[willyjack]

Originally Posted by A.Wayne

Interesting to compare S5 to Q5 .......

Magico Q5 loudspeaker Measurements | Stereophile.com

It does not have the wrinkle (resonance) at 110hz but it is tuned in the bass the same as S5 ,

"The Q5 has a rated sensitivity of 87dB. However, my estimate was lower than this, at an estimated 84dB(B)/2.83V/m, which is also lower than average. The speaker is also fairly difficult to drive, with an impedance that drops below 4 ohms in the high treble, the lower midrange, and the upper bass (fig.1). As well as minimum values of 2.75 ohms at 56Hz, 3 ohms at 200Hz, and 2.8 ohms at 40kHz, there is an amplifier-crushing combination of 3.85 ohms and a –56° capacitive phase angle at 45Hz. This speaker really does need to be used with powerful solid-state amplifiers to sound its best, I feel, such as Michael Fremer's Musical Fidelity Titan. The traces in fig.1 are free from any wrinkles that would indicate the presence of cabinet vibrational resonances; listening to the cabinet walls with a stethoscope while I swept a sinewave tone up and down in frequency, I could detect only a small degree of liveliness at 418Hz. The cabinet's heroic, all-aluminum construction is obviously effective at minimizing vibrational resonances."
-JA

Yes high powered solid state is best to wake this speaker up and hear what it can really do at all volume levels. Constellation amp(s) are a perfect pairing with tube preamp.