Thru-the-top soundpost

[Don Noon]

I saw this trick mentioned in another thread on a small viola, and it seemed interesting. This is where you cut a hole under the trebel foot of the bridge, and have it rest on the extra-long soundpost which does not contact the top. I had a pretty poor fiddle that seemed like a good candidate to try it on... Chinese thing that I used for varnish testing; high-density top. The signature modes were in just the right places, but there was some strong stuff around 1000 Hz and very weak "bridge hill", so it sounded ugly.

After conversion, I find the sound much more interesting. It is definitely much less violin-sounding. Unfortunately I didn't keep a spectral data file of the original impact spectrum, but this is generally what happened:

A0 -10Hz +3.0dB

B1- -9Hz +2.7dB

B1+ -7Hz +1.3dB

Additionally, the range up to 2500 Hz appears to be a dB or two stronger, and above that it drops off to be a dB or two weaker.

So the net effect is a stronger and deeper bottom end, a little more midrange power, and less brightness. Sounds like a viola. I might eventually put viola strings on it, but I don't have any right now.

[Johnmasters]

So the net effect is a stronger and deeper bottom end, a little more midrange power, and less brightness. Sounds like a viola. I might eventually put viola strings on it, but I don't have any right now.

So it is definitely a legitimate instrument. The Welsh Crwth has a long treble bridge leg going straight through to the back. The Euyghur* which I illustrated has a region for the post isolated from much of the top. Maybe one should try making such an instrument as a formal experiment.

*Spellings differ, I don't know where to find it in Wikipedia etc. You recall the political flap when three men called Euyghurs were in Guantanamo. The region is Western China in the .....stan areas. I have also seen a photo of a Pakastani street musician playing one of these instruments. It sounds like a soft violin.

[viola_license_revoked]

hello all

i suppose you could say the idea isn't new. it does come up once in a while for discussion.

this mod overcomes the spagetti C string on small violas.

works very well as a 5 string hot rod without having to re-design or build a bigger body.

works amazing well as a baritone violin.

for any fiddlers, jazzers and non-conformists out there, this is the best way to open up a new tonal palette for cheap. its like slapping on a hexacore for the first time.

for classical violinists, 5 strings is the most fun in a few hundred years. but you can't play in the nose bleed positions sul G. (which unfortunately kills the performance of 3/4 of the bleeding-heart violin concertos out there ) classical violists can scream away on the Bowen concerto. the quinton isn't exactly a new idea.

doesn't sound like a violin or a viola really... but very nice and pleasing because it no longer hurts to listen.

doesn't do very well with young or inexperienced musicians because the bridge will shift during tuning and start to buzz against the top.

can be "cured" with a lesson on careful tuning/set up. a hard foam ring can be glued into the hole to reduce the problem

until the next time teacher or luthier gets his or her hands on it for an adjustment.

works best with small thick tops. not so good with thin tops or bigger violas. i want to build this into a 1/16th sized double bass, maybe put in a bass reflex port too. it might do wonders for a Suzuki bass program somewhere. (if it works... home depot here i come!)

but don't take my word for it, i'm no body! try it for yourselves folks, most of us own at least a few vso's don't we?

working on a 6 string with this set up.. will post when ready.

cheers

r

[saintjohnbarleycorn]

violin revoked,

interesting, its sounds like a good idea for an electric violin, they tend to be shrill. Have you done any 5 string electrics?

[go_oa]

As the proud owner of one of the few violas that Stradivari made while in Romania in the 1960's, when the back came un-glued, I decided to do some carving, and ultimately did the Hole in the Heart. It worked very well on a 15.5". It changes the possible mode shapes.

the top is no longer locked by the sound post. So it may permit some different low frequency modes. It is true that the bridge can do alarming things when the string tension becomes unbalanced. And the set-up person can not play with the sound post position, but for a beat up student instrument with no intrinsic value, it can be educational to try some things. I have used my hole in the heart on a couple gigs with no adverse results.

[Wm. Johnston]

I saw this trick mentioned in another thread on a small viola, and it seemed interesting. This is where you cut a hole under the trebel foot of the bridge, and have it rest on the extra-long soundpost which does not contact the top.

Have you tried inserting a thin wedge between the soundpost and the top? It has been written many times that the function of the soundpost is to produce a node on the top, looks like this would be an easy way to test the idea on a functioning violin.

[Don Noon]

I haven't experimented any further with this, other than doing it and checking the response spectrum. Clearly the mode shapes will change, as there is no direct coupling of the back and top thru the soundpost. The change in mode frequencies can not happen without a change in mode shape... barring other changes like regraduation. At the moment, I have some soft foam filling the gap between the soundpost and the edge of the hole, to help keep the post centered. It might be adding some stiffness and damping, but I don't expect it to be much.

With this little diversion, and messing around with Stuart's CF creation, I haven't been getting much done on #5 and #6 lately; I want to get back to work on those before playing around with more experimental things.

[Anders Buen]

This is a principle used in the Chrotta: http://www.klangwerkstatt-musiktherapie.de...nte/chrotta.htm

Interesting to see the results of the changes as Don showed. A musician friend of mine has a violin that originally was designed with the bridge foot resting on the soundpost. I have also investigated a violin design with such a soundpost, but it was attached to a bar system inside the instrument intended to take up much of the string tension and helping the instrument act like a monopole. Some results were shown in this article (my first): http://www.akutek.info/Papers/AB_Deflection_modes.pdf

Here is a clever method of measuring the radiation efficiency on a naormal violin and a later version of such special violin. www.nvo.com/winmls/nss-folder/musicalacfiles/ICA_ArticleMorset.doc

According to Knut Güettler, the system worked better for the viola design of his.

[Anders Buen]

One early version of Hagetrø's violin now on the Ringve museum in Trondheim Norway: http://digitaltmuseum.no/BigImageContent.d...mp;imageIndex=0

He patented it in 1977. More text (unfortunately only in norwegian, use Google translator if interested): http://digitaltmuseum.no/things/thing/RMT/RMT%2077/8

[viola_license_revoked]

violin revoked,

interesting, its sounds like a good idea for an electric violin, they tend to be shrill. Have you done any 5 string electrics?

hello saintjohnbarleycorn

i use my instruments primarily as acoustic rigs, but yes, i remember setting up 2 5-string acoustic/electrics. both were given away and i used these pick-ups glued to the inside of the back: http://windworld.com/products-page/electro...re/piezo-films/ it helps with the shrill quality with most metal/hard piezo pick-ups . i've used schattens from stewmac (link here) in the past, but i wanted something a little more mellow. unfortunately, i chose the 6 inch films and they were too hot and acted more like microphones sometimes. still, a jazzer violinist friend of mine didn't object and used it on a gig the day i gave it to him... brave soul...

presently, i'm still coupling the soundpost to a modified bridge with a steel pin made from a large sewing needle. i hope to make purpose built bridges next time and embed a piezo pick-up right into the bridge. I have spoken to LR Baggs a while back and they told me they do custom installs, but i really want to figure it out for myself a pre-amp or EQ will help with the shrill.

a purpose built bridge will also help a little with the nagging premonition of a bridge snapping in half at a gig. the baritone violin vibrates quite violently. we'll see if it holds together for another year.

the overtones from these mods light up my harmonic tree in a very different and strange way. i don't think of them as violas but some sort of musical instrument that requires playing techniques related to the viola family.

r

[Raven Hawk]

I intend to build a violinish object that will have a very tall bridge resting on a cedar/fir back through an oval sound hole with a stop tail piece on a cedar/fir top. I don't know if anyone previously has experimented with this configuration but I thought I'd try it... I might even incorporate a concave top.

Rick

[Medicine Madison]

I have a cheap, factory made violin. I am not a luthier, but I still started modifying it, because a luthier charges more than the instrument is worth - this being said, a handmade instrument should always be fixed at a luthier but this is just a cheap instrument. The varnish was furniture varnish and it made it sound nasal. I took the varnish off and changed the shape of the bridge and it does sound better but I would like it to be darker and more mellow in tone. Could this idea be applied to such an instrument, and if so, should I open the instrument despite having no clamps to close it back on? Is it any way I could do this adjustment without having to open the violin? Thank you.

[go_oa]

My super cheep viola ($70 in 1963,  but hey that included a case!  -  was coming unglued, so, as long as it was open, why not carve a little.  After reassembling, about 100% better.  Then later I heard about 'Hole in the Heart'.  Drilled a hole and cut a chopstick as an extension - About 100% improvement.  

 

So you have a VSO.  Are you willing to value it at $0.00  and trust yourself to do something.  Whatever happens - you will learn things about yourself and violins!

[Marty Kasprzyk]

If you put the hole and sound post on the treble side you get stronger lower notes (dark sounding).  If you put the hole and sound post on the bass side you get stronger high notes (bright sounding).

[Oscar Stern]

The principle behind this is based on the Welsh Crwth (Bowed Lyre) where the Bass bridge foot goes inside the soundhole & rests on the back

[Oscar Stern]

The Hutchins Upright Viola works around the playability issue of the Bigger Violas by reorienting the instrument to be played Vertically like a Cello, which means the sound will project towards the walls, but still the Hole in the Heart technique might help improve the sound of those low notes even more.

[Oscar Stern]

Here's what I mean by that. This Stringers Viola Conversion for example has the Treble Bridge foot attached directly to the sound post, it goes down the hole & rests directly on the back.

[Don Noon]

 

On 3/28/2023 at 5:29 AM, Oscar Stern said:

The Hutchins Upright Viola works... but still the Hole in the Heart technique might help improve the sound of those low notes even more.

As I observed in the first post of this thread, 

On 10/11/2010 at 6:38 PM, Don Noon said:

the net effect is a stronger and deeper bottom end, a little more midrange power, and less brightness.

You can deepen and strengthen the low end with a larger body like the upright viola, or the thru-the-heart post will do some of the same thing.  Doing both will undoubtedly do even more... but "improve" is questionable.  It's all a matter of balance and personal taste, and it can be taken too far.

[Oscar Stern]

This is to help remove the Compromises that Violas have so that they have the same resonance as the Violins & Cellos which will give them more attention than before. The Crwth has a Long Bass bridge foot that goes down one of the sound holes & rests directly on the back. So what if Double Basses used the Hole in the Heart design to make the just as resonant as Violin & Cellos.

[SCorrea]

Ok, new guy here asking a question because this is interesting and I don't know any better yet.

Is this an alternative repair process for a sound post crack?  It seems like this may be viable on low value instruments that may not be worth the effort to fit a proper patch.  Just thinking out loud, so be kind.  Also, it seems like actually moving the sound post gets trickier, with the potential for a column failure if things misalign, so if you open the hole in the plate to get repositionability, do you glue the bridge to the sound post after you find where it sounds good?

Thanks. 

[Arsalan]

On 10/11/2010 at 6:38 PM, Don Noon said:

I saw this trick mentioned in another thread on a small viola, and it seemed interesting. This is where you cut a hole under the trebel foot of the bridge, and have it rest on the extra-long soundpost which does not contact the top. I had a pretty poor fiddle that seemed like a good candidate to try it on... Chinese thing that I used for varnish testing; high-density top. The signature modes were in just the right places, but there was some strong stuff around 1000 Hz and very weak "bridge hill", so it sounded ugly.

After conversion, I find the sound much more interesting. It is definitely much less violin-sounding. Unfortunately I didn't keep a spectral data file of the original impact spectrum, but this is generally what happened:

A0 -10Hz +3.0dB

B1- -9Hz +2.7dB

B1+ -7Hz +1.3dB

Additionally, the range up to 2500 Hz appears to be a dB or two stronger, and above that it drops off to be a dB or two weaker.

So the net effect is a stronger and deeper bottom end, a little more midrange power, and less brightness. Sounds like a viola. I might eventually put viola strings on it, but I don't have any right now.

Don the bridge foot rest directly on the sound post ? Is that what you meant ? 
thanks 

[martin swan]

On 6/27/2023 at 1:36 PM, Oscar Stern said:

Here's what I mean by that. This Stringers Viola Conversion for example has the Treble Bridge foot attached directly to the sound post, it goes down the hole & rests directly on the back.

Do you ever read any of these threads you comment on?

[Wood Butcher]

Seems to have been on a mission, to revive threads which are multiple years old. This must be about the tenth one.

[SCorrea]

3 hours ago, Wood Butcher said:

Seems to have been on a mission, to revive threads which are multiple years old. This must be about the tenth one.

Youre right ill check the original post date. Thanks for the pointing it out.  Sorry Guys

[Marty Kasprzyk]

Since the original 2010 original post by Don noon I've made about three dozen violas and violins with the "through the top soundpost".

I now believe this is a better design than the traditional bridge-top plate- soundpost and that it was an unfortunate mistake 500 years ago by the Italian violin inventors not to adapt the Welsh Crwth  soundpost design shown in Oscar Stern's recent Sept 7 photo posting.

Several Crwth features should be noted.  The the top plate is flat and bridge is flat and low and there is no C bout cut outs so individual strings could not be bowed.  The string angle over the bridge is very shallow.  This is similar to the violin's medieval ancestors.  The violin family originators raised the bridge and made it curved so individual strings could be bowed and the C bouts were cut out to give bow clearance.

The increased bridge height made the string angle over the bridge more acute which increased the downward load on the top plate.  The top plate was then changed from flat to an arched shape to better resist the downward string load. I believe the bass bar and soundpost were added to further resist this string load.

One consequence of the arched top plate and sound post is that they stiffen the top plate thus raising all of its vibration mode frequencies which is ok for violins where a high pitch range is desired, however for a viola (and cello, bass) a much lower pitch range is desired.  

A lower pitch range could easily be obtained by simply making the plates larger thus the early violas, cellos, and basses having arched top plates were quite large.

An alternate way of getting a lower pitch range would have been to use the Crwth's flat plate and "through the top soundpost".  Since only one bridge foot rests on the top plate the downward string force on it is only half the amount thus the arching can be much shallower which helpfully reduces the vibration mode frequencies. The "through the top soundpost" also eliminates the stiffening effect of the traditional sound post which further reduces the mode frequencies.

These enable much smaller and lighter instruments to be made which is especially important for violas where stress induced player injuries are common.

I had first thought the Crwth's design wasn't suitable for violins but I found that a flat plate could be stiffened with many internal braces such as guitars use and that a traditional violin's signature modes such as A0, B1-, B1+ could be duplicated and that the high frequency 2000-4000 "bridge hill" is also obtainable.