Magicos are chesty

More specifically you should say Magico S series speakers are chesty

having moved from V3 -> Q3 -> M3 I can say that there are profound changes in tonal profile moving between ranges

personally I have never like the S series finding them rather too hi fi in their presentation ie a bit over dramatic and florid, not unleasent but like a image enhanced digital print 

the shift from V to Q to M was all about reducing any colorations frankly such that at first blush the M sounds bland and lacking at the frequency extremes. Spend time with them however and you relax into what’s really on the disc, not what the speaker is imposing on it

the shift from V to Q to M was all about reducing any colorations frankly such that at first blush the M sounds bland and lacking at the frequency extremes.

Well that sure does sound like they have their  audience figured out!

Darn I thought those fancy extruded aluminum S series casings were all about absolute  low coloration ( and resonance)...

My guess is you are hearing the sound of the polypropylene plastic bucket that houses the midrange.

Polypropylene cones always had a chesty sound - as if the vocalist had a bit of a cold. It was apparent in many of those designs of the 80’s - BBC speakers and Mission 770 etc. Very popular back then as you punch the cone out of a sheet of polypropylene very cheaply.

The problem is that polypropylene is non-fibrous and tends to store rather than dissipate acoustic energy so it vibrates characteristically - not a good material either for a speaker cone or cabinet for a speaker cone.

You can observe this effect with any plastic bucket when you start filling it with water - the frequency is lower mid range.