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#81
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Speakers Then and Now
"Rusty Boudreaux" wrote in message ...
"Svante" wrote in message om... Sigh... If you were able to put the flashlight within a fraction of a wavelength from the mirror the power WOULD increase. In the audio case this is easily accomplished. I think it is frequently used with antennas too (correct me if I am wrong). Power DOES increase. Read the parallel thread, in particular Really? Adding a mirror changes the power output of the filament? So all we have to do is take a few mirrors and we can transform a tiny flashlight into a death ray to knock airplanes out of the sky. Better yet, couple it with some solar cells and we could power the Earth off a flashlight. The problem with this analogy is that it is very hard to put the filament within a fraction of a wavelength to the mirror. Antennas: An isotropic radiator is an antenna that radiates equally in all directions. Antenna gain is the improvement above an isotropic radiator. However, the gain comes at a price - directivity. Look at common antenna radiation patterns. The higher the gain the narrower the radiation pattern. Total radiation power is the same...it's just squeezed into a narrower beam. Study the photos he http://www.hdtvprimer.com/ANTENNAS/types.html Agreed. Antennas already have a high efficiency, and obviously it can never go above 100%. Speakers don't, so there is plenty of power left over. Increasing the radiation resistance will make use of some of that. I'm sorry about making the antenna analogy, it does not hold when it comes to efficiency. It the same thing with audio. Gain can increase at the price of directivity. Power can not increase. There is no free lunch in the physical world. Consider this parallel; an electrical voltage source has an output impedance of 10 kohms. You connect a load of 100 ohms to this source. A certain (small) amount of power will be dissipated in the 100 ohm resistor when you turn the source on. Now change the load resistor to 200 ohms. What will happen to the power in the load resistor? It will almost double. Efficiency will almost double. This is what happens in the loudspeaker, only the 10 kohm resistor corresponds to the mechanical impedances (mass etc) of the cone, and the load resistor corresponds to the radiation resistance. In the antenna case the source impedance would be ~0 ohms, and no efficiency change would occur. |
#82
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Speakers Then and Now
"Rusty Boudreaux" wrote in message ...
"Svante" wrote in message om... Sigh... If you were able to put the flashlight within a fraction of a wavelength from the mirror the power WOULD increase. In the audio case this is easily accomplished. I think it is frequently used with antennas too (correct me if I am wrong). Power DOES increase. Read the parallel thread, in particular Really? Adding a mirror changes the power output of the filament? So all we have to do is take a few mirrors and we can transform a tiny flashlight into a death ray to knock airplanes out of the sky. Better yet, couple it with some solar cells and we could power the Earth off a flashlight. The problem with this analogy is that it is very hard to put the filament within a fraction of a wavelength to the mirror. Antennas: An isotropic radiator is an antenna that radiates equally in all directions. Antenna gain is the improvement above an isotropic radiator. However, the gain comes at a price - directivity. Look at common antenna radiation patterns. The higher the gain the narrower the radiation pattern. Total radiation power is the same...it's just squeezed into a narrower beam. Study the photos he http://www.hdtvprimer.com/ANTENNAS/types.html Agreed. Antennas already have a high efficiency, and obviously it can never go above 100%. Speakers don't, so there is plenty of power left over. Increasing the radiation resistance will make use of some of that. I'm sorry about making the antenna analogy, it does not hold when it comes to efficiency. It the same thing with audio. Gain can increase at the price of directivity. Power can not increase. There is no free lunch in the physical world. Consider this parallel; an electrical voltage source has an output impedance of 10 kohms. You connect a load of 100 ohms to this source. A certain (small) amount of power will be dissipated in the 100 ohm resistor when you turn the source on. Now change the load resistor to 200 ohms. What will happen to the power in the load resistor? It will almost double. Efficiency will almost double. This is what happens in the loudspeaker, only the 10 kohm resistor corresponds to the mechanical impedances (mass etc) of the cone, and the load resistor corresponds to the radiation resistance. In the antenna case the source impedance would be ~0 ohms, and no efficiency change would occur. |
#83
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Speakers Then and Now
"Rusty Boudreaux" wrote in message ...
"Svante" wrote in message om... Sigh... If you were able to put the flashlight within a fraction of a wavelength from the mirror the power WOULD increase. In the audio case this is easily accomplished. I think it is frequently used with antennas too (correct me if I am wrong). Power DOES increase. Read the parallel thread, in particular Really? Adding a mirror changes the power output of the filament? So all we have to do is take a few mirrors and we can transform a tiny flashlight into a death ray to knock airplanes out of the sky. Better yet, couple it with some solar cells and we could power the Earth off a flashlight. The problem with this analogy is that it is very hard to put the filament within a fraction of a wavelength to the mirror. Antennas: An isotropic radiator is an antenna that radiates equally in all directions. Antenna gain is the improvement above an isotropic radiator. However, the gain comes at a price - directivity. Look at common antenna radiation patterns. The higher the gain the narrower the radiation pattern. Total radiation power is the same...it's just squeezed into a narrower beam. Study the photos he http://www.hdtvprimer.com/ANTENNAS/types.html Agreed. Antennas already have a high efficiency, and obviously it can never go above 100%. Speakers don't, so there is plenty of power left over. Increasing the radiation resistance will make use of some of that. I'm sorry about making the antenna analogy, it does not hold when it comes to efficiency. It the same thing with audio. Gain can increase at the price of directivity. Power can not increase. There is no free lunch in the physical world. Consider this parallel; an electrical voltage source has an output impedance of 10 kohms. You connect a load of 100 ohms to this source. A certain (small) amount of power will be dissipated in the 100 ohm resistor when you turn the source on. Now change the load resistor to 200 ohms. What will happen to the power in the load resistor? It will almost double. Efficiency will almost double. This is what happens in the loudspeaker, only the 10 kohm resistor corresponds to the mechanical impedances (mass etc) of the cone, and the load resistor corresponds to the radiation resistance. In the antenna case the source impedance would be ~0 ohms, and no efficiency change would occur. |
#84
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Speakers Then and Now
"Rusty Boudreaux" wrote in message ...
"Svante" wrote in message om... Sigh... If you were able to put the flashlight within a fraction of a wavelength from the mirror the power WOULD increase. In the audio case this is easily accomplished. I think it is frequently used with antennas too (correct me if I am wrong). Power DOES increase. Read the parallel thread, in particular Really? Adding a mirror changes the power output of the filament? So all we have to do is take a few mirrors and we can transform a tiny flashlight into a death ray to knock airplanes out of the sky. Better yet, couple it with some solar cells and we could power the Earth off a flashlight. The problem with this analogy is that it is very hard to put the filament within a fraction of a wavelength to the mirror. Antennas: An isotropic radiator is an antenna that radiates equally in all directions. Antenna gain is the improvement above an isotropic radiator. However, the gain comes at a price - directivity. Look at common antenna radiation patterns. The higher the gain the narrower the radiation pattern. Total radiation power is the same...it's just squeezed into a narrower beam. Study the photos he http://www.hdtvprimer.com/ANTENNAS/types.html Agreed. Antennas already have a high efficiency, and obviously it can never go above 100%. Speakers don't, so there is plenty of power left over. Increasing the radiation resistance will make use of some of that. I'm sorry about making the antenna analogy, it does not hold when it comes to efficiency. It the same thing with audio. Gain can increase at the price of directivity. Power can not increase. There is no free lunch in the physical world. Consider this parallel; an electrical voltage source has an output impedance of 10 kohms. You connect a load of 100 ohms to this source. A certain (small) amount of power will be dissipated in the 100 ohm resistor when you turn the source on. Now change the load resistor to 200 ohms. What will happen to the power in the load resistor? It will almost double. Efficiency will almost double. This is what happens in the loudspeaker, only the 10 kohm resistor corresponds to the mechanical impedances (mass etc) of the cone, and the load resistor corresponds to the radiation resistance. In the antenna case the source impedance would be ~0 ohms, and no efficiency change would occur. |
#85
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Speakers Then and Now
On Thu, 8 Jan 2004 00:29:16 -0600, "Rusty Boudreaux"
wrote: "Svante" wrote in message . com... Sigh... If you were able to put the flashlight within a fraction of a wavelength from the mirror the power WOULD increase. In the audio case this is easily accomplished. I think it is frequently used with antennas too (correct me if I am wrong). Power DOES increase. Read the parallel thread, in particular Really? Adding a mirror changes the power output of the filament? Well at least it will make it hotter, if focussed back on itself and guess what would happen then. So all we have to do is take a few mirrors and we can transform a tiny flashlight into a death ray to knock airplanes out of the sky. Better yet, couple it with some solar cells and we could power the Earth off a flashlight. Don't be silly now, nobody is claiming perpetual motion. As it happens. . . one already has 100MW pulses but it is not nearly enough for a "death ray to knock airplanes out of the sky". For that you need energy and making pulses shorter does not help there. Try to distinguish between energy and power, and amplitude and power, and coherent and incoherent summation, and effeciency changes and perpetual motion machines, if you are going to get sarcastic. |
#86
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Speakers Then and Now
On Thu, 8 Jan 2004 00:29:16 -0600, "Rusty Boudreaux"
wrote: "Svante" wrote in message . com... Sigh... If you were able to put the flashlight within a fraction of a wavelength from the mirror the power WOULD increase. In the audio case this is easily accomplished. I think it is frequently used with antennas too (correct me if I am wrong). Power DOES increase. Read the parallel thread, in particular Really? Adding a mirror changes the power output of the filament? Well at least it will make it hotter, if focussed back on itself and guess what would happen then. So all we have to do is take a few mirrors and we can transform a tiny flashlight into a death ray to knock airplanes out of the sky. Better yet, couple it with some solar cells and we could power the Earth off a flashlight. Don't be silly now, nobody is claiming perpetual motion. As it happens. . . one already has 100MW pulses but it is not nearly enough for a "death ray to knock airplanes out of the sky". For that you need energy and making pulses shorter does not help there. Try to distinguish between energy and power, and amplitude and power, and coherent and incoherent summation, and effeciency changes and perpetual motion machines, if you are going to get sarcastic. |
#87
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Speakers Then and Now
On Thu, 8 Jan 2004 00:29:16 -0600, "Rusty Boudreaux"
wrote: "Svante" wrote in message . com... Sigh... If you were able to put the flashlight within a fraction of a wavelength from the mirror the power WOULD increase. In the audio case this is easily accomplished. I think it is frequently used with antennas too (correct me if I am wrong). Power DOES increase. Read the parallel thread, in particular Really? Adding a mirror changes the power output of the filament? Well at least it will make it hotter, if focussed back on itself and guess what would happen then. So all we have to do is take a few mirrors and we can transform a tiny flashlight into a death ray to knock airplanes out of the sky. Better yet, couple it with some solar cells and we could power the Earth off a flashlight. Don't be silly now, nobody is claiming perpetual motion. As it happens. . . one already has 100MW pulses but it is not nearly enough for a "death ray to knock airplanes out of the sky". For that you need energy and making pulses shorter does not help there. Try to distinguish between energy and power, and amplitude and power, and coherent and incoherent summation, and effeciency changes and perpetual motion machines, if you are going to get sarcastic. |
#88
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Speakers Then and Now
On Thu, 8 Jan 2004 00:29:16 -0600, "Rusty Boudreaux"
wrote: "Svante" wrote in message . com... Sigh... If you were able to put the flashlight within a fraction of a wavelength from the mirror the power WOULD increase. In the audio case this is easily accomplished. I think it is frequently used with antennas too (correct me if I am wrong). Power DOES increase. Read the parallel thread, in particular Really? Adding a mirror changes the power output of the filament? Well at least it will make it hotter, if focussed back on itself and guess what would happen then. So all we have to do is take a few mirrors and we can transform a tiny flashlight into a death ray to knock airplanes out of the sky. Better yet, couple it with some solar cells and we could power the Earth off a flashlight. Don't be silly now, nobody is claiming perpetual motion. As it happens. . . one already has 100MW pulses but it is not nearly enough for a "death ray to knock airplanes out of the sky". For that you need energy and making pulses shorter does not help there. Try to distinguish between energy and power, and amplitude and power, and coherent and incoherent summation, and effeciency changes and perpetual motion machines, if you are going to get sarcastic. |
#89
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Speakers Then and Now
Svante wrote:
efficiency. This is not only an issue of directivity, it is also an issue of radiation resistance (which is doubled). Aha. Please READ the parallel thread I referred to! OK I can back this up with some math if you are interested. Kind regards Peter Larsen -- ******************************************* * My site is at: http://www.muyiovatki.dk * ******************************************* |
#90
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Speakers Then and Now
Svante wrote:
efficiency. This is not only an issue of directivity, it is also an issue of radiation resistance (which is doubled). Aha. Please READ the parallel thread I referred to! OK I can back this up with some math if you are interested. Kind regards Peter Larsen -- ******************************************* * My site is at: http://www.muyiovatki.dk * ******************************************* |
#91
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Speakers Then and Now
Svante wrote:
efficiency. This is not only an issue of directivity, it is also an issue of radiation resistance (which is doubled). Aha. Please READ the parallel thread I referred to! OK I can back this up with some math if you are interested. Kind regards Peter Larsen -- ******************************************* * My site is at: http://www.muyiovatki.dk * ******************************************* |
#92
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Speakers Then and Now
Svante wrote:
efficiency. This is not only an issue of directivity, it is also an issue of radiation resistance (which is doubled). Aha. Please READ the parallel thread I referred to! OK I can back this up with some math if you are interested. Kind regards Peter Larsen -- ******************************************* * My site is at: http://www.muyiovatki.dk * ******************************************* |
#93
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Speakers Then and Now
Peter Larsen wrote:
Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? |
#94
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Speakers Then and Now
Peter Larsen wrote:
Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? |
#95
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Speakers Then and Now
Peter Larsen wrote:
Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? |
#96
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Speakers Then and Now
Peter Larsen wrote:
Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? |
#97
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Speakers Then and Now
On Thu, 08 Jan 2004 16:29:58 GMT, henryf
wrote: Peter Larsen wrote: Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? No, that only affects the gain. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#98
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Speakers Then and Now
On Thu, 08 Jan 2004 16:29:58 GMT, henryf
wrote: Peter Larsen wrote: Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? No, that only affects the gain. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#99
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Speakers Then and Now
On Thu, 08 Jan 2004 16:29:58 GMT, henryf
wrote: Peter Larsen wrote: Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? No, that only affects the gain. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#100
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Speakers Then and Now
On Thu, 08 Jan 2004 16:29:58 GMT, henryf
wrote: Peter Larsen wrote: Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? No, that only affects the gain. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#101
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#102
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#103
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#104
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#106
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Speakers Then and Now
ow (Goofball_star_dot_etal) wrote in message ...
On 8 Jan 2004 00:59:37 -0800, (Svante) wrote: (Goofball_star_dot_etal) wrote in message ... On 7 Jan 2004 10:33:01 -0800, (Svante) wrote: Do you also have a feeling of déjà vu? ;-) Yes, but this time I don't see the fine print. :-) Errh... The parallel would be that two speakers in free space essentially is the same as one speaker in half space. Was that what you meant by "fine print"? I was thinking of the phrase: "Do you see how I EXPLICITLY chose to NOT talk about the acoustical effects? The reason being is precisely BECAUSE of the complex depednecny on frequency" This no longer applies. Ahh... You're right! Maybe I should withdraw my statement below... :-) I have a lot of faith in academic researchers. You should know your stuff and perhaps people should listen more. I don't want people accepting what I say without understanding. If someone thinks I'm wrong I want to know that. When I understand that I am wrong I say so, and I am mostly happy about that because it means that I have learned something. The goal of a discussion is, IMO, an ending where everyone agree, and everyone has learned something. But you are right, listening is of course a prerequisite for this to happen. Entering a discussion to prove that one is right, however, easily ends up in the sand box, and nobody learns anything. |
#107
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Speakers Then and Now
ow (Goofball_star_dot_etal) wrote in message ...
On 8 Jan 2004 00:59:37 -0800, (Svante) wrote: (Goofball_star_dot_etal) wrote in message ... On 7 Jan 2004 10:33:01 -0800, (Svante) wrote: Do you also have a feeling of déjà vu? ;-) Yes, but this time I don't see the fine print. :-) Errh... The parallel would be that two speakers in free space essentially is the same as one speaker in half space. Was that what you meant by "fine print"? I was thinking of the phrase: "Do you see how I EXPLICITLY chose to NOT talk about the acoustical effects? The reason being is precisely BECAUSE of the complex depednecny on frequency" This no longer applies. Ahh... You're right! Maybe I should withdraw my statement below... :-) I have a lot of faith in academic researchers. You should know your stuff and perhaps people should listen more. I don't want people accepting what I say without understanding. If someone thinks I'm wrong I want to know that. When I understand that I am wrong I say so, and I am mostly happy about that because it means that I have learned something. The goal of a discussion is, IMO, an ending where everyone agree, and everyone has learned something. But you are right, listening is of course a prerequisite for this to happen. Entering a discussion to prove that one is right, however, easily ends up in the sand box, and nobody learns anything. |
#108
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Speakers Then and Now
ow (Goofball_star_dot_etal) wrote in message ...
On 8 Jan 2004 00:59:37 -0800, (Svante) wrote: (Goofball_star_dot_etal) wrote in message ... On 7 Jan 2004 10:33:01 -0800, (Svante) wrote: Do you also have a feeling of déjà vu? ;-) Yes, but this time I don't see the fine print. :-) Errh... The parallel would be that two speakers in free space essentially is the same as one speaker in half space. Was that what you meant by "fine print"? I was thinking of the phrase: "Do you see how I EXPLICITLY chose to NOT talk about the acoustical effects? The reason being is precisely BECAUSE of the complex depednecny on frequency" This no longer applies. Ahh... You're right! Maybe I should withdraw my statement below... :-) I have a lot of faith in academic researchers. You should know your stuff and perhaps people should listen more. I don't want people accepting what I say without understanding. If someone thinks I'm wrong I want to know that. When I understand that I am wrong I say so, and I am mostly happy about that because it means that I have learned something. The goal of a discussion is, IMO, an ending where everyone agree, and everyone has learned something. But you are right, listening is of course a prerequisite for this to happen. Entering a discussion to prove that one is right, however, easily ends up in the sand box, and nobody learns anything. |
#109
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Speakers Then and Now
"Rusty Boudreaux" wrote in message ...
"Goofball_star_dot_etal" wrote in message ... You can argue all you want but you will be wrong. Betting is still open. . . Sorry, but the race is over. White light is incoherent and the wavlength of green, say 532 nm is considerably shorter than, say, a 1cm filament. You analogy is ********. Sorry, the analogy wasn't perfect. I was trying to explain in terms a moron could understand. Usually a visible example helps but I guess not for you. It amazes me you can't understand why changing the radiation pattern can not increase the output power of a driver. Goofball. I don't think it is the "Golfball" that is stuck in the sandpit... :-) Changing the radiation pattern (by changing from free space to half space) doubles the intensity (=+3dB), right. But in the case when the source is near its mirror image (compared to wavelength) the radiation resistance also doubles. Given that the cone velocity remains the same twice the power is produced in the radiation resistance, which yields another intensity doubling (=+3 dB). So, if a speaker is mounted in a wall, the intensity is raised by +6 dB (you may have heard that number (+ SIX dB) in this context before?), of which 3 dB comes from directivity, and 3 dB comes from increased efficiency. And please... Try to understand what I write, follow the links I presented before to a previous thread and at least CONSIDER that you might be wrong, instead of just deciding that you are right. If you, after that, still think the above is wrong, then please enlighten us on how and why. And please try to leave out the word "moron" in your explanation. Otherwise this discussion is going straight to the bunker. |
#110
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Speakers Then and Now
"Rusty Boudreaux" wrote in message ...
"Goofball_star_dot_etal" wrote in message ... You can argue all you want but you will be wrong. Betting is still open. . . Sorry, but the race is over. White light is incoherent and the wavlength of green, say 532 nm is considerably shorter than, say, a 1cm filament. You analogy is ********. Sorry, the analogy wasn't perfect. I was trying to explain in terms a moron could understand. Usually a visible example helps but I guess not for you. It amazes me you can't understand why changing the radiation pattern can not increase the output power of a driver. Goofball. I don't think it is the "Golfball" that is stuck in the sandpit... :-) Changing the radiation pattern (by changing from free space to half space) doubles the intensity (=+3dB), right. But in the case when the source is near its mirror image (compared to wavelength) the radiation resistance also doubles. Given that the cone velocity remains the same twice the power is produced in the radiation resistance, which yields another intensity doubling (=+3 dB). So, if a speaker is mounted in a wall, the intensity is raised by +6 dB (you may have heard that number (+ SIX dB) in this context before?), of which 3 dB comes from directivity, and 3 dB comes from increased efficiency. And please... Try to understand what I write, follow the links I presented before to a previous thread and at least CONSIDER that you might be wrong, instead of just deciding that you are right. If you, after that, still think the above is wrong, then please enlighten us on how and why. And please try to leave out the word "moron" in your explanation. Otherwise this discussion is going straight to the bunker. |
#111
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Speakers Then and Now
"Rusty Boudreaux" wrote in message ...
"Goofball_star_dot_etal" wrote in message ... You can argue all you want but you will be wrong. Betting is still open. . . Sorry, but the race is over. White light is incoherent and the wavlength of green, say 532 nm is considerably shorter than, say, a 1cm filament. You analogy is ********. Sorry, the analogy wasn't perfect. I was trying to explain in terms a moron could understand. Usually a visible example helps but I guess not for you. It amazes me you can't understand why changing the radiation pattern can not increase the output power of a driver. Goofball. I don't think it is the "Golfball" that is stuck in the sandpit... :-) Changing the radiation pattern (by changing from free space to half space) doubles the intensity (=+3dB), right. But in the case when the source is near its mirror image (compared to wavelength) the radiation resistance also doubles. Given that the cone velocity remains the same twice the power is produced in the radiation resistance, which yields another intensity doubling (=+3 dB). So, if a speaker is mounted in a wall, the intensity is raised by +6 dB (you may have heard that number (+ SIX dB) in this context before?), of which 3 dB comes from directivity, and 3 dB comes from increased efficiency. And please... Try to understand what I write, follow the links I presented before to a previous thread and at least CONSIDER that you might be wrong, instead of just deciding that you are right. If you, after that, still think the above is wrong, then please enlighten us on how and why. And please try to leave out the word "moron" in your explanation. Otherwise this discussion is going straight to the bunker. |
#112
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Speakers Then and Now
"Rusty Boudreaux" wrote in message ...
"Goofball_star_dot_etal" wrote in message ... You can argue all you want but you will be wrong. Betting is still open. . . Sorry, but the race is over. White light is incoherent and the wavlength of green, say 532 nm is considerably shorter than, say, a 1cm filament. You analogy is ********. Sorry, the analogy wasn't perfect. I was trying to explain in terms a moron could understand. Usually a visible example helps but I guess not for you. It amazes me you can't understand why changing the radiation pattern can not increase the output power of a driver. Goofball. I don't think it is the "Golfball" that is stuck in the sandpit... :-) Changing the radiation pattern (by changing from free space to half space) doubles the intensity (=+3dB), right. But in the case when the source is near its mirror image (compared to wavelength) the radiation resistance also doubles. Given that the cone velocity remains the same twice the power is produced in the radiation resistance, which yields another intensity doubling (=+3 dB). So, if a speaker is mounted in a wall, the intensity is raised by +6 dB (you may have heard that number (+ SIX dB) in this context before?), of which 3 dB comes from directivity, and 3 dB comes from increased efficiency. And please... Try to understand what I write, follow the links I presented before to a previous thread and at least CONSIDER that you might be wrong, instead of just deciding that you are right. If you, after that, still think the above is wrong, then please enlighten us on how and why. And please try to leave out the word "moron" in your explanation. Otherwise this discussion is going straight to the bunker. |
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Speakers Then and Now
Stewart Pinkerton wrote:
On Thu, 08 Jan 2004 16:29:58 GMT, henryf wrote: Peter Larsen wrote: Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? No, that only affects the gain. You're kidding, right? OK, then a simpler example. The "anything" is an audio amplifier, and the "surroundings" consists of a multi-pushbutton selector switch and a few sets of speakers. You know, the type of demo setup typically used at the local speaker supermarket. The selector switch can connect the output of the amplifier to 4 Ohm speakers, 8 Ohm speakers, 16 Ohm speakers, or to nothing at all. I think it's obvious to most readers of this group that the power delivered by the amplifier will depend more or less on which load gets connected to the amp's output. |
#114
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Speakers Then and Now
Stewart Pinkerton wrote:
On Thu, 08 Jan 2004 16:29:58 GMT, henryf wrote: Peter Larsen wrote: Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? No, that only affects the gain. You're kidding, right? OK, then a simpler example. The "anything" is an audio amplifier, and the "surroundings" consists of a multi-pushbutton selector switch and a few sets of speakers. You know, the type of demo setup typically used at the local speaker supermarket. The selector switch can connect the output of the amplifier to 4 Ohm speakers, 8 Ohm speakers, 16 Ohm speakers, or to nothing at all. I think it's obvious to most readers of this group that the power delivered by the amplifier will depend more or less on which load gets connected to the amp's output. |
#115
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Speakers Then and Now
Stewart Pinkerton wrote:
On Thu, 08 Jan 2004 16:29:58 GMT, henryf wrote: Peter Larsen wrote: Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? No, that only affects the gain. You're kidding, right? OK, then a simpler example. The "anything" is an audio amplifier, and the "surroundings" consists of a multi-pushbutton selector switch and a few sets of speakers. You know, the type of demo setup typically used at the local speaker supermarket. The selector switch can connect the output of the amplifier to 4 Ohm speakers, 8 Ohm speakers, 16 Ohm speakers, or to nothing at all. I think it's obvious to most readers of this group that the power delivered by the amplifier will depend more or less on which load gets connected to the amp's output. |
#116
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Speakers Then and Now
Stewart Pinkerton wrote:
On Thu, 08 Jan 2004 16:29:58 GMT, henryf wrote: Peter Larsen wrote: Intensity on some locations increase at the expense of intensity at other locations, total power from anything, be it loudspeaker-units or shocking pink lasers does not change becuase of what their surroundings do with their output I'm not so sure this is a universal truth. I think it depends somewhat on where one draws the boundary between the "anything" under consideration and the surroundings. For example, if we considered the "anything" to be an op amp, and the "surroundings" to include its feedback network, wouldn't the output power of the op amp depend on what the feedback network does with the op amp's output? No, that only affects the gain. You're kidding, right? OK, then a simpler example. The "anything" is an audio amplifier, and the "surroundings" consists of a multi-pushbutton selector switch and a few sets of speakers. You know, the type of demo setup typically used at the local speaker supermarket. The selector switch can connect the output of the amplifier to 4 Ohm speakers, 8 Ohm speakers, 16 Ohm speakers, or to nothing at all. I think it's obvious to most readers of this group that the power delivered by the amplifier will depend more or less on which load gets connected to the amp's output. |
#117
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Speakers Then and Now
On 8 Jan 2004 15:30:55 -0800, (Svante)
wrote: (Goofball_star_dot_etal) wrote in message ... On 8 Jan 2004 00:59:37 -0800, (Svante) wrote: (Goofball_star_dot_etal) wrote in message ... On 7 Jan 2004 10:33:01 -0800, (Svante) wrote: Do you also have a feeling of déjà vu? ;-) Yes, but this time I don't see the fine print. :-) Errh... The parallel would be that two speakers in free space essentially is the same as one speaker in half space. Was that what you meant by "fine print"? I was thinking of the phrase: "Do you see how I EXPLICITLY chose to NOT talk about the acoustical effects? The reason being is precisely BECAUSE of the complex depednecny on frequency" This no longer applies. Ahh... You're right! Maybe I should withdraw my statement below... :-) I feel I may have done some people an injustice in my my own mind. I had come to the conclusion that they lacked the "balls" to admit they were wrong (except one, I think), whereas, in fact, they had just not realized that they could be wrong. It is difficult to conclude, after your explanations, that the statement: "Actually, no, the efficiency, specifically, the ratio of total radiated acoustic power to total input electrical power does NOT change. The sound pressure level on axis MAY change, but the efficiency does not. The same power is distributed over a smaller area, and since SPL is a measure of power per unit area, the SPL changes, but the power output does not." is other than wrong. I have a lot of faith in academic researchers. You should know your stuff and perhaps people should listen more. I don't want people accepting what I say without understanding. If someone thinks I'm wrong I want to know that. When I understand that I am wrong I say so, and I am mostly happy about that because it means that I have learned something. The goal of a discussion is, IMO, an ending where everyone agree, and everyone has learned something. But you are right, listening is of course a prerequisite for this to happen. Entering a discussion to prove that one is right, however, easily ends up in the sand box, and nobody learns anything. |
#118
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Speakers Then and Now
On 8 Jan 2004 15:30:55 -0800, (Svante)
wrote: (Goofball_star_dot_etal) wrote in message ... On 8 Jan 2004 00:59:37 -0800, (Svante) wrote: (Goofball_star_dot_etal) wrote in message ... On 7 Jan 2004 10:33:01 -0800, (Svante) wrote: Do you also have a feeling of déjà vu? ;-) Yes, but this time I don't see the fine print. :-) Errh... The parallel would be that two speakers in free space essentially is the same as one speaker in half space. Was that what you meant by "fine print"? I was thinking of the phrase: "Do you see how I EXPLICITLY chose to NOT talk about the acoustical effects? The reason being is precisely BECAUSE of the complex depednecny on frequency" This no longer applies. Ahh... You're right! Maybe I should withdraw my statement below... :-) I feel I may have done some people an injustice in my my own mind. I had come to the conclusion that they lacked the "balls" to admit they were wrong (except one, I think), whereas, in fact, they had just not realized that they could be wrong. It is difficult to conclude, after your explanations, that the statement: "Actually, no, the efficiency, specifically, the ratio of total radiated acoustic power to total input electrical power does NOT change. The sound pressure level on axis MAY change, but the efficiency does not. The same power is distributed over a smaller area, and since SPL is a measure of power per unit area, the SPL changes, but the power output does not." is other than wrong. I have a lot of faith in academic researchers. You should know your stuff and perhaps people should listen more. I don't want people accepting what I say without understanding. If someone thinks I'm wrong I want to know that. When I understand that I am wrong I say so, and I am mostly happy about that because it means that I have learned something. The goal of a discussion is, IMO, an ending where everyone agree, and everyone has learned something. But you are right, listening is of course a prerequisite for this to happen. Entering a discussion to prove that one is right, however, easily ends up in the sand box, and nobody learns anything. |
#119
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Speakers Then and Now
On 8 Jan 2004 15:30:55 -0800, (Svante)
wrote: (Goofball_star_dot_etal) wrote in message ... On 8 Jan 2004 00:59:37 -0800, (Svante) wrote: (Goofball_star_dot_etal) wrote in message ... On 7 Jan 2004 10:33:01 -0800, (Svante) wrote: Do you also have a feeling of déjà vu? ;-) Yes, but this time I don't see the fine print. :-) Errh... The parallel would be that two speakers in free space essentially is the same as one speaker in half space. Was that what you meant by "fine print"? I was thinking of the phrase: "Do you see how I EXPLICITLY chose to NOT talk about the acoustical effects? The reason being is precisely BECAUSE of the complex depednecny on frequency" This no longer applies. Ahh... You're right! Maybe I should withdraw my statement below... :-) I feel I may have done some people an injustice in my my own mind. I had come to the conclusion that they lacked the "balls" to admit they were wrong (except one, I think), whereas, in fact, they had just not realized that they could be wrong. It is difficult to conclude, after your explanations, that the statement: "Actually, no, the efficiency, specifically, the ratio of total radiated acoustic power to total input electrical power does NOT change. The sound pressure level on axis MAY change, but the efficiency does not. The same power is distributed over a smaller area, and since SPL is a measure of power per unit area, the SPL changes, but the power output does not." is other than wrong. I have a lot of faith in academic researchers. You should know your stuff and perhaps people should listen more. I don't want people accepting what I say without understanding. If someone thinks I'm wrong I want to know that. When I understand that I am wrong I say so, and I am mostly happy about that because it means that I have learned something. The goal of a discussion is, IMO, an ending where everyone agree, and everyone has learned something. But you are right, listening is of course a prerequisite for this to happen. Entering a discussion to prove that one is right, however, easily ends up in the sand box, and nobody learns anything. |
#120
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Speakers Then and Now
On 8 Jan 2004 15:30:55 -0800, (Svante)
wrote: (Goofball_star_dot_etal) wrote in message ... On 8 Jan 2004 00:59:37 -0800, (Svante) wrote: (Goofball_star_dot_etal) wrote in message ... On 7 Jan 2004 10:33:01 -0800, (Svante) wrote: Do you also have a feeling of déjà vu? ;-) Yes, but this time I don't see the fine print. :-) Errh... The parallel would be that two speakers in free space essentially is the same as one speaker in half space. Was that what you meant by "fine print"? I was thinking of the phrase: "Do you see how I EXPLICITLY chose to NOT talk about the acoustical effects? The reason being is precisely BECAUSE of the complex depednecny on frequency" This no longer applies. Ahh... You're right! Maybe I should withdraw my statement below... :-) I feel I may have done some people an injustice in my my own mind. I had come to the conclusion that they lacked the "balls" to admit they were wrong (except one, I think), whereas, in fact, they had just not realized that they could be wrong. It is difficult to conclude, after your explanations, that the statement: "Actually, no, the efficiency, specifically, the ratio of total radiated acoustic power to total input electrical power does NOT change. The sound pressure level on axis MAY change, but the efficiency does not. The same power is distributed over a smaller area, and since SPL is a measure of power per unit area, the SPL changes, but the power output does not." is other than wrong. I have a lot of faith in academic researchers. You should know your stuff and perhaps people should listen more. I don't want people accepting what I say without understanding. If someone thinks I'm wrong I want to know that. When I understand that I am wrong I say so, and I am mostly happy about that because it means that I have learned something. The goal of a discussion is, IMO, an ending where everyone agree, and everyone has learned something. But you are right, listening is of course a prerequisite for this to happen. Entering a discussion to prove that one is right, however, easily ends up in the sand box, and nobody learns anything. |