J-45 Bracing Question

[jrodriguez311]

Long time reader, first time poster with a question about recent J-45 bracing. I own a 2016 J-45 that I bought new and it’s been my favorite acoustic guitar. I just recently purchased a second J-45 – a 2018. I noticed that the back bracing on the 2018 is a bit different – the back braces on the 2018 are less scalloped and the scalloping is less rounded, similar to the back bracing on a 2013 J-35 I own. The J-45s both sound great. And though a sample size of two is insufficient to draw any generalizable conclusions, of course, the 2016 has a bit more bass but also less projection and volume.

Anywho, does anyone happen to know if this is normal variation or did the back bracing change in 2018? Thanks in advance!

2018 is on the left and 2016 is on the right.

Edited November 29, 2019 by jrodriguez311

[j45nick]

I don't know if the back braces are CNC cut or hand cut on a bandsaw. It looks to me like a little additional hand sanding at the top of the scallop on your 2016.

It may have to do with the amount of time the person bracing the backs had on their hands at that particular moment.

Historically, there have been significant differences in the top brace carving, which Gibson usually refers to as "hand-carved". There are differences in back brace sectional shape and end carve over time as well.

I would expect this is a normal variation rather than a conscious change. It's hard to get a feel for the actual differences in your case, since the photos are taken at slightly different distances. You appear to be zoomed slightly more on the 2016, since the kerfing and label are at a slightly different scale compared to the other.

[62burst]

They're all individuals, and there are so many other things that can make one sound different than the other. When looking at an old guitar, a crack or damage repair to the back and sides is less likely to concern me, as long as the top/soundboard is in good shape, since what's going on at the top (or on it's underside) has a larger effect on how the guitar sounds. 

Good job getting those photos- both guitars unstrung. Did you get a chance to have a look at the top bracing? Is there a difference in the string action/height at the 12 fret? Neck angle, and also string break over the saddle (and saddle height differences) might be other things to look at.

[jrodriguez311]

Thanks for the replies, j45nick and 62burst! I attached another comparison pic – I kept the zoom the same in all the pics, but I tried to keep the distance closer this time. I don’t yet have a setup to get pics of the top bracing, but I do know that variation there would likely result in more of a difference in voicing than the back bracing. String action, saddle height, and neck angle are all very close on these two guitars.

In any event, it sounds like this is an instance of normal variation. Whatever the case, they’re both superb instruments. Thanks again!

[j45nick]

Based on the second set of photos, the difference is small, but real. I doubt that there is any tonal impact, given that the top is doing most of the work. It would certainly not be an effect that could be isolated from differences due to wood variations, etc.

Your question did pique my curiosity, however.

I pulled out my two 1950 J-45's, with FON's suggesting they were built a month or so apart. The back bracing on those two is very similar, but it is also apparent the end scallops were cut by hand, because they are not absolutely identical.

These are essentially handmade instruments, after all.

What really varies substantially in many vintage cases is  scalloping of top braces, since those appear to have been done largely by eye.

[slimt]

1 hour ago, j45nick said:

Based on the second set of photos, the difference is small, but real. I doubt that there is any tonal impact, given that the top is doing most of the work. It would certainly not be an effect that could be isolated from differences due to wood variations, etc.

Your question did pique my curiosity, however.

I pulled out my two 1950 J-45's, with FON's suggesting they were built a month or so apart. The back bracing on those two is very similar, but it is also apparent the end scallops were cut by hand, because they are not absolutely identical.

These are essentially handmade instruments, after all.

What really varies substantially in many vintage cases is  scalloping of top braces, since those appear to have been done largely by eye.

I agree.   The back bracing is not a critical  for tone but helps in the flow of the tone from the top bracing which is really important.  Those back bracings are  hand cut then put on a big disk sander for making sure the underside has a proper crown for glueing on the backs  as are the top bracings.   One employee may spend time finessing  the scallops while another might just rush those through without so much detail.  

The only CNC parts are cutting tops  , backs , multiple necks at one time.  , fingerboards ,  and the fingerboard cuts for the frets  . 

Im sure lots has changed since the last time I was there. 

[jrodriguez311]

I remember reading that Gibson uses different back bracing across their acoustic line, which makes sense of course. I'd been imagining that there was a template for the different back braces, but it sounds like that assumption was incorrect.

@j45nick - I had an early 50s J-45 until recently. It was a great instrument, but I honestly preferred my 2016 J-45. It's been my impression that the Gibson acoustics of the last 20 years are the best acoustics Gibson has ever produced. They don't have the benefit of age, but their construction tends to be excellent. YMMV, of course.

Thanks again to you all for the info!

[j45nick]

43 minutes ago, jrodriguez311 said:

I remember reading that Gibson uses different back bracing across their acoustic line, which makes sense of course. I'd been imagining that there was a template for the different back braces, but it sounds like that assumption was incorrect.

@j45nick - I had an early 50s J-45 until recently. It was a great instrument, but I honestly preferred my 2016 J-45. It's been my impression that the Gibson acoustics of the last 20 years are the best acoustics Gibson has ever produced. They don't have the benefit of age, but their construction tends to be excellent. YMMV, of course.

Thanks again to you all for the info!

The back bracing can be quite different from model to model. The braces in your J-45's are similar to the back braces in other modern slope-J models, such as the SJ. 

I have both modern and vintage mahogany slope-J's. My modern 1943 SJ re-issue is a superb guitar, but the completely original one-owner 1950 J-45 I bought earlier this year has one big advantage over it: 70-year-old wood. That one is hard to beat for classic Gibson tone.

Gibson Bozeman acoustics from the Ren era are, as you say, probably some of the best guitars Gibson has ever built.

[Guth]

Things like the bracing, back & side wood, top wood, etc. all can have an impact on tone of a guitar and certain generalizations can (and will) be made. Yet I feel it best to consider acoustic guitars holistically. There are a large number of measurable variables when it comes to a guitar's construction. In the end, a guitar might sound quite a bit different than one would expect given the elements that went into it's creation. A while back Murph made a statement to the effect of a good guitar knows no age and I couldn't agree more. I have played many vintage Gibson's with tone that to my ear was disappointing despite their well-aged wood. Why some of those old Gibson's sing like angels and others don't is anyone's guess. What I find of value is the knowledge that when it comes to tone, some guitars for whatever the reason are simply greater than the sum of their parts. They might be older or newer, built lightly or perhaps heavier, use only certain types of glue or not, so on and so forth.  In the end, the only way to know if a guitar really floats your boat is by playing it, listening to it and feeling how you yourself react to it.

jrodriguez311, there is no way of telling just how much difference the back bracing might have on the tone of your two J-45's. It can definitely be somewhat fascinating to ponder. Obviously what's more important to my way of thinking is which one of the two you enjoy the tone of more in spite of those differences.

[E-minor7]

My take is that these 2 are supposed to be similar in the Bozeman-book. 

However we know that fx Hummingbird back-braces differ from Std. to True Vintage/Vintage. - the latter bein' thinner. 

My pair of TV Birds, both from the spring of 2012, have exactly the same back(and top)-braces - yet 2 completely different bridge heights !!! , , , but that's another story. . 

Btw. went and checked the 2010 Std. J-45 bbs here and they seem to be like the long carved ones to the right.

These variations are an intriguing sometimes challenging charm.  Now you really know where to look next time you encounter a 45. 

[jrodriguez311]

Thanks for the thoughtful replies everyone!

 

22 hours ago, Guth said:

jrodriguez311, there is no way of telling just how much difference the back bracing might have on the tone of your two J-45's. It can definitely be somewhat fascinating to ponder. Obviously what's more important to my way of thinking is which one of the two you enjoy the tone of more in spite of those differences.

 

The two J-45s are very similar compared to my other guitars, but they do have different voices. The 2016 - the one with the more heavily scalloped back braces - has more depth, but the 2018 has more projection and volume. I prefer the 2016 for strumming and for leads - it has more overtones, but isn't at all busy. I prefer the 2018 for fingerpicking and for playing out as the neck is a little more substantial on it and I tend to prefer the K&K it has installed over the stock L.R. Baggs in the 2016. Fortunately, I don't have to choose! :)

Thanks again, everyone, for the replies.