Building a Cab!

Alanstrainor

Hey there fellas! I've decided, after some tinkering last night, to build a simple cab out of a 12" 8ohm speaker for my fender champion 600 (4ohm). Now, as for the wood to use, what differnece, if any would my selection make to the tone? And as for size, how much space should i give the speaker, both depth and spacee around the edges?
Ideally i'd like to eventually put a 4ohm 8ohm switch on the amp, but iirc, running a 4ohm amp through a 8ohm speaker shouldn't do any harm? I know tone wise it'll make a difference, but just want to make absolutely sure i'm not harming anything.
Cheers lads,
Al.

Eoin Madsen

If the cab is open, the size of it is largely irrelevent - it just needs to be large enough that you can fit the speaker inside comfortably. The more "solid" the wood, the more it will colour the tone, but again, it's much less relevent in an open cab. I think original champ cabs were solid pine, but I could be totally wrong. Birch plywood is the most popular material for building good cabs in general anyway. I know closed and ported Hi-Fi cabs are often made from MDF because it's the deadest and least "colourful" material, but if durability is an issue, yout can't get more solid than plywood. Don't use chipboard in any case, unless it's just for cheap prototyping followed by immediate destruction. :pac:

Afaik, as long as the cab impedence is equal to or higher than the OTs, it's fairly safe, if not ideal. Running a 16ohm OT into a 4 ohm cab is where things might start burning.

Paolo_M

You're probably not going to like my answer but could I suggest that you buy a good book on the subject and do some reading.
The reason I say this is because there are all sorts of factor involved when designing a good quality cab from construction techniques to wood type, thickness of wood and baffle board, porting, baffle board type, internal spacing, open back vs closed, speaker type etc. etc.
Each of these subjects is a topic in it's own right and it would be an aweful lot to get into on a thread.
The Ultimate Tone has a good chapter, Gerald Webers books have some good info and there's a good bit on the web.
Check out this thread from the gear page.net http://www.thegearpage.net/board/showthread.php?t=467468
You'll like it, this guy builds a champ from scratch including cabinet.

Don't worry about speaker impedance, the champ is Class A and can handle 100% impedance mismatch either way quite easily, Fenders often had 4ohm fixed OTs using 8ohm cabs back in the day.

Alanstrainor

Thanks for the replies lads! I think ill take your advice paulo_M and do some research, but it's really just going to be something simple to get me started. I'm just using a spare speaker i have lying around that used to live inside a blues deluxe. I had already decided open back is what i wanted to go with, purely going from experience on that one, always preferred open back speakers/cabs.

felim

I did some research online into building cabs a while back. I have dimension diagrams for both a Marshall 1960 4x12 and a Matchless DC212 2x12 that I found online. If you think either would be of any use to you, let me know and I'll send 'em on. Maybe it might be an idea to use the 2x12 plans and modify them to a 1x12 format??

Alanstrainor

Hey cheers, that'd be great! Send 'm my way.
Thanks for that!

felim

Alanstrainor wrote: »

Hey cheers, that'd be great! Send 'm my way.
Thanks for that!

No worries, I can't find an email address in your profile though...Wanna PM me one?

felim

Lets see if this works. I've tried attaching a zip file with both plans in there...

Alanstrainor

felim wrote: »

Lets see if this works. I've tried attaching a zip file with both plans in there...

That worked perfectly, will have a look at 'm later on. Thanks again for that!

felim

Alanstrainor wrote: »

That worked perfectly, will have a look at 'm later on. Thanks again for that!

You're welcome. If you go ahead with the project, take pics of the build process and post a kind of how-to. I'm sure there are plenty would be interested.

DeadSkin

I built one about a year ago, a 1x12 thiele cab. Don't get to play it much any more .
Made it from mdf. I made one major screw up, the back was supposed to be removable, so it can be open/closed back cab. I just nailed & glued the back on .
There are some good plans out there, it's just a matter of settling on what you want and taking your time building it.
I'll try and find the link to the plans I used, if you want.

Alanstrainor

Yeah, if you dont mind, just trying to get as much info as i can. Thanks for all the help, i can always trust the instruments forum regulars to come up with a ton of info on something not all that common. Cheers guys.
Think i'll hold off diving head first into building the cab and do as much research as possible.

DeadSkin

Have a looksee here.
I used the TL806 plans.