Wiring speakers for 16 ohms in a 412 cab

[DrownInk]

Ok, so I didn't write down the diagram for the wiring as I was replacing my speakers today...but I know three of them are right. I think one was wire in the reverse way that the rest of the speakers were(The first one), and I looked at the rest and they were different so I matched them up thinking i forgot which way they went. But after looking up some info I am wondering the the hell I did... or how messed up they might have been.I want it at 16 ohms, but I believe I just made it parralell wiring and 4 ohms(all connections to and from same terminals throughout)?

I knew I shouldn't have done this so late...but its the only time I have to do this...

btw, its a peavey 412M, but only the stere input ever worked(AS mono) since I've had it. Thanks for any help!

 

[drew_half_empty]

Re: Wiring speakers for 16 ohms in a 412 cab

so positive of jack to + of one speaker, run the other + of that speaker to the + of another speaker

do the same for the negative

then run a wire + to - on both pairs

 

[DrownInk]

Re: Wiring speakers for 16 ohms in a 412 cab

I think I understand, but my cab is confusing me. It has one + and one - output, and from how I read that I need two + to wire it like that. Is that right?

Or should I be reading it how you wrote the instructions more and only need one +. Which I would hook up to the first speaker, then that positive to the next, then the negative from both of those to the positives that are left on the two other ones, and then the negatives from those to the original two?

 

[supernosher]

Re: Wiring speakers for 16 ohms in a 412 cab

Drew's diagram works with one jack. So how many jacks and what are they labeled?

See where the + and - leads split and go the the second jack? Just forget about the split.

You would go + of the jack to both +'s of two of the speakers, then from the - terminals of those two speakers go to the + of the other two speakers, and from the - terminals of the last two speakers you go to the - of the jack.

The speakers are 8 or 16 ohms each?

 

[DrownInk]

Re: Wiring speakers for 16 ohms in a 412 cab

16 ohms each, and I think I get it now. It was how they split in the beginning of the diagram that was messing me up. That, and it is suppose to be a switchable mono/stereo cab, but wasn't wired anything like that so it threw me off as far as reading the diagrams .

There are two input jacks on the cb, but only one set of wires leading to the speakers. Only one of the inputs works though, and it seems to have been wired mono through that, even though its suppose to be part of the stereo wiring. Eh, its confusing... I'm going to wire it like Drews diagram later tonight and maybe try to find something to read the Ohms so I know I wont blow anything

 

[supernosher]

Re: Wiring speakers for 16 ohms in a 412 cab

Perfect! 16+16/2=16 :9:

Ya, Stop by RadioShack or a friend's house and grab a multimeter.

 

[Thermionik]

Re: Wiring speakers for 16 ohms in a 412 cab

drew_half_empty - in your excellent series/parallel diagram.....

What happens if you bridge the two purple wires?

Does it change the impedance.
Does it change the sound/tone.

 

[DrownInk]

Re: Wiring speakers for 16 ohms in a 412 cab

Sweet, Thanks for all the help guys. Even though Im a :newbie: at this stuff.

 

[drew_half_empty]

Re: Wiring speakers for 16 ohms in a 412 cab

drew_half_empty - in your excellent series/parallel diagram.....

What happens if you bridge the two purple wires?

Does it change the impedance.
Does it change the sound/tone.

yes, yes, and yes

 

[metlking]

Re: Wiring speakers for 16 ohms in a 412 cab

I like to wire my 4x12's like this: http://www.soundcitysite.com/sc_webpages/series_parallel_x.pdf

 

[StillLearnin']

Re: Wiring speakers for 16 ohms in a 412 cab

drew_half_empty - in your excellent series/parallel diagram.....

What happens if you bridge the two purple wires?

Does it change the impedance.
Does it change the sound/tone.

yes, yes, and yes

Ummmm.... no it doesn't change the impedance if you bridge the purple wires...
It will be two 16 ohm speakers in parallel (8 ohms) in series with two 16 ohm speakers in parallel (8 ohms). 8+8 = 16 (last I knew)

Tone change? a little - probably nothing to get excited about though.

Whatever you do, don't use fabric softener on them - then it's all shot to hell

 

[Thermionik]

Re: Wiring speakers for 16 ohms in a 412 cab

Confused of Blighty here.....

Bridging the inter-speaker links is a Series/Parallel 4x12 Cab.

drew_half_empty says impedance, sound and tone WILL all change.

StillLearnin' say impedance does NOT change, tone only changes a little.

The only reason I ask is because my 4x12 is 2x Fane and 2x Celestion and their resonant frequencies are different, so to balance things out and 'smooth out the peaks and troughs' I wired Series Fane/Celestion in parallel with Series Fane/Celestion. It occurred to my addled brain that bridging the inter-speaker links OUGHT not to change the impedance, but just MIGHT have an effect on the tone. And I also hoped that implied what the effect on the tone might sound like too.....

Now my brain hurts, so I am going to sit in a dark room with an acoustic.:crazy:

 

[drew_half_empty]

Re: Wiring speakers for 16 ohms in a 412 cab

wait, are you saying run 2 more wires + to + and - to -?

like this

or this?

because the top one would give you something like 32 or 64 ohms, i think 64, and the bottom would give you 4 ohms

and you can kinda hear a difference between 16 and 4, or at least more of one than from 16 to 8 or 4 to 2. It's not huge and most people wouldn't notice, but if you were to a/b them you could hear a little more airyness in the 16 and a little more punch in the 4

or am I just missing what you're asking? Seems like that may be the case

 

[glassman]

Re: Wiring speakers for 16 ohms in a 412 cab

I can't speak for the tonal differences between bridged and unbridged but this (bridged) setup would yeild 16 ohms load if all speakers used are 16 ohm speakers and would be the safest should you lose a speaker during a performance. In that case the tone and level would change significantly (and you should stop using it) but you would only be buying a replacement speaker and not an new output transformer and new output tubes.

Jerry

View attachment 12633

 

[StillLearnin']

Re: Wiring speakers for 16 ohms in a 412 cab

i can't speak for the tonal differences between bridged and unbridged but this (bridged) setup would yeild 16 ohms load if all speakers used are 16 ohm speakers and would be the safest should you lose a speaker during a performance. In that case the tone and level would change significantly (and you should stop using it) but you would only be buying a replacement speaker and not an new output transformer and new output tubes.

Jerry

View attachment 12633

+1

Glassman's diagram is the bridging of the purple wires which demonstrates that the impedance does not change from the original diagram DHE posted (if all speaker values are identical impedance - which would be recommended anyway)

 

[Thermionik]

Re: Wiring speakers for 16 ohms in a 412 cab

Aroooogah, arooooogah, now hear this..... WHO dat man glassman ?????

HE knew what "bridging the purple wires" meant and modified the diagram just so, and I have now implemented EXACTLY that link in my 4x12, and glassman was exactly right - no tone change, no impedance change.

And yes - now if one coil goes (mine are 8ohms) the cabinet impedance seen by the amp OT rises from the correct 8ohms to a perfectly safe 12ohms, and I hear it immediately and can replace said speaker at my leasure. Sure - the original wiring would jump to 16ohms with one failure and not be a big deal really, but this is a tad safer still, and now those pesky little electrons can go where they want to, Celestion or Fane, as the whim takes them.

glassman - you ARE dah man.

 

[glassman]

Re: Wiring speakers for 16 ohms in a 412 cab

I have my "good" days...glad I could be of service.

 

[wixedmords]

Re: Wiring speakers for 16 ohms in a 412 cab

Yes, looks good glassman.

I'd have to measure the wiring at the jacks for true impedance, but at first and second glance it looks good.