Although Rufus' answer is slightly flippant (and quite funny), I think he has a point. Very many things in normal life exist under very high pressures. Road bicycle tyres can run at 8 times atmospheric pressure, the combustion chamber of your car nearer 50 times, fire extinguishers higher than that and so on.
Devialet are doing a rather strange thing and quoting a sound pressure level, which is a measurement normally used to denote how loud something sounds, in a location where it would be difficult to locate a microphone, let alone a human ear. Plus, sound pressure levels follow the inverse square law, so it would be more meaningful if Devialet quoted the actual pressure in bar or psi if they wanted to boast about what is going on inside a Phantom. Who worries what the SPL is inside a car combustion chamber? After all, this is a very tricky place to stick your ear when the engine is fully assembled and running.
Undoubtedly, the pressure inside a Phantom is higher than you would find in a "normal" loudspeaker, and this explains why the egg shape is used, and why the bass "imploders" are dome shaped. For internal pressures, the sphere is by far the best shape, a cylinder is also quite good, but even a cylinder needs to be twice the thickness of a sphere for a given pressure. Large rectangular boxes are a very bad shape for internal pressures, but this is not too much of a problem for normal speakers because the pressures are not that high, in particular if you have a bass port, it is hard to pressurise something with a big hole in it. I guess you could do some very cleaver calculations, based on the internal volume of the Phantom, the degree of air compression you would get from the rapid movement of the drivers, but it should be noted that these pressures are transient, the Phantom has a hole in the front of it, effectively venting to atmospheric pressure.
So who is going to be brave and send a query to Devialet asking what the actual internal pressure inside a Phantom during one of it's 170dB moments?
I must stop now, I appear to be writing a load of annoying nonsense. (I wonder if they have any jobs going in Devialet's marketing department?)
Devialet are doing a rather strange thing and quoting a sound pressure level, which is a measurement normally used to denote how loud something sounds, in a location where it would be difficult to locate a microphone, let alone a human ear. Plus, sound pressure levels follow the inverse square law, so it would be more meaningful if Devialet quoted the actual pressure in bar or psi if they wanted to boast about what is going on inside a Phantom. Who worries what the SPL is inside a car combustion chamber? After all, this is a very tricky place to stick your ear when the engine is fully assembled and running.
Undoubtedly, the pressure inside a Phantom is higher than you would find in a "normal" loudspeaker, and this explains why the egg shape is used, and why the bass "imploders" are dome shaped. For internal pressures, the sphere is by far the best shape, a cylinder is also quite good, but even a cylinder needs to be twice the thickness of a sphere for a given pressure. Large rectangular boxes are a very bad shape for internal pressures, but this is not too much of a problem for normal speakers because the pressures are not that high, in particular if you have a bass port, it is hard to pressurise something with a big hole in it. I guess you could do some very cleaver calculations, based on the internal volume of the Phantom, the degree of air compression you would get from the rapid movement of the drivers, but it should be noted that these pressures are transient, the Phantom has a hole in the front of it, effectively venting to atmospheric pressure.
So who is going to be brave and send a query to Devialet asking what the actual internal pressure inside a Phantom during one of it's 170dB moments?
I must stop now, I appear to be writing a load of annoying nonsense. (I wonder if they have any jobs going in Devialet's marketing department?)
