Greetings:
Hello Michael C. and Fons A.,
Thank you for your detailed and informative responses to my questions.
Fortunately, the speakers I have chosen are well-matched and have good response
characteristics. I matched them some time ago; however, each speaker underwent
testing at an identical location, not at their respective positions in my
listening room. Because I am interested in three-dimensional Ambisonics, four
of the eight speakers in the (current) octagonal array will have to be close to
floor level: This is the only way to get moderately wide vertical separation
without putting the listener in a high chair. I recently observed that speaker
response (independent of room characteristics) changes because the floor
imparts an affect (I believe more than just the proximity effect). Fortunately,
large amounts of EQ aren’t needed, and I’m mostly interested in smoothing the
response in the 100 Hz to 10 kHz range.
I’m a minimalist when it comes to audio. I was never one to use graphic EQs (or
modern-day VSTs to achieve the same). I began building amplifiers while in
grade school, and a 10 watt, class-A amp designed by J. Linsley Hood and
described in Wireless World (1969-ish?) was a favorite of mine for many years.
Later I built a class-A, push-pull VT amp with 300Bs and an interstage
transformer. This was for my Lowthers. I never got into the single-ended stuff
because it seemed easy to mitigate transformer core saturation issues with
class-A push-pull designs that operated along the transfer characteristic as SE
biasing. My point is this: I don’t like too many things in the circuit path,
and I only use EQ when absolutely necessary. However, measurements serve to
“validate” my research findings, particularly when they’re slated for
publication or under scrutiny. If I use EQ, I try to use filter types that
yield the best transient characteristics and
minimal phase anomalies. I downloaded, as per your suggestions, the PowerPoint
/ PDF by J. Nettingsmeier. Looks like really good information. I will give it a
thorough reading after Christmas. Thanks for recommending.
RE MATLAB: Some of the cochlear implant (CI) simulations I do are simple phase
vocoder scripts written in MATLAB. While in graduate school, my doc committee
consisted of respected researchers (does W. Yost, M. Dorman, or S. Bacon ring a
bell with anybody?) who were huge proponents of MATLAB. The general attitude
was “if you can’t do it in MATLAB, it isn’t worth looking at; furthermore, if
it requires hardware, we don’t even want to look at it.” Kind-of strange
attitudes in my book, but I’ve always been more of a hardware person, whether
it’s digital or analog. I continue to do off-line wav processing in MATLAB
because I can show the underlying math as well as the statistical outcome. More
recently, I’ve been using Visual FORTRAN for projects.
RE Linux: I’m mostly a PC (Windows) user, but I’m not one to argue about the
superiority of one OS over another. I have a BIG investment in software, and I
don’t want to buy two versions of everything. It’s bad enough keeping up with
the latest Adobe media suite or incarnation of Windows. I’ve mostly stayed with
PCs so that I get best support for my National Instruments DAQ hardware or
other (legacy) devices. Because I have several computers, setting one up with
Linux is no problem at all. I used to run Red Hat Linux on one machine, and I
really did believe in the superiority of Macs when Windows 98 repeatedly
crashed. Nowadays I’ll use what works best or is accessible. So that I can
experiment with Ambdec, I’ll load Linux on a dedicated hard drive. My audio
hardware consists mostly of MOTU FireWire interfaces, but I also have an Avid
PC extension chassis that has four identical PCI SoundBlaster cards on it. I’m
sure I can find ASIO
drivers for Linux that will work with my MOTU gear. The SoundBlaster cards are
generic enough to work with about any OS (maybe even OS2 Warp).
I’ve been duly warned of the consequences of using more than six loudspeakers
in a horizontal-only, first-order Ambisonic configuration. Thanks, Fons, for
the very clear explanation. I do, however, want a flexible system because I’d
like to move towards a 3-D setup (or higher-order Ambisonics via recordings
made with an mh acoustics Eigenmic). Additionally, I have plans for an
experiment that compares energetic versus informational masking of vocoded
speech in the sound field, and I’ll be using two quasi-independent 4-channel
systems for this. When it comes to music enjoyment, I’ll stick with your
recommendation of six loudspeakers. Again, many thanks to all for the help!
Sincerely,
Eric
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<https://mail.music.vt.edu/mailman/private/sursound/attachments/20111222/dec78d4f/attachment.html>
_______________________________________________
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound
