stevie

I have a brand new Panaflow 24V, 80mm, 1.8A that you can have for a fiver plus delivery (say £3). It's a bit more powerful than what you have but you'll never need to replace it again.

I might have one of these spare. I think it's a Panaflo, which is one of the best makes. I'll check.

Excellent! keep the tips coming.

Five inches turned out to be the optimum port size for the cab. It's just unfortunate that nobody sells a commercial five-inch loudspeaker port. A six-inch port would be too long and a four-inch port (or multiple smaller ports) won't handle as much air at high power. The five-inch port I found is used in air conditioning systems, which I suppose is why it's only available in white. But it is cheap and you get two ports for a couple of pounds. Normal plumbing pipe is available in black but not in this size (unless someone knows different). A white port doesn't actually look that bad in practice and, of course, if you're using a fabric grille or foam behind your metal grille it doesn't matter what colour it is. I think most people would prefer a black port behind a metal grille and the Euro Car Parts primer offers a cheap solution (if you can get them to deliver).

My fully charged EBLs measure 8.44V. I used a cheap, simple, non-electronic charger without any problems. It seems to be quite difficult to overcharge 9-volt batteries - no idea why. The 1.5V ones get hot quite quickly if they are overcharged.

And so it begins......

These are all good points, well made.

Any bass players on this forum?

The speaker is pretty much in an optimum cab at 68 litres. Once you start moving away from optimum, the modelling programs give you different answers. It does look like you'll get more output between 40 and 60 Hz at 1 watt, but there's unlikely to be much difference, if any, in the maximum acoustic power at 500 watts. The easiest and most effective, if not the most convenient, solution, is the one you've come up with already: add a second cab when you need it.

You might like to try the cab with a bigger amp. Your BMS driver is rated at 500 watts. I don't know what amp you're using, but that might be the limiting factor rather than the speaker. Try something that produces 500W into 8 ohms and see what happens.

I'm really looking forward to seeing what you all come up with in terms of finish and appearance (although I expect most will be content with black).

There's a new Parts List up on page one of this thread, which includes a revision and details of the screws you'll need.

That's odd - they accepted and confirmed my order for a can. Mind you, £2.99 delivered sounds ridiculously cheap.

If you have the normal Tuffcab, the black finish will be quite shiny and many not be a great look. It will depend on the grille you're using, of course, but the one I'm sending you is quite open. I found a dark grey plastic primer in an aerosol from Euro Car Parts, which costs £2.99 delivered. Look for the product code OPT.DGPP300A on their website or try here: <https://www.eurocarparts.com/ecp/p/car-accessories/car-maintenance-accessories/paints-and-primers/primers/?OPT.DGPP300A&0&cc5_143> I'm going to order some myself because I'm painting my cab dark grey and it should look good without a top coat. It should also provide a good surface for overpainting with the matt black paint you already have, Pete. I'll add this to the Parts List when I get a minute.

Anyway, I'd advise funkle to take all the time he needs. Take it slowly. There's no rush. Do a dry assembly first to see how everything fits together. The panels will only fit one way but you do need to assemble in the right order. So follow the instructions on page 20 of the thread when you glue it together. I'll be available by pm to answer any questions.

I'm pleased I chose someone who knows how to work under pressure. 🙂 I've revised the crossover and am building it now. So it will probably be early next week before I can send it on. I'm still working on the screws. It's a lot more complicated than I thought. I've ordered some samples so that I can direct everyone to the right (and cheapest) suppliers. On the matter of painting the port tube.... I carried out an experiment using a typical blackboard paint (needed two coats), black car spray paint (cellulose), and the normal black Tuffcab paint. They all go on and cover the white. I expect they will stay on but you can remove them easily by scratching with a fingernail. So, the adhesion isn't as good as a specialist plastic paint. You can buy a small jar of Humbrol plastic enamel, which is supposed to work on PVC, for about £1.80 from your local model shop. That could be worth a try.

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.