wiring a 2x12 question about ohms

For those building and repairing amps on their own. Learna and share ideas.

wiring a 2x12 question about ohms

Postby geoff_bell on Sun Nov 08, 2015 12:59 pm

I had been using the cabinet from my old Valvestate 8080, a single 8ohm speaker. A number of years ago I had gotten an 8ohm speaker and a 4ohm speaker that I built a special cabinet for (effectively a 1x12 and another 1x12 in a 2x12 cab).

I had been using my Sound City 50+ though these, and, to be honest I they all sound the same, so I've removed the 4ohm speaker and now have both 8ohm speakers installed.

My issue is that my attenuator (http://www.ratvalveamps.com/dummy-load ) is an 8ohm load. Is there a way I can wire my two 8ohm speakers so I can get an 8ohm load? I'd hate to have to shell out more money for a 4ohm attenuator.

Any advice would be greatly appreciated
geoff_bell
Knight
 
Posts: 1335
Joined: Tue Jan 23, 2007 4:23 pm
Location: N. Ireland

Re: wiring a 2x12 question about ohms

Postby Vortexion on Sun Nov 08, 2015 9:01 pm

geoff_bell wrote:Is there a way I can wire my two 8ohm speakers so I can get an 8ohm load?

Sorry Geoff, the answer is no. You can wire them in series which will give you 16 Ohms, or wire them in parallel and get 4 Ohms, and those are the only options you've got.
Vortexion
Newt
 
Posts: 1251
Joined: Thu Jan 10, 2008 4:28 pm
Location: Norwich, UK

Re: wiring a 2x12 question about ohms

Postby Unit_1 on Sun Nov 08, 2015 9:32 pm

You should keep the 4 ohm speaker and get another 4 ohm. then you can wire them in series and they'll be 8 ohm. :highfive:
Image
The ability to play/make music is a gift that not everyone gets. Those of us who have it should use it.

Asimov:Individual science fiction stories may seem as trivial as ever to the blinder critics and philosophers of today — but the core of science fiction, its essence, the concept around which it revolves, has become crucial to our salvation if we are to be saved at all.
Unit_1
Prince
 
Posts: 3713
Joined: Mon Oct 03, 2011 3:29 pm
Location: Kali4ñia (a small planet orbiting the west coast of the United States)

Re: wiring a 2x12 question about ohms

Postby geoff_bell on Tue Nov 10, 2015 5:16 pm

Thanks for confirming what I already knew. I only asked in case I had picked it up wrongly. Lol.

As much as I would like to get another 4ohm speaker and make an 8ohm cab, I already have enough stuff kicking about that I can't sell. Lol.

I think I'll just have to consider a Jettenuator which can handle various ohmages (is that a word?)
geoff_bell
Knight
 
Posts: 1335
Joined: Tue Jan 23, 2007 4:23 pm
Location: N. Ireland

Re: wiring a 2x12 question about ohms

Postby geoff_bell on Wed Nov 11, 2015 12:53 pm

I was actually trying to see if I wired a mono amp to stereo Jack as straight-stereo would work but I think that would actually give 4ohm
geoff_bell
Knight
 
Posts: 1335
Joined: Tue Jan 23, 2007 4:23 pm
Location: N. Ireland

Re: wiring a 2x12 question about ohms

Postby geoff_bell on Fri Nov 13, 2015 9:01 pm

Neither sound City or marshall could run cab at 4ohm. So wired it to 16ohm
geoff_bell
Knight
 
Posts: 1335
Joined: Tue Jan 23, 2007 4:23 pm
Location: N. Ireland

Re: wiring a 2x12 question about ohms

Postby gusfinley on Sun Nov 29, 2015 6:19 am

Just to show what could be possible, if you wired your two 8 ohms in parallel you'd have a 4 ohm cab. If you then wired your 4 ohm speaker in series with the paralleled 8 ohm speakers, you would have a total of 8 ohms. Not very practical, though.

It would be a waste, but you could wire 8 ohm power resistors in parallel with each 8 ohm speaker, then wire these in series for 8 ohms. This would also add some attenuation to the cab.

Just trying to think out of the box a bit.
gusfinley
Knight
 
Posts: 1734
Joined: Thu Jul 07, 2005 11:15 pm
Location: SLC, Utah

Re: wiring a 2x12 question about ohms

Postby geoff_bell on Sun Nov 29, 2015 1:40 pm

Somebody told me that he n I word them in parallel that they may have been out of phase and that's why they did not work. Mind you, I just picked up a used marshall power break, so 4ohm would have been a bad choice anyway.
geoff_bell
Knight
 
Posts: 1335
Joined: Tue Jan 23, 2007 4:23 pm
Location: N. Ireland

Re: wiring a 2x12 question about ohms

Postby Papa Dog on Tue Dec 08, 2015 8:12 pm

actually the SOund City can handle the 4 ohm load just fine.
why on earth do you want to run an attenuator?
There Ain't No Such Thing As A Free Lunch.

"The time has come," the Walrus said,
"To talk of many things:
Of shoes--and ships--and sealing-wax--
Of cabbages--and kings--"
Papa Dog
Knight
 
Posts: 1337
Joined: Mon Mar 15, 2010 6:48 pm
Location: Narly Ampwerks

Re: wiring a 2x12 question about ohms

Postby geoff_bell on Wed Dec 09, 2015 6:37 pm

my amp guy maintains the speakers could have been wired out-of-phase in the parallel mode.

i like an attenuator for home use. i live in a built-up area.
geoff_bell
Knight
 
Posts: 1335
Joined: Tue Jan 23, 2007 4:23 pm
Location: N. Ireland


Return to Do It Yourself Amp Builders

Who is online

Users browsing this forum: No registered users and 2 guests