stevie

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.

[quote name='Al Krow' timestamp='1499369228' post='3331141'] A wider question to my fellow BCs: does the wood used in the cab construction have any bearing on the quality of the sound a cab puts out or is that pretty much entirely down to the speakers, electronics and drivers? [/quote] Yes, the wood makes a noticeable difference to the sound, as does the quality of construction and cabinet design. It's only part of the equation but quite an important one. Let me give you a tip. Next time you test a bass cab, play an open E (doesn't have to be loud) and feel for panel vibrations with the palm of your hand. The back panel is likely to be the most telling, although it depends on the shape of the cab. If you can feel vibrations at a low volume, imagine how much that panel is going to be vibrating when there are 400 watts slamming into it. Whenever I go to a Bass Bash, I spend 15 minutes or so testing cabs for vibration (I don't think anyone's spotted me doing this so far) and it's been quite illuminating. You won't be able to feel any vibrations with a well designed cab and that translates into better dynamics, better transients, lower colouration and less "lumpiness" at volume.

[quote name='ebenezer' timestamp='1499248344' post='3330224'] Love the engineering and thought that go into barefaced cabs, but i could not live with something built out of 9mm plywood !..... [/quote] 9mm (poplar) ply would put me off too. Weight-saving is all very well, but I'd prefer something a bit more substantial both from a practical and acoustical point of view. Having said that, for some players, weight is the number one priority. So I can see the attraction.

Only just seen this..... First you need to unsolder the coil. There are two wires coming out of the coil. Unsolder the wire still connected to the board and also the piece of broken wire. If it's the outside wire on the coil that has broken, just pull out a piece of the wire from the winding, scrape off the insulation at the end, tin it and solder it back in place. If it's the inside one that has snapped off (much more likely), it's a bit more difficult. You will be able to see the very end of the wire that has snapped off poking out of the coil former. Your mission, should you accept it, is to undo about one turn of that wire from the inside of the coil so that you can resolder it to the board. Use a very thin screwdriver to ease the wire out enough to be able to grab it with some snub nosed pliars. If that proves too difficult, use your snips to cut the plastic bobbin so that you can access that bit of wire and pull it out. Cutting the plastic won't do any harm. Also bear in mind that the insulation on the wire is quite tough, but don't go mad. I've done this loads of times. Good luck! Oh yes - glue the coil back with silicon sealant and a couple of tie wraps. Otherwise the same thing will happen again next week.

OK, good. The resistors won't get hot enough to damage the ply. A couple of tips for crossover assembly. Use non-ferrous screws, brass or stainless steel, close to the coils; anything ferrous will alter their value. Use silicon sealant to glue the components down. Unibond Power Extreme also works well but is a bit pricey unless you can get the Aldi version. Don't use heat glue; its shear strength is poor and the heavier components will become detached if the cabinet is dropped. Use cable ties generously.

[quote name='RichardH' timestamp='1497441141' post='3318144'] That sounds a good way to do - I had been thinking of using the phenolic sheet. The eyelets idea is genius - that way you can pass leads though the board rather than keep it all on the surface. [/quote] There is no wiring on the surface. The layout is as it would be for a regular printed circuit board, with all the component wires passing through holes in the board and then being hardwired underneath the board (instead of being connected by PCB track). The holes at the right hand side of the tag board are where the wires come back up through the board to connect to the tags. I think a photo would have saved a lot of confusion here.

Incidentally, Richard, I have sheets of blank PCB board fibreglass in my workshop, but I still find it easier to use 6mm ply. It doesn't look quite as "pro", but that doesn't really matter.

Excellent! That would be very helpful.

I'm used to designing and using proper fibreglass PCB boards, but they do need to be produced in quantity. I've experimented with a variety of materials for one-off builds, and 6mm ply and tag board is the best solution I've found so far. 6mm ply is also very cheap, but the problem is getting hold of small pieces. Wickes and Homebass sell a 1200 x 600mm sheet for about a tenner, and I'm sure there must be wood merchants and joiners prepared to sell smaller sheets of offcuts (my local DIY shop does). Anyone building their own cab from 15mm poplar ply could use offcuts of that. Homebase also sell a 1200 x 600 sheet of 6mm MDF for £6.

The port tuning was always going to be 50Hz.

The .56 and .18mH coils are close enough, but don't waste money on thick wire for the .17mH. - 7mm or thereabouts is fine. All the coils are air cored.

When you upgrade your speaker there is always a chance that you will have to enlarge the cutout, especially if you're going from a pressed steel to a cast chassis. Check the hole size in your cab and the cutout sizes in the driver spec sheets to see. If it's an RS112, bear in mind that the bass driver contains a tweeter, which you will lose if you change it. But if you only use it under another cab, I'd suggest the following. For a budget option, get the Celestion 12" driver currently for sale in the classified section of this site. Without knowing exactly what's currently in your cab, I don't know how much more you'll get from the Celestion, but it could be enough. Next up would be the Beyma SM212. This is a really nice upgrade long-coil driver that a few of us already have good experience with. Good value at about £80. If you want better, look at the Faital 12FH520 - a 600W high-end neo driver and probably the one used in the top-of-the-range Vanderkley. £650 in the Vanderkley but about £160 on its own.

Luke, the two designs for the Mk II are complete. There is a low cost version with a tweeter and a more advanced version with a compression driver. They both use the same cab, but that's it. Chienmortbb assembled the more advanced version and I measured it to make sure everything worked as intended. When I have time, I'll try to post some building guides in post #1 - but everything you need should be contained in the thread. If not, please ask. The cab is based on the use of 15mm poplar ply, which I thought would provide the optimum balance of light weight and strength, and this has indeed proved to be the case. There is, of course, nothing to stop you using another material, but if you want a proven lightweight design that will outperform 90% of equivalent commercial cabinets, go for the poplar ply and compression driver.

I've attached a PDF to post #1 showing the crossovers for both versions of this speaker. I am about to assemble my own version of this box (500W neo driver with expensive 1" horn) and will try to make a photo record of each stage of assembly. I don't think this cab is difficult for anyone with basic woodworking skills to assemble, but a step-by-step guide might help. Richard, if you would care to take some photos of the crossover you assemble, that might help, as I suspect building the crossover is more of a challenge to many people than building the box.