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8 ohm + 8 ohm SERIES = 4 ohm

8 ohm + 8 ohm parralel = use two 8 ohm outouts. Therin lies the confusion. Solid-state is a lot less messy when it comes to ohm mismatching. I wouldn't lose any sleep if I were you.

A modern stereo power amp should be okay with that. I know older tube amps (like my Fender PA100) are more sensitive to parralel outputting.

well 2 8 ohms cabs in series would be a total impedance of 16 ohms. Rtotal= R1 + R2

I'm pretty sure math works backwards for ohms. Like if you are mismatching ohms you find the total my taking (R1xR2)/(R1+R2). That equation is pretty long-winded for matching impedence, but the same principal applies.

16x8/16+8 = 5.33

8x8/8+8 = 4

I can't give you a good technical explanation, but that's the equation.

Series: +
Parallel: /

That's what I gathered. So taking my two 8's it will be 16 ohms in series and 4 ohms in parallel. Right?

But anyways, that doesn't matter if I get a stereo 8 ohm power amp, as I'll be feeding the cabs seperately at 8 ohms each. Right?

UglyCasanova wrote:Series: +
Parallel: /

That's what I gathered. So taking my two 8's it will be 16 ohms in series and 4 ohms in parallel. Right?

But anyways, that doesn't matter if I get a stereo 8 ohm power amp, as I'll be feeding the cabs seperately at 8 ohms each. Right?

You are correct.

Checked the cabs just now. Both 300W @ 8 Ohms

As not much more than a n00b, the one mnemonic I have for the difference between summing series or parallel is:
With par-allel, you're par-ing it down. (8 & 8 ohms parallel = 4 ohms total)

So the Trace Elliot PPA600 was already sold.

I'm thinking this would be a great power amp for the price: http://www.thomann.de/gb/the_tamp_e800.htm

Thoughts?

Does it say AH350 on the bottom panel of the front plate?

I ask because for whatever reason Trace Elliot was so proud of the pre-amp section in the GP12SMX series that the pre-amp got top billing above the actual amp model. They released quite a few heads that all had the same exact front plate where it says GP12SMX, and below that a panel with the actual amp model name. Although they also released a standalone GP12SMX preamp the presence of an 8ohm output on yours suggests to me that you have a full head, not just the pre-amp version.

Oh, okay. Weird. The front panel just says GP12 SMX - Bass Pre-amp. Nothing else.

This is the back of my GP12SMX





If it is in fact a head, I don't understand why I had to crank everything to get something remotely loud. I could seriously put my face right in front of the speakers at full blast and it was...meh.

I think that might be the AH250. Just plug one speaker into each 8ohm tap and yore good to go.

Front panel just says GP12 SMX - Bass Pre-amp though...

But then again, I wasn't the one who set it up when I tried it. Maybe he hooked it up in parallel giving it a 16 Ohm rating. Would that make it weaksauce? Hopefully we'll get the keys to the place in the next couple of days so I can check it out.

One of my first heads that I actually bought at a store instead of from a friend, was the 400 watt version of that head. I remember thinking it sounded pretty great but that was a long time ago.