How to wire 4 x 16 ohm speakers of different types

[walkman]

I'm looking to wire up a 4x10" box , with two celestion or 'British' sounding speakers and two eminence 'American' sounding speakers. I'd like two be able to run either all four as 16ohm or 4ohm. I like to be able to run two of the speakers together either matched in style or mixed in mono or stereo. Hope that I've made a clear description of what I'd like to do. Any help would be great as I'm not sure how to do the switching.

[Brad1]

That's a lot of options you ask for.

About the easiest thing to do is get something like this:

OEM Stereo/Mono Cabinet 4x12 Wired Jack Plate (Double 1/4") - Mojotone.com

It has two inputs. If you want to run all four speakers in either 4 or 16 ohm, you just plug into one input, and set the switch to the proper impedance (assuming you've wired the speakers to the jack-plate board correctly).

If you want to run each pair separately, just plug the two sources (amps) into the two jacks, which will run each pair at 8 ohms each.

As for swapping the pairs (say, with both Celestions as a pair, and both Eminence as the other...and switching to a Celestion/Eminence for each pair), that would require another switching system, along with (or modified into/attached) to the jack-plate system. I'm sure you could probably drill a hole and mount a multi-pole single-throw switch in that plate that would swap the speakers as pairs...but you'd better be darn careful about using all that extra confusing switching capability, lest you end up plugging in an amp that is less forgiving of impedance mismatches than what others may be. (I ALWAYS double- and triple-check all my settings on any amp(s) AND my Marshall cab that has one of those jack-plates, before firing up....ANY time anything has been unplugged/moved/changed.

With something like that, what would happen is you'd wire the "Normal" position (say, in the "Up" or "left" position) and a + wire from two of t


Interruption alert!

Well..I tried. I wasted AN HOUR putting together some info for you, but when I went to post it...it wanted me to "sign in" AGAIN. So, I signed in....AGAIN. Even checked the "Remember Me" box...AGAIN.

Damn thing sat there and churned...and churned. No post.

It gets tiring gathering up useful info, and trying to explain things...only to constantly get my posts kicked off into the nether regions of digital hell when I try to submit them!

So...sorry. Was glad to try, but this site doesn't seem to want to "remember me", if I spend too long crafting a response. Ain't got time to redo it, and only recovered about 1/2 from the "Autosaved".

Long story, short...I THINK you could do that with a Marshall stereo/mono switch panel, AND a DPDT On/On switch. Since the pairs are ALWAYS in parallel, each, you'd have interrupt the parallel connection of each pair, and swap them. Then, the ones that normally go to the jack panel can continue on to be used as normal. Wire one speaker of each pair to center lug of DPDT, wire top two lugs as normal, and bottom two lugs swapped to parallel mates. You'll have two wires going to one place on the speaker, but they'll be originating at opposite ends of the switch, which swaps the mating pairs.

I THINK that could work.

Anyone?>

Brad1

[leadfootdriver]

I did the same think to my 4x12. Wire each pair in parallel for 8 ohms, and then follow the diagram. You can just omit the switch in the middle and wire it as mono.

[walkman]

Brad

thanks for your response not sure that I followed it completely. I do appreciate the time that people put into replying on this forum there are some very good discussions.

leadfootdriver

The photo bucket picture is not available. Would like to see what you did.

[leadfootdriver]

Fixed!

[walkman]

Thanks leadfootdriver

What I wanted to do as well as the stereo mono switching was to be able to swap which speakers were in each pair.

[Brad1]

OK, let's see if this works? First, get one of the Marshall switch-plates. It lets you run stereo 8-ohm, or 4 or 16-ohm mono. The diagram will look something like this:

http://web.aoct.org/marshall/M19601.gif

Note that the switch (the little rectangle in the middle) is what changes the mono impedance, and it's all in the circuit board.

Now, you have to decide how to orient your two different sets of speakers. Do you want both of one type in the bottom, and the other two in the top? Do you want one set left, and the other set right? This will make a difference in how you want to wire them.

Do you want to use one matching set as a pair, and the other as the other pair...as set to normal? Or, do you want it normally (as set to stereo) to have one of each set in a mismatched pair? See, you have to decide how you want it "normally", and then decide how you want it to change.

Once you've figured out the matching, and the orientation...as "normal", then you need to just figure out how to flip the hot leads of two of the speakers.

Looking at the diagram, let's assume you've put the Eminence speakers in the bottom, and the Celestions in the top. As "normal", the way it is, if you switch it to "stereo" and use two amps, you'll have each pair as E&C (Eminence and Celestion), vertically, side by side. Or, you could put the E, say, on the left, and the C on the right, and in stereo, you'll have a pair of C right, and a pair of E left.

(In "mono", 4 or 16-ohm, none of this will matter much, unless you want the "beefier" pair in the bottom, and the "brighter" pair in the top.)

You COULD also think about simply splitting it in stereo as top and bottom, instead of left and right...as is stock. Just turn the diagram sideways.

NOW...you can see that there is ALWAYS a paralleled pair. There WILL always be at least one paralleled pair. Here is where it's going to get "iffy".

Theoretically, you could install a DPDT On/On switch, and swap the hot leads of one of the speakers of each pair (say, the bottom ones, if you have them oriented as left/right stereo).

Something like this:

30 Amp Toggle Switch DPDT On-On : Amazon.com : Automotive

Instead of the hot lead from each bottom speaker going to the speaker above it, each will go to a center lug of that switch. One end of the switch will carry the signal to one of the top speakers (say, the one above the corresponding bottom one, perhaps in the "Up" position), and the other end will go to the opposite speakers. In other words, you'll have, say, "Up" position, + from bottom left speaker going to left center lug, that signal going to the left end that goes to the top left speaker +, and your parallel circuit is complete "as normal". Flip the switch "down", and the signal goes from the bottom left speaker + to the center lug of the switch (still), but the opposite end lug goes to the top right +.

Do the same thing for the other speakers. Since they are all 16 ohm speakers, there should be no problems, and your Marshall-type switching plate should function as normal for stereo/mono, 4 or 16 ohms. All you have done is swap the leads of two speakers to continue to the opposite side.

As I said...this is IFFY, for a reason. If you were using something like a rack-mount Marshall 5000-series power amp, there should be no problem. It's all grounded the same. The ONE thing I'd worry about? What kind of grounding gremlins will happen when using two different amps? Is the ground through that Marshall-style switch common to everything in all positions...or does it split the grounds into two paths when used in stereo mode?

IF that might be the case, you could STILL do this, but it would take a switch with more poles...like a 4-pole switch (+ and - for each speaker). That would shift the + AND - to disconnect from and reconnect as isolated from the other circuit.

Does anyone know about that?

Anyway, you'll have to do some pre-planning on exactly what and WHY you want to swap speaker pairs, and orient the speakers, and wire it up, to give you the combination you want. As stated, it doesn't HAVE to be "stereo...left/right". It COULD be "stereo...top/bottom". The matching pairs could be left/right, or top/bottom.

Anyway, anyone know about that "grounding issue"? Is that going to pose a problem, if using two amps, and just switching the + leads of a couple speakers? If so, WOULD a 4PDT On/On switch work (assuming you could find one?)

Just something more to chew on.

Oh...and if you do end up doing something like that...I doubt I have to tell you, but just in case...always remember to do yourself a favor and triple-check all your switching on both the amp(s) and speaker cab BEFORE you power up, and don't start switching things with the amp humming away into the cab. Like I said...not saying you would do such a thing...but a friendly reminder never hurts.

Anyone? Am I close to a usable solution for him? If not...set me straight, please!

Good luck.

Brad1

[Jazz P Bass]

You sure did a lot of work there Brad1!
Then again, it sounds like a lot of work for....what?

[Brad1]

You sure did a lot of work there Brad1!
Then again, it sounds like a lot of work for....what?

Yeah...it did require some thinking, but I've wondered about the same kind of thing, actually.

I have a Marshall cab loaded with four V30's, and wondered about swapping a couple out with the two 16 ohm EVM12L's that are in my 2x12 Mesa Boogie slant cab. My 2203 JCM800 (early, w/6550's) actually seems to sound better through the Boogie cab than it does the Marshall cab. (Part of that could also be that the top half of the Boogie cab is open-back, the bottom closed).

I can see what he's trying to get at. In mono, of course, all four speakers will work in either 4 or 16 ohm. Using two amps, you could run one through a pair of V30's, and the other through the pair of EV. By switching, you could run each amp through a mismatched pair of V30's/EVs.

Then again...I never was THAT curious to try all that. He just wanted to know if there was a way to do it, and I'm sure there is...if someone really wanted to go through all the trouble, for whatever reason they have. I am curious enough to know if something like I proposed actually would work, though.

Brad1

[walkman]

Hi brad thanks again just got back from Christmas. Going to see if I can rig something up today.

The other thing that could be done would be to put in an attenuator for one of the pairs when matched speakers are paired. This way if the efficiencies of each pair were quite different , say 97db vs 103db then the overall tone could be balanced between the pairs.

Ok it may not make much difference if the speakers are similar in tone or type, but it allows for more possibilities. Also running just two of the speakers will mean a reduced volume if without turning the master volume down.

For example when running on the clean channel I might want to go through the eminence pair, then switching to lead switch to the celestion pair or vice versa. Why do this because the amp has a common equ for both channels.

Of course this would mean rigging something up like radial switchbone?

[g1]

For example when running on the clean channel I might want to go through the eminence pair, then switching to lead switch to the celestion pair or vice versa. Why do this because the amp has a common equ for both channels.

Of course this would mean rigging something up like radial switchbone?

I'm getting the impression you want to be switching speakers on the fly. This would be a big no no for a tube amplifier as you could have a no load condition while pushing signal. You would really want something muting the signal while the speaker switching is being done. Ideally you would want to be using "make before break" switches.
The switchbone (and similar switch boxes) are for line level signals, going into your amp, not out of it. For speaker switching you need high power/current switches.

[walkman]

Radial have the cabbone Tonebone Cabbone speaker cabinet switcher - introduction . This what I was thinking of. Yes to switch on the fly would be great. But for now I only want to see how the amp sounds with different combinations of speakers.

At this point I'm thinking that It may be easier to make a patch box up and patch in the connections as required at least for testing and experimenting.

[Steve Conner]

I think you should just make a patch panel on the back of your cabinet with 4mm banana plugs and sockets. Include a couple of 1/4" jack to 4mm socket converters in the panel.

Maybe "banana plugs" isn't the American or Australian name for them, but I'm pretty sure you have them over/down there.