Tap Tones

[Ragtime]

Recently I had the opportunity to vist a mid sized builder of high end instruments and was fortunate to be able to go through their B&S sets and put the different woods through a sort of tap tone evaluation.

The Maples, Mahoganys, Blackwoods ans Cocobolos all had a pleasant though different tone. The Hondouran Rosewood was so dense with resins and heavy to the feel that I wondered if it would float in a bucket of water, but it had an almost bell like quality to the tone.

Moving on to the stack of EIR I was amazed that the tone could best be described as tapping wet cardboard. It was well quarted and straight grained but had a consistency that I thought more resembled Walnut than the usual resionus qualities of other Rosewoods.

Is this description of my experience with EIR what one normally sees with this wood? I am not a luthier but a cabinetmaker with a lifetime of working with different woods and it was a treat to be able to listen to the qualities of the different woods and did not want to offend my host by asking questions about why the stack of EIR was vastly different than the other wood sets.

[gregg]

The Maples, Mahoganys, Blackwoods ans Cocobolos all had a pleasant though different tone. The Hondouran Rosewood was so dense with resins and heavy to the feel that I wondered if it would float in a bucket of water, but it had an almost bell like quality to the tone.

Moving on to the stack of EIR I was amazed that the tone could best be described as tapping wet cardboard. It was well quarted and straight grained but had a consistency that I thought more resembled Walnut than the usual resionus qualities of other Rosewoods

I'd say that most of your findings seem in line, the exception is EIR, not all of it is like tapping wet cardboard, in fact, I have a shop full of EIR that has a lovely taptone very similar to many other rosewoods.......each piece of wood is unique, regardless the type/species.

[Alan Carruth]

That 'ring' you hear when tapping is a sign of low damping: the wood doesn't dissipate energy as fast, so it rings longer. IRW does tend to have higher damping (a shorter 'ring') than BRW or Blackwood, but, like all woods, it tends to vary a lot in that regard. I've never seen a piece of IRW with damping as low as the best BRW, but a good piece of Indian can be close to an 'average' piece of Brazilian. A poor piece of IRW will have twice as much damping as a good one. Some of the 'stump' BRW is almost the same.

I've found when tapping wood that I get fooled sometimes. Based on taps, for example, I thought that Persimmon had fairly low damping, but found on making an actual measurment that it was more like maple than a rosewood. I think, in that case, it was just so massive that I had to really hit it hard to get it moving, and so it took a while to run down. You'll see the opposite in some ways with balsa and other low density woods: they aren't very good as 'flywheels', and lose energy fast moving air. I always thought balsa had high damping when I was tapping thin sheets, but when I got a piece that was 2" square and measured it, it was right in there with spruce in that respect.

If you really want to hear 'cardboard', try Mesquite burl. The piece I've got is somewhat inferior to Masonite as a tone wood, with very low stiffness and high damping. It looks interesting, though, and smells nice...

[dekutree64]

Yep, that sounds about right. Some EIR rings like a gong, others not so much. One of my sets is the gong type, two are good but not as good. Haven't encountered a cardboard set yet, but I've heard from several others who have.

Honduran is probably the most lively wood there is, but heavy. Brazilian and Pernambuco are more or less just as lively, but medium weight. Movingui is also similarly clangy and long ringing, but not much heavier than mahogany.

Mahogany itself is quite variable. Most of what I've handled was long ringing, but I have one gorgeous sinker set that sounds like cardboard I wonder if it's the time underwater or if it was like that to begin with.

Most of the maple I've tapped on has been pretty lifeless as well... but my two back/side sets are quilted, so maybe straight grain would ring better. But I have a quilted black cherry set that sounds quite nice, and a tight curled koa that's so-so.

And my most cardboardy of all is imbuia burl. Actually, I think cardboard sounds better. But it's also gorgeous and also smells nice, so I'm just going to brace the heck out of it to minimize its tonal contribution.

[Tim McKnight]

Just an FYI... If you are not a builder and don't have a good understanding of nodes then its possible that you were holding the wood on a node which would make it sound less than pleasing, more akin to wet cardboard. My EIR is 15 - 30 years old and all of it rings like a gong when tapped. Its possible the EIR you inspected was newer plantation grown EIR which may have higher damping properties?

[Kent Chasson]

Originally Posted by Tim McKnight

My EIR is 15 - 30 years old and all of it rings like a gong when tapped. Its possible the EIR you inspected was newer plantation grown EIR which may have higher damping properties?

That's what I was thinking too. Some of the plantation wood is less dense, more porous, and kind of stringy. Often lighter in color too. But even that should have a tap that rings more than maple. Maybe something else was going on. Like Alan said, different thicknesses can throw off comparisons. So can boards that are not rectangular. Dryness has huge influence too.

[Ragtime]

Thanks for all the interesting responses to my question regarding EIR. It is quite possible I was not properly holding the sets in a way that would bring out the true best tones.

I was however surprised that this stack of EIR back sets had the physical properties unlike any other Rosewoods I have encountered. The weight, the porousity of the wood and the lack of a resionous quality led me to the comparision to Walnut. Perhaps it was plantation grown and that might explain the difference.

Years ago I was able to obtain several truckloads of Brazilian slab off-cuts and a few nice dimensional pieces all with the hand adze marks from where the sapwood was cut off the logs before shipping to a sawmill in New York around the turn of the century. I still have some left from other projects, maybe enough for 6 or 8 guitars if I were to try my hand a building one day. But it's all pretty hard and resinous and is what I would normally expect to see in woods from the rosewood family.

[murrmac123]

Originally Posted by Tim McKnight

Just an FYI... If you are not a builder and don't have a good understanding of nodes then its possible that you were holding the wood on a node which would make it sound less than pleasing, more akin to wet cardboard.

Worth emphasizing.

You need to know how to hold a top or a back to get the right taptone.

If you just pinch the top corner between forefinger and thumb, it 's all going to sound like cardboard.