P. Hileman wrote:
Hello everybody, I'm currently in the process of designing a critical
listening room which
will be built seperate from the house. The ratio that I'm going with is 1
to 1.73 to 2.2.
With this ratio my demensions will be 11' H, 19' W, 24' 3" L.. I calculated
the room modes
of about 15 other ratios and this one gave me the smoothest room response
from 23 to 200hz..

On the walls I plan to use either 2 layers of 5/8" gypsum board or 1 layer
of 3/4" MDF..

The side walls(length) will be splayed ~5 deg each giving me a width of 18'
@ the speaker end and a 20' width behind listner for an average of 19'.
The ceiling will be splayed giving a hieght of 10' at the speaker end and
12' behind the listner.

Would appreciate any thoughts or ideas.

Thanks,
Paul H.


Clever.

It was Gilbert Briggs, founder of Wharfedale, who first brought the
advantages of asymmetry to the attention of audiophiles, before they
were called that, in his book Loudspeakers. Mr Briggs describes how he
played his speakers and played the piano on rooms in hotels all over
the England and sometimes in New York. He noticed that the sound was
different depending on the shape and size of the room, and then that
the sound was improved, over that in similarly shaped and sized rooms,
by abutments for fireplaces, water and electrical service channels,
support pillars and so on. He shows drawings of good abutments and bad
abutments with various speaker placements.

Though I have a beautiful Georgian room with perfect Phi proportions,
and long enough for natural bass on organ, I prefer listening in my
workroom and study.

In the developed loft on the fourth floor each room has a part-sloped,
part-flat ceiling along the length of the room. One can thus make an
arrangement of a seat facing the slope, the speakers under the slope,
the long wall well behind the seat, for intimate sound; careful
arrangement avoids cancellations; the slope of the ceiling acts as
baffleboard or, more fancifully as a reverse funnel extension for
either horns (Lowther Fidelio size and topology though of my own
construction) or dipole speakers (Quad ESL63). Or one can make an
arrangement along the length of the room sitting near one end, the
speakers near the other end, one speaker inevitably under the slope of
the ceiling, one under the flat part. Thirdly, a particularly useful
arrangement of Quad's ESL if you have two pairs in a long room is to
put two 63 in the middle of each of the longer side walls, the two
speakers at right angles to each other, the inner edges up against the
side wall; this is a means of bass reinforcement and sound
reinforcement (3dB louder) for parties. Again the sloped ceiling
provides a surprising amount of reinforcement.

I have liked what the shape of the room does for my sound so much that,
for most of my listening which is non-critical, wallpaper music while I
work at my computer, I use mono, at least two ESL (one 12in behind the
other for coincident point sources) for extra bass or one horn right in
under the slope. The effect is stunningly authoritative (1).

More regular asymmetry is also beneficial. Twenty-five years ago the
Philips engineer Tony Weimar lived up the road from me in his
retirement. His house was, to start with, a typical two-story Irish
country villa, four rooms down, four rooms up, a foursquare building
with peaked roof sloping down to the four walls. He ripped out the
entire inside and the loft to leave a large square space two stories
high plus the diamond peak of the roof. Along one side was an open
gallery with a bedroom and bathroom above and kitchen and services
below. The whole affair was a space for him to demonstrate his
soundshaping hi-fi. Very impressive. My initial connection with him was
that he gave me the pair of Quad II which had been the Philips
Eindhoven design department voicing amps for many years, so I persauded
him to play standard classical music (he loved Bach Cantata, as I do)
through standard equipment (Quad II, Quad 405 I had brought along in
case he wanted a gift in return, Audiolab, a British Class A SS whose
name now escapes me, his multi-driver arrays, an old-fashioned large
Tannoy horn, ESL57 and 63, and so on). The effect was totally stunning.
It was like sitting in the concert hall. It wasn't the hi-fi that
overwhelmed, it was the space and the irregularity of the space that
made that sound the most impressive I have ever heard outside of a live
performance in a concert hall.

It is therefore not difficult to believe that your planned asymmetry
will do wonders for your music. Congratulations on a clever idea.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"an unbelievably comprehensive web site" -- Hi-Fi News & Record Review

(1) Another way of using dipole panels is as huge earphones. Sit in
your chair exactly halfway between the side walls of the room. Place
the panels halfway from each ear to the back wall. Move panels further
away from ears until your music sounds right or, if you an obsessive,
measures right. Enjoy. If you sit in an office chair, you may have to
raise or tilt the panels. This also works with horns if your room is
big enough.