Originally Posted by kromkamp
Can you define "anechoic speaker-listener response" for me, and whether or not that would imply accuracy?
Originally Posted by localhost127
do you know what an anechoic speaker-listener response is? because it should be pretty straight-forward from the terminology alone...what is there to describe?
That is not a fair answer to him Local. He asked you to define the term and you ask him if he already knows what it means?
He is asking a good question relative to how many times you use that phrase. That you need to define and clarify your position there. I will go ahead and do that for him.
Since you are using that as a definitional term, I thought I go and see who has used in the literature. I searched for "speaker-listener response" with our without dash and got no hits on Audio Engineering Society library or that of Acoustic Society of America. I had to use quotes as otherwise the words in that term are quite common otherwise. So if this is an industry term, it is a very rare one and as such, folks should not be expected to know what it means automatically.
So to get to the bottom of it anyway, I did a general search on the Internet. Interestingly enough, I only got a handful of the responses. The first two were your post on the pro recording forum, Gearslutz. And one of the other a link to this discussion thread!
The other three links appear to be related to linguistic or some such thing and unrelated to this topic.
But we have what we need in you expanding the term on Gearslutz
. Here is the key quote with this term in it:"without traversing down the rabbit hole of psycho-acoustics, there are two basic concepts: the first is a completely damped room with respect to speaker-listener response. the direct signal is all that is heard and no room reflections are introduced to the listening position. the speaker-listener response is anechoic. this is referred to a Non Environment Room (NER). the ETC would show the direct signal spike, and then directly followed by the ambient noise floor. "
Now we get some place because Non-environmental is an industry term. Let's see who it is defined there. From AES Paper, Objective Evaluation of a Non-Environment Control Room for 5.1 Surround Listening, by Degara-Quintela, Norberto; Pena, Antonio; Torres-Guijarro, Soledad (2008):"The non-environment design of control rooms [1,2] was proposed around 1982 by Tom Hidley, where the goal was having an acoustical environment with the minimum of room sound. Sound radiates from the monitor loudspeakers with barely any sonic influence from the room. This basic principle allows a reflective floor and a diffuse reflecting front wall where the loudspeakers are flush mounted. Huge absorbers cover the side walls, rear wall and ceiling, creating an almost hemi-anechoic space for the monitoring while keeping comfortable working conditions thanks to the reflecting front wall. This design is supposed to preserve the sound characteristics of the mixing and production studios when taking the product to other listening environments, a fact that seems more and more important nowadays."
Before digging in, let's review what two goals the recording engineers are generally attempting to meet:
1. They like to hear just the direct sound of the speaker and no reflections. They consider this "accurate" which is the term Local keeps using. Taken to its ideal place, this means an anechoic chamber -- a reflection free space that adds nothing whatsoever to the sound of the speaker.
2. That an anechoic chamber is not a pleasant place to mix music or enjoy it.
For anyone doubting #2, here is F. Alton Everest in his book, Master Handbook of Acoustics:"The delicate and sensitive nature of our hearing can be underscored dramatically by a little experiment. A bulky door of an anechoic chamber is slowly opened, revealing extremely thick walls, and three-foot wedges of glass fiber, points inward, lining all walls, ceiling, and what could be called the floor, except that you walk on an open steel grillwork.
A chair is brought in, and you sit down. This experiment takes time, and as a result of prior briefing, you lean back, patiently counting the glass fiber wedges to pass the time. It is very eerie in here. The sea of sound and noises of life and activity in which we are normally immersed and of which we are ordinarily scarcely conscious is now conspicuous by its absence.
The silence presses down on you in the tomblike silence, 10 minutes, then a half hour pass. New sounds are discovered, sounds that come from within your own body. First, the loud pounding of your heart, still recovering from the novelty of the situation. An hour goes by. The blood coursing through the vessels becomes audible. At last, if your ears are keen, your patience is rewarded by a strange hissing sound between the ker-bumps of the heart and the slushing of blood. What is it? It is the sound of air particles pounding against your eardrums. The eardrum motion resulting from this hissing sound is unbelievably smallonly 1⁄100 of a millionth of a centimeteror 1⁄10 the diameter of a hydrogen molecule!
The man can write, can't he?
Given that, we see that the position the pros put themselves in is untenable. You can't have just the sound of the speaker and not have the discomfort that goes with it. So what is their solution? Let's make some of the surfaces reflective. Which one, leads us to the flavor of the day with a catchy term to go with it. In this case, non-environmental room. Localhost calls this room to have "anechoic speaker-listener response.
Let's start at the top: there is only one definition of anechoic and it says reflection free. That is what the term means. An NE room per definition above has its floor reflective. So clearly right there, we have floor bounce and nothing like an anechoic chamber. In another thread, Localhost post this graph to back his position of accuracy:
Clearly the graph articulates that floor bounce is bad. And that the definition of accuracy is zero reflections per the second configuration below. A transient is sent to the speaker (the spike) and zero reflections come back. Clearly we don't have that remotely being the case in an NE Room. Indeed we have the representation on top of the graph with floor reflections.
That being teh case, the terminology as used is not accurate. It is like saying the drink is sugar-free, only to find sugar as one of the ingredients, albeit much reduced. Yes, the motivation is clear. If you scare people about sugar, you don't want to look like you are still using it.
As a side note, who says floor reflections are a good thing in that NE Room model? Why that? What extensive research led to that choice being optimal? Dr. Toole's research says we like lateral reflections but those from other directions are not beneficial. If NE Room is where it is at as the prime example of the phrase Local is using, where are the listening tests that show that to be a superior method? If it is not a superior method, why keep using the phrase?
This is the reason you don't want to chase things done in the Pro world. A room model conceived in 1982 by Hidley prior to so much research past that into what reflections mean to us as listeners, should not be the formula put forward for people who want to enjoy music. For someone recording it, and wanting to hear what a knob adjustment is doing, that is fine and is their choice. But for a recommendation to stick for consumers, there needs to be more evidence of its goodness than, what don't you understand about this term?