Okay.. I only continue this because it directly relates to the subject of this post. The letter to Mix was in Jan 2000 referring to a guest article printed in the Nov 1999 issue... We took issue with the assertations of this artice. The initials are not DM.. below is the text of my letter... so that their are no veiled comments (and I agree with you Andre... my bad!)..As I said, this is all directly related to the subject of this post and thus I reprint it here as an educational item only. This is my original letter:
Dear Editor,
Back in November (1999) when our issue arrived and we read Mr. LaCarrubba’s article (“The Wide Dispersion Listening Space”) we had a big problem with a lot of his assertions. We thought hard about writing to Mix to ask who reads these guest articles and verifies the validity of the “facts” contained within. We didn’t (our fault). Now along comes January and we have read Mr. Schrag’s response to the article (Feedback) as well as Mr. Moulton’s reply, and we just can’t stand it anymore!! Over the past ten years or so, Lars Tofastrud and myself have also spent a good amount of time documenting how sound “bounces around a room”. Through testing and listening, we have come to understand and accept the basic principals of small room acoustics. Not only do we find most of Mr. LaCarrubba’s assertions to be contrary to most of the “facts” as we understand them, we are in complete agreement with the response as presented by Mr. Schrag.
Depth of imaging and sound-staging are part of the signal “captured” in a recording whenever one or more microphones are setup in such a fashion as to capture the time based information of the space where the original instrument was recorded. Presenting these signals accurately through a high quality loudspeaker system, into a playback environment, is what our business is all about. The listening environment must be void of significant early reflections within the first 20 msec or so, in order to not mask the time information that is captured in the recording. These “Localization Cues” that Mr. LaCarrubba refers to in his article are not supposed to be introduced by the listening environment. Lateral short reflections will only detract from the original recordings timbral and time information by adding comb filtering effects, regardless of whether these reflections are full bandwidth or not. This is not an issue of frequency, but one of time.
Also, although we agree that reflected sound can help localize a source, this is absolutely NOT what we want to do with loudspeakers. In all the rooms that we’ve been in that “Sound Good” (whether we designed them or not!) the localization of the loudspeakers is not what makes the music deep and enveloping. The illusion of the loud speakers “disappearing” is what makes for the most palpable sound staging and musical presentation. This is only achieved when early reflection in the listening environment are controlled and the Initial Time Gap (ITG) is free of significant reflections (in the range of -24 dB in relation to the direct signal from the loudspeakers). We DO NOT agree with Mr. Moulton assertion that loudspeakers in a playback environment should be thought of as a musical instrument with regard to their interaction with the room in which they sit. Yes, our auditory system (ear) is very good at making use of acoustic reflections, and yes, these reflection help us localize sound. However, if we are to “…perceive a unique signal sent to a single loud speaker as coming from that loudspeaker” then the room must not color the sound from the loudspeakers with early reflections. Such reflections would only serve to cloud the localization information encoded in the recording. At that point we are actually “listening” to TWO rooms; the one in which the music was originally recorded AND the listening room. The confusion presents itself when you try and figure out which room you’re hearing! As Mr. Schrag said, these reflections are not “Good Data” in a listening environment. We are concerned that this most basic concept of small room acoustics and psycho-acoustics is being misrepresented, and presented to readership as fact. We just don’t want these commonly misunderstood concepts to be further confused.
Francis Manzella – President: Francis Manzella Design Ltd.
Lars Tofastrud – Associate Designer: Francis Manzella Design Ltd.
Yorktown Heights, NY
______________________________________________
The important concept here was summarized by Mr. Schrag's letter: "Reproduction should not be confused with Production".. this just about sums it all up.
