Overdamped and Dead are two often used expressions that don’t really have a meaning as such.
It is more the expression of a feeling than something objective.
There is a whole thread on the subject called “Why is a totally dead room bad?” on the Gearspace dot com forum.
It is also important to know that the ear quickly becomes accustomed to a type of listening environment (even noise!), and to a specific reverberation time: the one of our environment. Any change can create discomfort. We don’t like change…
Imagine that you have lived in the jungle all your life, without walls. From one day to the next you find yourself in a 40 m2 shoebox-shaped room. Apart from the limited space, it’s the acoustics that will bother you the most. The sound environment is something to which we are extremely sensitive. Psychoacoustics is a fascinating subject.
From an acoustic point of view, what can happen is a non-even absorption over the spectrum.
For example, the use of curtains and thin absorbers (or foam) only.
Of course, such a minimal treatment provides interesting gains, especially when applied at the first reflection points. But it can create an imbalance. The high and midrange are absorbed, and the low midrange and bass not at all.
In some cases, for certain types of music, the result can be a sound lacking in sharpness, a thin sound, etc.
Obviously, the stereo image and definition are improved, but it may seem as if the shine of the music is lost. Especially with pop and rock music. The lower end of the spectrum overwhelms everything.
So no, I’m not worried about a potential dead room.
My Soulution/Magico set sounds much better at my place than at my dealer’s, even though my room is much smaller (38 m2).
Once you get used to less distortion, to a treated room, there is no going back.
Even worse, when you go to others’ homes you hear nothing but distortion : comb filtering, timing problems, unstable stereo image, etc. Even with really really expensive systems.