Harp: Extended Techniques

I've recently been researching the harp and have learned things such as the pedaling system, register colors, and idiomatic playing. I've also been exposed to a technique called "pres de la table" which basically means to pluck the strings close to the soundboard. The effect is a darker, edgier sound. I was hoping if a knowledgeable composer or harpist could answer my questions: Is pres de la table an extended technique that should be used sparingly, or is it a color choice that is up to the composer? Also, are there any other "extended techniques" on the harp that I should know about?

43 minutes ago, Jacob Hall said:

I've recently been researching the harp and have learned things such as the pedaling system, register colors, and idiomatic playing. I've also been exposed to a technique called "pres de la table" which basically means to pluck the strings close to the soundboard. The effect is a darker, edgier sound. I was hoping if a knowledgeable composer or harpist could answer my questions: Is pres de la table an extended technique that should be used sparingly, or is it a color choice that is up to the composer? Also, are there any other "extended techniques" on the harp that I should know about?

I would be wary of asking someone to pluck close to the soundboard on the lowest strings, especially considering that most harpists are females which generally have shorter reach. Plus it looks a little ridiculous, if you are sensitive to the theatrical side of music. There is no threshold, you will have to judge for yourself. It should be clear that plucking close to the soundboard is more tiring on the fingers, because the string is less flexible at the extremes and therefore you need to pluck it harder to get the same amplitude. But that's not the only reason it is quieter, because plucking close to the soundboard also works similarly to a high-pass filter on an oscillator in that it sieves the high partials from the string's harmonic spectrum, which have a naturally lower amplitude than the lower partials. So, you are not going to make many long-time harpist friends by abusing the technique.