A 1x12, or maybe two

[Gottastopbuyinggear]

Having thought about doing a 2x10 build for a little while, but being a novice at this sort of thing, I've decided to have a go instead at the basschat 1x12 (or hopefully something very much like it - I'm building in advance of the full write up, and my DIY skills aren't always the best!).

There's a few reasons for going 1x12 for a first build but most importantly it's the opportunity to build the thing that I've been reading about for some time, and the fact that it seems to be pretty well received by the (albeit relatively limited?) audience that's heard it so far.

I've bought enough materials to build two cabs, although only ordered a single driver so far, since the cost of the driver itself is the best part of half the cost of the cab. I plan to build both cabs and once I'm sure that I'm happy with the sound I'll order the second driver.

I got the ply from Avon Plywood in Bristol, and they've cut it (very accurately) to size. I've gone for 18mm Poplar, so it wasn't cheap - just a shade under £60 +VAT for the full sheet, so a total of about £82 including VAT and cutting. The small cutting cost seems like an absolute bargain to me - I don't have a circular saw, and I didn't fancy using a router to square every edge.

I'm not sure whether to reinforce every joint with a batten, but I've cut enough to enable me to do so. Raw materials so far, including template for routing the baffle:

[URL=http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0442_zpsctww53in.jpg.html][IMG]http://i1172.photobucket.com/albums/r573/andrewjdowden/1x12%20Build/IMG_0442_zpsctww53in.jpg[/IMG][/URL]

[URL=http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0447_zpsfv93bgxe.jpg.html][IMG]http://i1172.photobucket.com/albums/r573/andrewjdowden/1x12%20Build/IMG_0447_zpsfv93bgxe.jpg[/IMG][/URL]

Edited May 1, 2016 by Gottastopbuyinggear

[Gottastopbuyinggear]

There were quite a few reasonable pieces left over from the sheet, so I thought I'd try to make a template for routing the baffle. I have access to a bandsaw, which I thought might be easier to set up than a router. I didn't really have much of a clue how accurate I'd be, but I wanted to make sure the fit was a close as possible as I'm planning to use T nuts to secure the driver, and I don't want to be drilling the holes for them too close to the main cut out.

The spec says 277.5mm diameter. I aimed for 278mm, and by some miracle that's what I actually got. Not bad for what is essentially one piece of ply nailed to another and rotated round...

[URL=http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0444_zpsykqpaaf8.jpg.html][IMG]http://i1172.photobucket.com/albums/r573/andrewjdowden/1x12%20Build/IMG_0444_zpsykqpaaf8.jpg[/IMG][/URL]

I'll be waiting for the driver to arrive and checking it really does fit before I route the baffle, though!

Edited May 1, 2016 by Gottastopbuyinggear

[stevie]

Looking good! From a structural point of view, you don't actually need the battens at the back of the cab but they make assembly easier. In fact, not having any battens there gives you more bracing options such as (semi-)circular braces, for example. Like this: [url="http://www.eighteensound.com/Portals/0/EnclosuresKits/18sound_12%202ways.pdf"]http://www.eighteens..._12%202ways.pdf[/url]

Having battens at the front of the cab gives you the option of swapping the baffle out at some future time. If you fancy adding a tweeter or midrange unit later on, you'll be stuck if the front baffle is glued in.

Edited April 1, 2016 by stevie

[Beer of the Bass]

That's a much better way of doing the baffle holes than my "freehand with a jigsaw followed by lots of cleanup" method!

[Gottastopbuyinggear]

Hi Stevie, yes I'll definitely use battens all round for the baffle rather than gluing it, but not so sure about the back panel yet. Being a belt and braces type I'll probably go for it, but I might check what the weight is like first, though the difference will probably be negligible

Likewise I'll probably go for some minimal bracing as suggested by Phil in response to my question over on the Basschat 1x12 thread, though I have been poking around in my Purple Chili 112 cab (not too easy, but managed to take a few photos with an iPhone) and also my Ampeg PF115HE (very easy - the lid comes off...) and there's none that I can see in the PC, and only a single vane type brace in the Ampeg, hence the question.

The other question that came to mind from looking at the Ampeg cab was about the importance of sealing. I've read a lot about making sure the glue is well spread in order to ensure a good seal, and I'll probably use some form of caulk as well (like I said, belt and braces), but the lid on the Ampeg cab is only sealed with some gasket tape and is designed to be taken off frequently, so I can't help wondering whether the whole issue of sealing is a little overblown.

[Gottastopbuyinggear]

[quote name='Beer of the Bass' timestamp='1459516144' post='3017334']
That's a much better way of doing the baffle holes than my "freehand with a jigsaw followed by lots of cleanup" method!
[/quote]

There's a certain obsessive-compulsive part of me that appreciates a very neat and precise result, but there's another part that will hack out the hole for the speakon plate with a jigsaw because I can't be bothered to make a template for that!

[stevie]

[quote name='Gottastopbuyinggear' timestamp='1459517202' post='3017345']
There's a certain obsessive-compulsive part of me that appreciates a very neat and precise result, but there's another part that will hack out the hole for the speakon plate with a jigsaw because I can't be bothered to make a template for that!
[/quote]

There's a certain satisfaction to be had from using a circle jig to cut out a perfect hole with a router, but the only time I ever bother is when I want to recess the speaker. Otherwise, I take the easy way out and use the jigsaw. Nobody ever sees the hole anyway!

[Chienmortbb]

[quote name='stevie' timestamp='1459518262' post='3017358']


There's a certain satisfaction to be had from using a circle jig to cut out a perfect hole with a router, but the only time I ever bother is when I want to recess the speaker. Otherwise, I take the easy way out and use the jigsaw. Nobody ever sees the hole anyway!
[/quote]A jigsaw can be quite accurate if you use the proper wood blade, that is the really skinny one. The wider flatter blades resist turning.

[Phil Starr]

There's a few reasons for battening all round. It increases the glue area, actually it doubles it increasing the strength and reducing the chance of failure. It also braces all the panels, effectively supporting them further in towards their centres and helps with panel resonance. Mainly though for a home builder it means you can screw your cab together which holds it whilst the glue sets. This makes it a whole lot easier if you don't have a set of clamps to hand. Drill out the battens and screw them on from inside, make sure the screws are short enough that they don't penetrate through the cab walls.

I mark out all the panels before starting. Screw and glue all the battens on first then make a sleeve of the top bottom and sides. and sides. If you slide the back and the baffle in whilst the glue is drying they will hold the cab square until the glue is set. Then you can glue in the back. I fix the baffle with screws and a gasket. If you can't get the baffle out then screw something into the bit you will cut out for the speaker and pull on that, obviously not a problem if you have done the cutout first.

Good luck, I hope you like it.

[Gottastopbuyinggear]

Thanks Phil. I've already built one box as far as top, bottom, sides and rear panel. Basic approach was pretty much exactly as you said, with one exception in that I built back, sides and bottom with the top going on last, with the baffle piece in there to help keep it square. From looking at other build diaries I'd guessed that the usual approach was to build a sleeve and glue the back in afterwards, but I felt that I'd get more glue in the edges of the baffle piece if I did it that way. I'm not sure if I've missed a glaringly obvious reason for not doing it that way?!

I'm pretty confident that it'll be well sealed given the amount of glue squeeze out I had, but I'll probably use caulk as well. I've yet to make the second box, so I can change the approach for that if it'll give me any benefit.

Fortunately I've plenty of off-cuts the same width as the baffle so cutting a couple for side to side bracing should be easy, and likewise I have plenty for vane braces on the back panel. I should probably have put those on before gluing the baffle in, but I'm happy I can "clamp" them by putting the cab on its back and putting some heavy weight on them while the glue dries.

Looking forward to making some more progress, but work and other things have a habit of getting in the way so I'm not sure when I'll get the chance which is a bit frustrating.

[Phil Starr]

[quote name='Gottastopbuyinggear' timestamp='1460119139' post='3022765']

Looking forward to making some more progress, but work and other things have a habit of getting in the way so I'm not sure when I'll get the chance which is a bit frustrating.
[/quote]

That's why I don't have a full set of instructions written up yet.

[3below]

The other way to get a good circular hole with the router is to use a circle cutting jig. You may also have some extension bars that came with the router. I use these and screw the bars / jig to the centre of the speaker hole. Works really well. Similar picture here [url="http://web.stanford.edu/group/stanfordtaiko/manual/images/circle_routing_jig_2.jpg"]http://web.stanford.edu/group/stanfordtaiko/manual/images/circle_routing_jig_2.jpg[/url]

[6v6]

[quote name='3below' timestamp='1460151132' post='3023203']
The other way to get a good circular hole with the router is to use a circle cutting jig. You may also have some extension bars that came with the router. I use these and screw the bars / jig to the centre of the speaker hole. Works really well. Similar picture here [url="http://web.stanford.edu/group/stanfordtaiko/manual/images/circle_routing_jig_2.jpg"]http://web.stanford....uting_jig_2.jpg[/url]
[/quote]

Nice, I bodged my router onto a scrap of hardboard which served the same purpose!

[Gottastopbuyinggear]

Finally had the chance to make some progress. Box built, hole for speakon plate cut, and corners radiused. Had a bit of an issue with a little tear out on one surface, but that can be the bottom of the cab so no real issue.

[url="http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0460_zpsyyzz1a3i.jpg.html"][/url]



[url="http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0464_zpsjeqvryju.jpg.html"][/url]


Also cut the ports...

[url="http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0466_zpsrynouz7m.jpg.html"][/url]

That's a can of Tuff Cab lurking in the corner, so I'm nearly ready to start painting. Just need to paint the baffle and inside of the recess black first, and I have some matt black acrylic spray for doing that.

I need to decide how to fix the ports in place - any clues from those with some experience?

Edited May 1, 2016 by Gottastopbuyinggear

[Beer of the Bass]

Those are looking nice; very clean woodworking there. I just used a general purpose contact glue to fit my ports, I think it was UHU. It dries to a rubbery consistency, fills gaps and can be pulled apart if needed, so it seems to do the job OK.

[ColinB]

I used hot glue - the glue gun and sticks jobbie. Filled the gaps but is undo-able.

[Gottastopbuyinggear]

Made some good progress last weekend and this.

Three coats of Tuff Cab, left to cure for a few days:

[url="http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0472_zpss8ep0oxd.jpg.html"][/url]

Hardware attached:

[url="http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0476_zpshjrsofot.jpg.html"][/url]

And all of a sudden I appear to have a cab!

[url="http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0477_zpsteeegkbt.jpg.html"][/url]

I've used a hot glue gun to secure the ports for the moment (thanks for the idea, ColinB), and haven't braced or added any acoustic wadding yet, but couldn't resist putting it all together and giving it a quick try. Baffle is screwed in (stating the obvious) but with gasket tape around the edges where it meets the battens.

First impressions - I'm extremely pleased, and to my ears it sounds excellent. Pretty sure there are no leaks, and I doubt if there are any rattles or buzzes attributable to the cab itself, but I did get quite a lot of stuff in the living room rattling and buzzing for 15 minutes or so this afternoon! Not quite certain but I think I stopped just shy of getting my first ASBO.

Don't think I'll be able to resist taking it to rehearsal on Tuesday - I've some thick card that I can use to protect the speaker in transit, and it's a big room so hopefully it'll be safe. Now I need to get some grille cloth and make a frame up, and then get around to making this one's twin.

Edited May 15, 2016 by Gottastopbuyinggear

[ColinB]

That looks brilliant. Nice one!

[FuNkShUi]

Looks great!
Really tempted to have a go of this myself....

[Phil Starr]

Looks like you've done a lovely job. Did you use the dimensions of the 12 in the thread or did it just end up more or less the same? If you did then I'd like to point people over to this thread to get an unbiased account and review of how it sounds.

My experience is that one of these at a practice is enough to really drown out the drummer, though I generally use fairly flat eq with just a little bass roll off which makes it easy on the speakers. I use two only in the biggest venues. My drummer once asked for a bit more volume in the sound check. He complained at the break between sets that he couldn't hear his own snare over the bass Audience all enjoyed it though.

[Gottastopbuyinggear]

Phil, this is completely based on the dimensions in the diagram that Ghost_Bass's posted (#554) over on your design thread, so should be identical in dimensions to the 18mm ply cab you built. I've perhaps gone slightly more belt-and-braces than you in that the rear panel is battened, and there's no bracing in it yet, but apart from that it should be pretty much identical. Port tubes are 190mm. Weighs in at 13.5 Kg - not sure how that compares to yours, but I'd assume it would be pretty similar barring any differences in the ply density.

I'm more than happy for you to point people over at this thread, though whether they'll get an unbiased view is a different matter - it may be your design, but it's my build and I'm proud of it! Seriously, though, neither of my bands are gigging yet (though I sincerely hope that at least one of them is well on the way there) so it'll be a fairly small audience. Also, I don't consider myself to have a particularly discerning ear. Having said that, I know what I don't like about my Markbass cab (which was one of the original triggers for building a cab - I was originally thinking of starting with a 2x10...) so I'll be able to give my view on how it compares, and I'll also be able to compare to my Ampeg PF115HE.

[Gottastopbuyinggear]

Used this at a practice last night. GK MB200 just a shade over 12:00 on the gain, bass between 10:00 and 11:00, Lo Mid at 14:00, Hi Mid at 13:00, Treble between 09:00 and 10:00 (allegedly flat on the MB200 would be 10:00, 13:00, 14:00, 10:00). Played a MIM standard Precision with flats, with tone variously between full on and rolled about half way off.

I have to say that to my ears it sounded great. Bearing in mind that I don't like a lot of highs in my sound it seems to have a pretty even response across the entire range to me, possibly losing a tiny bit of volume low down on the E string, but I suspect that may be coming from the bass (and maybe my ears) a bit too. To put that in context, we play Been Down So Long by The Doors, and CCR's Fortunate Son, and there was plenty enough ooomph on the low E's, F's and G's in those two. Heading up the fretboard, Crosstown Traffic played across all strings up around the 8th and 10th frets didn't suffer from the issue I have when using the Markbass 2x10 (traveler) which always seems very boomy around those frets on the A string in particular. On the whole it's definitely nowhere near as forward in the mids than the Markbass, which is exactly what I wanted.

Another good indicator was that I didn't do any tone tweaking on the amp during the evening, and whereas I've been using a VT Bass to try and get a better sound for some songs (and not really succeeding much of the time), the only change I made was using the tone on the bass.

I'll try it next week with my Jazz, which has a bit of a stronger low end, and with which I've had a bit more success with when played through the Markbass. I suspect that the combination of mid prominent Precision plus mid prominent Markbass has been a big part of the problem I've been having (and add to that my inexperience), but I'm really chuffed with the sound I got last night.

A couple of other observations - I turned down just a smidgen towards the end of the evening, which may have been the drummer getting tired, or may have been that I was too loud to start, but I wondered if that could have been the speaker moving towards it's expected efficiency as it breaks in? I couldn't detect any significant panel vibrations, though I can't have been giving it more than a fraction of the 300W odd that it should (according to Phil's original design criteria!) be able to handle.

In summary, pleased as punch!

Edit: Almost forgot, I really can't see me actually needing a second one of these anytime soon. But as I've said before, since when has "need" got anything to do with it!

Edited May 18, 2016 by Gottastopbuyinggear

[Phil Starr]

Two stacked look so good too.

I'm not a great believer in speakers breaking in making a huge difference. I know Stevie of Basschat fame did some measurements/calculations on it a couple of years ago and there is a thread here somewhere.

I'm glad you've got the flat response I aimed at when I chose the speaker for this cab.

BTW Fortunate Son, what a great song.

[SH73]

[quote name='Gottastopbuyinggear' timestamp='1459513117' post='3017286']
Having thought about doing a 2x10 build for a little while, but being a novice at this sort of thing, I've decided to have a go instead at the basschat 1x12 (or hopefully something very much like it - I'm building in advance of the full write up, and my DIY skills aren't always the best!).

There's a few reasons for going 1x12 for a first build but most importantly it's the opportunity to build the thing that I've been reading about for some time, and the fact that it seems to be pretty well received by the (albeit relatively limited?) audience that's heard it so far.

I've bought enough materials to build two cabs, although only ordered a single driver so far, since the cost of the driver itself is the best part of half the cost of the cab. I plan to build both cabs and once I'm sure that I'm happy with the sound I'll order the second driver.

I got the ply from Avon Plywood in Bristol, and they've cut it (very accurately) to size. I've gone for 18mm Poplar, so it wasn't cheap - just a shade under £60 +VAT for the full sheet, so a total of about £82 including VAT and cutting. The small cutting cost seems like an absolute bargain to me - I don't have a circular saw, and I didn't fancy using a router to square every edge.

I'm not sure whether to reinforce every joint with a batten, but I've cut enough to enable me to do so. Raw materials so far, including template for routing the baffle:

[URL=http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0442_zpsctww53in.jpg.html][IMG]http://i1172.photobucket.com/albums/r573/andrewjdowden/1x12%20Build/IMG_0442_zpsctww53in.jpg[/IMG][/URL]

[URL=http://s1172.photobucket.com/user/andrewjdowden/media/1x12%20Build/IMG_0447_zpsfv93bgxe.jpg.html][IMG]http://i1172.photobucket.com/albums/r573/andrewjdowden/1x12%20Build/IMG_0447_zpsfv93bgxe.jpg[/IMG][/URL]
[/quote]
The final product looks of a higher quality than some Chinese makes.Where did you get the dimensions from and would you share it?

[Phil Starr]

It's already shared. You might want to skip a few pages though

http://basschat.co.uk/topic/227904-1x12-cab-design-diary/