impedance vs sensitivity

Which means that an extremely low impedance speaker (1-2 ohm) could be sensitive? A 50 Watts amplifier is therefore enough?

Chris

50W SS or tube? SS might work,tubes would be pushed too hard to develop power into that load.
My Air Tight ATM 3s drove the top-end of the VSAs,but were not enough to sufficeintly drive/control the woofers (same with Audio Physics Virgos).You could switch them into "ultra-linear",but the magic was gone.

I think when you look at the sensitivity of a speaker, the amplifier's watts are important but when you factor in the speakers low impedance, it becomes equally important that the amplifier can deliver adequate current rather than just power. For example, the old Quad ELS 57s only required low power (around 25 - 40 watts) but caused big problems for many amps that couldn't meet their current demands into their very low dipping impedance. I had many amps with the correct power ouput pack it in because they couldn't deliver enough current.

What you are saying initially is pretty common if you think about it... The more drivers, the lower the impedance usually resides.

The BW speakers act closer to being a 4ohm speaker than the 8 ohms they say they are... ex the 802N... Focal speakers too have lows beneath 4 ohms. Tyler units in the past have delved low as well... Even my Silverline Sonata IIIs respond better on some amps 4 ohms taps than their 8's.

Damping rate of the amp can indicate a better fit than mere topology... SS v. Hs. I refer to damping as 'control' of the loudspeakers drivers, preventing them from returning energy to the amp. Generally, lots of watts can overcome it too. Others here can explain this interaction between the amp and speakers far better than myself.

I've noticed this relationship just by how much more low level impact and timberal truth there is, and/or how much more the vol knob gets tweaked upwards to get the same SPL or satisfying sounds. BTW I'm not keen on high levels of Sound pressure, or immense listening levels. So I like an amp which doesn't have to be turned way up to sound good.

No, Low power is not enough for low ohm loads they need more power. Tube amps do not do well with low ohm loads unless designed for it. Your bass will suffer if loudspeakers below 4ohms and run on a low to med power tube amp.