Dynaudio contour with 30 watt amp

Yes, you would think so, but in my expereience with several monitors of the same efficiency, a tube amp of that power rating, (a deHavilland to be specific) was not up to the job of really controlling the speakers and making the sing as they should. And that applied at lower volumes as well.

Technically tube amp won't clip but will simply sacrifice the power. To bring these speakers to 87dB you'll need muchmuch more than 1W.

86 db is loud. I believe I listen to music at most at that level.
Is the sensitivity of this speaker measured by "2.83V/m"? 2.83 volt input and the microphone was placed 1 meter from the speaker’s front baffle.

If most of the amp send 2.83V to the speaker, then I only need 2 watts if I sit one meter away from the speaker.

Contour 2.8 has 4 ohm, so I guess it needs 2 watts of input to put out 87 dB.

There is good 87 db and not so good.

More power and current = better 87 db with dynaudios.

Tube amps best apply elsewhere.