stevie

Thanks for your kind words, rc. The cabinet design is finished - so you can start cutting as soon as you like from the plans in the thread. The crossover is still being tweaked, however. Once I've finished the crossover to my satisfaction, I'll post a list of parts and components you'll need to complete your cab. I'm struggling to find a company that will supply small quantities of badges for the front grille at a reasonable cost - say a fiver or less. Can anyone help?

And your design goals were?

Exactly. I think the bass guitar has suffered for many years from being confused with the electric guitar, where the speaker plays an important role in creating the sound. A bass guitar isn't like that. It's more like an electric piano or a double bass.

No, I'm afraid not.

During the past few years of messing about with bass cabs, I've come to the conclusion that a flat response, low colouration, constant directivity cab is the best solution for bass - certainly for me - and not just for use with modellers.

You might as well run your bass through the earbuds on your phone.

Yes. When they are positioned close to one another, multiple speakers couple at low frequencies (they act as a single driver) and sensitivity increases. This is fine at very low frequencies where wavelengths are long, but at higher frequencies the sound produced by the individual drivers will start to cancel (be out of phase) as a result of the inter-driver spacing. It's the same principle that causes a single driver to roll off off-axis. To avoid this when multiple bass drivers are used, they should be crossed over to a midrange driver before the phase cancellation takes place.

Basically, yes. There's very little actual design input in these cabs. The basic principle is - keep sticking drivers in a box until it's loud enough. With multiple drivers you get lots of midrange cancellation, which results in peaks and dips in the frequency response. The off-axis response is hopeless and there is usually no HF. When a tweeter is fitted, it usually operates too high to make any real difference.

The only bass guitar cab I know that has half a chance of being neutral is the Greenboy F-series. Apart from that, your best bet at the moment is a PA cab. It's impossible for your usual 2 x 10 and 4 x 10 bass cabs to be neutral.

Exactly right, Luke. The idea behind building the prototype cab was to discover what bracing was needed - so it was a bit belt and braces. Surprisingly, the spruce ply in that cab tended to ring more than the poplar ply we're using now. This is an ongoing project for me, which means I may revisit the bracing configuration at some future time, but I think what we have now is a good balance between bracing performance and complexity.

The drawing assumes the use of the original handle I used in my cab, which is a Marshall-type strap handle, but builders can of course choose whatever handle they prefer. The flat packs will have the round handle because it offers a number of advantages that I think owners will appreciate. For those rolling their own who wish to use the round handle – bracing for the top panel is a ring of plywood 35mm wide with a centre hole the same diameter as the hole for the handle. This arrangement not only stiffens the top panel but it also means that the handle bolts are fixed to 30mmm of plywood. The ring can be cut from the circular piece of wood left over from cutting the hole for the main driver.

Oh Canada? 😀 Otherwise, yes, very useful.

Yup. It's the cutout from the port. It doubles the thickness of the cabinet at its weakest point, which is at the centre. I have that arrangement in my own cab and it works really well. It's also very easy to do.

I'm pleased someone has a great eye for detail.

The drawings are now with my CNC flat pack supplier. Fingers crossed.

While that's true, it's not quite so easy for the average pub-type band. They often don't have any bass in the monitors and it can be hard to hear your bass clearly unless the cab's at ear level.

Two G braces in the cutting list?

Here are the drawings and cutting list. A big thank-you to RichardH (and Ghostbass) for doing these. I still have a bit more tweaking to do to the crossover - nothing major - and we'll add the final crossover to the PDF soon. BC112-v3 drawings v 4.pdf

It's likely to be the Faital 12PR300, but there's no getting round opening the cab up to take a look. The driver is readily available from a couple of suppliers in the UK, which is fortunate. That's an unusual fault, as I'd expect the clicking to get worse as the volume increases. It might not be the driver. So make sure you check for loose cables, screws, etc. and see if the problem occurs outside the cab (at a low volume, of course).

For me, the floating thumb is a more natural technique than the moveable anchor - nothing to do with playing faster or anything like that - because you don't have to think about it: the thumb is always there, doing its damping job. It sounds like it might be a personal preference thing.

Yes, that's the floating thumb. (I really hate to disagree with TKenrick, who is a proper bass player, while I am and will remain strictly an amateur).

I disagree with my learned colleagues. I use the floating thumb and am very happy with it. So I'd say give it a try and see whether it suits you.

It's been a hectic month for me work-wise, and I haven't been able to spend much time on this project. However, I have located a CNC company prepared to supply us at a reasonable cost, which is a big step forward. RichardH has been doing sterling work finalising the drawings, building on Ghostbass's original work, and we should be putting the final drawings up very soon for those wishing to use their local wood merchant. I'll be back on the job again within the next few days to organise a prototype flat pack, and I'll keep you informed of events. I'm hoping to have flat packs ready once this awful cold spell has finished, which is probably good timing.

That ebay one looks identical to the Lidl trolley. I've had one for a few years. It's light and fairly sturdy but you will definitely need a strap to tie your cab down and stop it falling off. Stows away quite neatly too.

I didn't realize you could drag and drop the image files. What I've done is created and named a folder for each individual transcription and then dragged the image files over. Sorted!