Bell-Like Tap Tone

A short demonstration of what luthiers mean when they say a top or back has "bell-like tap tone" - how it should sound!

Category:

Education

Tags:

• Luthier
• tap tone

[dandeliontea7]

you really like EI rosewood dont you? ;)

[CambrianGuitars]

@dandeliontea7 - I do, but not exclusively! I guess I made these videos when I had a few guitars being made with the stuff :) I love all kinds of wood for the back/sides, but these days I am drawn to the prettier/more figured woods. This sometimes compromises the sound a bit (e.g. spalted mango looks fantastic, but taps like wet cardboard!). I'll make some updated videos on my next builds, and post them....Cheers, Dave F.

[donepearce]

A guitar back that emphasises one note. Right - that'll be exactly what we want then.

[CambrianGuitars]

@donepearce - No so. The back in this example resonates easily at the main resonance (fundamental), but has many other secondary resonances and harmonics of same that allow the guitar to have a wide band response. These can be found/seen using electronics and an FFT function. It has been shown by many luthiers (not just me!) that a back or soundboard with a good fundamental ring tone (bell-like), when braced and tuned properly, has the best chance of making a great instrument.

[donepearce]

@CambrianGuitars If it has many other resonances and overtones, the sound will not be bell-like. Truue broadband response has no associated tone - you will get a click, not a bong.

[CambrianGuitars]

@donepearce - Ah-ha, you're right! Yes, the phrase "bell-like" is incorrect isn't it. As a long time synthesist (I designed and build my first synth in 1974) I should know better! A bell tone is attained by multiplying two tones (or more) together. This needs a non-linear element (the multiplyer), but there is no such thing in/on the guitar back. A better description might be "broadband response with good sustain".....I'll think about it some more...

[dandeliontea7]

@CambrianGuitars hey, thanks for the reply man. You should check out aussie natives (I am from australia so its a bias thing but oh well) Such as tassie blackwood (an acacia species, so very similar to Koa) and Tiger Myrtle (some very pretty stuff there) as well as QLD maple and Tasmanian Oak (also known as Alpine Ash). Tim Spittle at australian tonewoods (dot) com has some nice stuff and is also known for his excellent customer service.

cheers

[CambrianGuitars]

@lvst1 - Thanks! I make the backs and soundboards of my guitars as thin as I can while still retaining the right amount of stiffness. For an EIRW back like the one shown, I typically bring it down to about 80mil thick. The bracing is sitka spruce, quartersawn into pieces about 1" thick, then split and sized. I have used mahogany for bracing before, but I wasn't impressed with its stiffness and stopped using it.

[lvst1]

very good job, congratulation,

how tickness is the wood back and de wood of parobolic suport and what kind of wood do you use for this

[CambrianGuitars]

That was an experiment I did to make a guitar with finger joints between the sides and the back and soundboard. It was a failure, so I ended up using the wood to make a slightly smaller guitar.