J-45 T(1,1)1 at 80hz after boxing

[ChrisTiemann]

[/img]Greetings all from Texas! First post so I must say since getting the Gore/Gilet books I've found lots of help in this forum in the past so thank you to all of you!
I'm still in my infancy of building guitars (about 2 dozen) and only 6 after getting the books and I believe they have made me a better craftsman and as a result I feel my guitars have improved as well. Recently I started my first J-45 build using the plans from the book. After boxing and a tap test, my results are as follows:
T(1,1)1= 80.4
T(1,1)2=168
T(1,1)3=215
Plugged soundhole top=161
Plugged soundhole back=196
Question is, what to do now. I thought about cutting a sound port in the side but (without doing the math) doubt I could raise it to 90-95 once finish and bridge are on and I certianly cant opennthe soundhole that much. If I leave it alone I'm estimating final responses to be around 78-79 and 148-150.
I'm going to finish the build either way but would like some input about what possibly went wrong. I built a Dread with a very similar bracing pattern and it turned out great and looking back on my notes all the measurements are within the range of all my other builds. All I can think of is this top has quite alot of bearclaw figure and the sides are around 1/8" deeper than my normal Dread sides (I measured a real j-45 for the depth).
Here are some other specs:
Top thickness (per books)= .110" Sitka spruce
Top density= 7.5 grams/inch³ (a little heavy)
Bracing E= 12.8
Bracing density= 6.5 g/in³
All bracing as per plans in book
Mahogany back and sides
Looking forward to any and all responses!
Thank you!

[ChrisTiemann]

This is the tap response

[ChrisTiemann]

I'm in Brenham (Blue Bell ice cream) almost exactly between Houston and Austin on 290.
Yes the whole response is quite low and I'm uncertain as to how it will sound like that. Most of my Dread builds finish around 90/160 or 170 so I was expecting that here as well. Just curious as to why it's so different, if anyone else has a similar tap response, and if so how did the guitar sound as a final product.

[ChrisTiemann]

I'm in Brenham (Blue Bell ice cream) almost exactly between Houston and Austin on 290.
Yes the whole response is quite low and I'm uncertain as to how it will sound like that. Most of my Dread builds finish around 90/160 or 170 so I was expecting that here as well. Just curious as to why it's so different, if anyone else has a similar tap response, and if so how did the guitar sound as a final product.

I know Brenham! I’ve spent a lot of my life all over the state. Lucky you, are closer to Clark’s in Houston than I am.
So you built this guitar identical to the others?
I’m sure someone will eventually reply to you on the forum who is experienced with troubleshooting lower resonance frequencies.
I’m still trying to learn how to calculate the target brace heights by the book.
But I believe the low air and top could be related to maybe over carved braving or thin top or back
What I’ve noticed from reading thousands of comments on here and I have,,, it’s pretty tricky to determine issues, basically the best thing to is keep track of every weight and density of every part and make everything exactly the same ,, more scraping vs sanding, so troubleshooting can start from a comparable datum in reference to other guitars.

I’ve Gore say many times, the frequency measurements are not as important as the sound, like I had a resonance almost on semitone but it wasn’t woofing or deadened,
Testing is hard too, accurate readings aren’t easy to get , I’ll test the same top piece fifteen times to verify,
Idk, I’m still learning this vast realm of science.

I hear you. Math is not my strong suit and I had to enlist a math teacher friend to help me decipher the math and another friend to help set up a spreadsheet so I can enter values and pop out a result.
I also do deflection tests after bracing and after boxing and those numbers were right on point so I'm sure the top and bracing are where they need to be. Guess we shall see how it sounds in the end!

[ChrisTiemann]

Anybody else?