2 x 4 cab....2 or 4 on?

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mchauck
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2 x 4 cab....2 or 4 on?

Post by mchauck »

Can I install a switch that would allow me to run either 2 or 4 speakers in my new built 2 x 4 cab with Celestions in it? I want to use two for smaller venues and four for larger ones, or when I want to drive two speakers at a lower output. Impedence isn't a prob cause I will have 4, 8. 16 on the output. I was able to get this from a really far out dude. How's this??



Merrry Christmas....!!!!
Brian
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Last edited by mchauck on Wed Dec 26, 2007 5:21 am, edited 1 time in total.
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gearhead
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Re: 2 x 4 cab....2 or 4 on?

Post by gearhead »

Yes, but it depends on what you want to do with it. If you'd specify a bit more, that's be great.
Last edited by gearhead on Wed Dec 26, 2007 1:42 am, edited 1 time in total.
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VacuumVoodoo
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Re: 2 x 4 cab....2 or 4 on?

Post by VacuumVoodoo »

Not if you want 2 speaker combination to have same impedance as 4 speaker combination.

If each speaker has impedance "R":

2 speakers can be connected to give 2R or R/2 total impedance
4 speakers can be connected to give 4R or R or R/4 total impedance with reservation connecting 4 speakers in series for 4R impedance is not practiced.

If your amp has, say, 8 and 4 ohm outputs and each speaker is 8 Ohm than it can be done.

Wait till tomorrow for a drawing.
Aleksander Niemand
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mchauck
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Re: 2 x 4 cab....2 or 4 on?

Post by mchauck »

Oh man....sorry for the left out info. I left a post on the "other" site and didn't follow up here with all the info. Corrected in the original message........
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VacuumVoodoo
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Re: 2 x 4 cab....2 or 4 on?

Post by VacuumVoodoo »

Are there separate 4,8,16 ohm outputs on the amp or an impedance selector switch?
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mchauck
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Re: 2 x 4 cab....2 or 4 on?

Post by mchauck »

There is an impedance switch. I have three heads and they are all wired this way.

BH
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VacuumVoodoo
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Re: 2 x 4 cab....2 or 4 on?

Post by VacuumVoodoo »

Ok, here you go.

A 3 position 2 pole rotary switch allows you to choose between 2 or all 4 speakers. When using 2 speakers you have a choice of running the disconnected 2 speakers undamped, they'll behave like passive radiators, or damped with their voice coils short circuited.
Remember to set impedance selector on your amp accordingly.

You can skip the damping position and use a pole 2 position switch.

Now, please deposit whatever amount of money you deem this is worth to you into my off shore money loundering account. :lol:
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mchauck
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Re: 2 x 4 cab....2 or 4 on?

Post by mchauck »

OOOKKKKKKKKK!!!!!!!!!! Account number and pass code please!!

Brian
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mhuss
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Re: 2 x 4 cab....2 or 4 on?

Post by mhuss »

...and your original drawing will work fine, if the unused speakers being "undamped" is not a problem. :D

VV, is there really a large difference in sound damped vs. undamped?

--mark
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VacuumVoodoo
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Re: 2 x 4 cab....2 or 4 on?

Post by VacuumVoodoo »

mhuss wrote:.
VV, is there really a large difference in sound damped vs. undamped?

--mark
In a closed back enclosure there's a distinctive improvement in bass response when unused speakers are damped, at least to my ears.

Use a "make-before-break" switch and it'll be very easy to do on the fly A/B test with my switch arrangement as you won't be interrupting signal to the active speakers when changing between damped/undamped.
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nickt
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Re: 2 x 4 cab....2 or 4 on?

Post by nickt »

You don't need double pole switching. Try this:

Edit: missed VoodooMan's damped/undamped. In the below the 16ohms are damped while the 8's are undamped. I've never experimented with damped undamped (or turning off speakers for that matter!) so have no opinion :D
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mchauck
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Re: 2 x 4 cab....2 or 4 on?

Post by mchauck »

Well....thanks to all the great answers, I will have to try the dumped/notdumped switch. I will report back on my newb verdict...my ears aren't newb though!!!! :D

Thanks all and Happy New Year!!

BH
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