建構專業視聽室參考
這篇不知道有多少人看過,http://www.positive-feedback.com/Issue16/lavigneroom.htm,這位發燒友找了一個有穀倉的房子
,請了專業的設計公司幫忙,把穀倉變成音響室,過程也詳細記錄,非常有參考價值。
Building a Reference Grade Listening Room
by Mike Lavigne
All photographs by Mike Lavigne; image
processing by Robinson
So what possessed you to build a dedicated
room?
Back in 1994 I got into this hobby on a
serious level. I had always enjoyed music and back in High School (the '60s)
and College (early '70s) I had a 'Stereo System' that was semi-serious... at
first a Wollensack reel to reel tape recorder (bedroom in parent's home), then
AR speakers, Sansui receiver, and AR turntable (dorm room)... finally, Bose
901's, McIntosh, Dual turntable (own apartment). Then I got married and was a
Bang & Olufsen guy for 15 years or so (boats, TV, kids, etc., were the
priorities). The kids moved out, and I discovered the 'High End.'
At first I had the gear in the family room
(connected to the kitchen/eating space)... competing with the noise of the
dishwasher, the kitchen sink, and 'life' in general. I kept eyeing a large den
(a favorite room of my wife) where we had a desk and piano. One afternoon when
my wife was gone, I moved all my gear into the den. All of a sudden, I had a
dedicated room... which was to be my audio home for the next nine years. I got
lucky with the den; it had a very high ceiling (almost 11 feet), a bay window
and floor to ceiling bookshelves on the rear wall. Soon the desk and piano were
evicted and I settled into audio bliss in MY room.
I won't get into all the gear I eventually
went thru while in that room... but I touched a few bases... mostly Wilson,
Levinson and Transparent... then... Rockport, Kharma and Tenor. I did spend
considerable time trying to overcome the limitations of the 18 foot length and
12 foot width. As I came to the end of the road on system component performance
I became increasingly aware of the limitations of the room has on ultimate
system performance. Since my room was only 12 feet wide I had found that by
over-damping the sidewalls I could still listen at moderately high levels…but
there was still a closed in feeling... and the bass could get quite boomy on
many cuts. It seemed that the room was limiting resolution and restricting the
music from breaking loose.
Old Room - back wall
The sound of my system was satisfying, but
the knowledge that there was more got under my skin. In addition, I really
enjoyed having fellow audiophiles visit me... I wanted a bigger room... at
least 17 feet wide, 25 feet long and 11 feet tall... a concrete floor, and NO
noise issues. These were my minimum parameters for a room to be worthy of my
gear. I also wanted to be able to listen whenever I wanted without disturbing
the sleep of my wife.
How did you pick the place to build this
room?
For a year or so I considered adding a
dedicated room onto my home... but after exploring the possibilities I
determined that the cost and investment considerations in my neighborhood would
not pencil. After discussing this on and off for 6 months with my wife; we
decided to look around for another home that would either already include the
space I needed or allow an easy addition. We spent another 6 months looking
around... made 3 different offers on various homes... and finally found what
both of us were looking for.
The Barn
I found a home on 4 acres with a separate
barn. This Barn had the potential of a completely unrestricted space, 37 feet
long, 25 feet wide, and 11.6 feet tall. We proceeded and purchased the home,
then move into it in January of 2004. The barn had been home to a couple of
horses, a couple of Great Danes, and 3 or 4 barn cats.
Middle stall of the barn
So here I was with the potential space…
what next?
First, a little about my audio compass; my
viewpoints and listening goals.
I have always really enjoyed listening to
new music... which was a problem, as I have never had much knowledge about
music. So I would read reviews and buy a recording if the review described what
I thought I would like. Some people are afraid to buy music, just in case they
don't like it get stuck with it. I, on the other hand, am afraid that if I
don't buy an unfamiliar recording, I might be missing something. Over the last
10 years I have bought lots of new music... what is interesting is that music
that I bought and didn't connect with initially, many times became a favorite
later, as my musical tastes and knowledge matured. I grew to love Jazz, and now
I am progressing on my enjoyment of classical. My purchasing philosophies have
resulted in a fairly large music collection... which I like to have in the
listening room with me... as much as possible.
I have evolved in my philosophies regarding
what gear I like and how I want things to sound. Initially, I read reviews and
listened... then I would buy. As I went through a few years of upgrading along
the Levinson/Wilson path... I developed listening skills and appreciation for a
more refined sound... I evolved from focusing on parts of the music (the
sounds) to wanting to have as little between me and the event (the music) as
possible. I was attracted to gear that had as little of its own sound as
possible. As I found gear that fulfilled my particular tastes, it was clear
that at a certain point the room became a barrier to the system 'getting out of
the way' of the musical event.
I want a system with no part that draws
attention to itself and away from the musical message. Great deep bass is fine
if it is not 'prominent'... it must serve the music, and not vice versa. This
is what defined my communications to my room designer.
How did you pick your room designer?
I had met Richard Bird and Chris Huston of
Rives Audio back at the 2003 CES. I had become quite interested in room acoustics
while trying to tame my previous room. A few of my friends had had great
results from Rives' approach to room design. Rives Audio believes that many
rooms ended up over-damped, and that diffusion was a better method of 2-channel
design. The whole 'live-end/dead-end' approach was inadvisable in all but the
smallest rooms, as it robbed the music of its energy. This made sense to me.
Richard was out in the Seattle area in
March, so I picked him up at his hotel and had him over to my home for a short
visit. At that time I was actually considering putting my listening room in the
main house in a guest bedroom (I wanted my wife to be more involved). I
eventually went back to the barn concept as I feared I would screw up the
feeling of the house with an expansion, and my costs would yield no added value
to the home. Redoing the barn would add finished square feet to the property,
and would yield a return in that neighborhood if I sold. In any case, I liked
how Richard communicated, and his concepts made sense.
In April I contacted Richard and discussed
my thoughts on the barn. He was excited at the potential of a separate building
with virtually no design limitations... which in turn got me more excited. I
sent Richard blueprints, and then measured all the distances on the plans so we
would have accurate info for Rives to use. I gave Richard no limitations on his
design within the 37' x 25' x 11.6' space. He came up with approximately 30' x
21' x 11' as a starting point.
Front of Barn prior to construction
How did the design phase play out?
Over the next 3 weeks we went back and
forth with various ideas. I wanted a good deal of my software in the room, so
it was important to incorporate shelves into the acoustics. I like my source
gear on the side wall next to my listening position... I wanted a couple of
small windows... I wanted the ceiling to be special. My concept had been to
have a ceiling that started low behind the speakers and increased in height as
it went back... Richard explained that there were a few problems with that
approach, due to pressure zones. Finally Richard did a rough draft that I
liked. The basic inside framed dimensions of this original concept were 29 feet
long, 21 feet wide and 11 feet high.
Barn floor plan prior to construction
First concept
My next step was taking this rough draft to
my contractor for an estimate of what this might cost. There were structural
issues that needed resolving. Until my contractor knew the approximate room
size he could not get the engineering on the structural done. The three stalls
of the barn would need to be torn out, and the central wall running length-wise
thru the barn would need to be removed and spanned. Richard's concept called
for a 42" wide hallway running down one side of the room so my contractor
had the engineer design 2 main beams (16" x 4" gluelam) to run
horizontally at the 1/3rd and 2/3rd points of the room, as well as a
longitudinal beam connecting to the horizontal beams that would pick up the
load from the previous long wall. This was kind of major, but resulted in a
very stout structure. The hayloft above was already on 12" x 2"
joists on 12" centers... this same design was carried across the rest of
the ceiling. I wanted to have a pool table in the hayloft (as well as future LP
storage), so the ceiling needed to be very strong.
My contractor then actually began the
demolition and structural investigation... prior to figuring how the structural
beams would work. When the final structural issues were settled, Richard had
Chris Huston get involved to do the detailed construction drawings. I might
recommend reading Chris's bio athttp://www.rivesaudio.com/files/Huston_bio.pdf
to understand his credentials. He has possibly a unique background in music,
the production of music, pro studio design, acoustical theory, and 2-channel
room design. He isn't guessing about how things will sound with my money... he
knows from science and experience. Every acoustical component in my room has
already been used by Chris in other projects.
Like many audiophiles with a little
knowledge and experience... part of me felt I could figure this out. There are
other acoustical design products/services out there to choose from... but the
closer I looked, the more it appeared to me that other approaches were actually
the application of tweaks to existing spaces, whereas Rives was fundamental in
its stance and had more actual room design experience. Rives can 'band-aid' a
room... but it is not their first choice.
Chris took about 10 days to complete the
first draft of the construction drawings for me to review. He e-mailed and sent
me a hard copy of the plans... as I looked them over I got pretty excited...
here was what I had been looking for. I ended up building pretty much exactly
what that first draft showed. When Richard and I had gone over concepts we had
figured a few things out.
LAST Concept, pretty close to what we built
The above concept plan is where Richard and
I had taken things. Chris took this and went to the next level.
The horse trailer aisle and ceiling prior
to construction
The existing ceiling was 12" x 2"
joists on 12" centers. It had been constructed to be a hay loft, so it was
very substantial. A new ceiling was added above what had been the horse stalls
to match the existing one. All the electrical for lights and power were
installed... then R-39 insulation was stuffed into the gaps between the joists
in the ceiling. R-19 insulation was installed in all the walls, which were
constructed of 2" x 6" studs on 8" centers. There were 6 large
posts holding up the large beams; these posts became part of the walls. In all,
a very stout structure.
Chris specified a sandwich of 5/8"
sheetrock, 1/2" soundboard, and 5/8" sheetrock on the walls and
ceiling for the whole room. Everything would be built inside this cocoon. Half
the floor was already 6" of concrete over 6" of gravel. We extended
this to the whole floor. Since this was a separate structure from the main
house, sound isolation was not particularly critical. In addition, since this
would be a pretty large space, the walls needed to be very solid to 'hold' the
bass energy... in a relatively small room you might typically 'soften' the
walls to keep the bass from getting too boomy.
New room with sheetrock, speaker end
The focus of the room and most unusual
feature is the large center diffuser panel in the front of the room. This
curved panel protrudes about 18" into the room at the center point. It is
constructed of ¼" plywood over a stud wall and lined on the inside and
back wall with 2" fiberglass. This plywood is then covered in maple
veneer. Above and below of the diffuser panel are 12" soffits that follow
the same curvature. This diffuser captures all the energy of the room but won't
beam any first reflections. The adjacent fabric covered bass baffles create a
perfect balance of absorption and diffuse reflection... retaining phenomenal soundstage
layering and detail, while eliminating any smearing of detail.
Front Diffuser, without ¼" plywood…
…and with ¼" plywood
Side diffuser showing side relief
Next, he took the front tapered side walls
and made them a huge bass trap on each side. He lined the cocoon wall corners
with 2" fiberglass, pulled the false wall corner out about 18", and
then tapered the front wall too (so it tapers to the corners of the large
center diffuser). The final drawings show a false wall of fabric-covered
1" fiberglass. This creates a huge (it extends about 10 feet down the side
wall and 5 feet into the front wall and is floor to ceiling) bass trap (and
absorptive surface) on the front side walls and sides of the front walls; it
also eliminates the 90 degree corner. The size of this bass trap is much larger
than any tube trap and is built into the room.
Front corner bass trap walls
Chris added hardwood floor on the front 10
feet of the room, for added energy retention... a thick carpet and pad is
specified for the floor on the rear 2/3rd of the room. The speakers will be
positioned at the forward edge of the hardwood so their first floor reflections
are off the carpet.
Carpet/maple hardwood floor
On the ceiling, Chris designed a system of
soffits and chambers. The soffits drop down from the 11 foot ceiling about
14" and serve as one large bass baffle. There are 6 chambers, three per
side. The sides of these chambers have holes lined with fabric covered 1"
fiberglass to allow the bass frequencies to enter and dissipate inside. The
chambers break up any standing waves and eliminate first reflections off the
ceiling. This whole soffit system is one very large bass trap.
Ceiling design, chambers and soffits
As a final touch, Chris designed four
18" x 48" x ¼" hanging diffuser panels into the center two
chambers to further reduce first reflections. These angled diffusers 'trap'
direct sound from the speakers, but allow room energy to be retained.
Ceiling diffuser panels
The center of the side walls on each side
contain vertical diffuser panels that Richard had specified in his concept
above, and the rear side walls have floor to ceiling CD racks that will hold
almost 5000 CDs or SACDs. These diffusers are semicircles of hardwood plywood
filled with fiberglass. They diffuse any direct sound, but don't resonate.
There are 3 sections of CD racks that step
towards the center of the room and eliminate any parallel surfaces. The shelves
with CDs are ideal diffusers. The rear wall has LP shelving that tapers toward
the center on each side... holding almost 3000 LPs. In the rear corners and to
the inside of the LP racks are floor-to-ceiling built-in bass traps... which
are cavities lined with 2" fiberglass, with fabric-covered 1"
fiberglass on their outside surface.
LP and CD/SACD shelves
Rear corner bass traps
The door is solid and uses weather
stripping to keep noise and air from entering or leaving. I am a stickler for a
door that is tight, looks good, and closes nicely. This door has a solid oak
bottom jam and a 'trick' gasket that uses a cam mechanism to lower onto the jam
when the door closes... neat.
I like my sources to be on the side of the
room, and the (monoblock) amps to be between the speakers. My turntable weighs
550 pounds; I have installed a 24" x 24" piece of Travertine tile
directly on the concrete for the turntable on the left side of the room
alongside the left hand diffuser panel. The air compressor for the turntable is
in the attic above the room where it can't be heard. We installed 2"
conduit for the turntable air and control hose in the wall.
My digital source, passive switchbox, and phono
stage will be located on a Zoethecus rack alongside the turntable, in front of
the left diffuser. The amps and passive remote volume control are located
between the speakers. There is a 7 meter balanced interconnect running from the
passive switchbox on the left side to the passive remote volume control between
the speakers. This interconnect is raised off the hardwood floor by ceramic
cable elevators.
Sources and racks
HVAC, lighting, electrical, and other
system design
HVAC (heating, ventilation, air
conditioning) is designed into the room by Rives to be 'whisper-quiet.' It is
dedicated to this room only, and has the fan/heat unit in the attic above the
hallway outside the room. This unit is mounted on a vibration absorbent pad...
even when standing directly under it in the outside hallway there is no noise
or vibration. The air exchanger unit is mounted outside the Barn on the
opposite side from the room, so when engaged there is no sound detectable from
inside the room.
This HVAC system is a closed loop... the
main air duct emerges from the fan/heat unit and goes through an electronic air
purifier, then is separated into four outlet ducts... each of which travel to
four different outlet vents on the ceiling. Each of the four outlet ducts has three
90 degree bends to reduce any fan noise. With four outlet ducts the velocity
can be reduced. There are two cold air return vents located at the bottom of
the front bass traps (these cold air return ducts act as part of the bass
trap). These cold air returns are then ducted back to the heat/fan unit. With
the door closed and no music playing the room is completely quiet... not a
sound... when the HVAC unit comes on you can just barely tell it is on... any
music or conversation makes it impossible to hear the HVAC.
I recently added a vent and cold air return
in the upstairs rec room to reduce the air pressure/velocity in the listening
room... this reduced the already very low noise about 80%, to just about
nothing. Since I'm the only user of this upstairs room (except my kids when
playing pool), I have no sound leakage issue with this.
The problem with having a room with truly
NO outside noise is that there is nowhere to hide. Any noise is major... but
the benefits of any reduction in ambient noise is more musical information is
uncovered... ambience from the music is greatly increased.
Finished room
A completely separate 70 amp, 220 volt
electrical service was run to the room with its own dedicated panel. This is
taken from the home electrical panel in the garage, just after the meter. It is
upstream of any other panel. In the future I may attempt to have a totally
separate electrical service and transformer from the street for the room panel,
but I didn't want to tackle the politics of that at this time. All the motors
and such for the house are on their own separate sub-panel, and when these
motors cycle on I get no noise of any kind through the room-dedicated panel.
A 'home run' goes from the meter to the
dedicated panel outside my room in the hallway. There is no main breaker in the
dedicated panel, and it is the highest quality panel I could find. This panel
has its own quite robust dual grounding rods. There are 11 dedicated circuits
for the room, all with 'home runs' of 10 gauge Romex run to JENA Labs
'deep-immersion cryo'ed' duplex outlets... all grounded and run with the same
phase.
I have installed the wall panel in such a
way as to allow for easy installation of an EQUI=TECH 10kv Wall Cabinet System
in the future. Rives Audio recommends this approach since it allows for up to a
12dB reduction in noise. This is what Chris Huston specifies for the Pro Audio
studios he designs. For now, the budget won't allow it.
The electrical service to the barn, with
all lights, 'dirty' outlets, and HVAC, is completely separate from the
dedicated panel.
The lighting system for the room consists
of four separate lighting 'zones': one for the media shelves (seven recessed
cans), one for the side diffuser panels and source shelves (two recessed cans
on each side), one for the track lighting just above and behind my listening
position (three halogen spots on each side), and one for the front of the room
above the speakers and front diffuser panel (seven recessed cans). I aim two of
the track spotlights directly over my shoulder at the listening position to give
me great reading light with no shadows. One track spot is aimed at the
turntable position, and the others bring more light to the upper media shelves
for an easy selection of recordings.
Media shelves show lighting
These four zones are tied together with a
Lutron GRAFIC EYE 2404 dimmer control. This allows for four scenes, and all off
and all on, as well as any position in between. It is a totally quiet, very
simple to use control that is programmed into my Philips Pronto remote. I can
dim each zone separately on four different 'scenes' to get just the right
amount of light for every situation. It transitions between scenes very
smoothly.
To me, getting the lighting correct is one
of those 'fine details' that can make the enjoyment of the system much better.
Typically, the front lighting zone is always off unless I am doing cleaning or
setup of some sort. In fact, for serious listening I typically have all the
lights off except two 15 watt 'loose' cans that I put on the floor aimed up at
the ceiling directly behind the speakers. These 'up-firing' lights cast a warm
glow over the front diffuser panel and ceiling and really enhance the whole
musical experience.
I considered the issue of acoustical
problems resulting from all these recessed cans and track lighting. I was
concerned that the ceiling bass traps might cause resonance with the metal
cases of the cans. I had quite a bit of lead tape applied to these cans before
the ceiling was buttoned up to insure it would not become a problem. Once my
system was in the room, the first thing I did was to play a bass 'boom' track
over and over and search for any resonance. I found three of the cans did have
slight ringing from the trim, and secured them. I went around and put my ear
close to each light. In the near future I'll get a more sophisticated low
frequency sweep, to ensure I have found all possible sources of unwanted
resonance.
I anticipate having multi-channel hi-rez
music in the future. To that end I have installed 2" conduit in the
concrete floor for future runs of interconnect or speaker cable. There are runs
to each rear corner, the front center, and front side... and all these runs
meet at a box behind the side gear rack. Also, I prefer my digital transport
near my listening position, so I have another conduit run to a box behind my
listening position, which allows the ST optical cable that connects my
transport to my DAC to run under the floor. This box also has one of the
dedicated circuits included, which runs in its own separate conduit from the
dedicated panel under the concrete floor.
Regarding hi-rez multi-channel acoustics,
it will be slightly compromised, as the ideal rear speaker setup is at 110
degrees to the listener. In my room it will end up being about 130 degrees. To
get 110 degrees would have required a much wider room and would have
compromised the ideal 2-channel acoustics... so the priorities were clear for
me. On the plus side, all the speakers will be equidistant from the listening
position. I may end up with a 'phantom' center channel, as I have my
reservations regarding the true benefits of center channel speakers for music
only. My best multi-channel music experiences have been quad so far. I do have
a separate home theatre in my main house, and don't ever anticipate having film/video
in this room (although it is wired for a front projector and motorized screen).
The Construction process
I have known my contractor for over 20
years, and done maybe 20 work-related projects with him and his crew. That
said, it was a challenge to control the budget and the work pace with so many
unusual aspects to building a listening room. The results have been worth the
effort and expense... but there were times when it was hard to see the finish.
All the acoustical treatments required a big learning curve for my contractor.
In the beginning there were many phone calls between my contractor and Rives
Audio (both Chris and Richard). I was pleased with the level of communication
that went on. On the other hand, I also checked every single measurement and
construction detail for myself. I knew if I wanted to hold Rives accountable
for the final performance, then I would need to make sure that the plans were
meticulously followed.
As with any other construction project I
have been involved with; there were a few places where the construction
drawings could have had more detail. Possibly from the perspective of the
designer they were perfect... but there were areas that were somewhat difficult
to figure out. Over time, as Rives educated my contractor; everything was
figured out and things were put together correctly. Once the contractor was
clear on the 'what' and even more importantly the 'why' of things... the
contractor was able to find the most efficient way of doing things. This is a
normal process with any/all construction projects.
Even if the drawings were not perfect (they
never are) the communication was. Richard and Chris were always available to
answer any questions or discuss any issue no matter when or how long it took.
Many of the methods of solving problems were a result of great input from Rives
to my contractor. Any project like this will require tons of time between the
contractor and designer. Rives was able to suggest sources for acoustical
materials and different possible approaches for constructing the diffuser
panels. My contractor was never 'on his own' and felt very comfortable working
with Rives.”
It did all work; and my contractor did a
great job of figuring out how best to put things together. There were a few
different challenges…
There are lots of fabric wall panels... my
contractor became an expert at building them.
Integrating the windows into the angled
front bass trap was a real challenge. You have a window on the true outer wall
and an angled fabric wall inside it. The contractor disconnected the inner
frame from the window and built a larger window frame with the same angle... it
turned out great.
There was a real learning curve to get the
ceiling to come together and work properly. The construction drawings were
lacking enough detail to get the whole picture. It took many calls and
discussions to nail it down. Again, the contractor had to understand why things
were being done before he could get it done.
The diffuser panels were a challenge for
the cabinet maker... and took much longer to build than he anticipated.
At the two month point, Chris Huston
visited the project. Chris lives in Nashville, so he flew out for an overnight
visit to consult with the contractor and make sure everything was progressing
properly, measure the distances to ensure no problem there, and answer my
questions. It was great having Chris really explain concepts to the contractor,
and get everyone on the same page. Chris was very impressed by what he saw and
excited about the potential of the room.
Spending time with Chris was a treat for
me... we played a bunch of LP's that Chris had engineered, and I loved his
stories about all the 60's music scene. He gave me much deeper insights into
real world acoustics than I had previously understood.
After Chris's visit in early July, it was
mostly a matter of just getting the work done. This project was more than just
a listening room. We were basically finishing an 1800 sq. ft. house. There were
nine windows, five doors, floor coverings, finishing the upstairs hayloft, etc.
etc. There were many delays. Suffice it to say that anything that could take
longer did... about three times longer. Windows, doors, cabinets... they all
took forever. I have no patience to begin with... and this was torture for me.
As July turned into August... into September... I was pretty frustrated. Some
of the delays were controllable, but many were not. The building trades move at
their own pace. I had been through this before many times at work... but had
avoided remodeling at home. The one saving grace was that at least they were
not working inside our home... it was 50 feet away.
Finally, in early October, it was far
enough along I was able to move most of my gear into the room. The side
diffusers, ceiling diffuser panels and front fabric walls were not complete,
but there would be no more staining or sanding done in the room. It was
educational to hear what changes were caused by the different acoustical
elements as they were added.
I had contacted Rives prior to move-in
regarding speaker and listening seat locations. After doing the math, they came
up with 9' 6" tweeter to wall behind the speakers, the speakers 9'4"
apart, and my listening chair 9' 8" from the rear wall. After a couple of
weeks of experimentation and completion of the last element of acoustics, I
ended up fairly close to Rives original positions. The speakers are 10' 2"
tweeter to tweeter, they are 9' 4" from the front wall, and my listening
position is 10' 2" from the rear wall. I am sitting in a near-field
ratio... as my ears are 10' 7" from the tweeters (103% of the speaker width
of 10' 2").
The last big issue was installing my
turntable... which waited until all else was done. I finally reached the end of
my 18 month process of building a new room.
Front of room
Was it worth it?
Yes.
The room is a wonder. It is hard to be
objective about one's own room. From feedback I keep getting, my feeling is
that there is agreement that the room is about perfect... but that everyone
thinks I should get this piece of gear or that... make this change or that
change. I have realized that the room does have one big problem... there is no
place to hide. Any flaw in recording, recording format, performance, speakers,
amps, whatever... that imperfection is exposed for anyone to easily hear. I am
going slowly at this point. For one thing, my budget is blown. But also, it is
time to just listen to music and enjoy... to have friends over to share, and
just get myself back into a normal audio groove. There is no hurry to change
anything.
Richard Bird did visit in early November to
measure the room. I had already been satisfied with the way it sounded... and
had already determined that I wasn't going to get caught up in frustrations
about perfection. And yet, I wanted the room to measure as perfectly as
possible.
Richard was as taken by room as others have
been... then he got out his tools and went to work. Overall, the room measured
very well... in fact, Richard commented that above 134 Hz it was the flattest
room he had ever measured.
No room is flat; all rooms have nodes,
nulls and peaks. In any approximately rectangle room the listener will be
located along the center line of the long axis (for soundstaging purposes).
Along this axis at any particular point, there will be a null frequency and a
peak frequency in the bass. The only way to completely avoid this is to flair
the room 30 degrees or more… which then creates other acoustical problems more
severe than these nulls and peaks. The challenge is to minimize the nulls and
peaks... to make them very mild. In my case I have about a 5dB to 6dB peak at
134Hz, and a 5dB to 6dB null at 80Hz. Otherwise the room is pretty flat up and
down the whole audio range.
If you go halfway between the listening
position and the sidewall, the null flattens and the peak flattens. These are
room issues and not speaker issues. To my ears these are very mild problems.
There are potential cures, but I'm not sure I will EVER pursue them. From time
to time I do perceive a slight wooliness to the mid-bass... but only
occasionally (a very few cuts of female vocal, or maybe a cello recording). If
I focus on what is not perfect I can detect it... but that is not my way.
The other issue is that my speakers do not
go as low in the bass in this room. My previous room was about 1/3rd the interior
volume of this room, and my speakers extended to around 25Hz, pretty flat. In
this much larger room they only go into the mid-30Hz range (the rear ports just
can't pressurize this room to the same degree). It is not a big deal to me, as
the bass is, by far, the best, most articulate bass I have ever heard. I
wouldn't trade the articulation I am now hearing for all the deep bass in the
world. I may pursue remedies in this area... but later, not now.
This was the extent of the 'bad news.'
Richard measured all around the room for frequency consistency... and it is
amazingly flat wherever. There is not a bad seat in the house.
How do I like it?
I'll
finish by saying that I have never been much of a classical music listener, and
almost never to full orchestral works. Why? Because they almost always sound
like crap, or at best not very good... no matter what gear or room I've heard
them in.
Not any more.
It doesn't matter what you play... this
room/system will portray it in its full glory. You want size, scale,
dynamics... it will deliver. Without a trace of strain or fatigue. Each musical
element is fully rendered and complete. You hear musical elements on very
familiar discs that you have never before heard... and they are fully realized.
I have not found ANY full orchestral
recording that this room/system doesn't absolutely NAIL.
A conductor friend (who is also an
audiophile) brought over a few of his own recordings to listen to... now here
is someone with a correct reference. After an hour or so and three or four of
his recordings, he turned to me and said, “Yes, that is the way it was."
That's good enough for me.
As time goes by and I discover more room
truths, I will try to share them with you as articulately as I can... but it is
now time to listen.
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