James Mayer wrote:I have an oud, a cumbus and a mandola. All of them have doubled courses but very low sustain...
Yes, me too. The oud usually has gut or nylon strings, and tends to be played with a lot of stuccato; the cumbus has a vellum, it's basically a metal banjo; and the mandola has a small body; none of which is condusive to sustain. I've often wondered whether the presence of two strings right next to each other on the bridge tend to make the vibrations die out earlier, or reinforce each other. I haven't noticed that a 12-string guitar has greater or lesser sustain than a regular guitar. Some luthiers think that having a common bridge between all the strings means that the vibrations interfere with each other, and so they build six separate bridges. This is, in effect, what the Stratocaster's individual bridge units do, although they're still close to each other on the bridge plate. My thought is that, on an all-metal instrument, the strings should be able to vibrate just as much whether they're next to another or not, because the instrument itself is heavier, and so the natural frequencies of the body will be lower down the scale. We'll see. On the prototype illustrated, it seems to have plenty of sustain.
The sound of a double-course instrument won't be suitable for all applications, of course. Maybe two necks, with one double course, and one single course, would be useful. A few years ago I built a console guitar with two necks.... one was strung in octaves and the other in unison. I'll see if I can get round to recording a demo of that instrument over the weekend.
James Mayer wrote:...I'd really like to hear a some good long sustained notes and chords if you get a chance to record that steel steel.
The one strung-up prototype that we have available at the moment is being used by Tom. He's not played the lap steel before and is getting very enthusiastic, so I want to encourage him. We should have another prototype available within a week, with 7 double courses, set up for C6, and I'll make sure I record something as a demo.
(It's not going to sound like Jerry Byrd, of course. )