stevie

Progress. This is the first cab to come off the CNC machine and it looks fine to me - thanks to Chimike's sterling drawing work. That's also the metal grille wot I made. Grilles are still a work in progress as I'm exploring more avenues thanks to some bright ideas from Luke. It's going off tomorrow to Pete aka funkle. Unless he finds any serious shortcomings (unlikely), I'll be ordering the first batch next week.

Video cameras don't normally tell you much, but the mids are really crisp here. Note definition is good. The midrange driver's really showing its worth.

I've just charged two of my 9V batteries and they measure 10.1V. They're Uniross ones, but a type they don't make any more. I've just stuck an EBL in the charger and will report when it's charged. Because they last a long time, they also take a long time to charge.

My EBLs also last noticeably longer than the normal Ni-Mhi ones. Did you measure the 8.4V?

I've had half a dozen 9v rechargeables on the go for several years and haven't had a failure yet. They're all decent brands, i.e. made in Japan and not China. [Actually, scratch that. Some of them are made in China, but you need a magnifying glass to find that out.]

I used the parameters published by BMS. I have one of these drivers (which is why I know how good they are) but it's a 4-ohm version. I measured the TS parameters and they were reasonably close to the BMS figures. If you check that what you have is similar to what's in the BMS spec sheet and you should be all right. Your WinISD results look fine to me. Another thing worth mentioning, because not many people are aware of it, is that the low frequencies from a large, rear-ported cab don't develop fully until you're well in front of the cab, say 10 to 12 feet. So try listening from that distance and you'll hear the lows from the port becoming louder.

Even a small leak can make a difference. They can happen if there's no foam gasket around the driver or, in a combo, if the hole that the wires pass through to the amp isn't sealed. It's not that easy to see, but the wadding is probably OK. If there's some at the side of the ports (out of view in the photo) you could remove it. You don't want anything close to the end of the port. To extend the ports, wrap some thick cardboard round the plastic ports and tape it to give you the desired total length. If it works, you'll have to find a more permanent solution using something like Evostik and gaffer tape to make sure the cardboard doesn't vibrate in use.

I modelled the Ashdown and EV cabs based on their interior volumes and don't think there's much to be gained from going to a bigger cab. The extra volume will give you an extra 1dB at 50Hz and 40Hz, assuming the same tuning frequency. So that others can do the comparison, the Ashdown is 68 litres gross with two 100 dia. x 150mm ports (tuned to around 51Hz). You'd get more or less the same result by lowering the tuning frequency of the Ashdown cab, that is, extending the length of the ports to 180mm. Also, check very carefully for leaks, as they can cripple the low-end response. Make sure everything is gasketed and completely sealed and make sure there is no wadding within six inches of the port.

No, the screws in the parts list are fine. I only listed t-nuts and 30mm machine screws in the parts list and they are perfectly all right for the main chassis. If you want to use t-nuts on the horn, however, the hex heads won't look great. So you can either use black wood screws (without any t-nuts) or pan headed machine screws and t-nuts. The lengths I suggested above are nominal and 30mm (or even 40mm) is OK.

Sorry Pete - that's what you get for being first out of the blocks. 🙂 I'll try to sort the screw situation out as soon as I can and include the recommended types in the parts list. I imagine it's a bit confusing at the moment. To compensate for your mis-purchases, I'll send you some screws for the feet and handle when I send your kit off (shouldn't be too long now) , as I have some spares. If you need any more M5 t-nuts, I also have spares and can send you some of those too. Black screws are a pain to source in small quantities. As a temporary measure, you can use normal chrome-plated screws from B&Q etc. and just paint them with car touch-up or whatever you have once they're screwed in. They look all right behind a baffle.

The Speakons are included in the crossover and wiring kit. There's no need to worry about drilling vertical holes, as all the holes have been predrilled in the kit. They're a standard sized pilot hole, which is good for woodscrews but will need to be drilled to size for t-nuts. You'll have to drill holes for the feet, as it didn't make any sense to pre-drill those. I wouldn't use the method of installing t-nuts shown in that Youtube video because you'll deform the front of the baffle - bear in mind that poplar is a relatively soft wood. It's actually a lot easier to tap them in with a hammer before assembling the cab. The hole for the port tube is being cut to within half a milimetre to provide a friction fit. So make sure you fit it before you glue the baffle in because it takes ages to fit from the front. There's no harm sealing the port tube from the rear with some glue or silicone. To paint the port tube, there are a number of spray paints designed for painting plastics which cost between six and eight pounds a can. I used a paint designed for spraying car bumpers because I had some in my workshop. It's quite likely that something else would work, and I'll carry out a few experiments this week. It would be ideal if we could use the Tuff Cab paint. I'll check. I obtained a generous discount from Celestion on the compression drivers, as Luke mentioned. I'm not going to mention the price on list because it's more than just a few percent.

Back from my break. I'll take the queries in date order. The rollers Blue Aran sell are the same as the ones you can buy in most DIY stores. To get the stippled finish, use the foam roller. On the matter of costs, the cab is going to be less expensive to build if you already have tools and bits and pieces in your workshop. I expect quite a few people already have some matt black paint, wood filler, wood glue etc. in a cupboard that they can take out and use. If you have to go out and buy a drill and paint brushes, for example, the cost will go up. Nevertheless, if you could buy a cab like this one in a shop, it would cost at least twice what you can build it for. Thanks for bringing up the question of screws. There are actually quite a few different types of screw needed and I haven't really provided much info on that. For the main driver and horn, I'd suggest black 25mm M5 machine screws into t-nuts. The parts list says hex machine screws, which are great for the main driver, but look pants on the horn. So it's probably better to standardise on M5 pan head, Philips or pozidrive machine screws, 25mm long. The t-nuts need to be the smaller type. There isn't enough space for the large ones behind the horn. I've heard good things about the threaded inserts mentioned by Luke, and they could work for the horn - but I've no experience of them personally. I'd suggest flange headed screws for the feet. No. 10 size (I'll check on it) 25mm, although you could also use the same machine screws and t-nuts used for the main driver and horn. The four central screws for the handle can be normal woodscrews, say 25mm long. However, when you lift the cab, all the weight is on the central handle, and that is attached to the top of the cabinet with another four screws. I don't see a problem with using woodscrews here also, but some people might be happier using four t-nuts behind the handle. The machine screws would have to be about 40mm long because of the thickness of the handle support. Then you have the problem of getting all eight screws to look the same. If you've bought the Chinese corners I recommended a while back, you'll already have the screws needed for those. If not, you'll need screws for your corners depending on which corner you're using. You'll need M6 two hex head bolts to fit the compression driver to the horn - about 15mm long, but I'll check and confirm. Finally, you'll need four small self-tapping woodscrews, 25mm long for the Speakons. I'm not sure of the size, but I'll do some research. That's an awful lot of screws to source. I'll see if I can put together a screw pack to save everyone a lot of time and trouble.

I'll be thinking of you! 😀

I'm packing up to go on holiday, guys. So we'll have to discuss speaker power handling another time. And I'm not saying those of you who are using this combination are not getting a good sound. Just that if you have a 400W cab like the OP, it's not a great idea to buy a 200W cab to run it with. Better to get a (matching) 400W cab.

If you want to add a second cab, it makes sense to add one with a similar power handling capability.

Sorry to hear that, Stew. I'll send you a pm with the costs. Bear in mind that you can actually build the cab in two stages to spread the cost if you prefer. Stage one would be to fit the Faital Pro driver only. That'll give you a working cab. You'd just have to fit a blanking piece of wood behind the horn cutout - not a very difficult job. The Faital driver works well on its own. Stage two would be to fit the horn, compression driver and crossover. That would give you the complete cab. Don't feel you are committed to spending money you don't have.

1) Fine for bass frequencies, not so great for midrange, but I take your point. You'll get a slight sensitivity increase. 2) The one 10 is a 200 watt cab. The SC is a 400 watt cab. (Barefaced exaggerate their power ratings.) So you have 600W total power handling capacity but are limited to 400 watts in practice, which is what Frank is saying. So you really haven't gained anything. 3) Yes, you're going to be putting 2 x 200 watts through each cab if you have two. Or 400 watts if you have one. This is my point. 4) There's not much difference in the HF response of the SC and the One 10. 5) If TJ said the earth was round, would you take that as a vote of confidence over theoretical objections? He's entitled to his opinion.

Here's an update. Mike aka Chimike has now produced some really nice CNC drawings for us. I used these to approach a number of suppliers for quotes (again). I've now selected a company and ordered a single cab, which I'll check thoroughly before ordering the first batch ot ten. I'm not expecting any problems, as Mike has managed to produce a cab from the drawings on his own mini-CNC machine and tells me it goes together perfectly. If he sees this, perhaps he'll post a few photos on the thread. I'm about to go on holiday for ten days, but the cab will be delivered when I get back, i.e. around 12 August. I'm therefore expecting to send the first cab kit, complete with all the parts that I can supply, to Funkle by the end of week beginning 12 August. If everything goes to plan, I'll be sending the first batch of ten out at the beginning of September. Orders for a second batch are building up, and I'd expect those to go out at the beginning of October. I've spent some time trying to sort a grille out for everyone. I managed to find some very nice expanded metal, which is fairly lightweight, but I've been struggling to cut it to size. My tin snips aren't good enough and a jigsaw proved useless. So my next step is either to get a local engineering company to cut them up, or to do the job myself with an angle grinder. I'm not a big fan of angle grinders, as I value my body parts, but I'll be looking into it when I get back from my hols. I really appreciate everyone's patience.

This is good advice.

Definitely. It will make a difference to the sound. Scandinavian birch ply is considered the best for cabs and is well worth the extra. Don't skimp on the wood - you'll not save that much and you'll regret it in the end. I normally specify B/BB.

Only just noticed this - sorry Funkle. I wouldn't use the Faital driver in Phil's small cab: it's too small. It'll sound boomy with no low bass - a bit like the red curve in Stub's simulations above. The Faital is more efficient than the Beyma, but the downside is that it needs a larger cab.

It's in the Parts List on page one of the thread: "For the metal grille: 11mm x 15mm planed softwood x 2400mm. B&Q. They normally have it in stock but it’s not on their website. Also available from other wood merchants. 12mm x 15mm is also OK £3.00 Foam tape 1mm x 10-12mm – can also be used for the horn instead of TUFFGAS20. UK Ebay supplier item no. 163731460245 £2.59" The trick is to use a picture frame support that's not too wide - a wide support just looks cheap. And to go for 1mm-thick foam strip - anything thicker pokes through the holes in the grille and look cheap too.