GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Playback Listening
In the Thread: The dynamic range of our playback

Post Subject: Dynamics is not just differences in acoustic outputPosted by rowuk on: 6/28/2014

As I originally posted, audiophiles would like a convenient term for something that relates to moving air. Unfortunately it is not that easy.
The noise floor for events with substantial acoustic output is much higher than other types of music. Even 100 people in an orchestra make "noise" just by being seated. That of course changes the audiophool definition. If our noise floor at an "event" is 40dB loud, the 110dB peaks at the listening seat are merely 70dB louder.
In a more intimate chamber music setting, the dynamic behaviour - especially on recordings can diminish into nothingness. The attack of the quill on a harpsichord string requires extraordinary dynamic behaviour from the playback to insure "enough" but not "too much" bite. Characteristic noises that identify the instruments to the trained listener are present during the attack. On the harmonic structure of the instrument alone, we have problems. This part of reproduction IS dynamics and is sorely lacking in many recordings and playback systems alike. To get playback right, all of the drivers must do their "dynamic part". If the woofer is slower than the signal or tweeter has a different dynamic behaviour, the tonality of the speaker changes depending on the mean volume.
To hear the differences between a "quality MPG" and a recording without data reduction, we need "dynamics" to insure that enough tonal discrimination is present to resolve what the process leaves out. MPGs DO retain the proportions of soft to loud - but do not sound as dynamic.
When I practice my trumpet in a room "too small", it overloads the sensory perception - I practice differently. When we shoehorn a symphony orchestra into a small living room - an uncompressed recording would pressurize the room in a much different way - in addition to the standing wave pattern of the room not being present to "condition" our expectations at higher volumes.
I think that there is an overestimation in "headroom" not dynamics. Dynamics in my opinion is one of the major factors wrong in most playback. We have exaggeration of certain aspects and underrepresentation of others. Headroom is not only the capability of the source/amp/speakers to capture the min/max in an undistorted way, but also the room being capable of dealing with the pressure.

Rerurn to Romy the Cat's Site