Australian/New Zealand Luthiers Forum

I've found that if I use "old" wood (that I've had for at least 5 years), the guitar seems to get louder with age but the spectrum remains much the same. If I use "new" wood, cut and dried for less than 2 years, the guitar gets stiffer as it ages and whilst the shape of the spectrum remains recognis...

These guys keep changing their name but are still in the same business and is where I've bought the CF products called for in the books. The cloth (1m wide) is much more economical to buy than tape (or was!). Give them a call and see if they still stock CF. https://allnex-brookvale.business.site/

I am looking for a source of the reinforced packaging tape to use for binding work...any recommendations? What are you using and do you find that the tape is strong enough by itself or do you still bind with stretchy cord or rubber as well? Cheers! Ross I use the two-way filament tape from these gu...

Thanks for the kind words, Tom.

John, do the before and after tap responses tell you any more about what changes happened?

Good to hear it all worked out. Well done!

Your bridge looks the same size as mine (presumably made off the book drawings). Mine stay on! Them peeling off is as much about the bridge plate design as it is about the glue area, and you have the standard falcate bridge plate.

95,170, 214 is a great result. Carving the back brace to reduce the T(1,1)1 and T(1,1)2 sufficiently will bring the T(1,1)3 down way too far and cause acoustics problems that you don't need because you no longer have the 4 semitone separation. Stringing up will possibly drop the T(1,1)2 a little bec...

I haven't spoken to Charles about a future class. Maybe an idea for another occasion!

Eric, there's the possibility of another class at Robbie's 10/11/12 Jul 2020. Please contact Robbie if you're interested.

My rotation ended up at 1.3 degrees... Let me refer you to this post from a while back: http://www.anzlf.com/viewtopic.php?f=33&t=6321&p=71613#p71613 Don't get too hung up on the bridge rotation if the modal frequencies and the monopole mobility are right. However, if the modal frequecnies are too ...

The problem I find is that leaving only1.2mm on the back of the saddle, 6th string, tends to lead to too much crushing and wear on the saddle, especially if Tusq is used. Obviously this is also a problem when using the traditional narrow saddle. As the contact point only ever moves forward as the br...

What am I missing? ...that I say in the last two lines of para 2 Section 20.3.2 (both editions) that you work it out for the string that has the shortest distance (typically the first string). The longest distance is typically ~ 3mm more, so that gives you ~2mm "land" of saddle on a 5mm saddle for ...

John, I've seen some seriously "roller-coaster" tops that have sounded fine, so that in and of itself doesn't appear to be sufficient criteria for less-than-best sound quality. Similarly, "print through" of the bracing pattern is pretty normal on highly responsive guitars. One of the things that I'v...

DavidS wrote: ↑

Tue Oct 22, 2019 8:09 pm

I am trying to figure out whether I am going to be able to achieve a finished T(1,1)2 close enough to 170Hz given I am starting at 180hz closed box.

Provided you remove very little wood on binding and clean-up and use a very low mass bridge (< 15 gms), you should be close.

The Paulownia I've had is only one step removed from balsa and quite soft. I doubt it would hold up using the designs in the books. With some very cunning design work it might work, but I suspect some pretty complicated manufacturing would be required.

... Dimensions Fig 20-2 in the Build volume shows typical dimensions for the classical bridge with the height at 8mm Section 20.2 discusses the make up of the bridge and calls for three wood plies of 2,3 and 4mm thickness with two layers of CF between these plies. I haven't got the CF yet but it pr...

Sad news indeed. Graham was a pioneers in musical acoustics and guitar function, starting as an academic with a PhD in physics before moving to instrument making. One of the finest classical guitars I ever heard was one of Graham's. As Peter mentioned, a lot of the procedures and concepts in the boo...

It is almost impossible for me to determine what is going on from the pictures, but I suspect that some type of dipole activity was excited when you tapped with the back mass added; either because of the way you tapped on that occasion, or because the added back mass precipitated that type of respon...

I have always put CF above and below all the braces. That doesn't mean that you have to...

Sorry for the delay in responding. I've been overseas. A couple of things: Remember that the T(1,1)3 is the back response as seen in the top, rather than just the back response. So if the top is too stiff, which may happen with X bracing, you might not see much by way of the T(1,1)3 because of that....

The medium sized steel string (as per the plans in the book) fits into a Hiscox OM case.

There's some new videos on Robbie O'Brien's site which show how I do all the tap testing etc..

Probably worth doing some Chladni testing to set what is actually going on around the 210Hz to 240Hz region, with and without added mass.

String it and listen to it. With the added mass of saddle and strings the T(1,1)2 will drop and you may have to alter the side mass to hit 180 Hz for the T(1,1)2. You should end up pretty close to 180/226, which is not a bad place to be. With the sound port, the air resonance will always be higher t...