Phil Starr

I've just rebuilt a small guitar combo as a bass combo and it's great but needs more power and ability to run off a battery would be great. So, I'm going through the same thought process, fortunately with @Chienmortbb on tap for advice. He's kind of talked me out of buying the module you used. I've been eyeing up some of the class D car amps as a ready built, robust alternative. I'm following your build with a lot of interest. However I have built an extension speaker to match the combo and of course you have to try it so I plugged it into my 'proper' bass amp. I'm now wondering whether just buying a TC BAM wouldn't be an easier and affordable option with a cheap inverter if ever I do need to be portable. However that wouldn't be very satisfying so I'm still thinking of your option 3 the car amplifier. The only suggestion I can make is that I did consider using one or two 18v Li ion batteries as power supply, re purposed from my power tools. they are lighter than lead acid, you have a range of voltages available and if you could form sockets would be removable for charging. A +/-18V supply would let you get decent power into 8 or 4 ohms out of a bridged amp and you'd probably get an hour's playing or more out of them. Anyway well done with the progress so far.

Hi Richard. I use these, TheTransporterUK - 24 x Mixed Black Triple Flange Style: Amazon.co.uk: Electronics the small size fit me perfectly and the seal is excellent, as snug as my ACS earplugs. As a bonus they go quite deep into the ear canal and that helps a lot if you sing as well as play bass. The only word of caution is to change them every month or so, the old ones go baggy and I once managed to remove my ZS10's and leave one of the buds behind. Foolishly I asked my wife to remove them and she pushed them down into my ear and a trip to the minor injuries unit for their removal was needed. Apparently hearing aid users turn up there several times a week and the nurse thought it was hilarious

If you've not bought gear for a while i think you'll be pleasantly surprised, especially as you mention lugging the old Peavey stuff around. It really did weigh a tonne though. Most amps now are class D or switch mode. They are stunningly lighter and usually offer huge power specs, some of the older ones were certainly over specced and under performed but there are now plenty of good ones. I'd look for something that gave 300W into 8 ohms 500W into 4 and for me the sweet spot is 2 separate 12" cabs. I find one is good enough for rehearsals and most small gigs and two will cover everything else. That is just me though, don't get hung up upon size, @Dan Dare is right, listen to the amps not us. But then again you need a short list to start you off. I have a Mark Bass Tube 500 and a Peavey Minimax, I prefer the Peavey. They are both tiny and only weigh a few pounds. I can't help you with cabs, i build my own and use those but there should be plenty of suggestions. I'd be looking for a single high quality 12 to start off with and if I like it and need more volume then get a second one the same. If you buy used then you can usually sell them on with very little lost. The other option you might want to consider would be to go the PA cab route. high quality PA cabs with the amps built in are relatively cheaper than the same quality bass amp and will have the same bass handling abilities. You can then feed it through a pre-amp or pedal which will often give you a choice of simulating almost any amp and speaker you want. If you search for FRFR on BassChat you'll see this is well discussed

Great to see they are still in use

The original cab was designed to do a particular job and has a tailored low end to suit smaller venues/rooms. The 10 is going to have a smoother response and is being designed as a full range speaker with a horn. The 30l cab is a deliberately small cab for a 12 but is a decent size for a 10. It is only the box that is the same, they are two different speakers aimed at achieving different things.

Hi Serge, I was considering doing something similar, I've been gigging with various prototypes up until last year when the pandemic put a stop to it. I decided in the break that I wanted to settle on something for the next few years that would look a little better and become my regular set up. I allow around 7l for the ports and the speaker itself so a 40l cab is around 47l actual size The SM212 models very well in the 40l cab and does give a useful extra amount of bass. I haven't modeled the 12CMV2 yet but i've no reason to assume it would behave very differently. I'd probably make the cab slightly taller and less wide, square shapes are to be avoided to reduce resonances but i think a 40l cab would be an excellent compromise.

In the days of passive speakers my back-up was a four channel Yamaha mixer amp from a Stagepas system. Four mic channels that is. If the PA went I had a mixer with me, if an amp went this was 170w a side and if the speakers went then the floor monitors would let us make some noise at least. I used to carry a full toolkit including a soldering iron. Modern kit is so reliable now though that I only worry about backup for really important gigs or if it is a really long way from home. I probably carry enough leads to set up for two bands though. Like Al our floor monitors are RCF 310's which at a pinch will do anything. Nothing has gone wrong or failed to function for years and in the end I decided redundancy was redundant.

Looks better this way up, there's only a tiny overhang. I think this might become my go- to set up for working with acoustic acts. I need to try it in a bigger space of course but it has a really satisfying sound and is more than loud enough with a bigger amp. This was just meant to be a fun project but this is quite a usable speaker. I'm going to try it with a PA amp as the Peavey might be adding a little gilding to the sound. John @Chienmortbb and I are looking at a potential amp for this but it might be quite interesting to try it with something like the TC BAM with a view to building that into a permanent combo. It'd be about 6kg and whilst it wouldn't work with a drum kit it could be a very straightforward, lightweight, family friendly solution for home practice and just making you heard without having to carry a double bass everywhere. £33 for the speaker £125 for the amp and maybe £25 for the wood/finishing touches. Anyone interested?

Just winging it's way to Stevie for the next stage.

The dimensions of the box are the same as the 'Easy Build' cab. Easy 12" cab build - Amps and Cabs - Basschat. Obviously the baffle (front panel) cutouts are different. We moved the 10" down as low as possible to leave space on the panel to include the port and the horn. You can get the size of the horn and port from Blue Aran's website and the 10" pulse from Celestion if you want to crack on with a build. We will put up a complete drawing once we have the prototype working and tested.

Not with all that mess

I tried this with my Peavey Minimax last night, wow that surprised me, it really is quite a satisfying sound in a family sized room. The extra couple of litres gained by not having the amp built in makes a real difference to the bass. I think this would be a real contender as ideal home practice set up. The single six gives it a really useful extra bit of top end and dispersion and the use of a 'proper' PA driver gives some respectable bass at these volumes. I didn't drive it hard because it was loud enough but it was happy with a fair amount of bass boost so there is a bit of headroom available.

From the point of view of the speaker cabinet design the crucial thing is the volume, You'd want the same internal volume and space to fit the speaker(s) and port. Any volume that is substantially different would need a different tuning port. The cab we are building is of 12mm ply, anything thinner/less rigid is pushing towards the point where quite extensive bracing will be needed. This cab itself will be improved by bracing and we will no doubt discuss that later, once the basic design is finalised. At that point the success of the cab would depend upon the exact structure of the flight case. If you love that look then go for it, but I think you'd have to be prepared to do some mods or get it custom made.

Cabinet is complete in it's basic form. It weighs just 5kg and I've noticed that Jewsons where i bought the ply are advertising it now as poplar cored, when i bought it it was sold as Baltic birch though it looks like a generic hardwood on the outer veneers. the Chinese are making 'poplar' cored Eucalyptus skinned ply at the moment which is what I suspect this actually is. Anyway poplar cored is a nice bonus as the cab is extraordinarily light and i didn't pay a fortune for the ply. It has some voids which is a nuisance but It's tough to find a source of really good ply at the moment without going to specialist suppliers. It's good enough and 5kg is a very pleasant surprise. Photo's soon

They don't stack at the moment, I'll have to put rubber feet on. The other problem is finding grille cloth. there's a limited range out there from UK suppliers. The USA is much better served. I can't find anything to match the Kustom amp. If I had something similar enough i could change the cloth on that so the two cabs match but i'm struggling to find something I like. Any colour I like so long as it's black

Although I quite like the big corners on the cab. It looks faintly silly but it also makes the cab look even more tiny. What do you think?

OK I went for Vinyl, genuine 1970's Vynide brand, I had to scrub the cobwebs off!

Blue Aran are really cheap for the bits and pieces, I recently looked for some new corners and even the direct from China stuff can be more expensive. They are also the stockists for Tuff Cab the textured paint we all tend to use for cabs nowadays so worth thinking about ordering at the same time to save postage costs.

So a little progress with a few holes cut, all done with a jig-saw and using the blades shown above. You can see the marks for the original positions but Stevie wanted the horn closer to the bass driver. I've allowed for the extra width of the speaker surround and the lip of the horn and the bass port which will all cover up the minor imperfections

Yes I use the T101A blade, in fact I was using it 2 mins ago. Obviously it is not ideal for straight cuts. For speakers I use a down cutting blade the T101BR and cut from the side that will be on the outside of the cab. Don't use pendulum when down-cutting with a jigsaw and be aware that the cutting stroke pushes upwards so hold the saw stady and start with it away from the cut as it will jump a little if the blade is touching the timber. The T101B is the blade to use for general purpose cutting of ply MDF , the other blades are for deeper materials and coarser/faster cutting.

A jigsaw is good and you can get special blades for cutting curves which makes it easier. I'll put some practical tips into the build diary when we get to the end. We've chosen a port which has a lip which will cover up any inaccuracies

Now you have us thinking, we could do the crossover with one of these and these for connecting the speaker, no soldering needed.

Here's the cab, corners and cutouts tomorrow.

I've got the PR300 at £111 and the 320 at £120 so not much in it. The sensitivity is quoted at 2db higher but the 300 has a broader mid range peak under cone break up, the sensitivity in the bass is similar. What you gain is extra excursion so less chance of over excursion and ultimately more deep bass. Having said that using either as a single speaker without a tweeter the choice would come down to the sound you prefer. The Beyma's are only around a kilo heavier. However the SM212 is about to be discontinued and has also become expensive. However you are right, designing any cab is always a matter of making compromises and it is squeezing balloons. you squeeze down on one thing and something else pops up elsewhere. We've tried the Faital 320 (with a horn) and it works well, we haven't tried it in the smaller cab yet though. It'll be interesting to look at how the 10 and 12 model in the 30l cab. I'm trying to spend time actually doing the woodwork at the moment.

On it's way, just a couple of holes to cut and the edges to be routed off, then finishing. Anyone know where I can get some grille cloth to match? Can't decide whether to go for Tolex or Tuff Cab, I prefer Tuff Cab but I have a roll of vinyl roughly matching 70's WEM. It's not a great match but it is vinyl. Ho hum????