Quote:
Originally Posted by Zandit75
Apologies if I've missed this info somewhere, but are there restrictions on the body size when it comes building baritones?
I understand the scale length is different, but does the body size need to be larger to accommodate, or produce the added bass sound? Could a significant enough bass sound be produced from a body of a 000/OM sized body?
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Good question!
My understanding is that the size of the body affects the lowest frequency that it can generate. On that basis alone, the logic is that a larger body can support the generation of lower frequencies because of the lower air and body resonance. I think most of this is down to volume, but the size of the primary vibrating plates (back and especially top – and so the top plate fundamental), together with the size of the soundhole (which determines the Helmhotz frequency) are also relevant.
If you think of bowed stringed instruments, a double bass has a larger and deeper body compared to, say, a violin, viola or cello. Part of that is to support the longer scale length, but my guess is that the depth (which is deeper on a double bass than it need be/isn’t relevant to scale length) helps too for the above reasons (i.e. the volume is increased).
Of course, this all has to be balanced against projection, comfort, etc.
There are builders that make smaller bodied – e.g. OM sized (I’ve even seen some smaller ones) - baritones. (FWIW, my Montgomery palour, whilst not a baritone, has fan frets which are 25.59 – 26.77” and copes well with low tunings, despite the tiny body and so high lowest fundamental). Indeed I’ve heard some people suggest this – i.e. a smaller bodied baritone - works better (I forget the reasoning, but I can see it might project better and avoid muddiness). But the general consensus in terms of what builders are making (whatever the justification, and whether valid or not) is that most acoustic baritone guitars are large (e.g. jumbos).
Related to this is an interesting psycho-acoustics point. Whilst the bigger the instrument, the lower the fundamental, even a large bodied guitar like the baritone Tom’s building for me isn’t going to be able to generate a fundamental frequency for the notes I’ll be playing on it (which will be as low as a low A at 55Hz or a low G at 49 Hz). Indeed, you’re heading into the territory of being below what many hifis etc can reproduce (or at least, they’re rolling off quite substantially at this point, unless you’ve a sub, transmission line, a large cabinet or woofer, etc). But if you play, say, an A1 at 55Hz, it has a unique set of harmonics:
Partial no. Frequency (Hz) Note name Octave ¢ dev. from 12TET Microtone
1 55 A 1 0
2 110 A 2 0
3 165 E 3 2
4 220 A 3 0
5 275 C# 4 -14
6 330 E 4 2
7 385 G 4 -31 -1/4
8 440 A 4 0
9 495 B 4 4
10 550 C# 5 -14
11 605 Eb 5 -49 -1/4
12 660 E 5 2
13 715 F 5 41 +1/4
14 770 G 5 -31 -1/4
15 825 Ab 5 -12
16 880 A 5 0
Whist the fundamental of this A1 (55hz) would be missing if played on this baritone (or indeed, any acoustic guitar baritone) in any substantive way, the overtones produced imply a fundamental frequency (despite it not being present in the sound generated by the instrument). So the brain perceives/hears the pitch as being the low A – it fills in the missing fundamental based on the harmonics. So the missing fundamental in acoustic guitars isn't generally perceptible. So body size isn't inherently crucial - but bigger will be bassier (which may or may not suit, depending on taste).
It’s worth noting that the harmonic series of an A2 (110Hz) is different, so you wouldn’t mistake A2 for A1:
Partial no. Frequency (Hz) Note name Octave ¢ dev. from 12TET Microtone
1 110 A 2 0
2 220 A 3 0
3 330 E 4 2
4 440 A 4 0
5 550 C# 5 -14
6 660 E 5 2
7 770 G 5 -31 -1/4
8 880 A 5 0
9 990 B 5 4
10 1100 C# 6 -14
11 1210 Eb 6 -49 -1/4
12 1320 E 6 2
13 1430 F 6 41 +1/4
14 1540 G 6 -31 -1/4
15 1650 Ab 6 -12
16 1760 A 6 0
I think (and I may be wrong – happy to be corrected) that what happens in the acoustic baritone example is that the string does actually generate the lowest fundamental, but the body isn’t capable of supporting it. If that’s correct, a magnetic soundhole pickup (if it has the appropriate frequency response) could take that low note for electronic amplification. So I think it’s theoretically possible to play the baritone amplified with those otherwise acoustically missing fundamentals intact. Or get yourself a Boss OC3
