100 watts enough?

charles1dad7,812 posts07-03-2021 8:41pmFrom John Atkinson/Stereophile,

"The EgglestonWorks Andra is moderately sensitive, my estimated 87dB/

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Sorry to disagree with 
John Atkinson @ Sterophile
But I will
87db, ~~MODERATELY~~ sensitive??
The TRUTH is
87db = IN-Efficient 
IOW 
In/UN Effective.
= Blood sucking speakers. 
Below 91db = INefficient/low sensitivity. = all xover box designs Inefficient. 
Lets  be honest around here , would we please.

If the listener considers 80db loud, then CH 100 watt amp should work.  The listener should be able to achieve 98dB peaks at the listening position before the amp exceeds its rated power.  The Egglestons are not a demanding load and the CH is a robust design.  Based upon the information supplied by the OP, I would go with quality over quantity.

@tarheelneil51,
The listening distance (4 meters) factor was accounted for in kijanki’s calculations. See his post above.


’Based upon the information supplied by the OP, I would go with quality over quantity.’, Per @onhwy61.

Yep, this is my point. A very (Perhaps ultra) high quality solid state amplifier driving speakers that for the most part have a speaker impedance of 10 ohm or above. Dip no lower than 4 ohm in the lower bass. This is not a challenging load for the very robust designed CH Precision A1 amplifier (Substantial power supply and capacitance reserve). Quality indeed. 
Charles

Well, it certainly has a unique crossover and driver configuration.  Based on the Stereophile measurements, the absolute minimum impedance is 4 Ohms around 20 Hz, and higher elsewhere.

I would say a modest amplifier of 100 Watts should be plenty in a modest room, and that these speakers are good candidates for tube amps as well.

https://www.stereophile.com/content/egglestonworks-andra-loudspeaker-measurements

it is of course in the eye of the beholder, but i have considered the following over time as reasonable descriptions

below 86 db / w / m -- inefficient
87-89 db -- moderately efficient
90-92 db -- efficient
93 db and up -- very efficient

impedance and nature of reactivity of the speaker load figures in too ( eg -- an 'efficient' load of 90 db at 3.5 ohms impedance still may not be easy for certain amps to drive)... but based on the simple measure of db/w/m above that is a simplistic and proper ranging imo