twenty-five quid. Even a piece of unpainted steel mesh from eBay suppliers is north of twenty. The only really low-cost speaker grilles are the round ones you clamp in front of the speaker, but that doesn't protect the port, and I'm afraid I do think they look a bit amateur. The round grilles though, they do come in sizes all the way up to a whopping 46 cm (eighteen inches if you'd rather). That's quite a large area of grille material. I wonder if… A quick consultation with Mr. Pythagoras showed this plan had legs, and part of the CPC order that went in just before I discovered the handle issue was an eighteen inch round grille for seven pounds eighty-six. A few minutes of sparks-flying fun with the cutting wheel on the Dremel (in the back garden, WITH eye protection) and I have a perfectly proportioned grille. The edges are a bit messy, but happily the plastic trim easily comes off the circumference of the round grille (what's left of it) and should cover all that up if cut into the right lengths and attached to the rectangular one with a bit of superglue. I cut sections of batten as shown in pic which are now getting glued to the baffle to mount the grille but leave the baffle screw holes exposed - I could have made a continuous frame and used long screws but this way seems OK to me. The long horizontal piece in the middle is simply what was left over after cutting the other bits, but I decided to use it like that as it should add some stiffness to the baffle. Meanwhile the new handle arrived, and I cut holes for that and for the connector plate, also bevelled the edges and corners with some more Dremel madness (a bit rough, but I'll try and even them out with the proper sander). And here's the handle in place. I think we can say we're going for an 'oversize' aesthetic here, but it fits, and crucially the actual handle is only a centimetre off the centre-of-mass line for near-optimal carrying. As soon as the grille supports are all glued and dry (I only have four clamps, so be patient) I'll be able to assemble and test it… 7 Quote
tauzero Posted February 8 Posted February 8 When I made a grille for the Plenty cab, I used perforated aluminium. https://www.ebay.co.uk/itm/362491694497?var=631653707743 Quote
nekomatic Posted February 8 Author Posted February 8 (edited) That’s not a bad look, at a good price. Do you know what the percentage open area of that mesh is, and have you compared the sound with and without the grille fitted? Edit: Actually their price for 10 mm mild steel mesh is OK too, not sure why I didn’t find that in my own eBay search. Edited February 9 by nekomatic Quote
nekomatic Posted February 9 Author Posted February 9 Assembled for testing. It sounds pretty good! Maybe not quite as refined as the two-way 112 but that's only on a quick test, and I'm still learning how to get the best out of the Eden anyway (which deserves a NAD post at some point). There's a slight whirring sound on low notes at louder volume which I'm assuming is a bit of air leakage and unsurprising as I haven't put screws in all the mounting holes or properly sealed the port. Testing with an oscillator app on the phone, the tuning feels like 60-65 Hz and I can't feel any resonance on the side panels, but I can on the back at somewhere like 80 Hz. Any thoughts on bracing the back panel - a front-to-back brace would require that I glue the baffle in permanently (which is an option), alternatively a brace along the length, one across the width, or how about two diagonal braces from the back panel to somewhere around the centres of the sides? Also have other constructors lined this cab? I've got some wadding left over from the last project. 2 Quote
Pea Turgh Posted February 9 Posted February 9 Nice! And nice amp! The driver will sound better as you break it in. 1 Quote
nekomatic Posted February 10 Author Posted February 10 Two coats black satin applied to baffle and baffle reveal; first coat Tuff Cab to cabinet exterior; port siliconed in. Next update this time tomorrow. Quote
nekomatic Posted February 11 Author Posted February 11 Second coat Tuff Cab. Trim applied to grille. We’re getting close! Quote
Phil Starr Posted February 11 Posted February 11 On 09/02/2025 at 19:50, nekomatic said: Any thoughts on bracing the back panel - a front-to-back brace would require that I glue the baffle in permanently you can use vane bracing on the back panel; ribs of whatever material you have,maybe plywood offcuts. This creates a T beam structure so 25mm added to a 15mm gives you 40mm of stiffening along that part of the panel. You'll get less stiffening for a given weight of brace though but its very easy to apply. You don't need to glue everything in you can add a coupleof pieces of ply to your cross brace and then screw through the baffle into the bits you've added, or glue one end of the brace and use screws on the other end. 1 Quote
Phil Starr Posted February 11 Posted February 11 On 09/02/2025 at 19:50, nekomatic said: It sounds pretty good! Maybe not quite as refined as the two-way 112 That would be asking a lot The 112 has state of the art drivers and one of the best crossovers you'll ever see in a bass cab and it costs maybe 6x the price of the little 8". You should however get quite a 'grown up' bass for such a small cab and a nice musical sound but nothing like FRFR. Anyway I hope you like it 1 Quote
nekomatic Posted February 12 Author Posted February 12 15 hours ago, Phil Starr said: That would be asking a lot I’m always the optimist 😁 I went for the diagonal braces in the end. We’ve Got A Mitre Box And We’re Gonna Use It I’ll have to wait until the cab is reassembled to find out how much use they are but they barely add any weight so can’t really do much harm. Thank you for the further thoughts on the other ways though, which I’ll come back to if I think more is needed. A bit more painting action was needed (inspection in daylight revealed) so it’ll go together tomorrow morning probably. 2 Quote
nekomatic Posted February 13 Author Posted February 13 Cornered (this was more effort than expected, and the electric driver threatened to mash the little screw heads although I'm sure I was using the right size bit, so it was a manual job): Speaker mounted: I was not correct that self-tapping screws into the baffle alone would be fine; at least one of them has pulled its thread out of the wood. I'll have to live with it today but will come back to fix this, probably with T-nuts seeing as I have them. Grille attached, using a nylon washer under each screw to protect the grille from scratches. A couple of the blocks started to split, probably from the combo of not doing a proper pilot hole (I did after that one), tightening too quickly in one go, and trying to put the screw too close to the end of the block, but I reckon I can fix this by forcing a little wood glue into the split while the screw is in then removing the screw and letting the glue set. And subject to those snags, it's done. Obligatory pose with the Eden and the bass: How does it sound? Well, I could tell you more based on noodling about on the landing but since I'm taking it out to a jam tonight, why don't I report back after I've tested it in the field? However I do believe I'm getting ready take back what I said about refinement… 4 Quote
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