Looking at your projected absorption ranges for your 3rd panel, it seems they absorb mainly between 60 and 100 hz. Looking at the difference in that area on your graphs I think shows a lowering of 200 MS in that range, which when looking at the standard waterfall graphs would look more impressive I bet. Especially given how difficult those frequencies can be to control or absorb.
Great work on the modelling and actually testing with the changes you make. I am following along and learning.
@tom1066 , thanks.
The LF decay time did change in the targeted range but not as much as I was expecting. As you say, it's a difficult part of the spectrum to damp because of the wavelength. Yes, it also shows in the waterfall as well, but I would still like better. I suspect that the one Helmholtz panel is not enough, so its working, but just not enough of it.
The LF decay time did change in the targeted range but not as much as I was expecting. As you say, it's a difficult part of the spectrum to damp because of the wavelength. Yes, it also shows in the waterfall as well, but I would still like better. I suspect that the one Helmholtz panel is not enough, so its working, but just not enough of it.
In a PM with @fluid regarding AKABAK room modelling, the subject of Double Bass Array (DBA) or Controlled Acoustic Bass System (CABS) was discussed. In particular the CABS schema also attempts to control the reflections and hence the room decay time. It seems ideal for what I need, even bass, and reduced room decay times. The investigation details are in this CABS Thread.
The "target" decay curve (attached below) was provided in : Fazenda, Bruno M., Stephenson, Matthew and Goldberg, Andrew (2015) Perceptual thresholds for the effects of room modes as a function of modal decay. The Journal of the Acoustical Society of America, 137 (3). pp. 1088-1098. ISSN 0001-4966
CABS is described in : A. Celestinos and S. Nielsen, “Controlled Acoustic Bass System (CABS)—A Method to Achieve Uniform Sound Field Distribution at Low Frequencies in Rectangular Rooms,” J. Audio Eng. Soc., vol. 56, pp. 915–931 (2008
Nov.).
The "target" decay curve (attached below) was provided in : Fazenda, Bruno M., Stephenson, Matthew and Goldberg, Andrew (2015) Perceptual thresholds for the effects of room modes as a function of modal decay. The Journal of the Acoustical Society of America, 137 (3). pp. 1088-1098. ISSN 0001-4966
CABS is described in : A. Celestinos and S. Nielsen, “Controlled Acoustic Bass System (CABS)—A Method to Achieve Uniform Sound Field Distribution at Low Frequencies in Rectangular Rooms,” J. Audio Eng. Soc., vol. 56, pp. 915–931 (2008
Nov.).
