Are there wolf notes on classical guitars and is it the same as unwanted resonance

[John Cadd]

When I play some simple chords on a flamenco guitar the A string starts a little howl going.If I drop the tuning down slightly on all the strings this nuisance stops .Is the cure to remove some wood from one of the bars,and which one?

[John Cadd]

The other option to a troublesome resonance was to damp the string .You have a choice of which hand to use.One player mentioned a Russian he saw that used his chin.So I suggested making some symbols to edit the music the way piano players mark foot pedals (sustain or damping).Each guitar might need its own set of markings.Plenty to keep you busy.---Anyone got a spare foot pedal with some elastic?

[John Cadd]

I had another check and I was blaming the A string but the E was at it as well .So Bob hit the nail on the head ,It`s resonance if it keeps on going.I bet you Bach had all that taped.Ever see any complaints about this in Bach`s music? I shall just play in tune from now on.

[Tim Mace]

What brand is it ? Valuable? I've got a 60's Hernandez(nippon) that I want to replace the fretboard.
I love the guitar but I'm not afraid to try and improve it.It had a loose top brace that I located by tapping and fixed by sticking glue in there.It worked. That was over 30 years ago. It would be nice to hear the problem. Have you used a stethoscope yet? Yeah,Bach put out some great hits!
Hell all the top Flamenco guitars(guitarists)howl. Manitas was a brutal picker and Willie thinks his scratch hole
Martin is cool.
If it's really valuable take to a pro.Or a doctor...

[John Cadd]

Yes Bob Altering the top would be a mistake in my case as that would bring the top and back closer in tuning.So the back is the one that needs the note dropping.Ideal would be a one tone difference,back lower than front.Comparing low notes is awkward to do so I make a piece of wood to use as a tuning"fork".Same texture to the sound.

[Bob Webster]

John, the last thing you want to do is make the back lower than the top. It really does need to be the opposite; i.e. the top needs to be lower than the back. And..., if the top resonance is at or near 110Hz (A note), there's plenty of room to lower it and have excellent tonal properties for the guitar. Most decent classical guitars have air and top resonances somewhere between 92 and 103 Hz, part of that depending on the soundhole size.

Bob

[John Cadd]

Ah right .You have a closer grasp of this tricky stuff Bob.While I looked up this subject there was a site about Ramirez who spent a lot of time on this problem.A violin site also mentioned him when they were discussing violins with Wolf notes.One said if you tune down and the tone calms down it`s coming from the air (volume) resonating.Just out of curiosity I put a piece of foam rubber inside and the air resonance rose by a semitone.An easy reversible experiment.I shall have to write out your latest message for my homework.

[Bob Webster]

Now you're gettting it. One pretty cheap and silly way to manipulate the air resonance is to make the soundhole slightly smaller by a mm or 2. That will drop the air resonance enough to get rid of the match between the air and A note. By the way, what is the diameter of your soundhole?

Bob

[John Cadd]

Diameter of soundhole is 89mm.for the flamenco with the "resonance".With a thin body.
Interesting that the other guitar(Spanish)is 86mm,but that is a full depth body.

[Bob Webster]

Do you feel adventurous, John? That 89mm soundhole is ripe for some reduction; it's pretty large. I'd be tempted to reduce it to at least 87mm and that would definitely lower the air resonance enough to cure the problem that ails the guitar.

Bob

[John Cadd]

Yes Bob I have no idea what the average size of a soundhole would be.I took out the lump of foam rubber and made sure the strings were tuned up.Then I used some masking tape to fix a piece of cardboard across the hole and that reduced the air resonance by a whole tone Good start.It`s just straight across blocking about a third of the hole.Probably not a third of the area though. But amazingly the tone is really nice .Like a description I read once.A bitter sweet Mexican quality (with a dollop of honey too). The plastic protective layer on the flamenco made that a really easy experiment. What would you recommend as a practical step ? Although i can try different positions for best results with the cardboard first.Soundholes are like sattelite dishes.Add a few centimetres to the edge and it soon doubles the area. This is very important stuff for anybody making guitars.

[John Cadd]

When I mentioned tuning violin plates that was a bit out of date as my record book shows that backs and bellies are both tuned to F natural(all holes bar and varnish included.) Memory playing tricks on me.

[Bob Webster]

Changing/reducing the soundhole while not blowing the aesthetics can be a challenge depending on what the shape of the soundhole edge is. If it's rounded quite abruptly it would be possible to enlarge the soundhole back to the flat portion of the rim and then build it up again with layers of veneer (colors of your choice) to the target diameter, then reround the edge. If you add veneer incrementally, you can stop when you hear the wolf effect go away. CA glue is a big help in getting this done. And, like I said, it's only going to take a reduction of 1-2mm to make a big difference.

If the soundhole edge is rounded very progressively starting at the rosette, it will be pretty tough to do a nice clean job.

Bob