stevie

A 4-ohm speaker load is only useful when your amplification is struggling for power. Your amp has plenty of power on tap - so go with an 8-ohm driver.

I don't really have a lot to add to what Phil said. I'm not a big fan of doubling up on cabs. I appreciate that people like a "wall of sound" behind them, but it tends to emphasise the low end at the expense of everything else. I would definitely advise against doubling up on the tweeter in the BCIII system, however, as two widely spaced tweeters is a sure-fire recipe for comb filtering and won't add anything useful. As Phil said, this is a really loud system. I can't see many situations where a second would be needed. Also, the compression driver configuration means that you don't need to raise the cabinet off the ground to hear it. The full range of the bass reaches your ears standing from about 1 metre in front of the cab. It's nice to see another one of these coming together.

I replaced the (thin-sounding) rear Jazz pickup on a Yamaha P/J bass with a Stingray-type humbucker and was really happy with it. I also replaced the tuners with lightweight Hipshots, which made for a much better balanced instrument. On the other hand, I put lighter tuners on my current Ibby and I don't notice any difference in comfort or balance - which is odd, but there you go.

Phil Starr, Chienmortbb and I had one of our irregular meet-ups over the weekend. After an hour or two measuring and auditioning high-end bass cabs and drivers, including a well-known active PA cab favoured by a number of Basschatters (very interesting!), we plugged this little critter in. I'd briefly heard it before, but not seriously auditioned it. This time, we turned the volume up as loud as we could dare without annoying the neighbours - and the sound was impressive. It needed a bit of bass boost, although not a huge amount it has to be said, but we certainly didn't come away with the impression that this was a cheap cab. It's tiny size means that it's ideal for home use, because you can easily stash it away in a cupboard or behind the sofa. It'll go louder than you'll ever need at home and it sounds really sweet toboot. We were unable to drive it to its max, but I can see this tiny box handling acoustic and not-too-loud gigs with ease. You'll be surprised This is by far the simplest Basschat DIY cab project so far. If you've considered building your own cab but haven't done so yet, this is a great starter project. Once you've finished, you'll have something that's very usable.

Looks fine to me. It's very close to what I ended up with on the BC MKIII, which works well.

I must have missed this thread first time round, but am surprised to read that someone thinks there's only one way of bracing a box. It's not true, of course, and the bracing you choose depends to a large extent on the cabinet you're working with. Side-to-side bracing works well with tall, narrow cabinets like hi-fi cabinets, for example. For a typical bass guitar cabinet (as well as others), my approach is to start with a figure-8 brace near the centre of the cab. That braces both side panels as well as the front and back panels and ties them all into each other. Not only does it brace the largest panels precisely where they need it most - near the centre and just above the driver cutout - but it also substantially strengthens the overall structure of the box. The second area I look at is the baffle. This is usually ignored, but it is the weakest panel because of the cutouts and because the bass driver is clamped directly to it. I notice it's been included in the Barefaced drawing, which is interesting. After that, the improvements from additional bracing are not as great, but still useful. The key is to strike the right balance between an undamped cabinet that sounds dreadful and a Matrix arrangement that you can't carry.

Yes, great job - well done! I like the tilt and roll design. (Have you thought of using Speakons?)

Did someone mention Northern Ireland?🙂

Interesting question, and the answer is simple. With the MkIII specifically, the front baffle size and shape was dictated by the parts I wanted to use. I was toying at the time with using an RCF H100 horn and made sure the cab would be tall enough for it to fit. It was then just a matter of calculating the front-to-back dimension based on the total volume I wanted. And then making sure the vent would fit without coming too close to the back of the cab or needing a bend. It worked out well and resulted in a relatively slim cabinet that is easy to carry with a single handle. There are some theoretical differences between a tall, slim cab and a squat, deep one, but the taller one scores IMO by having the tweeter further from the ground and nearer to your ears.

You're not wrong, Luke.

Thanks, Jon. That's very useful. The cab drawings are of the very early prototypes and were revised later. The spruce ply I used for that first prototype was quite resonant and needed a lot of bracing. Later ones were better, allowing me to remove some of the bracing. I can't recall for sure now, but chances are that the crossover for the MkII with compression driver is the first one I did and published. The circuit I gave to Chienmortbb is likely to be a simplified version (using fewer components). Both will work.

I'll have a look and let you know what I can find. I'm currently under pressure with work deadlines, but somebody else might have the circuit.

The specs for the Genz Benz custom PR300 are available online for anyone interested in seeing what the difference is. Faital Pro is a quality brand and any bass cab fitted with their drivers is likely to be very good.

Yes, it would be interesting to know what the "design goals" were, how the driver was altered and why it was considered beneficial.

The PR300 is/was used in a number of well regarded bass cabs. Of the top of my head, I can think of the Bergantino CN 1x12 and 2x12 (which won the Essex bass cab shootout against serious competition some years ago), the Vanderkley EXT112 and the Genz-Benz Neox. As Phil says, the main difference between the PR300 and the PR320 is the length of the voice coil, which is one of the key factors in determining the driver's excursion capability, or xmax. This point alone makes the PR320 a much better choice for bass guitar. I've been working with much more expensive 12" drivers recently, using the PR320 as my reference point, and I have to admit that spending more money does not always buy you a better-sounding driver. I'd go so far as to say it's the best-bang-for-your-buck 12" bass guitar driver right now.

Please run that by me again, as I'm currently doing some routing work (as a complete novice) and am very attached to my fingers. Do you really need to keep tightening the router bit while you are working? It's a bit awkward with my particular router, as you lose the depth setting when you go in with a spanner.

You can't always compare manufacturers' power ratings directly. Some are more generous with their figures than others. The Ashdown is a sealed cab, which is a disadvantage in the "how loud will it go" stakes but often an advantage in the "lack of boom" stakes.

If I still lived in Edinburgh, I'd definitely be there. Love the band. It's a bit of a long drive nowadays though.

It's a while since I've been involved with pickups, but I do remember that the most common fault with those is a broken wire at the output. There are two output wires (obviously) - one is taken from the inside of the coil and the other from the outside. If the outside one is broken (it's not too difficult to check visually), it can be fixed without having to rewind the pickup: you just unwind one turn and re-solder. I've done it lots of times. Soldering those very thin wires takes a bit of practice, but it's not hard. If the break is at the beginning or inside of the coil, you will need a rewind. It might be worth inspecting the pickup before you send it off.

@Phil Starr built a small cab with a very cheap 6" driver and put the information here on the forum. A quick search should find it. That would be ideal. It sounded really nice when he demonstrated it to me. You're never going to be able to play Wembley with it, but for home use, it's ideal - and tiny.

Shame on you! 😄

Everybody knows where Airdrie is, don't they? I used to play the Airdrie Town Hall back in the day. And went to watch Airdrieonians every once in a while, even though they were rubbish.

I can maybe bring some prototypes for you to try.

Lots. 😃 Remember, PU glue is your friend - as is fibreglass filler. I speak from experience. They both cover a multitude of bodges. Finish with Tuffcab and nobody will know.