Table 1. Overview of processor load (realtime index) and amount of sources per filterlength measured with
BruteFIR v0.99f on a Dual Pentium III, 1004 MHz.
Sources 1 2 3 4 5 6 7 8 9
Filt. Len. Dist. (m) time
256 1.97 6 ms 0.17 0.23 0.30 0.38 0.49 0.58 0.67 0.77 0.82
512 3.95 12 ms 0.18 0.25 0.33 0.40 0.53 0.61 0.71 0.80 0.87
1024 7.89 23 ms 0.20 0.27 0.35 0.42 0.55 0.63 0.72 0.80 0.88
2048 15.8 46 ms 0.22 0.29 0.37 0.43 0.56 0.64 0.73 0.83 0.91
4096 31.6 93 ms 0.24 0.31 0.38 0.45 0.59 0.70 0.81 0.94 -
8192 63.2 0.19 s 0.27 0.36 0.45 0.55 0.72 0.85 0.96 -
16384 126 0.37 s 0.34 0.45 0.58 0.68 0.90 - -
32768 253 0.74 s 0.46 0.63 0.86 - -
65536 505 1.49s 0.65 0.84
131072 1011 2.97s 0.73 0.91
4 Interface software
In order to work with the system, interface
software was needed to calculate the necessary filter
coefficients. The aim was to create an interface that
allows composers to define the movements of their
sounds, independent of the system on which it
eventually will be played. That is, the composer
should be bothered as less as possible with the actual
calculations for each loudspeaker, but instead be
able to focus on defining paths through space for his
sounds.
The current version of the program allows the
composer to do so. The composer defines the
locations and paths through space and gives the time
parameters for these. The program will then
calculate the necessary filters, based on the hardware
setup of the system. As such, compositions can be
saved and loaded on different systems, with different
hardware setups, and the composition in space that
the composer intended will be played back. The
sound input needs to be presented at the inputs of the
sound card and can come from any source (also a
live source).
Figure 3. Screenshot of source and path definition. Graphical
results of this input is shown in figure 4.
