stevie

I reckon there's some confusion here with port sizes here. The 118mm size you've mentioned is correct for the larger 50-litre cab. However, if you want to fit that tube to a 30-litre cab while maintaining the same tuning, it needs to be about 250mm long, which won't fit. I'd suggest you recalculate with a 100mm port, a size that's available everywhere.

For the many people who depend on the EU for a living, this is stinky poo, there are no two ways about it. If I were in your position, @knicknack, I'd do the same. However, when the COVID situation is finally resolved and the work opportunities open up again, I'm sure you'll be back working in Europe again. It just won't be so easy.

Maybe 'pathetic' was a bit too strong. Pointless then.

Rear panel mounting is fine and a single port tube will work better than two (less friction).

I didn't call musicians pathetic - just to be clear. If there are any figures for the percentage of musicians who voted to leave the EU, I'd be interested to hear them.

It was clear from the outset that leaving the EU would end freedom of movement. It's also what the country voted for - twice. As Nigel put it, no more "spending British taxes on foreigners' jobs". So it's hardly a case of the EU digging its heels in. Why should the EU make an exception for our touring musicians? No UK touring musicians means more work for European musicians. We wanted control of our borders. We've got control of our borders. While I sympathise with the musicians who are about to lose their livelihoods, they are not unique in that respect. That petition is another example of the UK wanting its cake and eating it. It's pathetic, delusionary, has absolutely no chance of success, and I won't be signing it.

I bought one of those third hand devices years ago but I hardly ever get it out. The trick is to make a mechanical connection first if you can. So, if you're soldering wire to a jack socket (for example), poke it through the hole and wrap it round once. That way, the connection will stay put while you use the soldering iron.

Things are in the works.

Hmmm. The mods are in exactly the same position as everyone else with a business. They can't do anything because they don't know where we'll be on Jan 1st. Nobody knows. Maybe the government will decide to exercise its new-found sovereignty by bringing back purchase tax. VAT is an EU invention after all.

Now that was funny!😁

Tongue in cheek - of course.☺️

No, I think you nailed it!

In my search for a lightweight head, I had an LM3 for a while. It was OK but I prefer my current Ashdown RM500. It's certainly punchier. On the matter of cabs, a half-decent 15" will be fine for "small to medium pubs and clubs". A used one is normally a very good buy at the moment because they're not flavour of the month.

If you're not too bothered about weight and don't need the latest bells and whistles, there's a very nice Trace rig for sale in the classifieds on here that will keep up with virtually all the suggestions you've received so far. A nice 1 x 15" and a 300W head for £150 all in. It's a tried and tested classic that will easily do what you want. Not only that, but you can resell it without losing too much money if you feel you need to spend more later. Which - if you hang around here too long - you probably will.

Although not easy to achieve, my experience is that a flat response is desirable because then you know what you''re working with. If you want to add harmonic distortion or colouration, or accentuate or cut specific frequencies to get your sound, that's fine. But if your amp/cab is coloured to start with, you're stuck with that sound and have nowhere to go.

There are some benefits to crossing over actively, but a properly designed passive crossover does a lot more than roll the drivers off at either end and splice them together in the middle. You also have to equalise the bass/mid driver to compensate for the effects of the cabinet and horn as well as the usual anomalies in the drivers themselves and then you have to deal with the phase problems you get from the spacing of the drivers. It can be done actively, of course, but you need to be able to delay the bass driver so that LF and HF arrive at the same time at the crossover point. You may have to apply asymetrical rolloffs to compensate for any intrinsic rolloffs in the drivers beyond the crossover point. And you need to be able to equalise the entire system so that it's flat. If you can do all that, and have the measuring gear to ensure that you get it right, you can certainly use another compression driver and horn. However, sometimes passive is just easier. John is still looking for the circuit for the Beyma 12 and Celestion CDX1-1445 system and is hopeful.

This is how it's done. It's the tightest little beat combo I've heard in years.

I just checked - and I don't seem to have it. The problem is that I kept developing the cab (it was a diary-style thread) and didn't keep all the details of each stage of development. John who is Chienmortbb built one and he may have kept the circuit diagram. I've asked him. Otherwise, the Wayback Machine might help..... Sorry!

Yes, I published the crossover details for the Beyma 12 with a P-Audio tweeter, but since then P. Audio decided to change the diaphragm from titanium to phenolic. I've no idea how much that changed the performance of the tweeter, but it certainly will be different (and very likely worse), which meants that the published crossover won't work properly with current versions of the tweeter. There is a neodymium version of that tweeter with a titanium diaphragm, which I duly purchased to test. Unfortunately, it was nothing like my original ferrite one (and also nothing like the published spec sheet). So I sent it back and gave up on tweeters. The next design mated the Beyma 12 with the P.Audio PH-170 horn and a Celestion CDX1-1445 compression driver. That's a high-performance, low cost combination. I published the crossover too, but it got lost due to Tiny Pic's shenanigans. If it's of any interest, I can repost it.

I can see (hear) why you wanted to change the driver. That's much better!

To me, this is a 250-quid fuzz box - so I'm definitely not the target market. However, I can see the business logic behind the move and I'm sure Alex knows what his customers want. This is a tough time to launch a new music product and I wish him well with it.

All the photos I posted for the Diary Continued were removed when the previously free Tiny Pic hosting service decided to change its business model. I uploaded most of the later ones, particularly those showing how to assemble and finish the cab, but it was not always clear from the context which photos from the earlier part of the thread were missing. So I didn't bother with those. Then there was the fact that P. Audio changed the spec for the tweeter used in the first budget two-way design - I think that was the MKII - and there wasn't a lot of point in uploading those photos anyway. If there's any interest in a design for a budget 12" + horn tweeter, I can certainly do one, based on either the MkIII cab or the less complex but easier to build MkI. However, both of those cabs are perfectly usable with just a 12" driver on its own.

There you go. I actually nicked the idea of panel pins from Chienmort, although the self-drilling screws idea was my own. They sometimes work better than clamps. If you leave the panel pins in, just be careful if you're using a router to round off the cabinet edges.

Nice work! That Beyma driver is a classic and works well in that box. I agree about getting straight, square cuts - it's so important but not easy. If you're short of clamps, you can always use panel pins or self-drilling screws - remove and fill the the holes once the glue has dried.

The bass needs to be more forward. The whole thing sounds like it's in mono. Otherwise, it sounds pretty good to me. I'm no expert though.