Reference databases for material acoustics...

[FL123]

A client has asked, and I'm not sure where to find the answer... is there an appreciable acoustical difference between performing symphonic music on a painted masonite stage floor VS marley laid on top of said masonite floor? It's not very squishy marley, just the thin stuff.

My instinct is that the effect would be neglibile, but I'm wondering if there is a database online somewhere with reflectivity properties of various surfaces and materials?

 

[Malabaristo]

Not an acoustician, but my instinct lines up with yours: somewhere in the range of zero to imperceptible. I would also flat out refuse to consider it given the risk of damage to the marley from all the chairs--not to mention errant cello and bass endpins, and all the other pointy things involved.

 

[MNicolai]

There is no simple answer to this question.

Generally -- a wood stage floor versus a vinyl dance floor on top of that wood stage floor will perform the same in terms of decay time within the room. They're both equally reflective in terms of airborne sound. Keyword -- airborne.

However -- for instruments that are in direct contact with the floor (cello's, basses, some percussion equipment), the structure-borne resonance carried from the instrument into the floor that can provide additional warmth will be very diminished with a vinyl surface. That may or may not be an appreciable difference for your particular room though. If the subfloor has insulation in it to dampen footfall noise, for example -- that resonance is already getting killed. Any number of other factors in the stage floor construction can also kill that resonance. If you're uncertain about the resonance of your floor and are particularly concerned about providing a better acoustical experience for those specific instruments, you can put them on wooden platforms such as you see below.

Whether or not your room is already acoustically primed for a symphony to the degree where improving resonance will be audible to the overall audience is another matter entirely. It may or may not be that perceptible when your room's broader acoustic experience and background noise are considered.

 

[jtweigandt]

There is no simple answer to this question.

Generally -- a wood stage floor versus a vinyl dance floor on top of that wood stage floor will perform the same in terms of decay time within the room. They're both equally reflective in terms of airborne sound. Keyword -- airborne.

However -- for instruments that are in direct contact with the floor (cello's, basses, some percussion equipment), the structure-borne resonance carried from the instrument into the floor that can provide additional warmth will be very diminished with a vinyl surface. That may or may not be an appreciable difference for your particular room though. If the subfloor has insulation in it to dampen footfall noise, for

But there is a simple answer....you will need MORE COWBELL

 

[FL123]

There is no simple answer to this question.

Generally -- a wood stage floor versus a vinyl dance floor on top of that wood stage floor will perform the same in terms of decay time within the room. They're both equally reflective in terms of airborne sound. Keyword -- airborne.

However -- for instruments that are in direct contact with the floor (cello's, basses, some percussion equipment), the structure-borne resonance carried from the instrument into the floor that can provide additional warmth will be very diminished with a vinyl surface. That may or may not be an appreciable difference for your particular room though. If the subfloor has insulation in it to dampen footfall noise, for example -- that resonance is already getting killed. Any number of other factors in the stage floor construction can also kill that resonance. If you're uncertain about the resonance of your floor and are particularly concerned about providing a better acoustical experience for those specific instruments, you can put them on wooden platforms such as you see below.

Whether or not your room is already acoustically primed for a symphony to the degree where improving resonance will be audible to the overall audience is another matter entirely. It may or may not be that perceptible when your room's broader acoustic experience and background noise are considered.

View attachment 25577

This was my thinking, generally. Our specific floor has fiberglass batting tight-packed in the spaces between the sleepers, so footfall noise (and, presumably, resonance) is already being dampened. The part I wasn't sure of was if 4x8 sheets of masonite, specifically, being a spongy "wood" already, and with gaps between the panels might be worse than a relatively continuous sheet of vinyl. We're not getting locked-together-hardwood sound, no matter what we do!

 

[TimMc]

There is no simple answer to this question.

Generally -- a wood stage floor versus a vinyl dance floor on top of that wood stage floor will perform the same in terms of decay time within the room. They're both equally reflective in terms of airborne sound. Keyword -- airborne.

However -- for instruments that are in direct contact with the floor (cello's, basses, some percussion equipment), the structure-borne resonance carried from the instrument into the floor that can provide additional warmth will be very diminished with a vinyl surface. That may or may not be an appreciable difference for your particular room though. If the subfloor has insulation in it to dampen footfall noise, for example -- that resonance is already getting killed. Any number of other factors in the stage floor construction can also kill that resonance. If you're uncertain about the resonance of your floor and are particularly concerned about providing a better acoustical experience for those specific instruments, you can put them on wooden platforms such as you see below.

Whether or not your room is already acoustically primed for a symphony to the degree where improving resonance will be audible to the overall audience is another matter entirely. It may or may not be that perceptible when your room's broader acoustic experience and background noise are considered.

View attachment 25577

My thought is that the amount of energy transmitted down the "pin" of celli and bass viols to the floor is nearly zero. It's a mass and contact area thing. I suspect the benefit is more of the reflections from the floor back to the player's ears, and to those surrounding the player. Note that there are acoustic comb filters created that will vary with the distance between radiators (the instrument) and the floor, and the distance differences for other listeners. For those who may not be familiar - comb filters are the result of identical signals arriving at different times to the same location. Where the filter creates reinforcement, it's a +6dB boost, but the nulls it creates are nearly infinite (usually represented as -48dB notches in plots). This is the Wild World of Acoustics, and because we can hear (audition) only only place at a time, is why multiple listeners will receive different experiences of the same performance.

 

[MNicolai]

Depends on the end pin and pad. Mass and contact area doesn’t factor in much when the energy tuning forks from the body of the instrument.

This was my thinking, generally. Our specific floor has fiberglass batting tight-packed in the spaces between the sleepers, so footfall noise (and, presumably, resonance) is already being dampened. The part I wasn't sure of was if 4x8 sheets of masonite, specifically, being a spongy "wood" already, and with gaps between the panels might be worse than a relatively continuous sheet of vinyl. We're not getting locked-together-hardwood sound, no matter what we do!

Yeah. Maso/Hardboard is better than vinyl, but hardwood is better yet.

Lot of factors though. Subfloor construction, sleeper spacing, if it’s a sprung floor and what type of sprung floor construction it is (resilient pads vs basket weave vs the fifty other types of sprung floors).

For maximum effect regardless of floor construction though, park the piano on exposed wooden stage floor and the end pin instruments on wooden platforms.

 

[StradivariusBone]

I wonder too how much vibrational energy is transferred down the end pin. Most musicians I've seen use a foam or rubber rock stop aka hockey puck to avoid slipping and/or damaging the deck. That'd have a pretty significant attenuating effect.

I've never seen anyone super concerned about the floor, but drapes, shells and clouds raise a lot of opinions.