enough watts to drive these speakers? Help?

Good points Marco. My comments referencing the 300B pertained to some "manufacturers" claiming that their single 2A3 per channel ( or similar tube ) will do 8 - 10 wpc. Since you're amp is not a SET and each tube is only doing half the work, it is possible for two 2A3's to make that kind of power.

The reason that i mention this is that i remember a speaker manufacturer measuing a certain SET amp that was advertised at 8 wpc. The person that had bought their speakers was using this amp and complained that the speakers weren't as sensitive as the manufacturer stated. That is, 8 watts should have driven the speakers, but it wasn't. The speaker manufacturer wanted to see what the deal was, so they checked the amp. When it came down to it, the amp was having a hard time doing 3-4 wpc, which just wasn't enough. As such, one should look at the tube compliment of the output stage along with the rated power output. If you've got one tiny tube per channel, don't count on ore than a very few watts at most. Bigger tubes typically have bigger plates and can pass more power, offering higher output levels. One can also achieve this by paralleling multiple tubes or running multiple tubes in push-pull fashion ( like Marco's amps ). Buyer beware... Sean
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Fatparrot,

Just saw your comments.
6dB loss in SPL per doubling of distance is correct! We are not talking about a power measurement here; rather, a voltage measurement when we read off SPL on a meter. Hence, 20*log() rather than 10*log(). Another thing is that since it is a ratio (SPL at 1m vs. SPL at 2m) when we do a divide operation, the impedance cancels out.
Hope that this clarifies.

Bombaywalla, I understand where you got the 6 dB figure (voltage), which can throw confusion into the mix, depending on whether we are talking about voltage, or power readings. But I thought that actual acoustic sound waves (spl) were a measure of POWER, and not voltage. The spl meter converts this to a reading which represents dB's of power not voltage. But I will do further research, since you now piqued my curiosity!

Think of it as surface area. As the distance doubles the surface area quadruples...equal to -6dB/unit surface area.
I didn't read anyone's reminder that sensitivity values are usually expressed at 1k, which can be far less meaningful unless one knows the low frequency rolloff (and impedence). Since it's possible for a "high" efficiency speaker to have much lower response, let's say, at 50Hz than a lower efficiency one with flatter bass, one can indeed be fooled into predicting that a low power amp might have an easier time with the former...especially if a low impedence couples with a large phase angle diff in the bass. So it's not so simple...especially with a tube amp.