Getting ready to tune my A5

[Bob Schmidt]

After reading some threads on the forum, some articles by Peter Coombe, and especially the article by James Condino in GAL on tuning the mandolin strung up in the white I decided to give it a try.
I have a couple of questions:
How much deflection should I expect in the top when it is up to pitch? It is Engleman spruce. The only reference I have is my Gibson A, and it deflects .022 inches with J74 strings. It seems like a lot, but it has not imploded over these many years.
The 2 GOM's I built deflected .013 and .014 inches. I know there are a lot of variables here but a ball park target would be helpful.

I started the F holes with a jewler's saw but they are well undersized so I can open them up with files, sandpaper ect. What should I be looking for as I work toward the helmholtz frequency. Volume or ballance or both?

[Marty Jacobson]

Tuning to specific frequencies, and deflection to specific numbers, is about reproducibility, not tone.

Take measurements. Note them. Then, when you do it again, you have something to compare it to.

I bet it'll sound great!

[Richard500]

(Currently on auction at SGW)
How much deflection when sat upon?

[HoGo]

Forget about tuning to some pitches or deflection. Data from other makers are worthless to you unless you build with exactly same specs and processes as them.
What is your arching like and what are graduations and what type of wood you used? If these are consistent with known good instruments it will sound just fine (if you won't screw the setup :-))

[Bob Schmidt]

I traced the nominal (dotted line) outline of the F holes and penciled them on the top as a guide.I have opened them up to the point where there is up to around .030" left on parts of the tracing around the holes. The instrument went from sounding tight to having some amount of resonance and increased sustain when I sanded maybe .015" around the bottom holes. That seemed to be not very much to make such a difference in the response.
So I am wondering if it is really that sensitive, and should I stop there, or can I expect further improvement by opening it up some more.
At this point it does not sound bad, but it is not as loud as my gibson A2, so I would like to get more volume out of it, and perhaps improve the bass a bit.
Would that be possible or should I just declare victory and move on?

[Eric Oliver]

At this point it does not sound bad, but it is not as loud as my gibson A2, so I would like to get more volume out of it, and perhaps improve the bass a bit.
Would that be possible or should I just declare victory and move on?[/QUOTE]

My two cents -
If your A2 is an oval hole and you are comparing the new f-hole to it...not sure that is fair. I believe the player's experience is different from the listener's experience. You should listen to someone else playing the two in front of you. The f-hole might be projecting more away from the player.
The Gibson A oval models are the King for mandolin bass.
Nut, bridge fittment and strings are also major players in tone and volume.

[Rob Roy]

Eric makes several good points. When assessing loudness, you really have to be in front of an F hole mandolin (get someone else to play both for you) or at least go in the bathroom and play it in front of the mirror along with the oval hole. You may be surprised at how loud it is.

In terms of getting more bass, you can thin the back to get a deeper tone, but this will affect the balance. The reality is that F holes and tone bars make for an instrument that cuts through the mix when played in an ensemble. I would accept the A5 for what it is and cherish your oval A2, they each have their own place.

[Bob Schmidt]

Thanks Eric,
The bridge is fitted and the nut is set for correct string height, frets are leveled so it is set up pretty much the way it will be when I finish it.
I know the A2 is bassy and mine is particularly so, so I have to be careful with that comparison.
I was just suprised at how little I took off to go from an instrument that sounded tight to a point of resonance and I am wondering about taking it any further. I am sure these questions will be answered with experience, but this being the first one I am really shooting blind.