Wiring Cabs, Speaker OHMS all in one thread(possible sticky)

[JakeM]

An attenuator will definitely be cheaper than building a decent quality cab. Getting nice 8" speakers and some nice wood to build the cab itself could get a bit more expensive than you anticipate. Try an EQ pedal for when you are in the lower wattage settings and see how that gets you before the attenuator.

Good luck

Jake

[2themax]

Thanks for the feedback,

I do have a 10 band MXR EQ and I did try that and it did help with brightening up the tone, but cranking the 4w setting to the sweet spot is a much better tone. It just seems like the cab "sucks" up all the sound at the lower settings.

I also heard that the AC4's perform better at the 4w setting - I'm still getting a feel for the little amp.

[JakeM]

What speaker have you got?? Vox amps love greenbacks and alnico speakers. Maybe you could swap your speaker for either a WGS Green Beret or a Weber Alnico speaker...might be worth a shot and not too expensive.

Jake

[2themax]

The Egnator has a Celestion Elite 80w speaker (16 ohm)

[2themax]

The Egnator has a Celestion Elite 80w speaker (16 ohm)

[2themax]

The Egnator has a Celestion Elite 80w speaker (16 ohm). Vol. at about 6 at 4w it sounds great, just really loud for a small room. That's why I was thinking maybe a couple of 8" speakers might sound OK at the 1/4w and 2w settings without being too tinny (or maybe a way to switch between a single or dual 8" depending on the wattage setting). I could build a simple box to test it. The attenuator would work ok for line recording, but I don't think it will resolve the 12" speaker on the lower wattages. It seems like a sweet little amp with potential.

[JakeM]

Originally Posted by JakeM

I don't know about you guys but since I have joined here I have experienced many people asking the same questions regarding Ohms, I'm not going to go into Ohms law at the moment, that's what wikipedia is for.

I guess the purpose of this thread is to keep a wiring library of sorts like they have in the tonefreaks section. All members are invited to upload pics of their cabs, wiring diagrams with explanations of what speakers you chose and what way you have the wiring configured.1*10, 1*12, 2*10, 2*12, 2*15, 2*10+12, 4*10, 4*12, 4*15, 6*12. Whatever you have either generic or custom, upload a pic and a quick explanation.

This is not a "What speakers should I pick thread?", "what cab gives tone?" this is to help keep all questions regarding speakers, cabs and wiring together

Sorry for my ramblings but I hope this thread will be of benefit to many here

Cheers,
G'luck Jake

I quoted this opening post as my photobucket deleted the original diagrams so here they are for anyone who is still confused.

[GitFiddle]

Originally Posted by 2themax

The Egnator has a Celestion Elite 80w speaker (16 ohm). Vol. at about 6 at 4w it sounds great, just really loud for a small room. That's why I was thinking maybe a couple of 8" speakers might sound OK at the 1/4w and 2w settings without being too tinny (or maybe a way to switch between a single or dual 8" depending on the wattage setting). I could build a simple box to test it. The attenuator would work ok for line recording, but I don't think it will resolve the 12" speaker on the lower wattages. It seems like a sweet little amp with potential.

Have you thought about sticking with the 4 watt setting and experimenting with a baffle?

(This guy's voice reminds me of Tom Petty )

Homemade Lexan Amp Baffles using parts from Home Depot - YouTube

Homemade Lexan Amp Baffles using parts from Home Depot - YouTube

[2themax]

GF: He's definately laid back... and definately an idea.

Jake: Thanks for the diagrams:

It looks like either 2x8" @8 Ohms in series or 1 x 8" @ 16ohm are the available options. for some reason I seem to have a math block on this.

Speaker question: In my head it seems that a big part of tone is matching the correct speaker size with the amp (and wattage which I tend associate with magnet size). Years ago I had a great 70's Traynor combo, tube about 30w with spring reverb and it really had a great sound. It seemed that the speaker was perfectly matched and would overdrive just enough for great tone and not scatter. With this little Vox, my brain says the power difference between 1/4, 2, and 4w makes me question that a single speaker is going deliver well at all three settings - just checking my logic here.

Thanks,

[cmcoram]

Originally Posted by Tuya Customs

Very good idea. Thanks Jake.



Actually its the lowest wattage speaks X amount of speakers in cab. So 2 25 watt green backs and 2 60 watt V30s makes a 100 watt cab.



Also its typically to have your cab be a third or twice the power of your amp. Ohms mismatches are never good.

Ok, so if I'm understanding this correctly, if put 4 75w speakers in a cab (becoming 300w max) being pushed my a 60w head, I'm ok?

[2themax]

Update: Over the weekend, I did some playing on this amp with a Strat that I just got working again and it sounded pretty decent (at all wattages). Like I originally mentioned my Epi and Tele, both need re-wiring - the Strat had just been re-wired with decent Pup's and it sounded pretty good. Looks like any speaker mod's are on hold for now...

Really appreciate the input...

[tattooed hands]

Hey folks,
I have a noob question. I have a vox V110NT cab (with matching head) and Im a little confused as to what ohm rating the cab is. When looking on sites it says max input 16 ohm. so when I connect a different head, do I plug the cab in to the 16 ohm port?
cheers

[croaker]

Just curious how do you go about mixing a G12M @ 15 ohms with a G12H @ 16 ohms in a 2x12?

[rocknhorse1]

15 ohms is the same thing. Wire in parallel to get an 8ohm cab.

[GitFiddle]

Originally Posted by tattooed hands

Hey folks,
I have a noob question. I have a vox V110NT cab (with matching head) and Im a little confused as to what ohm rating the cab is. When looking on sites it says max input 16 ohm. so when I connect a different head, do I plug the cab in to the 16 ohm port?
cheers

The specs on it states it is a 16 ohm 30 watt cab. With a different head you would connect it to the 16 0hm speaker output of the amp head. I wouldn't use anything over 30 watts either.

Vox V110NT Lil' Night Train 1x10" Extension Cabinet | Sweetwater.com

[Led Zep Fan]

Here's more great info:

Scumback Speakers: How To Wire Your Speakers

[Grand Pappy]

Don't know if this has been asked, but lemme know the consequences of mixing speaker wattage in a 2X 12 cab.
Say I have 2 different 8 ohm speakers 1 @ 40 Watts and 1 @ 15 watts.
Will these work together in a 2X12 cab. or is that a bad decision?
I'm running max 14 watts through the cab right now.
Will the difference in wattage of the 2 speakers cause the cab output and tone to be less than optimal, or sound out of balance?
Is it best to use 2 speakers of equal wattage in a 2 X12 cab?
Please school me in the particulars of mixing different wattage speakers in s 2X12 cab.
Thanks

[Red2112]

Originally Posted by 2themax

Update: Over the weekend, I did some playing on this amp with a Strat that I just got working again and it sounded pretty decent (at all wattages). Like I originally mentioned my Epi and Tele, both need re-wiring - the Strat had just been re-wired with decent Pup's and it sounded pretty good. Looks like any speaker mod's are on hold for now...

Really appreciate the input...

Reading brought to mind I had a similar dilema with my Epiphone Valve Junior when it came out,

Like most 5w amps, the sweet spot is in the 10-12 o´clock spot, and as you say, can be a bit loud for home use.

Since I didnt have a cab back then, I would use the 8" speaker of a Vox Pathfinder15 combo plugged to my EVJ head. Later on I got a cheap 2x12 100w cab. If I remember correctly (dont have the Vox anymore), the EVJ sounded louder on my 2x12 and had more breakup on the 8". Actualy I think it´s should be revers, the more air you need to move means more watts needed, so it should be lower. No pro here just giving ideas...

See If you can get a 8" combo from someone and just make a special speaker cable so you can try out the 8" with your amp.

Getting an atenuator for a 4w amp (unless you make it yourself) can be more expensive then the amp it´s self in some cases. Unless you love the tone, I dont see the point.

You could also try to lower the amp and boost it with a booster like Xotic RC or the like, on your 1x12.

Have fun!

[camdenlp]

So I just scored some vintage Greenback (1974 Creamback) Celestions to put into my rig. I'm running a 2x12 cab currently with V-30s and a 50w Marshall Plexi head. So my 2 25 w GB's are okay to run to my amp, right? Also, I use a THD Hotplate I'm just making sure I'm not going to ruin my amp, or these speakers. Any pointers? I'm also considering using 1 V-30 and 1 GB, any feedback on that combination? What would be the benefits of running one of each, if any, or should I stick with the same in both cabs? Thanks folks...I'll be checking back

[harperlewis.]

Wondering if someone could help me out;

I have a Orange AD30R 2x12 combo with Eminence Legends in it, and im in currently in the process of building a 2X12 extension cab to run with it.

Now, i am more than well versed in the world of carpentry, so that part i have fully covered, however, i'm a bit of a rookie when it comes to the intricacies of impedance.

My combo has 3 inputs on the backside, 1 16OHM input and 2 8OHM inputs.

i'm really not sure how this works. If my amp is powering the internal speakers through the 16ohm input, would i change it to the 8ohm input and wire my extension cab for 8ohms?

some pointers would be appreciated.

[bobarino]

Originally Posted by harperlewis.

Wondering if someone could help me out;

I have a Orange AD30R 2x12 combo with Eminence Legends in it, and im in currently in the process of building a 2X12 extension cab to run with it.

Now, i am more than well versed in the world of carpentry, so that part i have fully covered, however, i'm a bit of a rookie when it comes to the intricacies of impedance.

My combo has 3 inputs on the backside, 1 16OHM input and 2 8OHM inputs.

i'm really not sure how this works. If my amp is powering the internal speakers through the 16ohm input, would i change it to the 8ohm input and wire my extension cab for 8ohms?

some pointers would be appreciated.

i'd do it like this:

internal 2x12 @ 16ohm connected to one of the 8ohm outputs
external 2x12 @ 16ohm connected to the other 8ohm output

[Powermetal]

Hi, newbie here. Came across this forum and looks great with a wealth of info. I have been literally confused from other forums so hoping to get a straight simple answer,please? I have two - 2 x 12 cabs and want to stock them with the Celestions G12T - 75 watts. I'm looking to buy the QSC GX3 power amp. I would like one cab one the left of stage and the other, well the right of stage. Daisy chain them. So, do I need the speakers at 16 ohms or 8 ohms, wired in parallel or series and will the QSC be too powerful and fry these speakers? Should I look for another power amp? Any input appreciated, thank you all.

[Longtailweasel]

Ok guys, I know this is an old thread but I don't want tot start a new post.
Question 1:
I have a 2x12 cab, with 2 output jacks, with 8 ohm speakers wired in parallel to get an 8ohm cab. Only one jack is wired right now. i have a 4 watt vox that runs at 16ohms and a 65 watt egnater renegade that i can choose between 4, 8, and 16. I run my egnater at 8 ohms because i want it to be louder. I also love the sound of my vox but a lil 8'' speaker doesn't cut it. Is there a way i can have one jack be 8ohms and the other be 16ohms so i dont have to re wire my ab every time i want to switch amps?

Question 2: I want to get new speakers. A greenback (25w) and a vintage 30 (60w). This would make a 50 watt 2x12 cab right? So would i blow the greenback because im using a 65 watt amp. My amp has a 65 watt and a 18 watt switch so should i just use the 18 watts if im going to go with this setup? thanks

[ashbass]

Old topic, I know. I've searched and read. I'm trying to straighten out what is safe for my gear, not necessarily what sounds best. Here's what I think is right.

A 4 Ohm amp can drive a 4, 8, or 16 ohm speaker.
(8 and 16 will not be optimal performance-will likely have less volume.)

A 8 Ohm amp can drive a 8 or16 ohm speaker.
(16 will not be optimal performance-will likely have less volume.)

A 16 Ohm amp can drive a 16 Ohm speaker.

==========

A 4 Ohm speaker can be driven by a 4 Ohm amp.

A 8 Ohm speaker can be driven by a 4 or 8 Ohm amp.

A 16 Ohm speaker can be driven by a 4, 8, or 16 Ohm amp.


Am I right?

[ltfullert]

Hey guys, I was wondering if it's possible to easily swap the lugs about in the back of my Fender Twin to switch the wiring between series and parallel?

Thanks.

[Comanche]

Hello, I have a Lil Night Train that is 2 watts.
It has one 1/4 speaker output.
I want to run two 10 inch marshal cabs that I have.
I would like to run the 1/4 mono output into a two 1/4 split.

Amazon.com: Hosa YPP111 1/4 inch TS to Dual 1/4 inch TS Y Cable - 6 Inch: Musical Instruments

Amazon.com: Hosa YPP111 1/4 inch TS to Dual 1/4 inch TS Y Cable - 6 Inch: Musical Instruments

If the 8 ohms output from the amp is split does it make the the output 4 or 16 ohms?
Are the speakers in series or parallel?
Thank you.

[picoman]

Can all this conusion be avoided if you buy amp that has variable ohm cabinet option?

[Greenman1976]

One thing I have yet to see is wiring two amps to one speaker. I've searched google and almost all the forums and havent found a thing. I have a few ideas to be able to do this but i can't draw out schematics. so I have the two amps slet up on a DPDT switch that is set up to direct the unused amps volume through a resistor of equal value of the speaker. would this work? build it into a power supply case where i can plug each amp to it with a speaker cable, maybe add an attenuator?. Im planing on doing this to a Fender super champ xd and the new Marshall DSL15h (if i can get it) with both going to the fenders cab. Ideas?

[martin H]

Ok time for a quick treatise: Hope this is helpful

[1] Speaker impedance, amp impedance and power

Discussing what cabinet to uses with what amp, the first thing to remember is that tubs amps and transistor amps react differently to the impedance of the speaker cab.

TRANSISTOR AMP:
The lower the total speaker impedance, the more current (and hence more power) the amp will provide. The relationship is roughly linear, i.e., an amp that will provide 20W in 16 ohms, will provide 40W into 8 ohms and 80W into 4 Ohms. The limiting factor is the minimum impedance that the amp can drive. Going below that will likely damage the amp, became too much current will flow from the output transistors. This is why transistor amps usually specify a minimum speaker impedance ( “4 ohms total” or “4 ohms minimum”) Running a lower impedance my damage the amp. Running a higher impedance does no harm, but reduces available power. A transistor amp is not damaged by running a signal through it with no speaker. Therefore, it’s best to run the transistor amp into its stated minimum impedance. Remember the example above. That amp rated at 80w 4 ohms produces only 20W into a 16 Ohm cabinet.

TUBE AMP
Different ball game. Unlike the transistor amp, the tube amp does not produce more power if you just drop the cabinet impedence. The tube amp produces maximum power into the specified impedance set by the output transformer. An amp rated at 100w with the output transformer tapped for 8 ohm speakers will produce less power into either 16 ohms or 4 ohms than it does at 8. This is why tube amps often have tapped output transformers to allow maximum power into 4, 8, or 16 Ohm cabinets. The tube amp is not likely to be damages by a short in the speakers, but can be damaged by running a signal through it with no speaker

[2] Impedance of multiple speakers: There are two ways to wire speakers, SERIES AND PARALLEL.

In series, the wire goes from the amp to the + of the speaker, then from the – of the speaker to the + of the second speaker, then from the – of the second speaker back to the amp. The current flows first through one speaker, then through the next, in series.

In parallel, the wire goes from the amp to the + of both speakers and the - of both speakers is connected to the other wire from the amp. The current splits and flows through both speakers simultaneously, in parallel.

Speakers in series have a higher impedance than the individual speakers. Two 4 ohms in series give a total impedance of 8 ohms. Two 8’s in series gives 16 ohms etc,

Speakers in parallel have a lower impedance than the individual speakers. Two 4 ohms in parallel give a total impedance of 2 ohms. Two 8’s in parallel gives 4 ohms etc.

[3] Distributing power among speakers

I see a lot of questions about how power is distributed among multiple speakers: In a two speaker setup the distribution of power is identical as long as the speakers have the same impedance, irrespective of whether they are connected in series or parallel. Two 25W speakers of the same impedance will always handle a total of 50W, and the power is distributed evenly among the speakers, 25W each. Things only get strange if you start mixing speaker impedances in the same cab. For example:

Mismatched impedances in series: if you put a 4 ohm speaker in series with an 8 ohm speaker, 2/3 of the power will be generated across the 8 ohm speaker; Therefore the 8 ohm speaker must handle twice the power of the 4 ohm speaker

Mismatched impedances in Parallel: Works the other way; if you put a 4 ohm speaker in parallel with an 8 ohm speaker, 2/3 of the power will be generated across the 4 ohm speaker. Therefore the 4 ohm speaker must handle twice the power of the 8 ohm speaker.

[4] What is the output impedance of the amp?

Working all this out can be tricky with amps that have multiple speaker output jacks and cryptic messages on the back like “8 ohms.” If there are two jacks, does this mean that you can plug more than one 8 ohm cab into the amp? Again the answer tends to vary between tube and transistor amps.

The speaker output jacks on a transistor amp are almost always in parallel. The amp manufacturer is relying on you to do your own calculations of the total impedance of what you are plugging into these jacks. Remember how parallel speakers work? – It’s the same with cabs. Two 16 ohm cabs in parallel = 8 ohms. Two 8 ohm cabs = 4 ohms. Two 4 ohm cabs = 2 ohms. If the amp says “4 ohms” on the back, the last combination is bad.

Tube amps can be trickier. If the amp has an impedance selector on the back, the jacks are usually in parallel, and you have to do the same calculation above; Two 16 ohm cabs in parallel = 8 ohms. Two 8 ohm cabs = 4 ohms. Set your impedance selector to 4 ohms or 8 ohms accordingly.

If it doesn’t have an impedance selector on the back, the amp can be wired in several ways. Some Fenders are wired in a clever way that actually changes the output circuits to account for the changed impedance if you plug in a second speaker. Some just put the second speaker in parallel without changing the transformer tap. A few put the second speaker in series. In these cases, it’s best to ask the manufacturer how it’s supposed to work.

Hope this was of some help

[Buzd]

Hi guys

I'm a newbie out here and I apologize if this question has already been asked but I have a 2x12 custom built cab with 2 x 8 ohm speakers. I understand wired in parallel would be 4 ohms and series 16 ohms. Is it possible to have 2 jacks in the back so 1 jack is wired in series (16 ohms) and 1 wired in (parallel 4 ohms)? I want to be able to connect 2 amps (one has 4 and 8 ohm out) and 1 has 16 ohm out only. I will then switch between heads using my tonebone VT only using 1 cab.

I saw the attached image earlier but I'm not an electronics guy and do not fully understand it.

Any help would be greatly appreciated.