2 cabs of different wattage.

[Tobiasthegiant]

I recently acquired a 4x10 Aguilar Cab and Genz Benz Shuttle 9.2. I am looking into getting the matching 1x15 cab, as there are moments when I want a nice thundery low end. Now, the Shuttle gives 900w at 4 ohms, the 4x10 is 700w at 8 ohms and the 1x15 is 400w at 8ohms. Does this mean that in total there is 1100w cabinet headroom or do I have to so some funky maths. Will I blow the 1x15 if I run it too hard?

[Phil Starr]

You'll get 450w into each speaker, but only if you run flat out all the time in practice you won't turn it up full because that will drown out the rest of the band and deafen you and because you have gaps between your notes and you won't play every note flat out. The chances are that if your very loudest point of the loudest note is 900W then your average power will be below 90W and your speakers will be fine.

[Spike Vincent]

As long as the cabs are the same impedence and you don't crank the amp up to full,shouldn't have any problems.

[PlungerModerno]

Keep in mind the 410's probably have more lows for the same input than the 115 - but that depends on the driver & cab specifics.

As Spike said, two 8 ohm cabs should draw the same power from the head (as long as the head can handle a load down to 4 ohms).
The only danger I can foresee is if you send too much lows at too high a volume and damage the speaker (Xmax exceeded) or you fry the driver by exceeding the thermal limits (the wattage ratings you get on the cabs) - both of these are pretty unlikely unless you really push the cabs very very hard.

If you listen out for signs of farting you should be fine. Of course the drivers may be faulty and fail under far less stress . . . but that's not very likely either.

[Mr. Foxen]

The 4x10 is going to be loads louder and handle loads more power than the 15, means that if the 15 starts farting out, the 4x10 will drown it out and you won't know to turn down. That's how 15s break when paired with 4x10s and its nothing to do with wattage numbers. Much better off getting two of the same cab, that you do like the sound of. If the 4x10 alone isn't low enough, replace it with something that is, and add more until loud enough.

[lurksalot]

I think you are in a bit of a minefield , if you can provide separate power to each cab, you can balance them as you need ie stereo power amp , but if you are trying to link to the same signal you have no chance .
each cab will have a different sensitivity to each watt they get , even if they were both the same resistance , so unless you can provide the power independantly forget it , you will have no contriol on your tone at all .

[Mr. Foxen]

Plus they'll have differing phase relationship between the voltage and output, which will cause all sorts of tonal oddities.

[chris_b]

Of course I don't know your playing situation, but do you really need more than that 410?

I used to put 300 watts into my Epifani 410 (cab rated at 1000watts) and it was much louder than any of my bands needed.

If you really have to have more I'd put an Aguilar 210 on top.

[chrismuzz]

[quote name='Mr. Foxen' timestamp='1355075745' post='1893714']
The 4x10 is going to be loads louder and handle loads more power than the 15, means that if the 15 starts farting out, the 4x10 will drown it out and you won't know to turn down. That's how 15s break when paired with 4x10s and its nothing to do with wattage numbers. Much better off getting two of the same cab, that you do like the sound of. If the 4x10 alone isn't low enough, replace it with something that is, and add more until loud enough.
[/quote]

Best answer by far!

[4 Strings]

I can't think of an occasion where, with 1100W of speaker capacity and 900W amp you'll be troubling anything like half the power handling of any of it.

The rating is to do with the heating capacity of the speaker coil. You won't blow anything unless you're completely daft with it for a long time.