Too much power?

https://www.youtube.com/watch?v=Sg14jNbBb-8

I would feel severely abused if I were required to listen at only 70 dB SPL. 

@dain wrote:

... I wonder other than bragging rights, what does more power get you? Since we aren’t here for PA style sound, is there a reasonable limit to how much you will benefit from higher power/ more expensive and? Especially since tire just using one watt most of the time?

It's about what serves an important purpose to the individual; to me it's making the better/most use of the plentiful of wattages at hand, and having them efficiently turned into acoustic energy. Where they're not, not least over a wider SPL- and frequency bandwidth, it sounds more like an effort is exserted, which in turn has a signature as something more readily reproduced.

Lower efficiency in the electric to acoustic energy transfer (which also includes the effectiveness of cone to air coupling) to me can sound like an added lag or a higher level of perceived "viscosity" to the presentation, apart from being less immersive and present sounding. Merely adding wattages into a lower eff. package isn't enough for the desired low viscosity, effortless and immersive feel of sound, when most of it here is converted into heat in the voice coils and cross-over components, and cone-to-air delivery is badly utilized via direct radiation - unless from a large(r) direct radiating surface.

On the other hand with such circumstances addressed - i.e.: removing the passive XO, more efficient and larger/horn-loaded drivers/radiation area - for a more efficient transfer of an electrical signal to what's eventually perceived by the ears, less wattages are needed for a given SPL, but that's not necessarily to say we need less wattages overall. Instead, with the same power output we're given quite a lot more headroom within which music can "roam" more freely, something we likely missed in the first place - perhaps without even realizing it.

Dynamic peaks in the 90-110dB range with fairly non-compressed music material can take quite a lot of power with moderate to low eff. and not least passively configured speakers, certainly at more than ~12ft. listening distance and depending on acoustics, and so even several hundred watts can easily be sucked up with neither amps nor speakers having any headroom to give of here. 

I really didn’t expect it, but every time I cross over beyond 200 Watts of tube power, I get significantly better dynamics, bass, impact, and subjectively better "grip" over the big 15" drivers as a whole. Like I said I do listen quite loud, but then my speakers are 96dB / Watt Tannoys - and even 20 Watt amps can blast them quite loud, but NOT with the authority of the higher power amps!

I have one set of tube monos good for an honest 250 Watts / ch, and another set of tube monos good for almost 300. There is a BIG difference with these over the sub-200 Watts tube & SS amps I’ve used. There are likely other reasons beyond the raw power output, like premium parts & construction - but I think there’s also something to running multiple push-pull pairs of tubes per side, if you can afford to.