RichardH

LOL!

Finished! With its dad Here it is with the G&L to give a better sense of scale Only bummer is that I'm getting some port chuffing centred around the bottom A. Odd, because for the size vent I chose, WinISD give a vent mach of 0.07 which is low enough. Maybe the cab volume was significantly lower than designed because I didn't bother to take account of speaker cone vol? Having said that, this was at fairly high volume... I may have to have another go - this time with better ply!

Nice MDF burl you've got there, Steve.

Some progress.... or how to build a cab in 3 hours. [b]9:00am - OK, let's build a cab.[/b] I'd already determined that I was going to build it with a volume of 0.88(ish) cu ft (25 litres) and a tuning freqency of 52Hz from tinkering with WinISD. So I took some measurements from my LittleMark and exisitng 1x12 cab, as I wanted to make sure the LittleMark would sit on top of my lovely new cab. From these I produced a fully rendered 3D scale drawing of the final cabinet, allowing me to fully appreciate the final product... ...Or not. I chose the internal width to be the same as the LM and the height to be the width of my 1x12, which then gave me the depth as shown. I wanted to do a full width "slot" port like on the Electrovoice designs, and thought that 30mm would be a good height for it - WinISD gave me a vent length of 252mm. From advice from Mr Claber, I reduced the vent depth by 2/3 to allow for the boundary effect, which gave me the 165mm depth. Oooo, I'll add 20mm to the depth to allow me to recess the driver and maybe fit a grill or something, eh? [b]OK, it was 9:20am by now - time to get going![/b] I only had an offcut of some nasty WBP 12mm ply, but this was meant to be a test run, so that'll do. Measure... measure - OK, it's 610x1450mm. Bloody hell -I can get all the 280mm panels from one rip down the length of the panel, with about 20mm wastage ...and cripes - the remaining panels (310 width) can come out of the remainder with minimal wastage, leaving me with a neat rectangle left over that can be used for something else. It's almost like it was planned! Look! Some G clamps, an aluminium section as a straightedge and my trusy cordless circular saw, and we have some panels. Now I'm afraid it's all a bit of a blur here, as my and my chum got moving a bit quick, and I neglected to take any photos. Anyway, before you could say "time for a brew" it was 10:30am, we'd tidied up the tools and we had this (Actually the sealant was put on later - after the glue (PVA) had dried). Our respective other halves were returning from an early moring sortie to North Weald market, so it was time to get the coffee on and start making breakfast (bagels filled with bacon, fired mushrooms and a fried egg, if you're interested). [b]Get the little chappy finished, then[/b] Just a few minutes work to get the final side panel fixed into place, and some sealant applied from through the speaker hole. Pop out and do a bit of rubbing down and filling at odd 5 minute intervals through the day... Oh, and staple gun some wadding in there. It's like it was meant to be - I had just enough left to do this cab. Hmmm - maybe this will look OK after all - and it's screwed and glued, so even that thin veneer won't be too much of a problem... Let's whack some Tuffcoat on shall we? I reckon so far it's taken around 2 and a half hours. Watch this space!

I was given a '70s Fender body that had a tiny bit of checking on the finish: This was a refinish though - but it had apparently been done by a decent luthier.

Oooo ta Alex, I'll give that a bash with a slot port, methinks.

Cheers Alex. So the 3" round port will be OK then - bit long for the prospective size of the cab though - I'll have to play in WinISD. If I were to build a slot port, and guidance on dimensions? Don't go spending loads of time on it though...

OK, I picked up an [url="http://www.eminence.com/guitar_speaker_detail.asp?model=ACOUSTINATORNH2008&speaker_size=8&SUB_CAT_ID=6"]Eminence Acoustinator NH2008[/url] with the intention of using it to make a decent small cab as a practice amp - but with the hope that I may be able to use it for acoustic style gigs etc. [url="http://www.eminence.com/pdf/acoustinator-nh2008.pdf"]Spec sheet[/url] Looking at the [url="http://www.eminence.com/pdf/cab-acoustinator-nh2008.pdf"]cab design sheet[/url] it appears that I can get something that is fairly flat (at -3db) down to 60Hz or so, using a 0.8 cu ft box, but it will reach displacement limit at 55W. Smaller cabs will roll off sooner but have a higher wattage displacement limit. Originally I'd intended to simply ccale down the design for the Electrovoice 1x12" cab, but thought I ought to look into it a bit more. The vent recommendation is for a single 3" round jobbie 9.23" in length, but I was wondering how using a larger "slot" style vent as per the Electrovoice, fEarful and Barefaced cabs would affect things. From what I understand, a larger vent than is "correct" can offer some benefits, or am I going completely bonkers?

Bracing is your friend.

The fretted comes with some fairly coarse roundwounds that came straight off, and initially I put TI Jazz Flats on. Thought I'd try the Gallis, and they feel nice, are higher tension than the TI flats, and have a fatter bottom end, I would say. Gallis are quite fat strings though - I worried that I'd need to cut the nut but it was OK in the end.

Now sporting a set of black Galli Tapewounds Looking at your avatar, I reckon they'd look very nice with black tuners rather than the shiny chrome 'uns.

[quote name='walbassist' post='451897' date='Apr 1 2009, 08:09 PM']Nope, it's standard on the new 2009 model, along with a spruce (not cedar) top.[/quote] Interesting - thumb rest pics not even on the Godin site yet, though they mention the spruce top (think spruce may have come in with the SA stuff, as mine looks to be spruce too). Makes sense to have a thumb rest, though. May look into having one fitted on mine. Wonder if Godin would supply one.... Here's mine:

Interesting with the thumb rest. IIRC the original version of this (was it called the Acousticbass then) had this, but it was dropped for the A4/5 models. I assume this is an aftermarket fitment? I have a fretted A4, and have just taken delivery of the last one of theose clearour GR20s - still waiting for a cable though, as they didn't have stock of them

MDF - it would be VERY HEAVY!!!!!!! Make sure you wear a mask when sanding/planing/routing MDF. If you went with 12mm ply, then I would keep the external dims the same and add some bracing. I would also use birch ply for the extra stiffness and void-free-ness it offers. These cabs aren't THAT sensitive to volume, IMO. As far as what bracing to add, then I'd think a couple of ply "ribs" down the back and side panels would do the job - say 40mm strips glued edge on to offer greater stiffening. Then maybe a couple of diagonals from these ribs up to the top and bottom of the cab. The foaming Polyurethane glue is your friend here (unless you get it on your skin). Extending the top of the port - you will be marginally lengthening the port, so it may have an effect. Insulation - I don't know this stuff, but I'm assuming it's not going to flake into little bits like the usual Rockwool stuff would? It sounds a bit thick - a lot of staples may hold it back - or could you half its thickness by peeling it apart?

[url="http://news.bbc.co.uk/1/low/technology/7870459.stm"]Uh oh....[/url] [quote]Originally Ofcom promised to safeguard spectrum in the 800Mhz band for wireless microphones and digital terrestrial TV services, but it appears to have had a change of heart. Now it proposes to make the whole 800MHz band available for mobile broadband and related services and find "alternative spectrum" for wireless microphones and digital terrestrial TV.[/quote]

Most people seem to reckon the stuff from CPC is better quaility than the Maplin stuff.

Don't really sell much stuff here, but have been around since the early days of Bassworld, if that's any comfort...