# 8 ohms speaker + 16 ohms speaker + ???



## Joebob (Aug 4, 2009)

I wanna try mixing two speaker that i like.
An ASW 60's 16 ohms and a Celestion G12-65 8 ohms.
I was told to put them in parallel, that it should be around 10 ohms
and drive the head using the 8 ohms output.

Any thoughts ?
Thx


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## bw66 (Dec 17, 2009)

If my memory is right - and it is quite possible that I've remembered this wrong, the resulting impedance would be around 5.3 ohms, which could cause your amp to over-extend itself - depending on what it's impedance rating is. If its comfy at 4 ohms, you should be fine.


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## Joebob (Aug 4, 2009)

ok so 4 ohms output then !!


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## Fader (Mar 10, 2009)

Most of your power will go to the 8 ohm speaker, so that's what you're going to hear with a mismatch like that in parallel. But it might be the sound you're after.
Try it.
You would have equal power to each speaker if wired in series but your impedance would be 24 ohms. That might me a little high, depending on what amp you have.


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## zdogma (Mar 21, 2006)

Yeah, I've tried this and it doesn't work very well, nearly all the power goes to the lower impedence speaker, and you don't hear the 16 ohm. I don't think it will hurt anything running through the 4 ohm out, but you'll just hear the G12-65. Not that that's a bad thing, that's a pretty nice speaker.


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## Joebob (Aug 4, 2009)

I see... i can put 2 G12-65 in it then...But then i get a problem with my 4x12. I would gave to put 2x 16 ohms and 2x 8 ohms. I would i do that ?


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## Andy (Sep 23, 2007)

Check the sensitivities of the speakers. You could always add an L-Pad to one of the speakers, which would change its impedance, but also the effective sensitivity of it. For example, if they were 100dB for the ASW and 98 for the Celestion, you could put a 16 ohm resistor in parallel with the ASW to bring it down to 97dB and 8 ohms. If the Celestion was louder, you would add an 8 ohm resistor in series, bringing the resistance up to 16 ohms and once again cutting the sensitivity by 3dB.


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## Joebob (Aug 4, 2009)

Thx for the answer bro, it's getting a little cpmplicated for my little brain, lol ! I would like to do that on my own without a tech.
What if i i hook up them up by pair: 
-2X 8ohms in serie= 16 ohms to a connector 
- 2x 16 omhs in parallel = 8 ohms to a connector
And 2 speaker cable from the output amp, from the 16 omhs out and from the 8 ohms out.
Do i still have more power going to one of the pairs ?
That setting would be great for using 2 amps at the same time !!!


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## greco (Jul 15, 2007)

Joebob said:


> And 2 speaker cable from the output amp, from the 16 omhs out and from the 8 ohms out.


The concept you have written above sounds logical and would seem like a good approach in IMHO

The only thing I would hope is that someone here can assure you that *you can use 2 output jacks from the same amp* (one on 16 ohms and one on 8 ohms) *without somehow taxing the output transformer.... or having other unwanted issues of some sort.
*
I will be interested in the answer.

Cheers

Dave


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## AlterEgo (Jan 12, 2010)

Dave, you are assuming that he is using a Tube amp. In this case doing so will definitely stress heavily the OT it connected to the same amp. *I would definitely NOT recommend that.* However, it might be different if the amp is using J-FET transistor for the output, Then mathematically, it should be not worst than mix and matching the speaker at a single output. Also Andy, is bringing an important point on the sensitivity of the speaker (indicated in db). I personally use two different amps with two speaker cabinets (BTW I own the excellent Voltage Speaker cabinet) then I insure that I can blend the tone as I need. 

Sylvain


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## greco (Jul 15, 2007)

AlterEgo said:


> Dave, you are assuming that he is using a Tube amp. In this case doing so will definitely stress heavily the OT it connected to the same amp. *I would definitely NOT recommend that.* However, it might be different if the amp is using J-FET transistor for the output, Then mathematically, it should be not worst than mix and matching the speaker at a single output. Also Andy, is bringing an important point on the sensitivity of the speaker (indicated in db). I personally use two different amps with two speaker cabinets (BTW I own the excellent Voltage Speaker cabinet) then I insure that I can blend the tone as I need.
> 
> Sylvain


Thanks AlterEgo.....Yes, you are correct, I was assuming that Joebob was referring to a tube amp as I have not seen many SS amps with a choice of output jacks for 4, 8 and 16 ohms impedance. 
However, I'm not very all that knowledgeable about the features of SS amps.

Cheers

Dave


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