Bass rig confusion

[Fleximus]

Hi all, ive never really understood the maths behind amp & speaker cab combos. I bought my peavey rig back in the 90's and i think i was sold something that didnt really give me full power potential.
Peavey mk 6 400 watt into 2 ohm, 250 into 4 ohm amp, with a 410TX 350w/8ohm quadbox & 115BX 400w/4ohm cab combo. From what i can gather, this combo would never achieve full power in my setup.
So how would i achieve a full 400 watts???
Anyhow, somehow i blew my 15" last month and ive replaced it with a 450 watt Eminence Kappa 15A 8ohm speaker.
So now i think i would be running my amp only at 250 watts into 4 ohms??
So considering i now have 2x8ohm cabs, 1 rated @ 350w & 1 rated @ 450w, what is the maximum power i could achieve with this speaker combo, or what amp could run it at full power??
Sorry for all the questions.....you would think after 15yrs of bassing around i would know this by now.....

[bassix67]

You're right, your only getting 250w because your only running at 4ohms(2 8ohm cabs). You need 2 4ohm cabs to get the full power of your amp.

B.

[Fleximus]

Cool, thanks bassix67. Now i understand that side of things.
But what about the full power potential of my speaker combo? Does anyone know what would be the maximum power @ what ohm's req, i can pump through my current 2x8ohm cabs, 1 rated @ 350w & 1 rated @ 450w?? Do i add 350+450=800 watts? or is it only able to handle 450watts?
I want to beef up my power by buying a new head of some description.
I tried out a locally hand made Woogie 600w into 4 ohm amp the other week running into 1x8ohm quad. It was side by side with an Ampeg SVT PRO of similar wattage, and the Woogie was way punchier.

[billfitzmaurice]

Your power concerns are moot, as your Kappa 15 driver can only take 50 watts before running out of excursion, your Peavey perhaps 200, and that's giving the Peavey the benefit of the doubt. More power won't get you single decibel of additional output. There are many factors that determine how loud you can go, watts being among the least significant.

[Fleximus]

So what would be the biggest determining factor amongst others?
What im trying to achieve is more bottom end grunt.
Mid range definition isnt a problem, as i can easily hear my notes over 2 Marshall stacks, but bottom end rumble i lack. Excuse my ignorance

[RickenBoogie]

More, and better speaker cabs.

[GrowlerBox]

Originally Posted by RickenBoogie

More, and better speaker cabs.

^^ True dat.

In response to an earlier reply, it appears that you were running a combined load of 2.7 ohms (a 4 ohm 115 plus an 8 ohm 410 cab if I read the OP correctly). So you weren't far off "getting the maximum wattage" out of your amp, relatively unimportant as that ultimately is, and it also explains how you "somehow" blew your 115, which was seeing twice the power of the 410, and capable of handling probably less than half.

[MysticMichael]

Originally Posted by Fleximus

What im trying to achieve is more bottom end grunt. Mid range definition isnt a problem, as i can easily hear my notes over 2 Marshall stacks, but bottom end rumble i lack.

IMHO, your entire rig is simply insufficient for what you're trying to achieve. The 4x10 + 1x15 cab combination is a notorious mismatch for one thing, as Bill has indicated. Moreover, you're way outgunned and underpowered for a guy who's up against two Marshall stacks.

If you're gonna play in a high-volume environment like that, you'd better be bringing big power - period. I'd say 800 watts into 4 ohms - minimum. And preferably 1,000 - 1,200 watts, if you value having decent headroom at all.

Get a couple of high-efficiency 1x15 cabs - again, minimum. Better still, a pair of 2x12s or a pair of 4x10s. Plus a pair of high-quality earplugs.

MM