I've just bought a Gallien Krueger Combo with 2x100W channels. On the back there are two balanced outputs for stereo output and an ext speaker jack with a switch for either 8 or 16 ohms.
I also have a Sovtek 4x10 box with eminence speakers. On the back is a sticker that says it's 300W and 4 ohms and has two inputs. It was made in Australia by a bunch of guys who may or may not have had Sovtek's blessing and there isn't much info about them on the web.
I have a few questions but the one I really want an answer to is what's the quickest and easiest way to get these two working together without damaging either?
Answers to the following would be a bonus.
What might the two Sovtek inputs be for?
How do I tell if the speakers are wired in series or parallel?
Can I use the balanced outputs for speaker boxes or would they be for PAs?
How do the wattages of amp and box relate to each other?
Sorry if this is in the wrong place, wrong site or has been answered somewhere before. I've spent a few hours searching for the answer to this problem without luck and now I'm just posting it a few times to try and get some help... I haven't really played since I was a teen and didn't really care about the techs of matching equipment then. Now I'm trying to learn.
Cheers
Matt
I've got an update - had a look inside via the airhole
Each speaker is 16ohms, but I can't see how many watts they are. I haven't opened the box yet, it appears some parts are glued together so wanted to wait til the last minute.
I believe it's wired in a series.
If viewed from the front, the top left speaker is wired to the left input, which is then wired to the right. The TL speaker is wired to the BL. The BL to the BR. The BR to the TR.
If I re-wire TL to the left input and TL to BL. Then wire TR to right input and TR to BR. Would that make it effectively two 2x10s in the one box each running at 8ohms. Like a stereo cabinet?
What are my other options and is there anything I have to be really careful of?
Ok, there are only a few options here so since you know the speakers are 16 ohms each and the cabinet is overall 4 ohms then you can work out the reasonable combinations and pick the one that matches.
Zt = total impedance
Zi = impedance of each speaker (no need to differentiate since all the same)
the indices and ranges of each summation is implied by the description of the speaker setup and isn't fully notated due to limitations in the text layout
1) All 4 in series
Zt = ∑Zi = 4 x 16 ohms = 64 ohms
2) All 4 in parallel
Zt = 1 / (∑1/Zi) = 1 / (4 x 1/16 ohms) = 1 / (1/4 ohms) = 4 ohms
3) 2 speakers in parallel that are in series with another 2 speakers in parallel
Zt = 1 / (∑1/Zi) + 1 / (∑1/Zi) = 1 / (1/16 + 1/16) + 1 / (1/16 + 1/16) = 1 / (1 / 32) + 1 / (1 / 32) = 16 ohms
4) 2 speakers in series that are in parallel with another 2 speakers in series
Zt = 1 / ((1 / ∑Zi) + (1/ ∑Zi)) = 1 / ( 1 / (2 x 16) + 1 / (2 x 16)) = 1 / ( 1/32 + 1/32) = 1 / (1/16) = 16 ohms
So, the only option that matches your cabinets claimed 4 ohms is option 2 - all in parallel. That would also then imply that each speaker must be capable of handling 300 watts / 4 = 75 watts.
The other jacks on the speaker cabinet might be for other topologies that you could select for by plugging into. Unless you can get a manual or info from the builder the only way to know for sure is to open the cabinet and trace the wiring. You could take an educated guess by using a multimeter but you may need plugs with leads to attach the multimeter to since the jacks may be switching jacks.
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