The virzi effect

[littlemoe]

Ok Ive played quite a few mandolins with virzi's in them and im hearing a consistent characteristic that Im really enjoying. The question is how does one virzi an instrument thats already built. Is there another technoligical breakthrough that any luthiers have discovered that has a somewhat virzi effect on an instrument? And without taking apart. Ive heard some things people have tried that they claim worked, but Im waiting to see if anyone else on here mentions it before I post it and sound like a absolute dork. hahaha. Also does anyone know if a virzi has ever been installed inside of a acoustic guitar?

Monica

[danb]

Some Loar L5s have them, yep

You can retro-fit a virzi.. pop off the back and in she goes!

[littlemoe]

Thanks Dan B,

Any suggestions on how to get that sound without takin the back off? Maybe I'll throw a table coaster in there hehehe.

Mon.

[JEStanek]

I think the bluegrass version is rattlesnake rattles tossed inside the mando. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

Jamie

[sunburst]

Dave Cohen did some measurements of top movement with and without Virzi. His conclusion was that it did very little that could be measured, and the added mass was probably a large part of what it did do. (That's what I got from reading the results, anyway.)
With that in mind, adding about 15 or 16 grams (approximate Virzi weight) to the center area of the top could have a similar affect. That's about like having two bridges, in terms of mass. Sticking a weighed lump of modeling clay or two here and there might confirm whether or not that would make a similar sound change.

[danb]

sunburst, I'll bet you a beer that a lump of modelling clay the same weight as a virzi will *not* make that sweet sustain and throaty tone http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[danb]

So suburst tell me, which side of the virzi debate are you on http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[Gail Hester]

I just put a virzi in an F4 I'm building and after extensive tapping before and after installation, there is way more going on than just weight. When I hold it up to my ear with the virzi, there is an extra something there. I can’t prove or describe it scientifically but it is a completely different sound with and without. More on that when it’s strung up. In addition, it looks really cool through the oval hole. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[sunburst]

So suburst tell me, which side of the virzi debate are you on http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif
Both, neither, don't know...

I don't think it's either/or. If ya like 'em, ya like 'em, if ya don't, ya don't.
Do I think they make a mandolin sound different? I don't know. I'd have to hear a bunch of mandolins with Virzis in and out to see if I hear a difference.
Do I think there's more going on that just added mass? Probably. Even if the lumps of clay made a difference, they wouldn't be attached in the same place, they wouldn't affect the air in the mandolin the same, who knows?
Do I personally like Virzis?, Not really. I don't think they contribute anything good to the mandolin sound that I prefer and try to build.
Would I try them in my mandolins? Sure, if I had time for the experiment. That would probably be the best way to tell if they make a difference in sound; put them in something I'm familiar with.

[Gail Hester]

I don’t think I would put one in an F-hole instrument but I decided to try one in an oval hole because of the reputation of some of the old F4s, F2s with virzis, including Loar’s personnel F2 with virzi. #I do hear a different sound coming off this virzi.

[littlemoe]

Does that rattlesnake idea really work? perhaps to some extent? I have actually heard of players doing this before

[Darryl Wolfe]

Virzi-shmerzi http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[glauber]

Does that rattlesnake idea really work? perhaps to some extent? I have actually heard of players doing this before
Yes, it's effective against evil-eye and other forms of witchery.

[JEStanek]

Glauber, I'm gonnna put a spell on you! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

Jamie

[John Ritchhart]

Virzi notes and lacquer coats
and rattler's tails are lively.
A bone nut is lively too,
if the grass is blue.

[Alex Fields]

Someone asked Mike Compton at Mandomania (at Merlefest) what the rattlesnake rattler did...he shook his mandolin around for a few minutes and said "not a damn thing."

[danb]

Well I hear a big difference with virzis. To my ear, it takes "janglies" out of the tone, makes it more pure on the fundamental or low part of the note. It makes the sustain ring longer, and also takes some of the aggression out of the attack. I have a virzi'd A4, and it has the deepest tone (more bass in the note) than any oval hole I've had. The one I had without a virzi was very nice as well, but this one with the little inverted coffee-table just seems to cast a spell on me.

And a friend had a rattlesnake rattle in an F2 for years.. it makes a slightly buzzy sound, as you might expect. I thought it would sound.. well.. dumb.. but it wasn't really a negative. Just was in there buzzing a little. Sort of like a distant snare drum..

[sunburst]

makes it more pure on the fundamental or low part of the note. It makes the sustain ring longer, and also takes some of the aggression out of the attack.
That's a about what I would expect adding mass to the top would do.

Dan, do you have a Virzi and a rattle snake rattle in any mandolins? Might be a good combionation! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[Eugene]

Long before the Virzi was used in Gibson, de Meglio of Naples was doing the same thing...only they didn't call it "Virzi."

[danb]

No, I don't have a rattlesnake rattle http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mad.gif

The thing about this virzi is that it adds something quite palpable to the tone, but it's not very easy to describe it. When I hit a note, and mute it though the soundhole, it sounds almost exactly like my non-virzi snakehead.

Here's my best attempt at putting it all into words.. To my ear the old F mandos in general (1922-1940) have a dry or woody sound, by which I mean that there is a very clear low knocking sound when you pick, similar to the sound of thumping the box itself, a sort of "thunk" in the note. I used to describe it as someone knocking on a door. A really hot fern or loar adds punch (high end on the attack) to that and sounds like the archetype bluegrass chop.. I think of Bobby Osbourne recordings, or Bill Monroe's chops.. the ones with the virzis add resonance in that part so that instead of a fast attack/decay it holds the note longer, almost like adding a bit of selective reverb on the mid-range.

Loars are all about the mid-range, but with a nice perceptable "thunk" when you chop chords. A virzi changes that into "Tunnnggg" and makes the single notes much sweeter, rounder, to my ear. Maybe that's something we should demonstrate the next time we have a couple of these things in one place http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

ON the A-model, it makes the notes deeper, sounding half-way between a snakehead and an F5. More sustain on the notes too. no really noticable drop in volume overall, though the high register is less pronounced.

[danb]

A lot of people think my virzi a4 is "The best oval hole they've heard", but it doesn't sound like an oval hole to me. People who say that tend to prefer the tone of an F5 to an oval-holed Gibson.

This virzi snakehead is about 3/4 of the way towards an old f5 sound.. the difference between a teens F4 and a snakehead is less pronounced to me than the difference between a virzi and non-virzi snakehead. It sounds like a mellower F5 maybe?

I can only really babble about this stuff I guess. Maybe this is a better way to demo it:

Sound Clips:
71261 1922 snakehead, NO VIRZI, varnish/sheraton brown (http://www.mandolinarchive.com/sound_clips/71261_scotland.mp3)
81564 early 1925 snakehead, VIRZI, varnish sunburst with lacquer topcoat finish (http://www.mandolinarchive.com/sound_clips/81564.mp3)

Both are set up with medium action, j74s. I'm using a thinner pick than most of y'all, a clayton ultem .72mm. Mikes are paired AKG C1000s (which will invalidate this test for km184 lovers!). Mikes 18" away, one aimed at the neck/body joint, one aimed just below the bridge bass side. no eq.

Pictures:
71261 pictures (http://www.mandolinarchive.com/gibson/serial/71261)
81564 pictures (http://www.mandolinarchive.com/gibson/serial/81564)

[danb]

Turn your speakers way up, and make sure you have adequate bass response on the playback to really catch the subtlety here.. this would be better heard on your stereo, I think I did these mp3s in 196k which should be pretty good for reproduction. The sound of this is pretty close to what I hear, maybe a little more trebly than it should be

[Martin Jonas]

Long before the Virzi was used in Gibson, de Meglio of Naples was doing the same thing...only they didn't call it "Virzi."
Eugene, do you mean "Ceccherini", or are there any de Meglio instruments with a second top, or other Virzi-like tone producers?

Martin

[evanreilly]

There are apparently some violins floating around with the Virzi installed.

[johnbaxter]

Here's the archive on the Virzi discussion that was part of the CoMando Guest of the Week series.

http://www.mandozine.com/resources/virzi.php

[Ken Waltham]

I have an F2 with a Virzi, and I agree with Dan in one point...
It does sound closer to an F5 than my other oval hole mandolins without Virzi. It is less hollow, and more focused. Is it the Virzi, or just the F2? I have no way of knowing, but it is different, and I prefer it over my other oval holes. Dan, it does have more bass, too.
This could also be exactly what some oval hole players would NOT want, I guess, but, I really like it.

[steve V. johnson]

Most interesting...

Could someone point me to a drawing or pictures of what this device really is and how it's made/attached, etc. ?

Many thanks,

stv

[grandmainger]

There you go:

http://www.mandolincafe.net/iB_html/uploads/post-7-97860-dude48.jpg
and details:
http://www.mandolincafe.net/iB_html/uploads/post-7-28958-virzii.jpg

More info can be found on many virzi-related threads from the Builders section of the site (http://www.mandolincafe.net/cgi-bin/ikonboard.cgi?act=Search&CODE=02&SID=44687c2716e5b801) http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

Germain

[danb]

There are apparently some violins floating around with the Virzi installed.
I have a Gibson virzi fiddle catalog.. never tracked one down, but Roger Siminoff has Lloyd's concert viola (bigger than a viola, played with a pin like a cello) that has one. I have pictures at home.. virzi hangs off the bass bar and is banana shaped.

I also have an endorsement letter from various eminient players circa '20s.. Jascha Heifetz claims to have put a virzi inside "the violin" (the david!?!?) on it. I've tried to contact the caretakers of this instrument to confirm/deny that, but have made no headway. Anyone know of top-end violin repairmen who have worked on Guarneri? at least half a dozen listed in that letter from Loar as endorsers/users in their Guarnerius instruments.

[Dave Cohen]

"So Sunburst tell me, which side of the debate are you on?"

What debate? #And why does there have to be a debate? #Quite a number of people seem to think that they can hear a difference between a mandolin with a Virzi in it and one without. #I see no reason to dispute that. #I will say that unless those observations can be repeated and verified by essentially any impartial observers, they remain anecdotes and nothing more. #I also will point out that experiments can be done to shed some light on the "debate". #An important experiment would be to have a number of Virzi'd and non-Virzi'd mandolins played to blindfolded listeners. #But despite my own empiricist leanings, the fact remains that Danb and many others are convinced that they hear a difference. #I am inclined to take them at their word on that. #The fact that I don't hear a difference may be a contrary anecdote, or it may reflect the limitations of my 61 year old ears...or both.

My own experiments do _not_ say that there is no audible difference between a Virzi'd mandolin and a non-Virzi'd mandolin. #But they do say that the differences in body mode frequencies and air resonance frequencies are few and likely unimportant. #Specifically, in 2005 I found that the Virzi had essentially _no_ effect on the frequencies of the main body mode or "trampoline" mode (known as the (0,0) mode) #The Virzi did tend to lower the frequency of the (1,0) or sideways rocking mode of the top plate. #That mode, howwever, is not associated with air pumping in either f-hole or oval hole mandolins. #In essence, the trampoline mode is responsible for most of the sound radiation at lower frequencies, and most of the higher body modes (including the sideways rocking mode) color the resulting sound of an instrument by contributing to energy losses. #Imo, that _does_ leave the door open for some coloration of sound by the Virzi, though any effect is certainly subtle.

As to Loar's contention that the Virzi allowed the air column to vibrate at different frequencies in harmony with the body of the instrument, I just didn't see any evidence for that. #I measured the first three air resonance frequencies of a number of vintage mandolins early in 2004. #Most were ovals, some with Virzis and some without, but one 1924 F5 (sans Virzi) was included in the mix. #I also measured the first three air resonance frequencies in my test mule mandolin in 2005, both with and without a Virzi. #What I consistently found was that the Virzi had no effect on the frequencies of the first two air resonances, but did raise the frequency of the third air resonance by a few hundred Hz. #From the standpoint of sound radiation, that is probably _not_ a good thing, but again, it leaves the door open for some sound coloration due to losses. #That sound coloration may be just the thing for some people, and worthless for others.

To sum up, my results do not and can not say anything about what is "good" and what is not. #They do say someting about what the mandolin does as a mechano-acoustic object, i.e., "how it works". #What is good news for some, and probably bad news for others, is that (at least so far) the mandolin doesn't violate the laws of classical physics.

[Jerry Byers]

This is an interesting dialog - I'm curious about this device. In layman's terms, does the Virzi act as a sail in the sound chamber that imparts energy back to the top plate?

[Darryl Wolfe]

Well, I was not going to comment, but

Whether you like them or not, there is no question in my mind that they DO something to the mandolin. #Having removed two Virzis myself, and having close familiarity with two other mandolins before and after Virziectomy, they certainly did not sound the same after removal. #In all four instances the mandolin "appeared" to sound louder and in all four instances there was a more clearly focused tone that no longer had some sort of hum like overtone or vibration.

[danb]

yes, and I can change the tone fairly dramatically by muting it. It does something other than just act as a mute/weight as some suggest

[Darryl Wolfe]

But, on the flip side, can I with absolute certainty tell whether a Virzi is present or not in a single mandolin taste test, the answer is no. Being handed two instruments one with and one without and chosing the the Virzi'd mando, probably, but not always.

[danb]

I see Dave's comments and I think that there is something just not being captured in the measurements. I think those descriptions assume it's just adding mass. How about one with a virzi in it muted and unmuted.. check the fourier graph or something.

I'm not technical in acoustics and I agree that it should be measurable and reproducible, but saying they have no effect flies in the face of common sense to me.

[Dave Cohen]

I don't know if these are layman's terms or not, and, "lay" with respect to what"? At any rate, I see no evidence that a Virzi acts as a sail, and it certainly does not impart energy back to the top plate.

If you want to get some feel for what is happening, Tom Rossing wrote a series of three articles on the physics of guitars for lay persons and luthiers in American Lutherie. They are now collected in "The Big Red Book of American Lutherie", in the 2nd volume, iirc. Availabe from the GAL, or possibly at larger libraries in your neck of the woods.

[littlemoe]

So anything I can do to put this in my mando without tearing the back off? anyone up for the challenge? Dan? hehehe

[danb]

Dave, all I'm saying is there's a noticable change when I strum it and then touch/mute it without disturbing the top or strings. I think you're missing something in the way you have been measuring them, or had some other effect clouding the results. They definitely *do* something, but it's hard for me to demonstrate withouth strumming the mando at you http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[sunburst]

Dan, I can't find anything in this thread where anyone has said a Virzi doesn't do anything to the sound. Nobody says you don't hear what you hear - how could they?
If there's no measurable affect on the 0,0 mode, or the 1,0 mode, the evidence speaks for itself, but that doesn't necessarily mean there is no sound change.

Dave's measurements don't measure what you, or anyone, hear/s, they just indicate some of what, in terms of physics, the Virzi does to the behavior of the mandolin; and he did find something, just not a lot. Who knows what experiment it would take to measure whatever it is you're hearing, or if it is measurable at all...?
I, even with my not-so-sophisticated ear, can hear the difference between a brass-wound string and a bronze-wound string, but I bet I couldn't measure the difference, so who am I to say what someone hears or doesn't hear?

Monica, have you ever seen one of those ships in a bottle? Maybe one of those people that make those things could build and install a Virzi through the sound hole/s. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[Chris Baird]

Dan, something you have forgotten about, with regards to your muting of the virzi, is that your own finger(or whatever you muted it with) is now factored into the equation and will certainly have a mass loading effect on the system. #It would be hard to identify whether the change in sound was the mass loading from your finger or the virzi's cessation of it's natural vibration. Probably both! The virzi DOES have elasticity AND mass. It is different from suspending a bag of sand(or something else with no intrinsic overall elaticisty) and so it will add more than just mass to the system. But, I'd wager that a significant part of its function is a result of mass loading. ALso, I'm positive that it has it's own vibration characteristics which become coupled with the rest of the instrument because it is glued to it. But, like I say, when you "muted" the virzi you did so by adding a lot of unelastic mass to the virzi and because the virzi is glued to the mandolin you basically changed the whole system. In such a case I'd be more inclined to say that it was just as much your finger as the virzi which caused the tone change. This is a difficult thing about musical instruments, you can't change just one component without also effecting all the others.

[danb]

Well the other thing I'd say, is it's vibrating like crazy, then I touch it, it stops, but the note keeps ringing. It's like tapping a harmonic. Touch it, it stops.. and it warms up again after if the top is still going.

Ah heck, I'll just have to travel around with the thing http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[Chris Baird]

I think it would be hard to figure out just exactly what the virzi is doing, but, I think there are some assumptions that can be made.

1. The virzi has a mass and so will impart a mass loading effect.
2. It is elastic and has no boundry conditions which would render it completely rigid. So, it will have natural resonances.

I'd bet that the effect of Dan's virzi is part mass loading and part a coupling between a virzi resonance and a radiating body resonance. I'd also think that not all virzis are created equal in the same way that not all mandolins are created equal. The effects of a virzi in one mandolin is not an indicator of the effects of a different virzi in a different mandolin.
I also think that the trained human ear can be very sensitive to what could be contrued as minor changes in an instruments dynamic response. I'm sure just some random John Doe off the street wouldn't hear much change in anything but a professional musician who plays a lot of one particular style of mandolin will likely develop an ear which is remarkably sensitive to that particular type of instruments response. If there were to be some type of blind fold test I think it would have to be done using folks who have a good ear and are very familiar with the type of instruments at hand. By testing the "best" ears you will then be testing the potential for hearing not just the average hearing ability.

[Dave Cohen]

Either Dan and Darryl didn't read my first post very carefully, or they _really_ misunderstood it. So I guess that I better clarify a bit.

First, a reiteration (already reinforced by John Hamlett). I started with the assumption that Dan's and Darryl's -and others'- observations are genuine. That is why I don't see the need for a "debate". That is probably all that needs to be said about that.

Second, some of the responses were in the nature of "killing the messenger". "If Cohen's science was any good, he would come to the conclusion that our convictions are correct." To begin with, I did not start with _any_ assumptions in making the measurements. The results are neither theory nor hypothesis nor conjecture; they are entirely empirical. The data consists of holograms paired with frequencies, impulse and accelerance spectra, air resonance frequency measurements, etc., and doesn't involve any assumptions of any kind. Like all experiments in physical science, the experiments are reductionist. That is, they have to be directed at finding one thing or a few things at a time in order to find anything at all. So, Darryl and Dan, please try to understand that my first post was _not_ intended to negate your observations, nor did it do so. You are correct that my measurements may very well have missed whatever it is that you are hearing although they may not have), but you are incorrect in assuming or implying that something is "wrong" with the measurements. You have to understand the limitations of physical measurement. They do say exactly what I said above, i.e., that the lowest body mode frgequencies and shapes and the lowest air mode frequencies and shapes are not significantly affected by the presence or absence of a Virzi, but they do _not_ under any circumstance say that there is no audible effect of the Virzi on mandolin tone.

Regarding the effect of mass: There are two main parameters that affect any vibrating system. One is stiffness, and the other is mass. Reducing the stiffness of a plate by making it thinner will lower its' vibrational frequencies. So will increasing its mass. So saying that the effect of mass is not enough to explain what you hear is really not giving due credit to the effect of mass.

You might reasonably counter with something like, "Well, if all you need to do is make the plate heavier, why not just leave it thicker? We all know that _that_ will not work." But that would be overlooking something important. The thicker plate would be heavier all right, but it would also be stiffer, and that would mean not much drop in frequency. Also, possibly not any increase in amplitude. By making a plate the 'right' thickness, whatever that is, then adding a strategically hung mass to it, one can drop the frequency even more. That is exactly how the Australian luthier Greg Smallman 'tunes' his lattice-braced guitar plates. He tests with a piece of modelling clay, then weighs the clay and adds that amount of mass with a more durable and permanent material (epoxy, iirc). Of course, the frequency lowering comes at a price. The heavier plate will waste more of the energy supplied to it that could otherwise end up as sound radiation. But 15 grams worth may not be a large price to pay. Some pretty reputable mandolin makers deliberately go for heavier. For that matter, archtop instruments in general _are_ heavier, and that greater mass is part of what defines the sound of archtop instruments.