which ohms in a 4x12?

tdor49 · Post by **tdor49** » Sat Apr 10, 2004 8:27 pm

Can anyone advise me on what ohms the speakers should be in a 4x12 cab. I know they should be vintage 30's but not what the correct ohms should be.
Also if anyone knows how they should be wired up.
I have just purchased an original empty 4x12 to go with my ors100, and I am searching for the correct speakers.
Can't wait to get it up and running.

Post by **bclaire** » Sun Apr 11, 2004 3:19 pm

16 ohm.

I have definitely seen wiring diagrams for 4X12's online but I can't remember where... Marshalls are wired the same if that's any help.

Billy

Meole · Post by **Meole** » Sun Apr 11, 2004 3:53 pm

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

tdor49 · Post by **tdor49** » Sun Apr 11, 2004 6:51 pm

Thanks Billy.
I'll now start looking for some 16ohm Vintage 30's.
I knew I could rely on this forum to give me the info I needed.

A big thanks to Meole too
The diagrams on that site are fantastic.
I've worked it out to be the Mono diagram option 3.
All I need to do now is find the speakers and get them fitted asap.

One other thing guys
Does anyone know why a large portion of the back of this cabinet has been cut away?
I do intend to replace the back panel and obtain some vinyl from orange, but I just wondered if anyone had heard of this being done to a 4x12 cab before.

Dave

Meole · Post by **Meole** » Sun Apr 11, 2004 11:30 pm

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>

I've worked it out to be the Mono diagram option 3.

One other thing guys
Does anyone know why a large portion of the back of this cabinet has been cut away?
I do intend to replace the back panel and obtain some vinyl from orange, but I just wondered if anyone had heard of this being done to a 4x12 cab before.

Dave <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Did you see diagram 10. Another good option.

The back was cut away to reduce the lows, making it sound like an open back combo.

Post by **bclaire** » Sun Apr 11, 2004 11:32 pm

Hi Dave-

sounds like someone was trying to get the sound of an open back cab from that 4X12... weird, what people will do. I'd definitely make a new back for it- does it still have the center support?

The speakers respond differently in a closed back cab. The cab is sealed so there is a permanent cushion of air preventing the speakers from traveling as they would in an open back cab. It also allows greenbacks to be used with a more powerful head than they are rated for... but if you open that cab and play with greenbacks, they'll blow pretty quickly if you play at volume.

Billy

tdor49 · Post by **tdor49** » Mon Apr 12, 2004 9:56 am

Thanks Guys
The centre support is still there, I see what you mean Billy about the pressure inside the cab and how it would affect the performance of the speakers. Strange how some people have different ideas on things, although with this cab being one of the early ones I suppose they were still very much experimenting with the sound.
Thanks Meole the option 10 is another method I could use, but seems a little more complicated.
I do hope I can get some vinyl from the Orange factory, although I've been told that you have to prove to them why it is required.
I only live 4 miles away from Matamp UK, I asked them if they had any orange material left from the old days, but alas it's all gone.
Must say they are really nice guys.
Dave

jake lefler · Post by **jake lefler** » Tue Apr 27, 2004 4:20 am

I just picked up a new ad30tc 3 days ago and I played it the next night at a show. I usually play through a Mesa recto but decided on class a orange. The sound was absolutly incredible and everyone wanted to know about the amp. I absolutly love to tone of this amp.

Anyway my question is, I unpluged the speaker of the orange combo for the show and plugged in my mesa 4X12 into one of the 8ohm jacks on the amp. the cab has vintage 30s like most mesa do. and it runs 8ohm. anyway, The night of the show I really cranked the amp {both channels to match each other} Like to about 3 oclock on the master volume. the sound was great but after about to songs the amp stoped making noise exept for a loud hum. I thought it might be a cable problem so I switched to standby and replaced the cord with a new one. I continued to play for another four or five songs with no problem at the same volume. Then it did it again. this time I switch the standby switch of for a few secounds and fliped it back on and it worked fine.

My question is, is there something wrong with my amp? Did I push it two hard? Did I plug the cab into the wrong jack? Are four vintage 30s to much for the amp to handle? Would a 16ohm cab work better?

I'm really fliping out because I just got it and I can't afford to play on something so unreliable. I just want to know if I did something wrong, or if it is something I need to get fixed.

Sorry so long

Post by **bclaire** » Tue Apr 27, 2004 1:09 pm

shouldn't matter at all whether there are 2 or 4 speakers. That's really weird. I would have tried it again with the combo's speakers and seen if it did it with that at that volume.

jake lefler · Post by **jake lefler** » Wed Apr 28, 2004 3:07 am

I think I figured out the problem, it was one of the cables on my pedal board that needed to be replaced. Duh. My power cord to the pedal board was rapped around that particular cord and every time my bass player would step on the power cord it would move the patch cord. so I souldn't have any problems with the amp itself. Which is good.

But on the other hand, the front grill got booted last night and dented the strawlike grill on the front. I was devistated. So I pulled the speaker out of the back and heat the grill up with a blow dryer, it seemed to do the trick. But after it cooled of it kind of bubbled back a bit. I left it in my car to day in the heat and it stretched back strait again. but tonight i looked at it and it was bubbled out again, but not as bad as last night. SoI think with a little time the grill should wack itself back into place. But heat does work I think. Is there a different way to fix it, or has anyone else had the same problem? The kicked in grill I mean.

Let me know, please thanks

irish_admiral · Post by **irish_admiral** » Tue May 11, 2004 10:02 am

If you're still looking for places to get Greenbacks (or any other Celestion speakers for that matter), try taking a look at the speakers section on www.watfordvalves.com... they've got a good range of Celestions and Jensens (should you for some reason want them) at a very decent price.

Don't tell me the best way, just tell me the cheapest way...

which ohms in a 4x12?

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