" Do you have a link to the study that mentions this? Thanks "
He describes it in his book, don’t remember whether or not he included a reference. I’ll try to remember look for it this evening.
" what was the explanation? "
I don’t recall offhand what Toole said about it.
I have read that it may have to do with the absorption of high frequencies as sound travels significant distances through the air. At a live performance the distances involved would reduce the amount of high frequency energy reaching the audience, whereas the relatively short path lengths from instrument to microphone and later from speaker to listener do not attenuate the high frequencies significantly.
Duke |
Chances are very good Toole’s test system was overly bright. Oh, well, back to the drawing boards. Shut the cave door and back to pigmy country!
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audiokinesis, we may be in agreement and we may not be. A speaker that is ruler-flat on-axis, anechoic chamber, will have a typical room response that slopes off at high frequencies. It is this response, the room response that slopes off that people prefer predominantly. Generally first reflections will always be sloped as they are off axis. I copied pieces of my post below as I wanted to be quite clear that ruler-flat on axis anechoic response is much different from room response and it is room response that people respond to and determine as too bright. In Floyd Toole’s latest presentation he heaps praise on a speaker with ruler flat on axis anechoic response. He also states in his excellent 00 paper on Maximizing Loudspeaker Performance the need for a "flattish, smooth, axial frequency response". His personal preference at that time was room friendly loudspeakers (i.e. most rooms). Do you know when that first study was done? If it was old, it could be an artifact of speakers at the time? The real solution, for professionals as well as consumers, is loudspeakers that deliver similarly good timbral accuracy in the direct, early reflected and reverberant sound fields. This can be described as a loudspeaker with a flattish, smooth, axial frequency response, with constant directivity (which together result in flattish, smooth, sound power). audiokinesis2,102 posts10-30-2019 4:49pmKenjit wrote: "a ruler flat response... is too bright for most folk."
Floyd Toole, Bruel & Kjaer, and I all agree with Kenjit on that point.
Atdavid wrote: "I do not think overall that most people consider a ruler flat response too bright."
Toole conducted extensive double-blind listening tests and found that most listeners prefer a gently downward-sloping response trend, both for the first-arrival sound and for the early reflections. Most people perceive a "flat" response to be "bright", and a gently-downward-sloping response to be "flat". atdavid OP12 posts10-30-2019 3:14pmA ruler flat response on axis only matters in an anechoic chamber and/or listening very close to the speakers. The room response is likely to be much different which is what my post speaks to.I do not think overall that most people consider a ruler flat response too bright, especially since it is the room response they respond to, not the anechoic measured on-axis. |
A speaker that is ruler-flat on-axis, anechoic chamber, will have a typical room response that slopes off at high frequencies why would it slope off in a room that is less absorbent than an anechoic chamber? |
In an anechoic chamber, typically what we are showing is the on axis response typically tailored to be perfectly flat.
The room response is a combination of the direct and reflected. Higher frequencies are typically absorbed more by things in the room, even just painted drywall, but they travel farther distances, so also attenuated more by the air. Add in the highest frequencies tend to be the most directional, so it may be flat on-axis at 20KHz, but 10db down at some angle off axis, and room response is sum off on axis and reflected off axis.
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