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Why is it you don’t see carved top or arch top stringed instruments with fixed bridges?
I have heard that arch top guitars can have a better dynamic range but can lack in volume. Flat tops with fixed bridges are louder but seem to favor a narrow dynamic range. Are there good reasons why we don’t see this combination?
Thanks,
Wade

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Wade
Nashua, NH
http://www.wadefx.com

It's been my experience that true archtop guitars (not thinline electrics) are typically louder than flat top guitars.

Gibson did have some fixed bridge archtops, about 100 years ago (I've played a 1906 version) - but it's hard to evaluate the sound, since it was such a unique instrument.

Also, the first Gibson harp guitars had fixed bridges, but they switched to floating bridges not too long after their introduction.

If I understand the physics correctly, and I may be totally wrong here, The purpose of the arch in an arch top instrument is to have a thin top that will withstand the downward pressure of the strings. You get a downward pressure only if you have a bridge and a tail piece. Archtop have considerably less bracing than flat tops.

If you were to mount a fixed bridge on an arch top, you wouldn't get a pure downward pressure. You would get a twisting pressure. Also, the arch of an archtop is not a simple sphere but some other complex curve. Making the bottom of a fixed bridge exactly match that curve would be a challange. It took me an hour to fit just the feet of a violin bridge recently. I can't imagine getting a bridge that fully conforms to the top to fit right so I could glue it down.

The original Orville Gibson guitars had glued down bridges.

What Mike said: glueing down the bridge and tieing the strings to it torques the top, and you have to make it heavier or add bracing to withstand the load. Why not take advantage of the geometry and just use a tailpiece?

An article in the recent 'VSA Papers', the putative replacement for the old Catgut 'Journal', claimed that the twice-per-cycle tension change in the strings could drive a violin top. The language in the article is vague, but basically it's because the strings are not parallel to the plane of the top, but at an angle. Changes in tension push down on it. This is the main 'benefit' claimed for flat-top type bridges, and it may bnot be all tat much of a difference after all.