|
Tech Square Technical and speculative discussion of amps, cables and other topics. |
|
|
|
Tech Square Technical and speculative discussion of amps, cables and other topics. |
|
In Reply to: TVCs and the subjective loudness curve (Fletcher/Munson) posted by Carlos on October 18, 2003 at 21:37:11:
THere is another set of modified equal loudness contours that were researched by Jensen in the 40's. They are shifted upwards in the bass, so that the threshold of detection at 35 Hz is about 85 dB. These modified curves agree quite closely with some experiments I ran back in the early 70's using very low distortion transducers and vibration isolation of the observers.This is quite significant as the standard Fletcher Munson curves imply low frequency audibility that does not exist and leads one into some false conclusions about the specifications of systems.
I suspect that the original F-M curves, such as you show, are data that is contaminated by several percent of harmonic distortion at the lower frequencies which results in "improved audibility" of the lower frequencies, say below 50-60 Hz.
The Jensen modified F-M curves can be found in the Radiotron Handbook. Probably other places as well, but that's where I came across them.
Jerry
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: TVCs and the subjective loudness curve (Fletcher/Munson) - Bold Eagle 07:22:53 02/25/04 (1)
- Curves were re-specified by - CharleyW 17:31:56 01/10/05 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]