Archtop Bridges on Flat-top Acoustics?
Giri Iyengar
Yet another question.
I've seen a few guitars with an archtop style bridge (the strings go over
the saddle and on to a tailpiece that's attached to the tail-pin) with
the strings pushing down on the top instead of pulling up. Dupont's
Macaferri (sp?) style guitars have that, as well as Manzer's classical
guitar.
Simple question: Why? Or if not, why not, for that matter?
It's an interesting look for sure, but what difference, if any, does it
make to the sound of a guitar?
Thanks again, O wonderfully informative group.
..Giri
Charles Tauber
Giri Iyengar wrote:
>
> Yet another question.
>
My, you ARE full of questions: the sign of a fertile mind, perhaps.<g>
> I've seen a few guitars with an archtop style bridge (the strings go over
> the saddle and on to a tailpiece that's attached to the tail-pin) with
> the strings pushing down on the top instead of pulling up. Dupont's
> Macaferri (sp?) style guitars have that, as well as Manzer's classical
> guitar.
>
> Simple question: Why? Or if not, why not, for that matter?
From one perspective, arch top guitars can be viewed as a 'cello body
fitted with a guitar neck since many of the construction and design
features of the arch top are borrowed from the violin family. As you
probably already know, the plates (top and back) of arch top guitars are
considerably thicker than steel string and classical guitars, and are
consequently braced much differently. In addition, the use of the 'cello
style tailpiece supports the axial string tension so that the only
a relatively small downward component of the string tension is exerted on
the top via the bridge. In short, an arch top guitar is a very different
animal than a steel string acoustic guitar or classical guitar.
Thus, the use of a tailpiece negates the need for much of the top
bracing, and certainly the bridge plate on steel string guitars. Without
the same driving force of the strings pulling directly on the top, as is
the case with an arch top bridge, using a standard classical or steel
string bracing would likely sound rather dead. To make full use of the
tailpiece/arch top bridge arrangement would require rather a different
top bracing arrangement.
>
> It's an interesting look for sure, but what difference, if any, does it
> make to the sound of a guitar?
That, of course, would depend upon what you did on the *inside* - the top
thickness, bracing arrangement, etc. If, for all intent and purpose, you
simply added a tail piece and arch top bridge to a steel string or
classical guitar, it would probably sound quiet and fairly dead.
>
> Thanks again, O wonderfully informative group.
> ..Giri
Charles
Chief Noda
giye...@aec004.ve.ford.com (Giri Iyengar) writes:
>I've seen a few guitars with an archtop style bridge
I think it's called a floating bridge, by the way.
>the saddle and on to a tailpiece that's attached to the tail-pin) with
>the strings pushing down on the top instead of pulling up.
>Simple question: Why? Or if not, why not, for that matter?
I can't offer why but would like to point out a difference. With a fixed
bridge, the strings pull the bridge up. With the floating bridge, the strings
push down the bridge. Arched top is structurally very resistant to the force
pushing it down (compared to a flat surface) and can be made very efficient.
OK, so why? ANyone?
Chief
david_means
In article <51mpn3$c...@eccdb1.pms.ford.com>, giye...@aec004.ve.ford.com says...
>
>Yet another question.
>
>I've seen a few guitars with an archtop style bridge (the strings go over
>the saddle and on to a tailpiece that's attached to the tail-pin) with
>Macaferri (sp?) style guitars have that, as well as Manzer's classical
>guitar.
>
>
>make to the sound of a guitar?
>
>..Giri
Giri,
Off the top of my head, I would say that one difference would be in the way
the strings' vibrational energy is imparted to the top. With a tailpiece/
bridge setup, the strings' vibrations would be translated into a strictly
up and down vibration of the bridge, driving the top more as a uniform piston
(except possibly at some resonant frequencies). With the typical flattop-
type bridge configuration, I would think there would be additional modes
creating a more complex vibrational pattern in the top. For example, as the
string vibrates, its instantaneous tension increases and decreases during
each vibrational cycle. Unlike on the "archtop"-type bridge where this
simply contributes to the up/down motion, on a flattop-type bridge the change
in string tension would impart a "rocking" motion, tending to pull the part
of the soundboard above the bridge down during the part of the cycle when the
tension increases, and pulling the lower part of the soundboard up at the same
time. The opposite would occur during the reduced-tension part of the cycle.
Therefore, I would think that there would be at least a component of the
total vibration of the top that is 180 degrees out of phase, imparting a more
complex waveform to the air displacement that occurs directly off the top, and
thereby affecting the timbre.
I don't have any research to back this up -- this hypothesis is stricty
intuitive.
Dave Means
dme...@fcc.gov
David Newton
Separate this bridge-group into two camps. The "it"s because it is cheaper
and easier" group; Stella, Harmony, et.al. This group sounds just ok.
Cheaper wood, less developed bracing and looser tolerances on neck angle
and scale length. I think the BLUES was invented in Chicago so harmony
and stella guitars could sound good.
Of course the other camp is the "really an archtop guitar camp"
sincerely, dave.
W.D. Cutlip
giye...@aec004.ve.ford.com (Giri Iyengar) wrote:
>Yet another question.
The sky is full of questions.
>I've seen a few guitars with an archtop style bridge (the strings go over
>the saddle and on to a tailpiece that's attached to the tail-pin) with
>the strings pushing down on the top instead of pulling up. Dupont's
>Macaferri (sp?) style guitars have that, as well as Manzer's classical
>guitar.
>Simple question: Why? Or if not, why not, for that matter?
A different sound, maybe a better sound for some genres. Ever hear a
samba played on a dreadnaught? Gimme a break! I'd bet the overall
intonation is easier to tweak, too. That would be worth something to
me, dude.
>It's an interesting look for sure, but what difference, if any, does it
>make to the sound of a guitar?
William Cumpiano says in "Guitarmaking: Tradition and Technology" that
the entire structure determines the sound of a guitar, and not just
the top wood and bracing scheme. By anchoring the strings to the heel
block, I think you'd get more total body resonance -- more of the
tonal qualities of the neck and back/side wood.
(Want to know what that's like? Get a stick-em-on pickup like a Dean
Markley Artist -- the world's cheapest -- and use mastik to mount it
on the neck, back, sides et al while monitoring it through an amp or
tape recorder. There are some good sounds in there. I'm thinking about
mounting a piezo pickup under the nut, and mixing it with one mounted
under the saddle. Anybody out there tried this?)
And speaking of bold experiments, ever seen/heard the Sexaur Coo'stik
Dominator, a jumbo F-hole archtop-bridge/flat top thing? This is right
up your alley, Giri. The archtop bridge puts less stress on the top --
it sez right here -- and yet the neckset and bridge line (to my eye)
presents a pronounced angle of incidence, meaning a lot of top
movement and body resonance. People who know say this is a warm, loud,
full sounding guitar. Looks good in the Elderly catalogue, anyway...
Which reminds me: Ever wonder why Santa Cruz puts that extreme neck
set and tall, tall saddle in their guitars? Big angle of incidence,
right? Sounds great, but don't those bridges split eventually? Are the
laws of physics in abeyance here?
Just curious.
P.S. Why is a banjo not like an onion? Because no one cries when you
cut one in half.
P.P.S. Why did Willie Nelson cross the road? To sing a duet with a
chicken.
P.P.P.S. What is the definition of a gentleman? Someone who knows how
to play the accordian but doesn't.