Help!! First time setting up a 4x12 cab

[Awkwardperkins]

Hello,
I'm getting ready to buy a set of speakers to fill a 4x12 cab. However, I don't want to setup for disaster and blow my speakers or worse, my head 15min into playing. Before I ask my question I'd like to describe my setup:

Amp head: Carvin V3 50w
Cab speakers:
1x Celestion alnico gold (50w, sensitivity 100)
1x Celestion G12 anniversary (30w, sensitivity 100)
2x Scumback H75 (30w, sensitivity 99)
All 8ohlms

I'm playing out of a 50w head, but my total speaker output will be 140w with an average efficiency/sensitivity of 100. I plan to set my amp head volume at a 5-7 range to utilize the tubes and speaker potential. I'm aiming for more tonality, less volume.

My question:
What is my risk here? Do I have too much speaker at 140w through a 50w head? Can I mix these speakers safely, or is this configuration just going to blow up? I can't afford to get this wrong- please help

[demonufo]

It will be fine, but your total power handling will be 120W.

You will need to wire the speakers in standard series/parallel configuration so that the total impedance will be 8ohms. Wire two pairs in series, and the two pairs of pairs in parallel.

[Scumback Speakers]

Wiring diagram for you...

[Awkwardperkins]

Thank you for your help!! Hope you had a nice Thanksgiving

[stef]

Wiring diagram for you...

Looks like two speakers wired in series then paralleled at the jack - series/parallel wiring.

Randall Aiken http://www.aikenamps.com/SpeakerWiring.pdf" onclick="window.open(this.href);return false;




These two diagrams are the same (top one is with less wire used but series/parallel just like the one from the bottom)
http://www.scumbackspeakers.com/wire.html" onclick="window.open(this.href);return false;
Right

Top left picture is parallel series, the other two are series/parallel (attachment)

[Scumback Speakers]

Wiring diagram for you...

Looks like two speakers wired in series then paralleled at the jack - series/parallel wiring.

Randall Aiken http://www.aikenamps.com/SpeakerWiring.pdf" onclick="window.open(this.href);return false;




These two diagrams are the same (top one is with less wire used but series/parallel just like the one from the bottom)
http://www.scumbackspeakers.com/wire.html" onclick="window.open(this.href);return false;
Right

Top left picture is parallel series, the other two are series/parallel (attachment)

The diagram on the aiken site is for wiring with a switch to go between two wiring schemes. That's not what I'm showing in my diagrams. I'm just showing one wiring setup per cab. I don't believe in switches on cabs for wiring. Way too easy for someone to pull a stupid and eff it up, IMO.

The wiring diagrams I have on my site are the ones I've actually seen in original Marshall cabs from the 60/70's I've owned. I'm sure there are multiple ways to get cabs wired, but I'm only focusing on the era correct versions from Marshall.

The reason the Parallel Series setup has the additional wire is to make sure you have three speakers still working in case you have one blow. It's never happened to me, but there are some who think four G12M 25w will hold up to cranked 100w Marshall putting out 170w plus, and at least with the speakers popping/frying one at a time, instead of two at a time with other wiring setups, they have a chance to shut the amp off before they go completely open circuit and fry their output transformer.

Out of curiosity, are you "StephaninMelb" on the TDPRI forum?

[neikeel]

I always use series-parallel as per stock for the reason suggested (although do not cane 100w into a GB cab!). Also all the early cabs I have seen are wired that way!

[stef]

Out of curiosity, are you "StephaninMelb" on the TDPRI forum?

Jim, I just tried to send you a reply but I could not!
I'm not "StephaninMelb" on the TDPRI forum? nor am I a member there The e-mail (hotmail) address is not mine.

The reason I'am asking this about the wiring is because I wired my cab using the diagram on the right (or the one on the top of your web page) - I wanted the series/parallel wiring (two pairs wired in series then paralleled at the jack) - and according to the picture in the attachment both top right and one in the middle (bottom) are the same thing - series/parallel.
The parallel/ series is the first one - top left

[stef]

I always use parallel- series for the reason suggested (although do not cane 100w into a GB cab!). Also all the early cabs I have seen are wired that way!

Neil, please look at the picture - which one do you (always) use? Left, Right, Bottom?

[Scumback Speakers]

Stef, uh, not sure how you arrived at your conclusion. Probably because your diagram is named incorrectly.

From your diagram, the bottom pic(middle) is series/parallel, meaning series wiring at the speakers (two sides separated), then wired in parallel at the jack (four wires at jack, two +, two -). In this setup, each pair (or half) of the 4 speakers is wired in series. The two 16 ohm speakers wired in series is 32 ohms, then it's in parallel at the jack (with the other two speakers) to make 16 ohms total load.

The parallel/series wiring that I use is what your diagram has as the upper right, but it's named wrong as series/parallel. In that diagram, the speakers are wired in parallel, then in series to the jack. In this setup, the 16 ohm speakers are wired in parallel, making each pair an 8 ohm load, but then when wired in series to the jack (one +, one -) it doubles to make 16 ohms total load.

I think the problem is that whoever named those diagrams in your file named them incorrectly as to how Marshall names them.

[stef]

Then what is the first one -upper left It's different than the upper right one

Jim, the way I see it they are all named correctly.
First one is parallel-series (speakers are wired in parallel - parallel at the speaker), upper right is indeed series/parallel (the speakers are not wired in parallel, or I don't see it ), and of course the third one is the way old cabs were wired (again series/parallel).
Back to Aiken's diagram (switch OFF - series/parallel -top right one , switch ON - parallel/series or top left one)

[Scumback Speakers]

Stef,

I'm not going to argue with you on the naming or how they arrived at it. I just follow the Celestion/Marshall examples at the link below.

http://celestion.com/speakerworld/guita ... gurations/" onclick="window.open(this.href);return false;