ANOTHER speaker ohm/amp volume question

[Dave Locher]

I have an 8-ohm Eminence Tonker in my 2x12 caninet, with the other hole blocked off. It sounds really good for just one speaker.
However, I am now thinking of adding a Swamp Thang in the other hole. My 1978 Randall RG100ES had two 8-ohm output jacks, and my cabinet has two input jacks, one of which is currently disconnected.
My question is, will running my ss head into two 8-ohm speakers cause a big jump in volume? It is already a loud amp - I have never played it on a stage above 4 or 5, and I certainly don't want it louder.
My basic problem is I don't get whether two speakers running seperately will change what the head does?

I know this is a lot like several other threads but a couple variables are just different enough that I am not sure how they apply to my specific setup.

 

[dystrust]

Re: ANOTHER speaker ohm/amp volume question

The difference between 1 and 2 speakers of the same type is roughly 3db. The bigger issue with a solid state head is getting the load figured out correctly. If the amp is able to handle a 4-ohm load, both speakers in parallel will give you maximum output power and should be much louder than series (16 ohms).

 

[Dave Locher]

Re: ANOTHER speaker ohm/amp volume question

I guess I left out that detail: the amp has two 8-ohm output jacks on the back. So I would be running one of those to the 8-ohm Tonker, like I already am, and I would use a separate speaker cord out from the other jack to the 8-ohm Swamp Thang.
I am not worried about harming the head, it was made to handle two 8-ohm 4x12 cabinets. I just don't know if two different cords running to two different speakers from two different jacks is "series" or "parallel"?
I assume it woyld be parallel?
So would dropping the amp's load from 8 ohms to 4 ohms give me a big volume jump? I do NOT want that!

If I connect the two speakers in series would I be likely to blow the speakers? Each is rated up to about 150 watts and the amp puts out a max of 120.

If that gave me a volume drop and would not destroy the speakers then I would be a happy man.

 

[crusty philtrum]

Re: ANOTHER speaker ohm/amp volume question

Here's the owner's manual ...

http://www2.randallamplifiers.com/images/stories/manuals/RG100ES-RG80ES-OwnersManual.pdf

Here's the schematic ...

http://music-electronics-forum.com/t32749/

If you want to lower the output power a bit, wire the two 8 Ohm speakers in series for a total of 16 Ohms, and connect them with one cable to one of the head's output sockets. Doing this will not harm anything, provided the two 8 Ohm speakers are in series ... parallel is a different story.

 

[IM4Tone]

Re: ANOTHER speaker ohm/amp volume question

Yep, for your stated objective, wire the two 8 ohm speakers in series for a total load of 16 ohms. SS amps can handle greater impedance with no ill effects, other than a drop in output power translating to a drop in volume (but probably not as significant as you might imagine).

 

[Dave Locher]

Re: ANOTHER speaker ohm/amp volume question

Thank you both for the clarification. I appreciate it.