The sleeping, blanketed
brick is thus constrained in every direction, acoustically
isolated, mechanically cushioned, and electrically locked into
submission, and consequently, must be awakened with a strong kick
from powerful amplification. So a few hundred watts of
feedback-controlled power amplifier may not even be enough. It may
take totals of a thousand watts of bi- or tri-amplification, to
awaken some of the sleepier overgrown bricks.
Anyone with trained or
experienced ears can tell you that virtually any music
playback construction has its own sound -- whether a messy euphonic
color-generator, or an overdamped lockdown from which lifelike
sounds can never bloom.
It would be false to claim
that my approach here to speaker systems is 1oo% a refutation of
the 'locked-down-brick' school of high end loudspeaker. Because the
truth is that this level of build overkill and coffin-like
cabinet-making is very much beyond my skills and resources anyway.
Because half the approach here is that of necessity, there will be
no huge table-saws, cnc-cutting, routering, vacuum-clamping
stations or ovenbaked finishes; there will be no eight-foot sheets
of materials, no inch-and-a-half thicknesses of anything. Because I
have no experience with those procedures, no real competence with
those materials, and just don't have any of that on hand.
But there should be no
mistake-- fifty percent of the approach is still is the idea that
amplifiers with full harmonic qualities but lower wattages should be
able to drive reasonably efficient speaker systems, in
well-thought-out cabinetry that is light and rigid. Like a cello's
sound box, strutted and braced with numerous site-specific ribs and
crosspieces each designed to their own purpose, each reinforcing the
overall integrity of the whole.
Since I knew that these
wouldn't be the last enclosures for my new/old Tannoy dual
concentrics, I had the idea that the first efforts might just be the
right time to try something adventurous. I had the idea that
lightweight construction-- but with fairly sophisticated bracing --
might be an approach to good sound that wouldn't deaden the harmonic
bloom, or discourage lively pacing & poise in the time domain.
Perhaps I could sidestep the curse of the hibernating bricks.
As a first look into the
world of the Tannoy renaissance, I had read the indispensible
TannoyMania by Harvey Rosenberg. My thought was that soon
enough, my Tannoys would evolve into a Transmission Line effort, and
eventually, a Back-loaded Horn enclosure, but like any completely
new project with its own learning curve it might be best to start
with something simpler. So why not first try some simple boxes with
walls intact, as with 'infinite baffle' types, and live with those
for awhile. Not too further down the road, 'bass reflex' ported
boxes could be the next effort.
Well on the way by now, I
ran into an article on the Hans Hilberink Tannoy Monitor Gold©®™
site, that mentioned the phrase 'torsion box' ... an
interesting approach that accomplishes a large, braced enclosure
that isn't life-threateningly overweight. But this version
apparently required a serious wood shop. So I promptly looked
elsewhere, in that such cabinet work was beyond my resources here.
My "resources" in the woodworking department, it should be
mentioned, are best described as budging the needle just beyond
zero. I knew for a fact, for example, that building any rectilinear
box of 12" speaker scale with perpendicular walls and accurate
joinery was pretty much beyond my range of capability. But that
really couldn't be the end of the story.
Because the storyline I'm
sticking with is that you should extend all of your budget into the
part of the system you can't manufacture yourself, ie the raw
speaker drivers -- and moving along in time you'll be able to build
cabinets of increasing sophistication and/ or eventually settle on
original Tannoy or custom carpentry. This should ensure an
ongoing baseline of playback integrity, with each new
level enlarging the frame, validating that those expensive drivers
are expanding their capabilities.
So, I'd have to do a bit of
range-finding, taking various stabs at under- and over-building some
small-box woodworking, like transformer or powersupply boxes and
chassis projects, and I did just that.
The dull glow of limited
success illuminated a path, a way in through the kitchen door, just
for me. If I couldn't reliably make razor-straight cuts or mitered
edges or ninety-degree corners, I'd just have to order some in from
the outside world.
Since purchasing custom-cut
panels of virtually any woods or plys was an expensive invitation to
fouling the joinery (I knew without trying), I hit on the
hollywooden idea of using stand-ins for the real
thing. All that was required, really, were inexpensive,
uniform, and relatively square wooden forms around which I could
construct my cabinetry.
Before I go on, it should
be apparent that I had absolutely no qualm or uncertainty that my
Tannoys might sound their best in a matched set of Westminster
Royals -- or Canterburys -- or Churchills or Glenairs, for that
matter. It's just that the raw drivers are so ridiculously
expensive these days, and the first couple of cabinet renditions to
house them would have to be conscious of my budget. As in: no
budget at all for cabinets, due to the budget having been spent
entirely on the perfect vintage speaker drivers.
A long road to get to this,
but that's the way some of this do-it-yourself audio goes; a couple
of eventual days of execution, preceded by months of figuring
out your own peculiar strategy. And that road came to a
halt outside my local wine-merchant's premises. Not the shop,
exactly, which was also a help in its own way, but outside, at the
Dumpster.
Where I found stacked,
higgledy-piggledy, a dozen or so average wine crates. It was the
holidays, and they were moving a lot of product. The crates are
made of low-grade boxwood but displayed exactly what I didn't have
-- reasonably square ninety-degree corners, clean edges, and a
workable, building-block size & scale appropriate to speaker cabs.
These could be tacked together to obtain the shape, used to build
the cabinet forms around, and then knocked apart from within and
discarded.
As I thought further about
the idea, I noted that these stand-ins were themselves capable of
transporting twelve bottles each, somewhere between thirty and forty
pounds in total, across international distances, and had proven
themselves over hundreds of years and still counting. Although they
were in many respects contrary to loudspeaker objectives (resonant
and flexy, non-rigid) they might endure the trial run to provide
more than just temporary forms, and could be used as skeletal
frames, once glued, strutted, braced and then mass-relieved via
cutouts, to create an internal bone-structure on which to build
outwards ...
So at least there
was something of a roadmap, an itinerary of maybe-yes maybe-no
experiments to make, none of which involved completely closing the
door on future versions, and none of which required much in the way
of expenditure.
We were on our way toward a
landing. We know you have many choices of speaker enclosure
strategies, and we congratulate you on choosing the cheapest seats
in the house.
Next, let's revisit that
Torsion Box idea ....
02-2010.
Intro