Sustain?

[Link]

What instruments have good sustain?

[Jim Broyles]

Electric guitars, bowed instruments and fretted ones with long, new strings and a good soundboard.

[Link]

Among acoustic mandolins, I mean.

[sunburst]

To convert energy from the string into sound, the body of an acoustic instrument "steals" energy from the string. That loss of the string's energy slows and eventually stops it's vibration, so instruments who's bodies steal less energy from the string allow the string to vibrate longer and have more sustain. A body that steals more energy from the string can be louder, but will have less sustain.
There is a general trade-off between loudness and sustain, with lighter, more responsive instruments being louder with less sustain, and heavier, less responsive instruments being quieter with more sustain.
Of coarse there's more to it than that, only a small part the energy stolen from the strings gets converted into sound, so instruments that are more efficient at turning string energy into sound can have more loudness and more sustain than inefficient ones that waste more string energy.

So acoustic instruments with a lot of sustain are either the ones that are most efficient at using string energy or those that don't use as much string energy.

Think of a steel guitar. The body is a big block of wood, metal or something, intentionally made heavy and unresponsive. The strings will sustain for a long time but are very quiet. Since the pickups convert string movement into electrical impulses rather than the body turning them to sound that's an advantage, unlike it would be in an acoustic instrument.

[man dough nollij]

Oval holed, carved-tops, and round-holed flat-tops. Yep.

[barney 59]

I would go with an oval hole flatback with a spruce top and brazilian back and sides--- or a mandocaster played through a fender twin reverb.

[Chuck Naill]

There is a general trade-off between loudness and sustain, with lighter, more responsive instruments being louder with less sustain, and heavier, less responsive instruments being quieter with more sustain.

My experiance is that a heavy instrument do not sustain well, but it is quieter as you write.

Given two instruments from the same maker, the lighter one will be superior in response as you say and tone, sustain, and volume.

What is your opinion about how time will factor in with these two instruments?

chuck naill/knoxville, tennessee

[barney 59]

I have two pieces of wood, one is mahogany and the other rosewood -they are approximately the same size with the intention that one day they will be guitar backs. Without putting them on a scale the rosewood is clearly heavier than the mahogany but if I hold each piece by one corner and tap it the rosewood will have an audible sound that lasts much longer than the mahogany. I find that true also with my guitars. A d18 against a d28Mahogany I think gives a much truer sound but with less sustain than rosewood -but the rosewood has a higher specific gravity than the mahogany. If I did the same test with lets say a piece of cement board it would be heavier but wouldn't transfer hardly any sound at all -a piece of poplar- it would be the lightest of all it and wouldn't make much more sound than the cement board. It's not the meat it's the motion.