Wednesday, October 5, 2011

Carbon fiber used for guitar tops? Aren't you kiddin'?

I want to echo here a really good text written by Joe Luttwak, CEO of Blackbird Guitars, about using carbon fiber to build guitar tops -> the link

Carbon fiber vs. wood sound board + stiffness
Over the years, we've observed a lot of mystery around the material and construction of acoustic guitar sound boards amongst the guitar playing public, after-all sound boards account for the majority of 'tone' of the instrument. In particular, the art/design/science of making guitars achieve a certain quality of sound, volume, frequency response. This became very clear when we received the following comment on our Youtube account:
These guitars are CRAP, considering the price you pay... Guitars are made out of flexible wood. Carbon is one of the most rigid materials known to man... It's good for bracing and truss rod support, but not for anything else. Especially not building a resonating chamber. -AlisonChaynes 

Here is what I more-or-less responded:
'Actually Guitar-top material Aka Spruce is exceptionally stiff for its weight- this is the most basic point of acoustic guitar building and you missed it! Good spruce is a hard material to beat actually, but composites have the advantage of being tune-able so you can dial in the stiffness. Just like a wood guitar, we have bracing to determine stiffness of the top (except we use carbon fiber for our braces), but we also can adjust the thickness, material, weave, orientation of the top to determine stiffness.'

I reached my character limit at that point, but there is another big advantage over wood tops, namely consistency. Because our tops exhibit nearly the same mechanical properties every time, we can quickly develop the perfect blend of top bracing and the other aforementioned variables (aka  thickness, material, weave etc.) so we get the desired responsiveness- every time! Responsiveness is what we are after which broken down means volume, frequency response, dynamic range. Blackbird guitars are closer to the more response boutique guitars by design. Your mass-produced wood guitars (even the pricey ones) are typically 'over-built' aka too stiff... One more thing about the post, if carbon fiber is good for bracing, which is the basis of achieving good tone and stiffness, shouldn't is also be good for the top itself?

1 comment:

  1. No matter how many times you explain this, you'll still get those same types of comments in a hundred years, when there's no wooden guitars anymore, cause we cut everything down.

    I think early Rainsong guitars didn't help carbon fiber's reputation either. I read some blurb of theirs, where they admitted they didn't get it quite right at first, and subsequently redesigned their sound boards and made them thinner too.

    Its like any new material... Luthiers had hundreds of years to work out how to use wood to its limits.

    I have a pair of Panasonic earphones where the shell is made entirely of zirkonia (a composite with ground up artificial diamonds) Who knows when we will see guitars made out of things like that...

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