Tube power vs Solid state power, how much is enoug

Blindjim, what'd you end up doing?
.

My 2 cents (like anybody asked...)?

Trying to get disparate amplifier technologies to get along in the same system is challenging to say the least. You'll need some sort of electronic crossover, which is an additional (and audible) building block, and rarely has the correct crossver curves that a passive crossover does. So that will be a real challenge.

The speakers you listed are not that unfriendly to tubes, but beware the B&Ws that list nominal impedance at 8 ohms then wind up actully being 4 ohms in the woofer region, where most of the amplifier power is demanded. Not a good combo for a tube amplifier! The 802 is an example of such a speaker.

I strongly recommend that for any tube amplifier that you choose, contact the manufacturer and see what their experiences with the speaker you choose is. They may have some tips for you.

I also stongly advise you to heed this tip: try and get a speaker that is as efficient as possible! This was mentioned earlier in this thread and the value of this cannot be understated. If you choose a speaker that is 95db, it will require an amplifier of 1/4 the power to be as loud as a given combo with a speaker of 89db. Tube power in particular is difficult to make! So where a speaker of 89 db might need 200 watts in most rooms (I have found that to be the minimum in my room with such a speaker), you will find it much easier to find a musical tube amplifier if you only need 50 watts to make the speakers sing. In 200 watt amps, you can count the ones that actually sound like real music on one hand, and have a finger or two left over (there are no musical transistor amps, BTW...). But at 50 watts its a different story.

So be careful. Otherwise stand ready at the toilet to flush those dollars goodbye.

blindjim, your last post hit on an important point controlling output and that would be amp design details. Especially class a/b verses pure class a. For the audio rig i have VTL mb185s which are rated at 230 w/side running on 6550 tubes. My guitar rig is a boutique 35 wt el84 class A rig. The guitar amp is insanely loud. It will smoke 50 watt el 34 and 6550 based amps (ok that ain't a real big difference because to double spl you need to 10x output) and hangs perfectly with larger amps and the home rig. A lot of that is in how the amp is voiced as well...it cuts like a knife where as a home rig will be voiced more neutrally...at least you'd hope so.

Atmasphere,

Without sliding too far off field here, I'm curious as to the point where a speaker's high rated sensitivity is undermined by other criterea.

For instance, the Athena AF-2 is rated at 93db and sells for $600 a pair. Wouldn't these speakers do well handling 40W to 50W per channel tube amps?

93 db is a medium efficiency, not high. High would be over 100db. Plus you have to factor something else when you use the word 'senstivity'. It is NOT the same as efficiency.

The Senstivity spec is 2.83 volts measured at the speaker terminal and the sound pressure measured at one meter on axis.
Efficiency is the same, but measured with 1 watt at the speaker terminals.

If the speaker is 8 ohms, the two numbers are the same. If the speaker is 4 ohms though, now the actual efficiency is 3 db less! This is because 2.83 volts driving a 4 ohm load works out to 2 watts, not 1. All of a sudden 40-50 watts may not be enough!

I don't think the cost of the speaker plays a role here, although obviously if you are investing in a tube amplifier it only seems reasonable to use a speaker that allows the amplifier to perform in its best light...