stevie

The figure 8 brace connects the cabinet side walls together with the front and back, and is the most important brace in terms of overall rigidity. Now on to the second brace. This one can't be a figure 8 because it goes directly behind the driver. The idea is tomake it as close to a figure 8 as possible by cutting out a space into which the driver will comfortably fit. Then cut holes for air flow without weakening the structure. I'm using hole cutters because they're easy, but a jigsaw works well too. Mark it up first. Then cut. I have rounded all the edges using a powerfile and sandpaper to improve airflow somewhat, but I expect it's not really necessary.

Just listened through a Creative 0202 USB soundcard with Sennheiser 650s. There's quite a marked difference IMO. The Streamliner is much fuller.

[quote name='gjones' timestamp='1504959019' post='3368562'] Just before the second set I had another look at the amp and realised that I was plugged into channel 1 and I had been adjusting my sound with the EQ of channel 2. I could have sworn I was hearing the sound change when I was adding more bass and reducing the treble but in reality, it was all a figment of my imagination. [/quote] Been there, done that. It's a really important lesson.

Now that I’ve gigged the prototype, I’m ready to assemble a finished cabinet in our cabinet material of choice, 15mm poplar ply. Although I am now using different drivers to the ones we started out with, this doesn’t affect the construction of the cabinet. The bracing is slightly different, due to the fact that we want to get two cabs out of a single piece of plywood. However, the lessons learned in building the prototype will be applied here. First, cut the figure-8 brace and glue in place on the back panel. I used a couple of screws to clamp it down, but my plan is to assemble the whole box without any (external) screws. Filling and sanding these can be a real pain. To assemble without screws will require some longish clamps, which I ordered from eBay. If you don’t want to invest in the clamps, there’s nothing wrong with using screws, but you’ll have to fill and sand the holes later. The first problem I hit was that, despite my best efforts to drill the holes at right angles, the screws pulled the brace slightly off target. When I wiped the excess glue away, I noticed that there was a slight gap at one side. I quickly grabbed a couple of clamps to straighten it up. Phew!

Bought a very nice Behringer preamp from Chris. All good.

Way to go Geoff and Richard! Have you now modified your Ashdown cab?

Don't you hate it when that happens? I've had to dump several Canon printers over the past few years with simple faults that can't be repaired. Great when they're working, but not so great for the environment.

Splitting the crossover in two has a number of benefits. It makes the layout easier to design; it's simpler to assemble; it puts distance between the LF and HF coils, and gives you more flexibility when deciding where to locate them inside the cabinet. As far as weight saving is concerned, the crossover for the version Richard is making is about half a kg lighter than the more complex compression driver version (because of the size and number of LF inductors). You could also save nearly a kg by using the neo version of the tweeter or the neo version of the compression driver, although that would likely require some modification to the crossover. You could save about 2kg by using a neo driver like the Faital Pro PR300 used in the Bergantino CN112 and Vanderkley 112EXT, or an Eminence Deltalight, although neither of those will go as loud as the Beyma and they would add another £50 or so to the cost. By going neo, I reckon a version with a tweeter could come in at under 12kg.

It's not as difficult as winding your own pickups, and certainly feasible for the adept DIY'er, but you'd have to invest in the wire and an inductance bridge at the very least. So it's probably not worth it if you're only making a few.

Using cardboard as a template is a great idea. The standoff strips are another good idea, allowing for some free space below the board for the wiring and tie wraps.

I'm looking forward to seeing how it works out.

That's a bit of a long wait, Richard.

Here are a few photos showing how to assemble the LF section of the crossover. The circuit is the same as the one used for the Celestion compression driver version, but the values are different as I'm using different drivers. I also changed the layout slightly to cater for a larger coil. The method is the same, however. First, place all of your components on the board and draw round them with a pencil. I'm using 6mm plywood, but you can also use offcuts from your cabinet. When you are happy with the layout, cut the board to size. Drill the holes for the wires. You'll need a couple of small drill bits, say 1mm and 1.5mm, and a larger one for your tie wraps and bolts (if you use them). This is your bare board marked up and drilled. Yours will probably end up with too many holes like mine, but don't worry - nobody will know. Cut the tag board to size and fit. I've used 2 stainless steel bolts and nylon lock nuts, but silicon sealant will also work. Next comes the large inductor. I've used a larger stainless steel bolt, nylon lock nut and stainless washer here (plus a few dabs of silicon) but silicon sealant with a couple of tie wraps will also work. For the resistors, I used a special Everbuild heat resistant silicon, good to 300 deg. C, although you can use normal silicon if you wish. Here is the assembled crossover. I'm not going to cut the wires and connect everything up yet, as I want to do some more testing, but wiring up the back should be straightforward now that you've got this far. I'll add a photo of the rear of the finished crossover when it's done. When buying silicon sealant for this purpose, you need to go for a high modulus type. If you're on a budget, don't get the cheap one they sell in Screwfix, as is is not firm enough (low modulus). The Pattex one they sell in Lidl is perfect, however, and relatively cheap. You could also use the Everbuild Heat Mate silicon throughout. It costs £5 to £6 from builders' merchants.

Such an amazing band. They make it look so easy. And where does he find those great drummers?

[quote name='Ghost_Bass' timestamp='1321895073' post='1444160'] Ok, time for my review. I must say i'm well surprised by this cab. Very light, well buildt and great finish. The first thing i've done to it was to take it appart and see the quality of the components. Everything looked in good shape, not top notch material as we would suspect from a low-budget cabinet but very well put together with no visible flaws. Nice solders, good placing of the damping, very professional looking, only 4 screws securing the driver when it has 8 holes ( ), no paint flaws, tolex well glued, rough handle... [/quote] Ghost_Bass, nice review. A review is not a review IMO unless you look under the bonnet (aka hood). I hope others will take note and get their screwdrivers out. Build quality is important and it's good to know when a manufacturer takes it seriously. I'm also with you on the Speakon issue.

Some very sensible advice coming through finally. Lots of good points in that last post by Markstuk.

One gone - one left.

There's certainly a lot of truth in that, but the AES standard is accepted throughout the industry now and provides a useful basis for comparisons, even though some people think it's a bit lame (the test only lasts 2 hours, for example). Nice summary, Phil.

Exactly! Thanks Chienmortbb.

Nothing odd about it at all. I didn't consider your comment to be judgemental. I think you misunderstood what I was trying to say, WoT. That is, when it comes to sound, we don't all look for the same thing - nor should we. (Maybe I should spent more time crafting my messages).

Your prerogative. I want a big f*off studio monitor sound. Doesn't mean I'm right and you're wrong, or vice versa.

I totally agree with Dave. Just don't let anyone tell you what you should like. But back to the subject of robustness for just a minute..... Surprising that people think a cabinet is sturdy just because they can sit upon it - or because it doesn't collapse in a heap when they put it in the boot of their car. Even my hi-fi speakers pass that test, and I certainly wouldn't take them out on the road. No - pro-equipment is supposed to be more rugged than that, especially equipment intended for a touring environment. Pro gear should withstand shock, vibration and temperature extremes - and still keep on working. Dropping a cabinet on concrete (especially on the corners) is normally sufficient to separate the wheat from the chaff. Not everyone is bothered about having bombproof gear, but if ruggedness is a concern, buy a cabinet made from 18mm birch and accept that it will not be light. There are plenty available from the likes of EBS, Ashdown, Mesa Boogie, Bergantino, Aguilar, etc. If you buy a cab made out of 9mm poplar, it will be much lighter, but don't kid yourself (or others) that will also be rugged, even if you have put it in your boot 200 times. For many people the sensible solution will lie somewhere between the extremes. There is lots of choice out there and only you know what your priorities are. You have to live with it. The Vanderkley NeoLites seem to use a combination of poplar and birch ply, the latter most likely for the baffle. That's a very sensible engineering choice for a lightweight design IMO, because the weight penalty of using birch on the baffle is relatively small and the benefits considerable. They're not the only bass cab manufacturer to do this.

I have two Dell Vostro 200 PCs with Core Duo processors (about 3GHz I think) and 3-4GB of memory. In good condition, working perfectly, quiet, but you'll need to fit a hard disk and operating system to complete them. They originally came with XP and Vista. Still powerful enough for most PC-based tasks. Collect from Dorchester, please.