1. A sound system processor configured to enhance the quality of sound produced by reducing the perception of point-source sound generation, the sound system processor configured to process a left (L) channel signal and a right (R) channel signal generated by an audio source to generate output, the sound system processor comprising:
a mid-side processor configured to convert the left and right channel signals into three output signals, one output signal comprising an L+R output signal, another output signal comprising an L\u2212R output signal, and yet another output signal comprising an R\u2212L output signal, the sound system configured to split the L+R output signal into a first split L+R output signal and a second split L+R output signal, the first split L+R output signal being deliverable to a first speaker driver when generated;
a low pass filter configured to take the second split L+R output signal from the mid-side processor and remove frequencies of about 100-800 Hz and greater from the second split L+R output signal to generate a low pass L+R output signal; the sound system configured to split the low pass L+R output signal into a first split low pass L+R output signal and a second split low pass L+R output signal;
a first high pass filter configured to take the L\u2212R output signal from the mid-side processor and remove frequencies less than 100-800 Hz to generate a high pass L\u2212R output signal;
a second high pass filter configured to take the R\u2212L output signal from the mid-side processor and remove frequencies less than 100-800 Hz to generate a high pass R\u2212L output signal;
a first sum processor configured to take the first split low pass L+R output signal and the high pass L\u2212R output signal from the first high pass filter to generate a composite left channel output signal deliverable to a second speaker driver when generated;
a second sum processor configured to take the second split low pass L+R output signal from the low pass filter and the high pass R\u2212L output signal from the second high
pass filter to generate a composite right channel output signal deliverable to a third speaker driver when generated.
2. A surround sound speaker system comprising the sound system processor of claim 1, further comprising a plurality of speakers, a first speaker comprising a driver for receiving one of the split L+R output signals from the mid-side processor, a second speaker comprising a driver for receiving the composite left channel output signal from the first sum processor, and a third speaker comprising a driver for receiving the composite right channel output signal from the second sum processor.
3. The surround sound speaker system of claim 2, wherein the plurality of speakers are positioned to operate in a common rear air chamber.
4. The surround sound speaker system of claim 2, wherein the plurality of speakers are positioned on separate walls of a speaker box.
5. The surround sound speaker system of claim 4, further comprising a passive radiator.
6. A sound system processor configured to enhance the quality of sound produced by reducing the perception of point-source sound generation, the sound system processor configured to process a left (L) channel signal and a right (R) channel signals generated by an audio source to generate output, the sound system processor comprising:
a mid-side processor configured to process (a) a first split left channel input signal and (b) a first split right channel input signal into an L+R output signal and an L\u2212R output signal, wherein the L+R output signal is deliverable to a center speaker driver;
a first low pass filter configured to take a second split left channel input signal and remove frequencies of about 100-800 Hz and greater to generate a low pass left output signal;
a second low pass filter configured to take a second split right channel input signal and remove frequencies of about 100-800 Hz and greater to generate a low pass right output signal;
a high pass filter configured to take the L\u2212R output signal from the mid-side processor and remove frequencies less than about 100-800 Hz to generate a high pass L\u2212R output signal; the sound system processor configured to split the high pass L\u2212R output signal from the high pass filter into a first split high pass L\u2212R output signal and a second split high pass L\u2212R output signal;
a first sum processor configured to convert both the low pass left output signal from the first low pass filter and first split high pass L\u2212R output signal into a composite left output signal deliverable to a left speaker driver when generated;
an inverter configured to invert the second split high pass L\u2212R output signal into a high pass R\u2212L output signal; and
a second sum processor configured to convert both the low pass right output signal from the second low pass filter and the high pass R\u2212L output signal from the inverter into a composite right output signal deliverable to a right speaker driver when generated.
7. A surround sound speaker system comprising the sound system processor of claim 6, further comprising a plurality of speakers, a first speaker comprising a driver for receiving the composite left output signal from the first sum processor, a second speaker comprising a driver for receiving the composite right output signal from the second sum processor, and a third speaker comprising a driver for receiving the L+R output signal from the mid-side processor.
8. The surround sound speaker system of claim 7, wherein the plurality of speakers are positioned to operate in a common rear air chamber.
9. The surround sound speaker system of claim 8, wherein the plurality of speakers are positioned on separate walls of a speaker box.
10. The surround sound speaker system of claim 9, further comprising a passive radiator.
11. A method for processing signals generated by an audio source so as to enhance the quality of sound produced by reducing the perception of point-source sound generation, the method applicable to processing a left (L) channel signal and a right (R) channel signal generated by the audio source, the method comprising:
converting the left and right channel signals into three output signals, one comprising an L+R output signal, another comprising an L\u2212R output signal, and yet another comprising an R\u2212L output signal;
splitting the L+R output signal into a first split L+R output signal and a second split L+R output signal,
directing the first split L+R output signal so that it may be received by a center speaker driver;
filtering the second split L+R output signal to remove frequencies of about 100-800 Hz and greater so as to generate a low pass L+R output signal;
splitting the low pass L+R signal output into a first split low pass L+R output signal and second split low pass L+R signal output,
filtering the L\u2212R output signal to remove frequencies less than about 100-800 Hz so as to generate a high pass L\u2212R output signal;
filtering the R\u2212L output signal to remove frequencies less than about 100-800 Hz so as to generate a high pass R\u2212L output signal;
combining the first split low pass L+R output signal and the high pass L\u2212R output signal into a composite left channel output signal;
directing the composite left channel output signal so that it may be received by a left speaker driver;
combining the second split low pass L+R output signal and the high pass R\u2212L output signal into a composite right channel output signal; and
directing the composite right channel output signal so that it may be received by a right speaker driver.
12. A method for processing signals generated by an audio source so as configured to enhance the quality of sound produced by reducing the perception of point-source sound generation, the method applicable to processing a left (L) channel signal and a right (R) channel signal generated by the audio source, the method comprising:
splitting the left channel signal into a first split left channel input signal and second split left channel input signal;
splitting the right channel signal into a first split right channel input signal and a second right channel input signal;
filtering the first split left channel input signal to remove frequencies of about 100-800 Hz and greater so as to generate a low pass left output signal;
filtering the first split right channel input signal to remove frequencies of about 100-800 Hz and greater so as to generate a low pass right output signal;
converting the second split left channel input signal and the second split right channel input signals into at least an L+R output signal and an L\u2212R output signal;
directing the L+R output signal so that it may be received by a center speaker driver;
filtering the L\u2212R output signal to remove frequencies less than about 100-800 Hz so as to generate a high pass L\u2212R output signal;
splitting the high pass L\u2212R output signal into a first split high pass L\u2212R output signal and second split high pass L\u2212R output signal,
combining the low pass left output signal and the first high pass L-R output signal into a composite left channel output signal;
directing the composite left channel output signal so that it may be received by a left speaker driver;
inverting the second split high pass L\u2212R output signal into a high pass R\u2212L output signal;
combining the low pass right output signal and the high pass R\u2212L output signal into a composite right channel output signal; and
directing the composite right channel output signal so that it may be received by a right speaker driver.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A transparent, monolithic or laminated sheet material based on a methyl methacrylate homopolymer or copolymer, the laminated material having at least one of its two outer layers made of the methyl methacrylate homopolymer or copolymer, characterized in that the monolithic sheet of methyl methacrylate homopolymer or copolymer or at least one outer layer of methyl methacrylate homopolymer or copolymer of the laminated sheet has, in the region of the surface, over a depth of at least 50 nanometers from the surface, an increase in its average density of 0.1 to 1 gcm3, the average density being determined by X-ray reflectometry.
2. The material as claimed in claim 1, wherein the increase in the average density is 0.1 to 0.4 gcm3.
3. The material as claimed in claim 1, subjected to a treatment capable of densifying it on the surface to a depth of up to 5 microns.
4. The material as claimed in claim 3, subjected to a treatment capable of densifying it on the surface to a depth ranging from 0.5 to 1.5 microns.
5. The material as claimed in claim 3, wherein the surface densification treatment is a treatment with fluorine which results in the formation of a concentration gradient of fluorine atoms from the surface toward the inside of the material.
6. The material as claimed in claim 5, wherein the concentration of fluorine atoms, determined by SEM-EDS, is at least 0.25 fluorine atoms per repeat unit:
4
in the outermost surface layer of the material.
7. The material as claimed in claim 6, wherein the concentration of fluorine atoms, determined by SEM-EDS, is 0.25 to 8 fluorine atoms, especially 0.25 to 5 fluorine atoms and in particular 0.33 to 1.5 fluorine atoms per repeat unit:
5
in the outermost surface layer of the material.
8. A process for manufacturing a the sheet material as claimed in claim 1, wherein one or more sheets based on a methyl methacrylate homopolymer or copolymer undergo a surface fluorination or oxyfluorination treatment by a gas mixture consisting of F2 or NF3 or ClF3carrier gas such as helium, N2 and CO2, when appropriate in the presence of residual oxygen from the air, in a reaction chamber until the desired increase in the density has been obtained.
9. Glazing made crazing-resistant by densification of that surface intended to be exposed to the external atmosphere, especially aircraft glazing, in particular outer window panels, incorporating the material as defined in claim 1.
10. A process for the manufacture of glazing as defined in claim 9, wherein a base sheet of methyl methacrylate homopolymer or copolymer is cut into several individual sheets intended to form the glazing and in that each individual sheet undergoes a drawing operation, a fluorination or oxyfluorination treatment as defined in claim 8 being carried out before cutting, or before drawing or after drawing.
11. A process for restoring aircraft glazing, wherein the outer layer of the sheet constituting the glazing to be restored, by a mechanical polishing treatment to a depth of 0.3-0.7 mm, is removed and then said sheet undergoes the fluorination or oxyfluorination treatment as defined in claim 8.
12. A process allowing a monolithic sheet material based on a methyl methacrylate polymer to be made crazing-resistant andor its bonding strength to be improved, wherein the methyl methacrylate polymer is selected from among methyl methacrylatefluorinated comonomer(s) copolymers, methyl methacrylate polymers treated by immersion in a solution of anhydrous hydrofluoric acid or of a salt chosen from NaF, KF, LiF and CaF2, followed by an electrolytic fluorination reaction, and methyl methacrylate polymers surface-treated by the fluorination or oxyfluorination process as described in claim 8.