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I'm working on a new classical guitar.  This time around I'm thinking that I'd like to try a Tornavoz.  I'm working on a Torres model, a cross of FE19 and the plans in Courtnall's book.

I've been reading as much as I can find, including Joshua French's website.  There he mentions that a guitar should be built with the Tornavoz in mind.  Any suggestions as to what that might be?

Also, how long does it go into the guitar, that is, how much space should there be between the tube and the back?

Any other info would be much appreciated, especially installation methods.

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

Douglas-
You should check out Neil Ostberg's site- it's got lots of info on Torres replicas, including tornavoz construction, plans, etc.

Neil Ostberg Torres guitars

Cheers
John

Thanks,

Been there, done that (quite awhile ago).  That's where this whole ride started!  While he includes a pattern, the info for length and installation is rather thin.  Surprising considering how much detail he provides on everything else.

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

Douglas-
You could try dropping Neil an email- he was pretty prompt and helpful in answering me when I arranged to have him send me the printed plans.
Let us all know what you find!

John

Douglas, I'm assuming that you have the Romanillos book on Torres and are familiar with the illustrations on pages 176 and 178. 

Last week I went to see FE-17 at Christies' before it sold and was surprised to see that its tornavoz had been removed. I'd like to make a copy of that guitar and now I can't decide if I should include the tornavoz or not................

best! 

That book is the next item on "have to but it" list!

Quite a bit of it is available on Google books, but big chunks are not.  Sigh.

Do tell about FE17!

I've found out quite a lot about the Tornavoz.  What has me stumped are the details:

how long it should be (the Ostberg template shows 65mm). Its also pierced.  Does the piercing lessen the effective length?  Other builders  do not pierce their Tornavoz (Sorry, that sounds a little radical!)

How is attached?  Apparently the originals had blocks on the guitar back which pushed it into contact with the top.  Ostberg seems to have it snug fit against the soundhole reinforcement, utilizing the spring action of the rolled brass.  I also read Romanaillos has done some that are screwed in, presumably to the harmonic bars.  How is it done securely to prevent buzzing and rattling?

How is the Brass plate secured into its cylindrical/conical form along the edges?  Is it loose?  What keeps it from rattling?  If its a permanent join, how can it ever be removed?  Its no problem to make and secure it before fitting the back,, but this doesn't seem to be typical.

Joshua French writes on his website that the guitar needs to be built for the Tornavoz, that simply retrofitting one into an existing instrument doesn't provide the desired results.  From what I gather, the Tornavoz raises the body frequency, and to balance things out, the lower harmonic bar is arched, which lowers the tops main resonance frequency.  Well, something like that.  So, is there anything else that needs to be done?

I did find some interesting discussion about this on a Spanish luthiers forum, alas, no real new information.  I wish that I read Spanish, the translated page was a charming read.

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

I will wait for Joshua to respond...he has been dealing with the flu this week but should respond at some point.

Torres was not the only one to build with Tornavoz...he was just the best at it as I am sure that he took into consideration how it would affect the voicing of the instrument while others did not.

A number of the existing Torres guitars have had their Tornavoz removed at some point as the sound and style fell out of favor and use.  While some may see the Tornavoz as a historic artifact, I believe that we do not know enough about them to abandon them and admire Joshua and the other classical builders that are building very successful guitars with Tornavoz.

If I can learn more about them I intend to build a Torres derative guitar with a Tornavoz so that I can learn how it changes the approach to building a classical guitar and as a benefit to be able to play period pieces with as close to an authentic sound as possible.

Douglas,

Here are some pics of FE-17

http://picasaweb.google.com/d28swdlp/FE17

By all means get the Romanillos book before you proceed further, the illustrations I mentioned show much of what you want to know.

Hey Shawn, have you finished your Siguenza guitar yet??

Best!

Hi Douglas,

You should definitely get the Romanillos book before making a tornavoz guitar. There is some technical information in there that is a helpful starting point. Such as dimensions, the taper (its conical), how its mounted, etc. The taper on the one on the nostberg site is practically cylindrical by comparison.

Not to mention you should have a good grasp of Torres' work to really be successful at it and the Romanillos book is the best place to start.

It is normal for a tornavoz to be non-removable and mounted to the soundboard before assembly. There is a flange bent on the tornavoz and it is fit into a mounting ring.

The tornavoz is something of a complicated matter and other issues arise along the way. But it is definitely possible to make a great tornavoz guitar.

Aside from having some much needed help from people close to original Torres tornavoz guitars, I figured out most of what I intended with the tornavoz drunk on Absinthe. Most of it is public domain now. I've had great luck with it, but it may also be that it simply compliments my "style". It requires something of an intuitive and adventurous approach.

Its kind of an arcane thing... and it makes for a different kind of guitar. Really a 19th century type of guitar.

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Instagram: @jfrenchluthier
Web: https://www.jfrenchguitars.com/

Ohhh, that FE17 sure is nice, even if it has gone through Hell and back.

My friend Daryl Perry is making one right now.  Can't wait to see it.

I think that the book may have to wait till Christmas...

My present build isn't going to be an exact copy, as it will have a white cedar top and lacewood body...but I will try harder on a future build.

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

Yes...I am now working on another blanca made with sides and back of Huon Pine that smells like cloves.  I got the set from a luthier that Sean Hancock of the 2007 class knows well and that several other Aussie builders here know, Barry Kerr.

I wanted my Siguenza Cypress bound in BRW but did not want to risk bringing BRW with me to Siguenza so I waited until I was home to bind it.  The headplate and bridge are also BRW and I was paranoid that at some point in customs it would be seized along with the guitar.  Washington Dulles Airport has been beefing up security quite a point as politically they want to show that a Washington, DC airport is more secure than others (whether it is true or not) and they have been doing this by inspecting and seizing more incoming goods.

 

 

Yes Shawn, I too reworked some of my pre-prepared Siguenza parts to substitute Indian rosewood for Brazilian to avoid any problems.

Joshua, perhaps you should consider having Tornavoz produced and supplying them to makers? I don't think anyone else is doing this.....?

BTW wishing you a speedy recovery........

best!  

So, Joshua, what you are saying is that, after I get The Book, I should just build it and tinker with it and build again, and again? 

Its hard to say when I'll actually get the book, I'm hoping soon.  Right now all my "spare" cash is getting poured into a complete basement rebuild.  Now, if I hadn't just paid the concrete cutter to put 3 holes in the basement wall...who needs windows when there are guitars to build?

Am I on the right track with a 65mm tube length and the arched lower harmonic bar?

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

Thanks David. I never thought about selling them. There are a couple of other people (Gerhard Oldiges, Jun Nakano) doing occasional tornavoz guitars and they make them themselves as well.

Douglas, I end up wth a length of around 75-78 mm. I really wouldn't consider this any further until you've read the entire Romanillos Torres biography... otherwise you're kind of going at it blindly. There's not a whole lot of tornavoz info there, but it is a great basis.

best wishes,
Joshua

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Instagram: @jfrenchluthier
Web: https://www.jfrenchguitars.com/

Joshua,

Thanks,

I did check on its library availability; closest I can get is N. Dakota or Alberta.  I"ll have to check on interlibrary loans if I want to get it anytime soon. 

Google books, of course, has the appropriate sections missing.

I've been steeping myself in the subject as thoroughly as possible.

There's a chance that I a friend of mine, Daryl Perry, mentioned above (www.perryguitars.com) might have a copy that I can borrow.  He's got my Selmer book right now, so if he has one, I might be in luck!  He knows more about this stuff that I ever will.   My plan is to do some study with him in the near future, he's agreeable, we've already started to talk about it.

I'll give him a call right after lunch.  I don't really like to bother him about this stuff.

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

I spoke with Daryl this morning.  He said that he's had the book for many years, refers to it regularly, but is willing to lend it to me for a few weeks, 'cause he trusts me.  Its always a gamble when I lend out books, mostly I don't trust my memory of who I lent them to.

My wife will be securing a copy for Christmas.  Yeah!  This is becoming a tradition, one good (read: expensive) book per year.  A gift that lasts and is appreciated, thats what I like.

He also encouraged me to make it to the next local guitar society concert, wherein the performer will be playing her new copy of FE17 that he just finished, his second.  He hasn't built with a Tornavoz, so I'm out on my own here.  He said that there was discussion about the Tornavoz for the first, but in the end it was decided to leave it out.  The second was commissioned on the basis of the first, so he couldn't change things; the customer should get pretty much what they expect to get.

He also mentioned that a couple of his friends played the original FE17 in concert prior to the Christie's auction and said that the restoration was wonderful and that the tone was still excellent, in spite of the sad history of the guitar.

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

Hi Joshua,

Sorry if I highjack the thread.
After reading the Romanillos book on the tornavoz,
I had a question in mind.
How do you go about attaching the bridge with the tornavoz block the sound hole?
Do you attach the bridge before closing the back?

regards,
Sen

_________________
-----
Sen CL Goh
http://senguitar.blogspot.com

A couple of serious questions here...

Is it the romantic idea of a tornavoz or is it the performance that is appealing?   

How many of you who want to build one into a guitar have heard a guitar with one?

And from loudspeaker theory, I'd think it would lower the air resonance a bit (mass loading of via the "neck" of the resonator), and drop the perceived volume a bit. Is that what one hears?

Rick,

That's just it, isn't it?  There just aren't any around to hear in order to judge its attributes.  If  I had to wait till I could  hear one I'd be waiting  a pretty long time.

For me, its about understanding the performance.  I'm not  interested in quaint  romantic ideas just for their own sake.  I understand that the Tornavoz fell out of favour, and I can't find out any reason why.  Could be that the installation became loose and it rattled.  Who knows?  If somebody does, I'd love to hear about it.

I have no real compelling reason NOT to build this guitar with a Tornavoz, just as I have no real compelling reason TO build with it.  So why not give it a try and see what I can find out? 

In the end, I'm left with the precedent that if it was good enough for Torres' personal guitar, and that he sold that guitar to Tarrega, one of the most accomplished guitarists of his day...then its worth giving it a try.

_________________
Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

Ah, Rick; the voice of reason. I've been staying out of this one, but....

On reading the Romanillos book I did a little experiment on the tournavoz. I took my 'corker' classical, which has become my 'test mule', and put one in. I could not get a copper one into a completed guitar, for obvious reasons, so I made the thing out of heavy card stock, to the dimensions that Romanillos gave. It was then possible to insert it by folding it a little, and get it set up inside in the right place.

Rick's expectations as stated were quite a bit less than what I saw. The pitch of the 'main air' resonance dropped right down; well below 60 Hz, iirc, and the spectral peak of the mode essentially was gone. The effect was roughly like that of closing the soundhole down to about 1" diameter or less. The sound, aside from being much quieter, lacked bass fundamental. It was, interestingly enough, much more like the timbre of a small bodied Baroque guitar than a modern classical, but somewhat louder owing to the larger size. I rather suspect that was the objective.

Several objections will be raised. The guitar was not 'built for' a tournavoz. Although it has a decent Europen top braced similarly to the standard Torres pattern, I did not do anything to adapt it for the soundhole restriction. In fact, I find it more than a little difficult to think of how one would do so, and the folks who talk about it are, to say the least, not very specific. I'll note that the originals that have had the tournavoz' removed seem to be perfectly acceptible without them, so the adaptation can't do anything major to the tone.

The tournavoz I made was not metal, but cardboard. One would expect it to damp the sound more than a metal one, although, again, it is very hard to say what the difference would be. If the tournavoz is actually a sound producing surface in itself the difference might be noticable, particularly at high frequencies. If it's 'merely' somthing to direct or alter the air flow, the difference should not matter much. Who can say?

I'd love to get my hands on an original Torres with a tournavoz that I could measure acoustically, or even a good modern copy. Finding anything objective out any other way is unlikely. With so few around I'm not holding my breath.     

[QUOTE=Alan Carruth] Ah, Rick; the voice of reason. I've been staying out of this one, but.... [/QUOTE]

I wasn't aware that Rick had any experience with the tornavoz...

[QUOTE=Alan Carruth] Several objections will be raised. The guitar was not 'built for' a tournavoz. [/QUOTE]

A fair objection, no? I could have saved you the time on this experiment.

[QUOTE=Alan Carruth] I'd love to get my hands on an original Torres with a tournavoz that I could measure acoustically, or even a good modern copy. Finding anything objective out any other way is unlikely. With so few around I'm not holding my breath.     [/QUOTE]

To the best of my knowledge only 3 or so exist in original condition. Any others would just be a waste of your time.

On not being specific - it's quite simply not my research and not my place. If you want to know about the tornavoz, the information is not missing, its overlooked.

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Instagram: @jfrenchluthier
Web: https://www.jfrenchguitars.com/

[QUOTE=Rick Turner] A couple of serious questions here...

Is it the romantic idea of a tornavoz or is it the performance that is appealing? How many of you who want to build one into a guitar have heard a guitar with one?
[/QUOTE]

I'm pretty sure I'm the only one here who has actually done it. I've made 20-25 of them. For me its the performance.

[QUOTE=Rick Turner] And from loudspeaker theory, I'd think it would lower the air resonance a bit (mass loading of via the "neck" of the resonator), and drop the perceived volume a bit. Is that what one hears?[/QUOTE]

If you added a tornavoz to a guitar, that's likely what you'd hear. Otherwise there must be a kind of symbiotic relationship created between the guitar and the tornavoz.

_________________
Instagram: @jfrenchluthier
Web: https://www.jfrenchguitars.com/

Hmmm, "lost secret" is what I'm hearing... Lost and found?

OK, so you change the impedance matching of the top to the air mass in order to take advantage of the lowered air resonance, and perhaps you want more excursion from the top in order to make up for the loss in efficiency. That's what I'm reading between the lines here...

I wonder how a very fast responding and really loud top would match up...Something like a Smallman, perhaps.

I'm not sensing answers here just mysteries upon enigmas.   Perfect for the romantic notion of the lost secret, though...   So if one build with a tornavoz and it isn't wonderful, then it's not because of the tornavoz; it's because the builder didn't understand it. But as there's no clear explanation of how to build with it, the whole thing is held as a dark arts secret.   Jeez, I thought we were getting away from that whole trip.

This has much the same kind of aura about it that the Virzi does. Most people rip 'em out and keep 'em that way.   Sure it does something, but is it worth what you give up?

I don't know the answer to this question, by the way, I just see this as being something that seems to come with a lot of smoke and mirrors and fancy dancing.

You are correct- this device would act like a ducted port and lower the
fundamental resonance of the sound box. In loudspeaker design a ported
system is the mechanical equivalent of a 3rd order high pass filter.
Making the port smaller or adding a duct lowers the resonance . This can
be used to augment the low frequency sound coming from the front (i.e
the speaker) with energy delayed (i.e. phase shifted) coming from inside
the box.   However there is no free lunch. You get a resonance peak that
is unlikely to always be in harmony with the input signal and the price for
the increase output is high group delay - i.e. boomy bass. Take note of
the terrible car stereo bass you hear from that passing car with the
windows rolled down. In that case you have a tuned box (the interior of
the car) in front of the sound source and a 6th order filter that makes
loud bass - but only at one note!

I'm new to guitar building (working on #11) but have been in sound and
speaker design for 30 years.

So you build the guitar with a hole in it's bass response that gets filled by the higher Q resonance from the tornavoz? The plain soundhole contributing to a lower Q filter, and the higher Q of the tornavoz fixing that?   Is that what I'm understanding?

And I'm not saying I don't think it can work. Ducted port bass reflex cabinets have a long and successful history, but it would be nice to hear how one alters the top to take advantage of the qualities of the tornavoz. Or is it something that is a trade secret with a handshake and a decoder ring?