Tuesday, August 6, 2019

Speaker Driver: Comparison of Options

Speaker Driver: Comparison of Options Speaker driver choice is a very important consideration, since the transducers themselves are of course the most fundamental part of the speaker. Regardless of other factors, one can never expect inferior drivers (and hence the system as a whole) to perform well. There are two main options when choosing drivers; electrostatic or conventional voice-coil designs. Although many seem under the impression that electrostatic loudspeakers are a modern invention this is not the case; Janszen was granted the first U.S. patent for such a device in 1953[1]. Considering the relatively small market penetration of electrostatic transducers and the fact that they tend to appear largely in high-end designs, one might be led to assume that electrostatic panels are superior to conventional drivers. This however is only partially true. One advantage of electrostatic panels is that full-range designs are possible, eliminating the need for crossovers and hence the associated problems with frequency and phase response in the crossover band. Another advantage is that the electrostatic panel is generally very light and hence offers excellent transient response, whilst also offering very good directionality and imaging. The latter may also be seen as disadvantage, since it effectively makes the ideal listening position rather narrow. In terms of disadvantages, the chief problem with electrostatic designs is a difficulty in reproducing bass frequencies at high SPLs. Generally the panel excursion is small, which makes it hard for electrostatic transducers to move the required volume of air at low frequencies. Furthermore, since electrostatic transducers are not meant for use with an enclosure, phase cancellation is an issue, again resulting in reduced bass performance. Audiostatic, a company that manufactures audiophile full-range electrostatic speakers, admit of their own devices with regard to bass that â€Å"Obviously because of the limited membrane excursion they wont produce ear shattering levels at that frequency†[2]. As a result of the aforementioned bass performance, many high-end electrostatic speakers are in fact hybrids, using voice-coil woofers for low frequencies with electrostatic panels covering the mid and high range. One example is the Martin Logan Summit[3], which whilst described as â€Å"our most advanced and sophisticated full-range loudspeaker† nevertheless makes use of two 10† woofers for low-end reproduction. Of course in this situation a crossover is still required, so the advantage of the possibility of a full-range design is often nullified in practice. Still, electrostatics may prove very attractive as high quality mid to high frequency drivers, although they are certainly not cheap. In choosing conventional voice-coil drivers, there are many factors to consider. In terms of quality, it is certainly true that one does indeed get what one pays for. Whilst high quality manufacturers such as SEAS[4] are happy to provide detailed frequency response plots and Thiele-Small parameters for their transducers, many cheaper manufacturers are less transparent about their devices. One common trick to beware of, often used by less scrupulous manufacturers, is the quoting of a recommended frequency range without stating the variation in output (in dB) across this range. A recommended operating range without any indication of the actual performance within the frequency band is virtually meaningless. Many assume a  ±3dB range is implied when reading such data; it is unwise to make such assumptions. Furthermore, even if frequency response across a range is qualified with the variation in output in dB, this is still not ideal. Obviously one desires that any variation in output magnitude will be a smooth variation; one still has no idea of how â€Å"lumpy† the response might be. For these reasons it is best to choose drivers that are accompanied by frequency plots, since this gives a far more accurate representation of true performance. Another important consideration in choosing a driver is the application for which it is intended. For example, a woofer with a high maximum cone excursion and low Fs may perform very well in a large sealed cabinet but be totally unsuited to a ported implementation (Dickason, 2000). One can make use of the quoted Thiele-Small parameters to ascertain whether the driver is suitable for its intended purpose. Construction materials also give an indication of how the driver may sound. In terms of woofer and midrange drivers, for example, an aluminium cone may indicate greater bass precision than an otherwise equivalent transducer with a paper cone; softer cones are associated with greater distortion than their stiffer counterparts. However, as Larsen (2003) notes â€Å"cone break-up behaviour and frequency response was shown to be strongly dependant on the Geometrical Stiffness of the Cone†. Hence the geometry of the design may be more important than the material used. Diameter of the driver is also a hugely important factor for woofers, although of minor importance for tweeters. To reproduce bass frequencies at good SPLs, a large volume of air must be moved by the driver. To this end, there is absolutely no way a 6† driver can compete with a 12† driver of similar quality in terms of bass extension; it is simply not physically possible. Power handling is another consideration that must be given thought when choosing a driver; the peak short-term power dissipated by a transducer can easily be double its long-term rating. Naturally for the best performance it is desirable to ensure that the driver is not operating too close to its quoted limits. One should think carefully about how hard the driver is likely to be driven and ensure its power handling is adequate; overdriving a unit at best will result in distortion and at worst may cause irreversible damage. In many cases users overdrive and damage units in an attempt to achieve a higher SPL, particularly in the bass region. If the system requirements are adequately specified and designed for, this should not happen. For the high-budget client, the best solution will either be high-quality voice-coil drivers carefully selected to complement each other, or a hybrid electrostatic implementation. It is difficult to recommend a fully electrostatic solution due to the associated problems with low frequency performance, although for some clients this may be acceptable. For the low-budget client, standard voice-coil drivers are the only solution. The quality of the drivers used will largely be influenced by pricing; one should carefully consider all factors and attempt to find the best solution within budget. Datasheets should be closely scrutinised to identify the strengths and weaknesses of each option before a solution is chosen. In conclusion, notwithstanding the electrostatic debate, driver choice is largely influenced by price and performance. In general, the better specified the driver, the more expensive it is likely to be. If working with a high budget, one is likely to simply choose the best specified drivers. Conversely, with a limited amount of capital, one must make the best compromise that can be reached within budget. Sources Larsen, Peter. (2003). Geometrical Stiffness of Loudspeaker Cones, Loudsoft. Borwick, John. (2001). Loudspeaker and Headphone Handbook, Focal Press. Dickason, V. (1995). The Loudspeaker Design Cookbook, Audio Amateur Publications. Rossing, T. (1990). The Science of Sound, Addison-Wesley. 1 Footnotes [1] United States Patent 2,631,196 [2] http://www.audiostatic.com/faq.html [3] http://www.uk.martinlogan.com/speaker_intro/summit.html [4] http://www.seas.no Effect of Globalisation on Culture: Annotated Bibliography Effect of Globalisation on Culture: Annotated Bibliography John Tomlinson Globalization and Culture John Tomlinson analyses the globalization and the culture relationship, Globalization is in the center of modern culture; cultural practices are in the globalization center.  In John Tomlinson view, globalization and culture could be interpreted as relationship that they complement each other. John Tomlinson thinks that researching Globalization from the fields of political science, economics, sociology and communication to lead the field of culture, cultural practices are designed to reveal the meaning of globalization On globalization, John Tomlinson thinks the point of view from the daily life experience and to analyze the sense of intimacy, uniqueness.  On culture, John Tomlinson reflect on the cultural and political and economic relationship between the practice to clarify the complex cultural purposes, that is what makes life full of meaningful experience. John Tomlinson focused on the Deterritorialization of the concept that deterritorialization of our current globalization and cultural conditions, it exists in everyday experience among the grasp of many aspects of cultural globalization. Globalization fundamentally is the place we live, it makes our cultural practices, cultural identity and cultural experience and the relationship between the occurrences of the transition, it reduces or removes the daily dynamic between cultural and territorial positioning Contact; This culture, the opportunities and pitfalls. So, John Tomlinson called for world unity. Hardt, Michael; Negri, Antonio, (2000) Extract from Hardt, Michael; Negri, Antonio, Empire pp.xi-xvi,3-21, Cambridge, Mass.: Harvard University Press Hardt, Michael; Negri, Antonio, hardt criticize the globalization, their bookempire could be considered as the representative of the anti-globalization works. They argue that the globalization is the capitalist production and economic relations have become more autonomous from political controls ,But with the traditional left to some of the different anti-globalization, this book address the global changes in an attempt to put forward in the context of globalization, new practice ideas. Hardt, Michael; Negri, Antonio books argument can be roughly simplified as follows: Globalization has led to changes in capitalism, the nation-state boundaries disappear, the new Empire has been formed, showing a new form of sovereignty, is composed of many countries and a joint supranational organizations  . Empire does not establish a power center, nor rely on fixed boundaries or barriers. Empire is a decentralized to the regions with the tools of the rule, and gradually  areas into the global expansion of its open and whole. Such an abstract rather than concrete empire how to rule? Finally, Hardt, Michael; Negri, Antonio called the masses are a utopian construct. Sociology of knowledge that, in the absence of any organized sports, leadership, and the dominant ideology, even if there is no amount of suffering, it will only submit to humiliation.  The authors argue that the masses is the seed of the revolution, they need international links to change the empire, but these people in todays nation-states under the barrier, how could the international links, how to overcome language differences Saskia Sassen (2008), Neither global nor national: novel assemblages of territory,  Authority and rights Columbia University, USA,  Ethics Global Politics, Vol. 1, No. 1 2, 2008, pp. 61 79 Saskia Sassen is the Professor of Sociology, Columbia Universityà ¯Ã‚ ¼Ã…’the globalization leads the Unequal distribution of material resources, cultural colonialism and the depletion of non-renewable raw materials, the source of political conflict between North and South. Consequences of this phenomenon, such as global climate change to all social classes and the widening between the poor countries  gap between the rich have led to greater social crisis. Sassen thinks that the world only about 40 nodes in a transnational influence in the city, most of them located in the North Atlantic global subsystem; Globalization and World Cities Study Group believes that the world only 50 World City  , and another 60 to 70 cities to show the world the city part of the evidence Saskia Sassen states that Economic globalization not look at the globalization of capital accumulation, but also the production process of globalization.  If the economic globalization, the globalization of the production process as we see more than just capital, capital is only one aspect of economic globalization, it is another aspect of the globalization of labor, especially in the international movement of labor.  In the process of economic globalization, the cities, especially global cities, a place of convergence of capital and labor, the coordination center of the world economy, and thus become the problem of inequality in the globalization process of strategic intervention  place.  Specifically, how interventions, A Brief History of Neoliberalism, David Harvey, Oxford University Press David Harvey Examine the new liberalism in the past few decades to stir up trouble, and largely reshaped the pattern of international politics, not only for our understanding of the financial crisis, but also for understanding the development of global capitalism. With the new round of financial crisis sweeping the world and impact on all walks of life, people have tried from all aspects, directly or indirectly, to discuss the origin and development of the crisis, including the re-study of world history over the past few decades in the political  and economic theory and practice.  In this context, there is a scholar claim that the capitalist world have long been in crisis for a long time.  People who make this assertion is David â‚ ¬Ã‚ ¢ Harvey At the beginning, David Harvey analyze the U.S. war in Iraq, the United States in the implementation of the new Chilean liberal reform, pointed out that neo-liberal reforms, but at outside the United States once again in the experiment, then it could be the sample as their internal reform Of course, we should not forget the teachings of Marx In the past philosophers only interpret the world, but the important thing is to change the world. For understanding the status of our world today and the new liberalism of the context, although this small book may be many areas for improvement, but still occupies an important position. Arjun Appadurai, Disjuncture and Difference in the Global Cultural Economy, 1990 7: 295 Theory Culture Society, DOI: 10.1177/026327690007002017. Arjun Appadurai thinks that disjuncture and difference are normally in the global cultural economy, today, the central issue is the tense relationship between global interaction heterogeneity and cultural homogeneity. Homogenization is globalization and the universal, heterogeneous, that the pursuit of ethnic, indigenous rights and the maintenance of cultural identity.  As mentioned earlier, the key is, homogeneity of the substance at the expense of heterogeneity as the price, The basic efforts are to discuss the disadvantaged and marginalized groups in the cultural status quo from the inequality freed.  From an academic perspective, the demands of cultural heterogeneity consist of the following reasons: First, the cultural standpoint, it has a position of cultural relativism.  The need for different cultures to maintain their autonomy, because whether it is strong or weak culture, are equal in rights, no one culture is superior to other cultures, nature.  Therefore, there is no one culture can be for other cultural legislation, and its own advantages and disadvantages of other cultures for the evaluation criteria.   Thus in Arjun Appadurai thinks that which derived from the resistance of a strong culture means that it is not for the emphasis on their own than any other culture their own special appeal, but in Europe or the male-centered center of power has become a universal rule in the context of intercultural  the pursuit of equal status. Ulrich Beck, the Terrorist Threat: World Risk Society Revisited, 2002 19: 39 Theory Culture Society, DOI: 10.1177/0263276402019004003 the British sociologist Ulrich Beck, with his point of view, representation of contemporary social structures and life patterns generated by the many changes in availability of a second modern the character, and different from the traditional modern / post-modern painting points.   In this book, the second modern and cosmopolitanism, points out the first modern over-development, will turn off the collapse of global market and the nation-state patterns, and will generate reflection type of cultural development.  Cultural development in the reflection type, the modern rational and the Universe would have been a powerful challenge of all; society will also be the inner self to begin conversion.  Peoples cultural experience and experience in space, including the cultivation of various degree of recognition, diversity of life forms of the cross, the Political Action Without Borders, etc., will have a more diversified development. Risk society has the global common foundation, because in the second modernity, whether political, economic or ecological crisis, the risk of the spread is no national boundaries; so modern risk society, must put in the context of globalization down interpretation.  However, Baker on the second modern in the description of the world, the globalization of the past simply is not the same.  In order to interpret more in line with the concept of global development community, and puts forward a cosmopolitan, containing the words all men are brothers, David held Anthony McGrew, David Goldblatt Jonathan Perraton, Global Transformation Early in the 20th century, David held and the famous sociologist Anthony Giddens, Professor, who put together the relevant risk society of the concepts and theories Ecological, financial, military, terrorists, biochemical and information, and other risks in our contemporary world in a way there is overwhelming.  To the risk we experience everywhere; we could only make the following three types of reaction: denial, indifference and transformation.  The first approach is largely rooted in modern culture, but it ignored this attitude has denied that the political risks; second approach succumb to the kind of postmodern nihilism which type of argument;  The third approach led to my theory of world risk society issues raised: the future of man and the diversity of the expected consequences with the risk of changes in how the impact and awareness of modern society, survival  conditions and the system? Global default is a rational increase in demand uncertainty.  Caused by industrial society because of the uncertainty does not necessarily lead to confusion or disaster.  Rather, the uncertainty can not be calculated can also a source of creativity, which is a contingency to allow reason and experiment new things.  Thus, the current end of a pervasive sense of the kind of odds Mike Featherstone, Global Culture: Nationalism, Globalization, and Modernity Mike Featherstone is currently Britains consumer culture theorists.  In this book, consumer culture, as his object of study, reviews the theory of consumer culture Featherstone three main aspects: first by an aesthetic theory of everyday life, this is the theory of consumer culture Featherstone core and foundation.  While the previous practice of daily life and consumption has some research, and creation of daily life for the Featherstone laid the foundation of aesthetic theory, but he did not think life is a tool that strict control of rational consumer space, but also  do not think life is a fragment of a fragmentation.   Featherstone believes that everyday life is consumer spending the main field of practice, and in this field, the emergence of consumer practice of aesthetic tendencies. Featherstone follows the performance of the control and resistance theory. practice in the analysis of consumption during the fight right to speak, on the one hand explains how to control the ideology of everyday life cultural practices of consumers, but also pointed out how consumers the possibility of a boycott., on the whole, daily control of the consumer ideology is growing, but from specific consumer practice, consumers have been symbols of consumer culture transformation and substitution.  Mike Featherstone lamented that some disorder of literature, Michael Gurevitch, Culture, Society and the Media Michael Gurevitch based on the world, from an interdisciplinary and cross-cultural perspective of globalization and democratization of the media between the complex and sometimes mutually reinforcing and sometimes conflicting multi-faceted relationship.   This book proposed a new theory about generalities, but not to provide a description of the micro, but the relevant proposition was different theoretical and historical sort, from which new problems.   firstly discusses the theory of globalization and the globalization of media organizations in the media, marketing, form, movement, effects and management aspects of change, and the media bottom-up globalization process and practice.  Then, the article in English literature of the existing market liberals, liberals in the public domain, and the radical democrats of different concepts of democracy and the spread of globalization and its significance for the different media analysis were reviewed, Finally, the book was put forward, including media ownership diversity, multi-directional flow of the global media in the political and theoretical significance, the Western model and views the adequacy or relevance media for political information than the broader identity  role during the formation of macro issues such as 7, to promote the breadth and depth of study.  The globalization and democratization of media there are complex interactions between the relationships between two, which is far from even a discussion of two books could come to an end.   Oliver Boyd-Barrett, Terhi Rantanen. The Globalization of News   Oliver Boyd-Barrett, Terhi Rantanen research from the social perspective ,and emphasizes the role of government era of globalization, and the Government can play a complementary effect and the market potential to give more attention. Using of statistical methods proved that external risks can not be ignored, but the state is playing an important integral role in providing social security and protection of social justice. Government maintains economic openness and balance between domestic needs of the community as a crucial and irreplaceable role.  The implication is: If the Government is up to the role that globalization will be able to smooth the contrary, this process will be reversed.     Oliver Boyd-Barrett,Terhi find some latest new which find the process of globalization, which in many ways is very different.  For example, todays international financial system from the conclusions of historical research in analysis and interpretation should be applied to contemporary events, there will be quite limited indeed.  But the basic values of the market mechanism and social hundred years did not occur in a large change fundamentally.  Since the markets expansion on a global scale in fact has brought individuals and the income gap between countries and the widening gap of economic welfare, just as happened 80 years ago as; it will be useful to draw lessons from history. How is Hamlet Character Influenced by Greek Philosophy? How is Hamlet Character Influenced by Greek Philosophy? Hamlet, protagonist of Shakespeares tragedy of the same name, is one of the most ambiguous and enigmatic characters of the history of literature. He is a thinker, and extremely philosophical, meditative and suspicious, indeed, he is always pondering about question with no answer. His monologues are very contemporary, because they are about psychological struggles that are still unresolved. His character is strongly influenced by philosophy and, particularly, by Greek philosophy. We can understand that Hamlet was interested in Greek culture by his numerous references to Greek mythology, and by the main topics of his soliloquies: the conflicts between right and wrong, thought and action, life and death, and the importance of the mind and thoughts of an individual. They all refer to important philosophical concepts of Greek philosophy, such as relativism, skepticism and humanism, which are rooted in ancient Greek philosophers thoughts and studies. About the references to Greek mythology, we can observe citations about many characters belonging to myths. Hyperion, Satyr, Niobe, Hercules (Act I, Scene II, 140-153), where Hyperion is a Titan or a byname of Helios, God of the sun; a Satyr is a lecherous creature, half-man and half-goat; Niobe was the Queen of   Thebes, who wept for her dead children even when she was turned to stone; and Hercules is a mythical Greek hero, notorious for his strength. Nemean lion (Act I, Scene IV, 83), which was a vicious monster who lived at Nemea. Priam, Hecuba (Act II, Scene II, 422-459), where Priam was the King of Troy during the Trojan War, and Hecuba was his wife. From this analysis, we can observe that not only was he interested in Greek mythology, but also on Greek literature, indeed, he probably read Homeric poems, Iliad and The Odyssey. Another evidence that Greek philosophy influenced Hamlet is that he often refers to Relativism. For example, when he says to Rosencrantz: there is nothing either good or bad, but thinking makes it so (Act II, Scene II, 240), he is referring to the Sophist theory that the truth or justification of moral judgments is not absolute, but relative to the moral standard of some person or group of persons1[1]. Another example is the most iconic monologue of the tragedy: To be, or not to be: that is the question: / Whether tis nobler in the mind to suffer / The slings and arrows of outrageous fortune, / Or to take arms against a sea of troubles, / And by opposing end them?. Hamlet is struggling whether is more noble to kill himself or to continue living though the problems he is facing. We can consider this as a form of moral relativism because, from Hamlets perspective, even something collectively thought as so morally incorrect like suicide can become correct, noble. According to Protagoras , a pre-sophist philosopher, The human being is the measure of all things, of those that are, that they are, and of those that are not, that they are not. By this, Protagoras apparently meant that each individual person is the measure of how things are to that person: things are or are not, to me, according as they appear to me to be or not be. Briefly stated, moral relativism is the view that moral judgments, beliefs about right and wrong, good and bad, not only vary greatly across time and contexts, but that their correctness is dependent on or relative to individual or cultural perspectives and frameworks.2[2] We can also consider the same monologue as an example of skepticism, because Hamlet is fond of pointing out questions that cannot be answered because they concern supernatural and metaphysical matters. Hamlets monologue What a piece of work is a man! / How noble in reason! how infinite in faculty! in form and moving how / express and admirable! in action how like an angel! / in apprehension how like a god! the beauty of the / world! is an evidence of another philosophical trend: Humanism. Even if the word Humanism was invented by Latins (Humanitas), we can observe Humanist thoughts in Sophist philosophers, Socrates and Plato. In that period, indeed, the subject of the philosophical speculation changed from transcendental topics, like Gods or the origin of the universe, to the human being. They became interested in human mind and experiences, and related topics such as ethic and ideas. To understand Hamlets tragedy deeply, first we have to understand its historic, religious and philosophical context. From the philosophical point of view, I found evidence of many philosophical trends influences, to both Hamlets character and Shakespeare, but I can state that most of them are related to the most important Greek philosophical trends.

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