The correct knowledge of sound quality provided by Joly

The development of a product must be guided by the correct theories so that a proper, practical product can be designed and developed. In addition, only with those theories, a product then can be improved continuously??     The standards of the traditional speakers have been stagnated for over 60 years without any actual improvement. We can see that the sound theories used were wrong - and this mistake has lasted for over 60 years ! Therefore, the speaker manufacturing technology has been stagnated for 60 years too.     Now, Joly would like to explain a few things regarding the criteria of judging speakers used by the general public as the following: 1. Efficiency:     People usually use "db value" as the efficiency criterion for speakers, but this is wrong. For all the speakers, the conversion efficiency of electricity into sound energy is below 3%; if the sound volume is louder and higher, the efficiency is surely larger too. However, the db value is related to the density of sound and sound volume should be the multiplication of "db" and "spread - out area size of speakers". Speakers with larger diameter have larger spread - out area size. Therefore, we should not use the db value as the sole criterion in judging speakers' efficiency. 2. Sensibility:     In our sound perception, the sensibility means "to what degree of details that the sound can be reproduced". People use the db value as the sensibility criterion - i.e., speakers with higher db value have higher sensibility. However, this theory is only partially right. There are a few reasons for this misunderstanding. The db value is the "sound pressure" measured one matter in front of speakers with the speakers power rating equal to 1w. Therefore, when we use speakers of 1w or 5w to send out some music, their power rating must be lower than 1w; some small sounds may even have the rating lower than 0.1w ! In conclusion, because the db value was obtained by "one meter/1w" method, if can mot be used se the general description of speakers. In addition, the sensibility varies with the power input; it varies with the structure and sound intensity too. 3. Invariance of frequency response:     People think the smaller frequency variation the better speakers are. This is only right if the frequencies are measured one meter in front of speakers; in fact, all the data measured were done one meter in front of speakers. However, if the frequencies are measured shorter or longer than one meter, the results will surely be different from the one measured at the one meter position. In addition, it is impossible for people to listen to the sound coming from speakers at exactly one meter in front of the speakers. Therefore, as mentioned in the text books, the frequency response will be evaluated along with speaker diameter, structure and listening distance. 4. With the higher power rating the better speakers are:     This if wrong too. Usually, speakers with lower efficiency and lower sensibility can withstand higher poser input. 5. The sound coming out of a single speaker is two dimensional:     This is wrong too ! With the only exception of the 'light projection", all the phenomena that human can perceive in our 3-D environment are three dimensional. The traditional speakers can only present the flat 2-D sound out of the 3-D "sound image", therefore, those speakers mistakably lead the listeners to think this sound is actually 2-D. On the other hand, the Joly speakers do not have this disadvantage. 6. The 3-D sound can be generated by two of the traditional speakers:     This is wrong again ! The sound produced by them is still 2-D sound. The only things that those traditional speakers can do are to generate the faulty perceptions of "surrounding sound" and "sound motion" to the listeners. 7. The walls can be used to improve the sound quality:     This is wrong too. The walls can generate some "exaggeration effect" by the amplification of the "sound intensity difference" and our faulty perception. In fact, the walls can only make the wound quality worsened and unreal; these adverse effects can damage our mind.