building a cab

[futuregun]

i have no idea how to go about this...anyone done it an can advise me?

i can do the wood work an that but have no idea about wiring and what other electrical stiff i need apart from speakers   :oops:

[WezV]

some links:

http://www.duncanamps.com/technical/speaker_cab.html

http://www.guitarplayer.com/story.asp?storyCode=15476

http://colomar.com/Shavano/4x12wiring.html



also some flat packed or ready made cabinets available here if you wanted to save on woodwork:

http://torresamps.com/

[futuregun]

awesome man cheers thesell shed some light on it

[Oli]

I built and open-backed 2x12 a while ago, and when i get the money to get the speakers, will be building a 4x12, as i've still got most of the timber.

The electronics are really really easy, just need two 1/4" jack sockets, some heavy-ish gauge wire, and the speakers.

I wired mine to have mono-stereo option, without a switch, so if you plug the amp into the left side, it'll be mono and run both speakers together (8ohms), but then if you plug into the right side as well, they'll split and become 16ohms each side. I can draw you a diagram if you need it, as it isn't the 'natural' way to wire it up.

Building the cab is great fun- be sure to post some pictures :)
My 'top tip' for building the cab, would be: Rear-mount the speakers (unlike what i did), it'll be much easier, and you won't have to worry if the hole in the baffle isn't quite right, but if you front-mount them, then you have to make sure the speaker fits in properly, and it much more of a pain in the arse!

One of mine:

[futuregun]

well the head i got either runs on 4 or 8 ohms....im not to sure what that means lol
totally new to this sort of thing.just dont wanna spend liike 250 on a cab when with a bit of work i can  do it for half that.a 2x12 will suit me fine.what type of timber is best do you think or does it really matter?

oli   it'd be fantastic if you could do me up a simple(for thats what i am )  diagram of the wiring.im not sure which is best to run at 4 or 8 or even what that means  :oops:
.im at work so have to be stealthy online lol so cant check it up
i guess it boils down to the speakers.whats best for metal?

thanks guys

[WezV]

if you are after a 2x12 cab you either need to wire the speakers in series  or parallel.  (see the links i posted for an explaination)

when you wire speakers in series you need to add the ohm rating together so to get 8 ohms you would need two 4 ohm speakers.

when wiring two sepakers in parallel the ohms end up about half.  so two 8 ohm speakers will give you 4 ohms, or two 16 ohm speakers will give you 8 ohms

any of these combinations will work for you amp by the sound of it


really its just important that you buy two speakers that will be able to give you either 4 or 8 ohms when wired togther and the speakers also need to be able to handle the maximum output of the amp - i.e. if its a 50w amp you want the speakers to be able to handle more than that

[WezV]

heres a quick basic diagram for 2 speakers either wired series or parallel

[Oli]

well the head i got either runs on 4 or 8 ohms....im not to sure what that means lol
totally new to this sort of thing.just dont wanna spend liike 250 on a cab when with a bit of work i can  do it for half that.a 2x12 will suit me fine.what type of timber is best do you think or does it really matter?

oli   it'd be fantastic if you could do me up a simple(for thats what i am )  diagram of the wiring.im not sure which is best to run at 4 or 8 or even what that means  :oops:
.im at work so have to be stealthy online lol so cant check it up
i guess it boils down to the speakers.whats best for metal?

thanks guys

Ok, for your amp, you need to get 8 ohm speakers (not the slightly more common 16ohm), as then you could have 4ohm mono/8ohm stereo. With 16ohm speakers, you'd get 8ohm mono/16ohm stereo. Not to piss on your parade, but when you've got everything (speakers, timber, hardware etc.), it doesn't work out much cheaper at all... that said, it is enjoyable to  build one, so i'd say go for it anyway :)

I got my timber (18mm ply) from good ol' B&Q, and if you get one of their large sheets (i think its 4'x8' or 4'x7', can't remember), then you can actually get two 2x12 cabs out of it- minus the baffle; i used some 12mm MDF for the baffle. I also used some internal bracing, some hardwood is preferable- about 30mmx30mm is a good size. ** because you have to buy a whole sheet of the ply, if you're making one cabinet, it isn't very cost-effective, but if you're gonna make two, then as you'll get both out of the one sheet, it does make it more worthwhile.

I'll draw that diagram later today for you :)

[WezV]

Ok, for your amp, you need to get 8 ohm speakers (not the slightly more common 16ohm), as then you could have 4ohm mono/8ohm stereo. With 16ohm speakers, you'd get 8ohm mono/16ohm stereo

I understand that in mono mode you have both speakers wired parallel so get a 4 ohm load from two 8 ohm speakers . . .

. . . but i am not quite following what the amp does in stereo mode, i cant quite see how you can get an 8 ohm load from two 8 ohm speakers - would the amp just be running one speaker  and if so how is that stereo!

I am relatively new to the amp game so forgive my ignorance on this subject but.

slightly of topic . . .

I can imagine quite clearly how to add a series (16ohm)/parallel (4ohm) switch to a 2x12 cab  with 8 ohm speakers but thats because i had to add a series/parallel switch to a jazz bass recently and its basically the same thing to get my head around

actually that might be usefull for me when i get my cab sorted because i have a matamp little rock coming that can run on 16 ohms and i have a kit build champ head that needs 4 ohms

[Oli]

Ok, for your amp, you need to get 8 ohm speakers (not the slightly more common 16ohm), as then you could have 4ohm mono/8ohm stereo. With 16ohm speakers, you'd get 8ohm mono/16ohm stereo

I understand that in mono mode you have both speakers wired parallel so get a 4 ohm load from two 8 ohm speakers . . .

. . . but i am not quite following what the amp does in stereo mode, i cant quite see how you can get an 8 ohm load from two 8 ohm speakers - would the amp just be running one speaker  and if so how is that stereo!

I am relatively new to the amp game so forgive my ignorance on this subject but.

slightly of topic . . .

I can imagine quite clearly how to add a series (16ohm)/parallel (4ohm) switch to a 2x12 cab  with 8 ohm speakers but thats because i had to add a series/parallel switch to a jazz bass recently and its basically the same thing to get my head around

actually that might be usefull for me when i get my cab sorted because i have a matamp little rock coming that can run on 16 ohms and i have a kit build champ head that needs 4 ohms

The stereo mode just separates the speakers into individual drivers, so you have two separate inputs- you could either run a stereo amp head (usually solid state), or the output from a poweramp in a rack setup, or you could run two separate amp heads into the same cab (one speaker each).

Most of the time, it'll be running in mono, as the majority of tube amps are mono (a 100w stereo tube amp could have 8x el34s, and two big output transformers... completely daft, but it's nice to have the option to run two amps at the same time.

To conclude, it's only 'stereo' if you have a stereo source :)

[c0bblers]

"Stereo" mode is used to plug 2 different sources (amps) into the same cab, or some amps have stereo outs for stereo effects like leslie sims and the like, and rack gear is often stereo too (20-20s are called 20-20 for a reason ;)).  Most of the time you'll probably be in mono mode though unless you run it from a digi amp or a rack unit.

[WezV]

yeah i figured it must be something like that - seems simple enough to do