We should reject hard-to-drive speakers more often

speakers make the sound we hear in our rooms... and wonderful sound is what we are striving for in our rooms

speakers should be evaluated when performing at their best, which is properly set up in room, driven by a suitable amp to get peak performance (or something very close to it) from them

efficiency of the speaker, and the requisite amp, are all part of the tradeoffs to get the sound we really want

all others things equal, yes, easy to drive, efficient speakers are nice to have... but it is foremost about the sound... that is the big dog that wags the tail of efficiency and amplification

@steve59 

https://youtu.be/AhB8uL12gtk

this may help...

... also don't confuse input sensitivity of an amplifier with its power output

in your experience ralph, when an autoformer is used to better couple tube amps with lower impedance speakers, is there a meaningful sonic penalty? seems to me that what is happening is many many more metal windings are being placed between tube amp's built in transformer (leaving aside the otl’s for a moment) -- and so my guess is that there must be more of the classic wooly, expansive, slightly echo-y transformer sound that is introduced into the music, more or less....

of course, this point and my question is moot for speakers that could never be driven by the tube amp in the first place, but have you done an experiment with a more ’normal’ higher impedance speaker... then adding the autoformer ... then trying hearing the sonic change from the additional transformer present in the chain?

just curious

@atmasphere

i completely follow what you are saying... i actually used paul’s zeros years ago when i was trying to run maggies driven by roger mojeski’s rm9 tube amp... you are right, when the amp really can’t handle the load, the autoformer poses no tradeoff... its autoformer or no music...

i was curious on the sonic degradation if used on an easy to drive speaker

also, i had never thought of using them with solid state amps! makes perfect sense, the autoformer provides any amp with greater electrical 'leverage'  irrespective of amp type...  ok i am going to try to find those zeros in my storage closet this weekend, maybe i still have em!