Building Some 2x12 Cabs...

SnoopKatt

Member
2008-10-27 2:23 am
I just bought a Peavey XXX 120W amp (didn't like it at first, but after some EQing and letting the tubes warm up, it definitely gets the job done), and now I need to build a couple of cabs for it. It supports 4ohms, 8ohms, and 16ohms. Seeing as I don't need to bring a 4x12 all the time, I feel like building 2 2x12 cabs would suffice much better. I want to build each cab with an Eminence Wizard and an Eminence Governor. My current plan for each cab is 14"x28"x12" (HWD, infinite baffle, so no back piece). I plan on using 3/4" birch plywood, and then finishing it for a nice look :)

My only questions are on wiring:
1. The speakers are available in 8ohms and 16ohms. What would be better for each cab, 2 16ohm speakers in parallel for 8ohms, 2 8ohm speakers in series for 16ohms, or 2 8ohm speakers in parallel for 4 ohms?
2. This amp only has one speaker output, so I'll have to daisy-chain them to do more than one cab. How would I go about getting each cab ready for such a setup?
3. Are there any filters or anything I can do to possibly make the cabs sound better?

Thanks!
 
If it's not too late, use 8 ohm speakers to get 16 ohms per cab (series) so when you connect them in parallel you run the amp at 8 ohms. There will be no difference in power, as it's a tube amp with a transformer, but I like to use as many windings as possible.

Make the cabs a bit bigger for better bass response, esp. for the Governor. Close the back if you want some thump.
 

SnoopKatt

Member
2008-10-27 2:23 am
Nah, I probably can't order the parts for another week or so. I can still make changes to the plans.

I looked up the dimensions of the Blackstar Artisan 212 cab, and I saw that was about 28.14x22.39x10.35. Would those work a lot better?

As for closing the cab, I'm definitely debating that. When I build it, I'll probably compare how it sounds, and see which sounds better.

Thanks for the input!
 
Hey SnoopKatt,

From the quick read I did, that wiring is what I was thinking of. As the write says, pick the style of switch you want (I would go for a two position rotary here), and follow the wiring instructions. Keep in mind the current that will be going through the switch and the voltage rating.

As far as a removable back, I can think if a couple ways.

1) Use some form of cabinet latch that allows easy release, but also keeps things held tightly when latched. That way it doesn't rattle.

2) Install T-Nuts or some other form of insert, to allow usage of machine screws, into a mounting flange internal to the back of the enclosure. Basically, you want a good mounting flange that is recessed into the cabinet by the thickness of the back panel. By using the T-Nuts mounted into holes in the flange, you can then have corresponding holes in the back panel. You then use some type of screw to hold the back panel on. I would use at least six screw/T-Nut combinations (3 per side), but more is preferrable. Up to the point where it's a pain in the tush to take them out. You can also use a finger screw for this, that way you don't need a screwdriver everytime you want to remove/install the back.

Hope this helps.

Peace,

Dave
 
Hello again, I was thinking some more (that was your warning;)), you could also use a 4 position rotary switch and with some more thinking, you could wire it up so that you would have your series and parallel positions on each cabinet, and you could also have switch positions that allow you to use just one or the other driver.

And in regards to the cabinet construction itself, you could even build separate sub enclosures within the cabinet for each driver, then have the back panel removable in two sections. Thus one driver could be open back, one closed back.

The thing to remember here is that unlike a stereo system, the amp, speakers, etc. are all part of the instrument with electronic music. Thus you can tailor the sound you want by the way you build the cabinet(s).

Peace,

Dave
 

SnoopKatt

Member
2008-10-27 2:23 am
Hm, those are good ideas too! The separate enclosures might be a bit difficult to pull off, but I'll give it a try. I bought some 6A 125V switches for each cab to put them in series or parallel. I'm buying the rest of the speaker parts next weekend, when my next paycheck comes in.

Thanks for the suggestions!
 

SnoopKatt

Member
2008-10-27 2:23 am
I got all the stuff in :)
I can't start until about a week because of finals, but here's the parts:

1 Eminence Wizard 8 ohms
1 Eminence Governor 8 ohms
3/4" 4'x8' Birch Plywood Prefinished (it was actually cheaper than the unfinished, but it looks beautiful...)
2 12" metal speaker grills
2 large handles for the sides
A DPDT switch for switching between 16 ohms and 4 ohms
2 1/4" input jacks
Some 18AWG wire
And A set of Corners

I only bought enough parts for one 2x12, since I doubt I can finish both in the time frame, due to work and school.

For the holes, I'm thinking of tracing out the necessary hole and then using a jig saw to cut along it. Won't be a perfect hole, but as long as it's close enough it should be alright, right?

As for putting the wood pieces together, what would be the best way? Would liquid nails suffice, or should I use screws/biscuit joiner/other method?

Thanks!
 
Hey SnoopKatt, good idea to start with just one cabinet. Get it all done up the way you want, then copy it for the second one.
Cutting the hole with a jig saw can work, as long as you are good with it. If you are a fumbler like I am, then getting some sort of hole saw is better. The important thing about the hole(s) for the drivers is that they let the driver flange seal against the cabinet properly.
For assembly, I would suggest using wood glue and some sort of fasteners at the joints. It might also be good to reinforce the corners where the front baffle connects with the sides/top/bottom with some pieces of 1" x 1" block, glued and screwed to both the front baffle and to the adjoining panel.

Peace,

Dave
 

SnoopKatt

Member
2008-10-27 2:23 am
Thanks for the quick response :)
I'm decent with those tools, if I use a protractor and draw a line out on pencil, I can follow it...usually :p I may be investing in a Jasper hole saw soon, so I may stick with that.

These are the corners I got for the cab:
Dayton PC123-16 Plastic Stacking Corner 16 Pcs. | Parts-Express.com
Would those with screws be sturdy enough with wood glue, or should I use screws across each edge? I'd like to keep as little visible as possible so the cabinet can look nice, but sturdiness is definitely a factor.

That 1"x1" inside piece is a good idea - I'll have to do it :)

Thanks!
 
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