RichardH Posted June 28, 2012 Share Posted June 28, 2012 Been [url=http://greenboy.us/fEARful/]reading up on these beasties[/url] for a while, and fancied building one. Bearing in mind my house is in "a bit of a state", and I'm in no position to do any DIY (i.e. we had a massive fire a while ago and half the house is uninhabitable, inc my workshop), a certain Essex based contact of mine who happens to have a CNC machine and a workshop bulging with lovely tools offered to give me a hand. The Greenboy designs are not for commercial use, so I should stress that this is being done for me as a favour, and no money is changing hands. Anyway, here we go: Programming up Cutting the cab We're using some of the ultralight ply - only pain is that it's 15mm and the design is based on 12mm, so it took a while working through the dims to retain the interior volume. The CNC machine also works in metric rather than imperial, so plenty of calculatorisation needed The nice thing with the ply is that it is significantly lighter than 12mm birch ply We cut the plain panels on the bench saw, and then in a blur of activity we found that we'd actually got the braces glued to the panels. We have thicknessed the port brace down to 12mm so we don't lose width in the port. I then had to go home, kicking myself I'd not taken more photos through the day. Got a call this morning to say he's now put the cab together. How's that for a build thread! Time to get crossover parts and drivers, I think!!! Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 9, 2012 Author Share Posted July 9, 2012 (edited) Well, crossover parts are on their way - bought the components from [url="http://www.europe-audio.com/Producten_aB.asp?code=10"]Europe Audio[/url], and the drivers should be soon - I'm adding a variable L-pad for the tweeter and that was out of stock, so will need to wait until that comes in. While I've been sat on my backside with a stinking cold, my chum has rolled the cab edges and started covering it (black tolex). He's great at doing stuff - not so good at progress pics though!!! Edited July 9, 2012 by RichardH Quote Link to comment Share on other sites More sharing options...
LawrenceH Posted July 9, 2012 Share Posted July 9, 2012 This'll be great! Will be following the thread, very jealous of the CNC machine! Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 9, 2012 Author Share Posted July 9, 2012 Cheers - just had the tweeter waveguide arrive from the US, too - so we're getting there! Quote Link to comment Share on other sites More sharing options...
rubis Posted July 9, 2012 Share Posted July 9, 2012 LawrenceH and RichardH, are you boys identical twins? Quote Link to comment Share on other sites More sharing options...
stevie Posted July 9, 2012 Share Posted July 9, 2012 (edited) [quote name='LawrenceH' timestamp='1341830469' post='1724613'] This'll be great! Will be following the thread, very jealous of the CNC machine! [/quote] Yes, me too. Be careful with your crossover parts. If you can, find out what their power rating is. Most ferrite-based inductors will start to saturate well before you reach the maximum output of this system. Use laminated core or air-core. The latter is the best but expensive. Are you using poplar ply? Edited July 9, 2012 by stevie Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 11, 2012 Author Share Posted July 11, 2012 The crossover components are not the precise ones specced by Greenboy (as you can only get them from the US), but are equivalents. Air cored where specified, non ferrite solid cored (not quite sure what the core is!) when a solid core is specced. The wire gauge is also as specified, so all should be well The 15mm ply is poplar, yes - though I understand it has magic inner cores that are extra light. If I said my mate with the CNC machine also makes bass cabs that have a name that used to rhyme with Toot and now (sort of) rhyme with Turtle Silly maybe that will give you an idea of the source of the ply, and it's lightness. Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 13, 2012 Author Share Posted July 13, 2012 [quote name='rubis' timestamp='1341849694' post='1725083'] LawrenceH and RichardH, are you boys identical twins? [/quote] I've got the horn It's a big boy! Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 18, 2012 Author Share Posted July 18, 2012 (edited) Crossovers done: mid/bass: High pass for the tweeter Family shot Components held down with zip ties and hot melt glue. Only downer on this is that we were going to add a variable LPad for the tweeter, but the supplier's out of stock. So we're just going to put an on/off switch in for the moment, as we want to have the cab done for Saturday. Edited July 18, 2012 by RichardH Quote Link to comment Share on other sites More sharing options...
Musicman20 Posted July 18, 2012 Share Posted July 18, 2012 Can someone please build me one of these cabinets?!?! There seems to be a lack of builders of these cabs in the UK. Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 19, 2012 Author Share Posted July 19, 2012 The box, all tolexed up We (I) got a bit caught out when having to cater for my miscalculation when resizing for 15mm ply - the front lip ended up having to be a bit shallower than it should be to retain the correct cab volume. That didn't seem to be a problem at the time - plenty of space for the drivers to front load - but we didn't have the tweeter's waveguide to hand. The waveguide projects by 1" - so the routing around the tweeter cutout is there to rebate the waveguide a bit so it fits behind the grill. Still to do - trim back the wadding at the back of the port, fit the crossovers and wire the beast up! Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 19, 2012 Author Share Posted July 19, 2012 [quote name='Musicman20' timestamp='1342623291' post='1738071'] Can someone please build me one of these cabinets?!?! There seems to be a lack of builders of these cabs in the UK. [/quote] You have a PM. Quote Link to comment Share on other sites More sharing options...
eude Posted July 19, 2012 Share Posted July 19, 2012 [quote name='RichardH' timestamp='1342699471' post='1739485'] You have a PM. [/quote] Oooo - Interesting... Quote Link to comment Share on other sites More sharing options...
Dood Posted July 19, 2012 Share Posted July 19, 2012 Wow! That's looking great!! - Funnily I was looking at a 1212/6/1. I'm terrible with a saw though!!! I'd be interested to hear about the overall cost and maybe included in the conversation with MM20 above? I'm certainly shopping around for a 2x12 solution right now. Quote Link to comment Share on other sites More sharing options...
Conan Posted July 19, 2012 Share Posted July 19, 2012 [quote name='Musicman20' timestamp='1342623291' post='1738071'] Can someone please build me one of these cabinets?!?! [/quote] You must want it for a coffee table. You can't [i]possibly[/i] need any more cabinets!! Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 19, 2012 Author Share Posted July 19, 2012 Some more progress: More horn, please missus Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 19, 2012 Author Share Posted July 19, 2012 ...and into the home straight Piping round the grill to give it a bit of a retro vibe Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 19, 2012 Author Share Posted July 19, 2012 Here's a rearful of the fEARful: The switch is a bit of a jury rig, as the one we were intending to use wasn't available, and we wanted to be sure it was ready for the weekend. At some point I will try and get the variable L-Pad fitted, too. Quote Link to comment Share on other sites More sharing options...
Owen Posted July 19, 2012 Share Posted July 19, 2012 [quote name='dood' timestamp='1342707116' post='1739680'] Wow! That's looking great!! - Funnily I was looking at a 1212/6/1. I'm terrible with a saw though!!! I'd be interested to hear about the overall cost and maybe included in the conversation with MM20 above? I'm certainly shopping around for a 2x12 solution right now. [/quote] I also need to be included in any behind the scenes discussions here. Quote Link to comment Share on other sites More sharing options...
Dood Posted July 19, 2012 Share Posted July 19, 2012 That cab looks absolutely great!! Quote Link to comment Share on other sites More sharing options...
TPJ Posted July 20, 2012 Share Posted July 20, 2012 (edited) [quote name='Musicman20' timestamp='1342623291' post='1738071'] Can someone please build me one of these cabinets?!?! There seems to be a lack of builders of these cabs in the UK. [/quote] Doesn't mrtcat on here build them? He also does BFM cabs. [url="http://basschat.co.uk/topic/144296-bill-fitzmaurice-builder/page__view__findpost__p__1291757"]Says so here[/url] Edited July 20, 2012 by TPJ Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 23, 2012 Author Share Posted July 23, 2012 Well, took the cab down to the little gathering in Reading on Saturday, and the cab dun well It looks like the tweeter's not doing quite what it should - switching it in and out made very little difference to the sound - can't imagine it's meant to be that subtle. And, the handle location's not right. Mike placed it for visual "rightness" a bit too early in the build sequence, but that means the cab hangs slightly off vertical when lifted - not a big deal, but could be better. We've decided that we'll go down the "handle on the side" route instead, so that the handle doesn't get in the way any head placed on the top of the cab - not all have big enough feet to sit above it. The handle's held in with M5 bolts through into tee nuts, but the lower density of the lightweight ply means that one of them was spinning very slightly, so we're going to glue a small patch of 12mm birch for the teenuts to locate into when the handle gets moved. So, round 1 over - time for a few tweaks and then we should have it nailed! Here it is with my G&L in front of it with the TC RH450 on top (angled by my proprietary folding amp ramp Group shot of various gear Quote Link to comment Share on other sites More sharing options...
charic Posted July 23, 2012 Share Posted July 23, 2012 It may seem very subtle with the RH450 because of the high frequency cut (everything over 6k I believe?). Check it with another amp before doing anything drastic Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 23, 2012 Author Share Posted July 23, 2012 (edited) Ahhh - very good point, but that's not it - we A/Bd it against one of Dave Perry's excellent EAD cabs (with the same amp), and that had way more top end to it - and not in a bad way. It may well be that the voicing is different, but we're going to give it a good check over to ensure we've not done something silly Edited July 23, 2012 by RichardH Quote Link to comment Share on other sites More sharing options...
RichardH Posted July 24, 2012 Author Share Posted July 24, 2012 Just been checking and the high pass for the tweeter is designed for a 6k pass, so that would explain why not much was getting through. So it looks like the differences we were hearing between the two cabs was more about the mid voicing than the tweeter - although Dave's tweeter high pass may be crossing over a lot lower, hence the reason twiddling his tweeter knob affected the sound from his cab. So it may be that we need to check all is well with the mid section rather than anything else. Quote Link to comment Share on other sites More sharing options...
.jpg.7e18f76540598a8efc0e6ca9be453059.jpg)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.