ADVICE NEEDED: 8/16 ohm speakers and jacks for a 2x12

[bjlotus]

Hi all,

I'm trying to start a diy 2x12 cab project and get it loaded with v30's. Then i was reading about ohms and got a bit confused, so I'd like to have some advices from you guys.

At first, i was planning to get one of those marshall style wired mono/stereo jacks... (http://www.mojotone.com/amp-parts/Ja...Plate-Double-1) but then, got even more confused about it...

This cab is gonna be under my Marshall 1987x, which has a 4, 8 and 16ohm selector and 2 speaker outputs.

So, what should i get (looking for versatility, since in a future i could have another 2x12 cab): a pair of 8ohm speakers, or a pair of 16ohm ones?

Can these marshall jacks be modified to run with a 2x12 instead 4x12?
if thats correct, for a "stereo" setting, you should use both outputs from the head and speakers must be 8ohm each, isnt it?


I was also reading about wiring them in series or parallel, but i guess this depends on the speakers i get...

Please feel free to suggest different options (speakers, jacks, etc), i just got confused around getting 8 or 16ohms speakers, and i don't really know if those jacks just worth it...
lot of questions (maybe stupid questions), but need some guidance!!

Thanks a lot

[slacker]

Two 8 ohm speakers will give you 4 ohm in parallel and 16 ohm is series. If you use a stereo power amp or two separate amps each channel/amp will 'see' 8ohm. If you connect the stereo 8ohm outputs to one amp the load will be 4ohm.

The load is also halved when using two cabs of the same impedence. So if you set both of your cabs to 16ohm and connect them to one amp the load will be 8ohm. If you connect both cabs with the 4ohm setting the load will be 2ohm.

[bjlotus]

thanks slacker.
any more suggestions?

[VanR]

With that jack you would want 2-8 ohm speakers in a 2-12. Then you could get 8 ohm stereo X 2, 16 ohm mono (series) and 4 ohm mono (parallel) Marshall puts those in a 4-12 cab with 16 ohm speakers, but in a 2-12 you would need 8 ohm speakers.

[bjlotus]

Originally Posted by VanR

With that jack you would want 2-8 ohm speakers in a 2-12. Then you could get 8 ohm stereo X 2, 16 ohm mono (series) and 4 ohm mono (parallel) Marshall puts those in a 4-12 cab with 16 ohm speakers, but in a 2-12 you would need 8 ohm speakers.

so if i get a pair of 16ohms speakers, i should use just a standard jack right?

Does this jack worth it, i mean, to have the mono/stereo setting, makes any substancial difference?

thanks!

[VanR]

Originally Posted by bjlotus

so if i get a pair of 16ohms speakers, i should use just a standard jack right?

Does this jack worth it, i mean, to have the mono/stereo setting, makes any substancial difference?

thanks!

I prefer all my cabs to be 16 ohm. That way I can use 1 cab (16 ohm), 2 cabs (8 ohm) or even daisy-chain 4 cabs together for 4 ohm load (I never do this, but could). If you are going to add another cab in the future I would suggest going for 2 8 ohm speakers wired in series for 16 ohm. Makes it easier to add more cabs later on.

[bjlotus]

Thanks. In case i get 16 ohm speakers, load the cab and wire them in parallel, so there should be an 8ohm load... What should i do in a future if i want to add another 2x12 cabe with the same settings? is it possible, or i'm complicating things?

I ask cause I'm trying to get the speakers shipped overseas, and the only people that were ok with that, has just 16ohm speakers for sale heh...

Thanks, once again