Still not getting the sound I want...help!!

[davidafterwork]

Hello all
just wondering if anyone has any ideas here that might help me make some progress.
I have now built approx 15 guitars and although they are getting better I am still not satisfied with the sound.
The finish etc is getting a lot better but I keep comparing my sound to the sound of my Taylor or Collings guitar and it still feels a long way off. The sound is not consistent and sometimes one built previous sounds better than the current one. Its very disheartening and I would love to get some input as to what I can do.
I have the TG books and although the build one is excellent I find the Analyser/Excel stuff just a bit beyond me technically.
The ideal would be to bring my guitars to a luthier but I don't have that chance where I am.
I am ASSUMING that the fault lies in the top voicing/bracing ( i get all the other parts pretty good at this stage).
Basically I sand the top when its joined until I get that "Sheet metal sound" as taught by say Robbie O Briens course.
I then brace the top and shave the braces until until I hear what I THINK is a pleasing sound...I know, thats pretty vague..!!
Anyway, has anyone any tips on how I can up my build standard and get nearer to that sound I am chasing???
Any tips and on any aspect will be more than welcome!!
Thanks in advance
Dave

[Dave M]

Dave that must be very disheartening, and I admire that you are still trying.

As an amateur, as with so many others, my early attempts were badly overbuilt. With my classicals I have reverted to a Torres type fan bracing which is very light and a thinner top. This now gives me quite a good sound - not great but better than many commercial guitars.

For steel strings I use Trevor's design with falcate bracing. Without using the pre build analysis with the maths, I have found two things to be useful: Measuring the rotation of the bridge under string tension tells you if you are building too stiff. This is of course after the build is complete, but can inform the next one. Also getting the response spectrum is good for telling you just how the guitar is performing. Although not trivial to learn to use, Visual Analyser it isn't too difficult - there are some good threads on here to help.

Hopefully more experienced builders will have some useful things to say.

Cheers Dave M

[peter.coombe]

I would put more effort into trying to understand the Gore/Gilet design book. The technique to improve your consistency is all there, and you don't have to use falcate bracing. You don't need to go into the maths, just understand the main principles, but it is a different way of thinking from tapping and listening to the sound. In fact nobody has shown any close relationship between tapping sounds of the free top and the final sound of the guitar so that is probably not a terribly useful thing to be doing. How the back relates to the top is also important. Are you doing any measurements? If not then you do need to measure the modal frequencies of the finished guitars to get some idea of what the heck is going on and how you might improve. Personally I found the design book far more useful than the build book and have applied the principles to mandolins with great success, not just to guitars.

Another thing you might find interesting is Allen Carruth's video on free plate tuning. Allen has over 40 years experience and does have his followers (including me), but it is a different approach from Gore/Gilet. I tend to combine both.

[Mark McLean]

Dave
I agree with the comments that Peter and Dave M have made. It will probably be very useful to get some hard data about how your instruments function, and to compare this to your target. If you have a Taylor and a Collings that you like (1) you are a lucky guy, (2) you have the capability to do some great experiments to assess your builds against them as "gold standards". The techniques described in the G&G books that are likely to be most relevant to your analysis are top deflection, bridge rotation and spectrum analysis. They might seem a bit daunting at the start - but they are actually quite doable by an amateur builder, with pretty simple kit. These measurements are hard and objective data that really do correlate to functional outcomes in instrument performance. Other things we tend to assess as we are building (tapping, flexing, sniffing, tasting) are much more vague and unquantifiable.

If you could generate those three measurements on a few of your instruments as well as on the factory built control specimens you would be a long way ahead in understanding how your product differs from what you are hoping for. Then you can start to plan what to do different - or even to do some modifications to your previous builds that will move them closer to the goal.

Where are you located? There might be someone near you who could help you work it out (social distancing permitting).

[WJ Guitars]

Hi Dave

I would also recommend that you should use T&G book methods.

To help you using visual analyser Trevor / Robbie O'Brian has produced a video set that demonstrates how to setup and use these methods. I purchased the videos online from Robbie O'Brian and found this very helpful when setup the computer to do the tests.

You should also be able to find an excel spreadsheet copy on line in the Luthier forum's that is already set up to put in the data and run on your computer.

I have used the T&G book principles for all my 'X' braced steel string guitar builds. This has proven to be reliable and I have been very happy with the sound results from these guitar builds. For my 8th guitar build I use the Falcate bracing system. The sound results were amazing and the best that I have ever achieved.

I hope you are able to setup your computer to use the very helpful instructions available as mentioned and then be able to reach your goal to achieve the sound qualities you are aiming for your next guitar build.

Wayne
https://wjguitars.wixsite.com/mysite-1

[seeaxe]

Got to add my 2c here.
The big investment is the cost of the books and you have already done that.
Using the spectrum analysis and bridge rotation method to get data from your target guitars and previous builds is actually much easier than it sounds. Have a go. You have nothing to lose and everything to gain.

The really big benefit will be from using the same build techniques, be that falcate or whatever, and then making incremental changes and being able to measure the result. You will no longer be "flying blind".

I've just built my first falcate classical and even though it wasn't even close to the right bridge rotation (way too stiff) it stills sounds much, much better than the other classicals i have built. Im excited to build the next one.

Building the braces is a bit of a faff but if you have already built 15 guitars it won't be a challenge.

Have a go!! Plenty of great help here.
Good luck.

[davidafterwork]

First of all thanks a lot for the great response everyone.
It never entered my head to use the 3 mentioned TG items to test my excellent Taylor guitar... although I have used it to check lots of other things!
I assume all of that is in the Build book???
I also am going to look at the Falcate bracing and see what that is about and if I can get the necessary materials in Ireland .
If anyone has a copy of the spreadsheet and wouldn’t mind sharing it that would be great as well....that’s the part that throws me every time I look at it!
I will get VA if that’s the recommended software and see if I can get my head around it.
Thanks again lads and don’t be shy about dropping a few more tips please!
Cheers

[seeaxe]

Hi David.

Im certainly no expert, but here's my advice for what its worth.

The CF tow (or strand) is actually very small. I used the CF tape shown below and pulled out one strand at a time. This helps keep the rest of it tidy as each strand is made up of 3000 tiny filaments (hence 3K) and it come undone fairly quickly. I had a quick google but couldn't see any obvious places to get it in Ireland. When you find it, I'd suggest you buy a couple of metres of this as 1 metre isn't long enough to do two main braces. If you get desperate I can get some here and mail it to you but cant believe its not in Ireland.

Here's what I used

The epoxy brand isn't critical. Clear is good for visibility and appearance but its all inside so not that important. I use West Systems which I think you can get anywhere. Any problems, just go to your nearest boat shop, they'll have tonnes of the stuff. Dont buy too much, keep it fresh.

Making the plies for the braces is time consuming. Make a mould/moulds first, as you will need to apply a fair bit of pressure to laminate well. IF you like the outcome, which I predict you will, you will use them again and again. Trevor recommends King Billy Pine for the main braces but thats really only available in Straya, so the rest of us used spruce by the responses I got. The CF is fiddly but you get there. Put it on with a little paintbrush, technique is all in the book. If its not stinking hot then you will have enough time to get it right before it sets. I glued the strand under the brace with the brace, then came back later and put the one on the top.

As for where all the info is in the books, info is spread in different places. The index is fairly lightweight so use the section summaries to find things and then mark them with a tab or highlighter so you can find them again.

I'm going to do a Trevor and suggest you have a go at the spreadsheeting. Unless you are a total Luddite its not that hard and there are many benefits to getting some basic capability. You will have a PC (cant run VA without it) so you should have access to some spreadsheet software. Most of us use Excel so do the same if you can. I for one would be unwilling to share my spreadsheets as I wouldn't want to be responsible for passing on a potential cock up in the numbers, if I have made one. Others may feel the same. There is a bit of math involved, if you are truly not going to be able to do it, maybe get one of your/someone else's kids to help??

For me the most important spreadsheet was the one working out the design thickness of the top. There is a table in the design book that gives both the inputs dimensions of the wood and measured tap frequencies and the outputs. Use this to check your spreadsheet, put his numbers in and see if you get the same result. If you don't there's something wrong, go back and check.

For VA use the first appendix in the design book, tells you how to set it up. Also tells you why but a lot of that goes over my head too.

You need a microphone to do the tap testing. I used what I had but I don't think its ideal as it is an audio mike for vocals and I think a directional mic would work better. There are plenty of those around. That's my next purchase.

All the bits arrived for my next guitar the other day so I'll be making a start soon. Just need to wait for Auckland's 95% humidity to abate a little before I start on anything thin and critical. Its persisting down with rain here today, good for the veges though.

Cheers and have fun, they're just bits of wood. (and now CF and epoxy of course)

[kiwigeo]

"Trevor recommends King Billy Pine for the main braces but thats really only available in Straya,"

King Billy pine bends like butter but make sure the KBP youre using is stiff enough.....Ive found this wood varies quite a bit in stiffness and on my first falcate build I ended up ripping off the KBP braces and replacing them with spruce.

[davidafterwork]

Again thanks for such generous and detailed replies!
I am going to get VA and have a go at this so fingers crossed!
I understand about the spreadsheet but perhaps if I do one up someone might have a quick look at it and tweak for me if necessary...!
Do the majority of people using this TG analysis use the CF or are there those who still use Traditional x bracing??
I would like to delve into this method by testing my own Taylor guitar and see if I learn anything so from you are saying this is possible? Bridge rotation test is in the book??
Has anyone bought the TG course on Robbie o browns and does it shed any light on the PC/Excel part ???
Ps
The tops I buy are AAA Sitka spruce from Madinter in Spain for around 55 euro each and IRW back and sides AA for about 70 euro ( 115 Aus dollars I think)
Thanks again
Dave

[Mark McLean]

Dave
You can use any form of bracing you like, and X-bracing is certainly tried and tested. Falcate is just another way to do it, and it is becoming popular- but the bracing pattern is not really what we started talking about in this conversation. It is about getting some objective data about the structural aspects of certain guitars (however they are built) and starting to identify the characteristics of “good” guitars versus not-so-good ones. Then you might be able to work out how to make gooder ones.

For top deflection testing you just need a dial gauge (from E-bay or a good tool shop) and you make some sort of a rig to get it to sit over the middle of the soundboard. Then just measure how much the plate is depressed by a weight placed on the bridge area. Take a look at this thread for some discussions of different rig designs:
viewtopic.php?t=5464
It can actually be pretty simple, such as this one that Trevor Gore showed at one of his classes:

8A1D00C9-CF18-41FF-A03B-9767381E6B53.jpeg (65.07 KiB) Viewed 189210 times

Bridge rotation testing can be done with an inclination measuring app on your mobile phone. Just stick the phone to the bridge of the guitar with Blutac and then zero the incline meter. Measure how much rotation occurs when you take the guitar from full string tension down to no tension, and then back up to concert pitch. Those two measurements will give you a good idea of how stiff and heavily braced your top is, and you can make the same measurements on your Taylor, and as many other guitars as you can get your hands on (maybe a Lowden?).

[davidafterwork]

That’s a great reply again and perfect timing!
I am sitting here with both TG books beside me and have written down the 3 recommended tests to do on my Taylor guitar from the email response
These are
1 Bridge rotation ( build book?? Not in index..)
2 Top deflection
3 spectrum analysis
I will set up VA later on my laptop and try to get a spreadsheet going
I am thinking that If I manage these 3 tests on an existing guitar it might lead me on to doing it on my next build as I will have become a bit familiar with the whole thing...it’s such a prohibitive first book and a shame a spreadsheet isn’t provided with it for those not so tech minded) The 2nd book I have used a lot and it’s excellent.
Thanks again for such effort put into the response and don’t be shy about dropping any more hints re testing the Taylor guitar for learning purposes!
Cheers

[Dave M]

Bridge rotation is described in the build vol section 4.4.2. (1st edition)

Whoever suggested marking the relevant sections in the books is dead right. Mine bristle with post-it notes!

If you do go for using carbon fibre I bought mine from Easy Composites in the UK. They sell a plain weave 3 K cloth, 1 metre wide. I bought a metre and it goes a long way.

Cheers Dave

[davidafterwork]

Thanks again Dave
I am looking at getting the O Brien Gore class online to see if it will give me a kick start..! I have to say that I would have preferred to do the “ traditional” voicing method but I really think you would need to be working with a Luthier to show you and I just don’t have that opportunity. I will let you know how I get on and if by chance anyone has a spreadsheet don’t be shy about sending it on!!
Do you use the method yourself Dave and how many have you built with it???
Dave

[kiwigeo]

I am thinking that If I manage these 3 tests on an existing guitar it might lead me on to doing it on my next build as I will have become a bit familiar with the whole thing...it’s such a prohibitive first book and a shame a spreadsheet isn’t provided with it for those not so tech minded)

One thing Trevor's books aren't are a step by step spoon feed style step by step guide to making a Gore guitar. I found coding up a spreadsheet to work out top thickness time consuming but I got there in the end and I'm fairly maths illiterate. I encourage you to give it a go and if you have problems...well youve got a bunch of ppl on this forun who can guide you in the right direction.

[davidafterwork]

Thanks for that and I might take you up on the offer!! I am putting together the sheet, have downloaded VA and bought the course from O Briens
I also done the Bridge rotation test and that was easy enough ( i picked what looked like the simplest thing to do!)
My result was 2.9 degrees but my Taylor was 1.3 so hopefully I got that bit right.
I now need to do the Spectrum Analysis of a finished guitar so hopefully I can get that one right.
I see a lot of gear needed to do Chladin (??)patterns... is that a must or can I get by without that gear???
Thanks again for the time given to replies everyone
Dave

[kiwigeo]

My result was 2.9 degrees but my Taylor was 1.3 so hopefully I got that bit right.

Rather than using that Taylor as your guide I'd be using the information in Trevor's books as your guide......you may surprise yourself and end up making a guitar that sounds better than your Taylor

[davidafterwork]

Thanks for that
I was just trying to get used to the whole TG method in baby steps..! I am trying it all this weekend so if your have any problems can I forward my spreadsheet for you guys to have a quick look??
Do I need the gear for Chladni patterns or is that optional???
Cheers

[kiwigeo]

Chladni patterns are useful for visualizing how much of your soundboard is active and also for identifying/confirming resonant peaks. Get VA up and running and get familiar with tap testing before getting geared up for Chladni work.

Thanks for that
I was just trying to get used to the whole TG method in baby steps..! I am trying it all this weekend so if your have any problems can I forward my spreadsheet for you guys to have a quick look??
Do I need the gear for Chladni patterns or is that optional???
Cheers

[davidafterwork]

Hello again
I have now done my tests using a copy of excel sheet done for me using a screenshot and the book formulae
I have done my tests but there appears to be something amiss as the thickness is too thin.
Also I seem to get a few readings for each tap and not always sure which one is correct... is there a way for VA to spit out an average??
If there was anyone willing to have a quick look at the spreadsheet for any silly mistakes it would be really appreciated although I must also say that I am not super confident that VA is working correct or maybe it always shows a few different readings for each tap???

10 mins later...for some reason I cannot upload the excel file (invalid file extension message...) but have uploaded the pdf so if there is anything that jumps out at you guys please let me know
Thanks

[kiwigeo]

Hi David,

As far as I can ascertain the forum software isn't set up for Excel attachments...jeremy and I are looking at this.
Re spreadsheet results...first thing to check is units and in particular number of zeros in same.
Re tap tests. VA has a facility to average tap results over a selected number of taps.

Hello again
I have now done my tests using a copy of excel sheet done for me using a screenshot and the book formulae
I have done my tests but there appears to be something amiss as the thickness is too thin.
Also I seem to get a few readings for each tap and not always sure which one is correct... is there a way for VA to spit out an average??
If there was anyone willing to have a quick look at the spreadsheet for any silly mistakes it would be really appreciated although I must also say that I am not super confident that VA is working correct or maybe it always shows a few different readings for each tap???

10 mins later...for some reason I cannot upload the excel file (invalid file extension message...) but have uploaded the pdf so if there is anything that jumps out at you guys please let me know
Thanks

[kiwigeo]

David did you code up that spreadsheet yourself or get it from another source? It looks suspiciously a lot like the sheet I coded up a couple of years back. If the latter is the case then the coding should be ok......I'd check your input data.

[davidafterwork]

Hello
I definitely took it as a screenshot from the forum and then got someone from my job to do up a spreadsheet taking the formulae from the book. The sheet was titled 013 Classical
Now I have gone back to that screenshot and put in your ( if it was yours..!) measurement exactly and it still is almost a full mm thinner as target thickness so I am assuming there is something wrong with my spreadsheet.. I will have to get it checked again!
WhT about the different readings per tap from VA ?? Is that normal and can it calculate an average??? Sorry for what must appear to be silly questions but I feel I am nearly there and if I can get this sorted I will be well on my way to building. TG method guitar!
Dave

[davidafterwork]

Of course if someone had a spreadsheet that they could send for me check mine against that would be fantastic as my work colleague struggled with it as well..!
Dave

[kiwigeo]

Hello
I definitely took it as a screenshot from the forum and then got someone from my job to do up a spreadsheet taking the formulae from the book. The sheet was titled 013 Classical

LOL..yeah definitely one of my spreadsheets. The title refers to one of my engleman top sets