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evgenetic
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נושא שלא נקרא #16 

כשתמצא לי מגבר טרנזיסטורי עכשווי עם FR שהוא לא ישר כמו סרגל, אולי יהיה לך טיעון נורמלי, בינתיים דברייך הם בגדר הבל אודיופילי טיפוסי.

PolarBear
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נושא שלא נקרא #17 

אה, כי אתה הרי הבאת אינסוף מידע מדעי בטיעון שלך. :lol:
סאונד לא קשור רק ל-FR. אתה בור בדברים האלה.
בקיצור אתה טוען שאין שום הבדל בין איך שנשמעים היום מגברים.
אני אפילו לא הולך להתווכח עם השטות הזו. שכל אחד פה יקרא ויחליט בעצמו.

PolarBear
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נושא שלא נקרא #18 

http://www.electronics-tutorials.ws/amp ... ponse.html

Most amplifiers and filters have a flat frequency response characteristic in which the bandwidth or passband section of the circuit is flat and constant over a wide range of frequencies. Resonant circuits are designed to pass a range of frequencies and block others. They are constructed using resistors, inductors, and capacitors whose reactances vary with the frequency, their frequency response curves can look like a sharp rise or point as their bandwidth is affected by resonance which depends on the Q of the circuit, as a higher Q provides a narrower bandwidth.

evgenetic
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נושא שלא נקרא #19 

בקיצור אתה טוען שאין שום הבדל בין איך שנשמעים היום מגברים.
...
ושוב פעם אתה מפגין רמת הבנת הנקרא של תלמיד כיתה ג'.

PolarBear
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נושא שלא נקרא #20 

http://www.learnabout-electronics.org/A ... iers14.php

Most audio signals will be complex waves of many different and ever changing shapes. Audio signals are complex AC waves having fundamental frequencies in the range of 20Hz to 20kHz but also many higher frequency harmonics. To preserve the original shape of the signals (i.e. not introduce distortion) it is important that at least some of these harmonics are preserved. Therefore it is not advisable to sharply cut off the high frequencies at an arbitrary 20kHz, but rather allow some amplification of the apparently inaudible harmonic frequencies, which will contribute to the complex shape of the audible waves, especially where these signals contain sudden changes (fast transients) that require the presence of high frequency components to maintain their wave shape.

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נושא שלא נקרא #21 


PolarBear
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נושא שלא נקרא #22 

http://www.audioholics.com/audio-amplif ... amplifiers

However, if two different transistor amplifiers have the same smooth, linear frequency response, low distortion, and are operated within their output ratings, then they will tend to sound identical until they are called upon to produce great quantities of clean, unclipped power. With one amplifier, there may be a quality of effortlessness to the sound quality on big dynamic peaks in sound level, whereas another amplifier may start to sound strained or harsh on dynamic peaks because it cannot handle peaks free of distortion.

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נושא שלא נקרא #23 

תפרוש, אחי, תפרוש.

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נושא שלא נקרא #24 

http://www.audioholics.com/audio-amplif ... -amplifier

There are some differences that cannot be readily explained. An amp that is deemed "identical" to another in a test situation, may sound completely different in a normal listening environment. It is these differences that are the hardest to deal with, since we do not always measure some of the things that can have a big influence on the sound.

The Dyna worked, but the difference in sound character was stunning. Stunning. We raised and lowered the volume. The differences persisted at all levels. We reconnected the Kenwood and re-listened. Then we re-connected the Dyna again.

Now, remember, originally we weren’t consciously looking for differences in their sound, but it was so obvious that it just hit the two of us over the head like a ton of bricks. It was so obvious and apparent that we spent the rest of the night listening to all manner of records, first on the Kenwood, then on the Dyna, and over and over.

There might be several explanations for the differences, but they were real, without question.

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נושא שלא נקרא #25 

ובכלל, אם אין הבדל בין מגברים, למה יש כל כך הרבה חברות מגברים ודגמי מגברים?
ולמה אנשים מכובדים מאוד (כולל כאלה שיש להם הכשרה מדעית) אומרים שהם שומעים הבדל?
ולמה אנשים שיש להם תארים בפיזיקה לוקחים על עצמם לפתח ציוד כי הם חושבים שהם יכולים להציע משהו שחברות אחרות לא מציעות?
לדוגמא, Meier Audio, שהסיסמא שלהם היא "The Art of Hearing Differently". והבעלים הוא דוקטור לפיזיקה. כנראה שהוא מבין פחות ממך. חחח.

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נושא שלא נקרא #26 

https://en.wikipedia.org/wiki/Reading_comprehension

Reading comprehension is the ability to read text, process it and understand its meaning. An individual's ability to comprehend text is influenced by their traits and skills, one of which is the ability to make inferences. If word recognition is difficult, students use too much of their processing capacity to read individual words, which interferes with their ability to comprehend what is read. There are a number of approaches to improve reading comprehension, including improving one's vocabulary and reading strategies.

Contents

1 Definition
1.1 Reading comprehension levels
1.2 Brain region activation
2 History
3 Vocabulary
3.1 Three tier vocabulary words
3.2 Broad vocabulary approach
3.3 Morphemic instruction
3.4 Reading strategies
3.4.1 Reciprocal teaching
3.4.2 Instructional conversations
3.4.3 Text factors
3.4.4 Visualization
3.4.5 Multiple reading strategies
3.5 Assessment
4 Difficult or complex content
4.1 Reading difficult texts
4.2 Hyperlinks
5 Professional development
6 See also
7 References
8 Further reading
9 External links

Definition

Reading comprehension is defined as the level of understanding of a text/message. This understanding comes from the interaction between the words that are written and how they trigger knowledge outside the text/message.[1][2] Comprehension is a "creative, multifaceted process" dependent upon four language skills: phonology, syntax, semantics, and pragmatics.[3] Proficient reading depends on the ability to recognize words quickly and effortlessly.[4] It is also determined by an individual's cognitive development, which is "the construction of thought processes". Some people learn through education or instruction and others through direct experiences.[5]

There are specific traits that determine how successfully an individual will comprehend text, including prior knowledge about the subject, well developed language, and the ability to make inferences. Having the skill to monitor comprehension is a factor: "Why is this important?" and "Do I need to read the entire text?" are examples. Lastly, is the ability to be self-correcting to solve comprehension problems as they arise.[6]
Reading comprehension levels

Reading comprehension involves two levels of processing, shallow (low-level) processing and deep (high-level) processing. Deep processing involves semantic processing, which happens when we encode the meaning of a word and relate it to similar words. Shallow processing involves structural and phonemic recognition, the processing of sentence and word structure and their associated sounds. This theory was first identified by Fergus I. M. Craik and Robert S. Lockhart.[7]
Brain region activation

Comprehension levels can now be observed through the use of a fMRI, functional magnetic resonance imaging. fMRIs' are used to determine the specific neural pathways of activation across two conditions, narrative-level comprehension and sentence-level comprehension. Images showed that there was less brain region activation during sentence-level comprehension, suggesting a shared reliance with comprehension pathways. The scans also showed an enhanced temporal activation during narrative levels tests indicating this approach activates situation and spatial processing.[8]
History

Initially most comprehension teaching was based on imparting selected techniques that when taken together would allow students to be strategic readers however in 40 years of testing these methods never seemed to win support in empirical research. One such strategy for improving reading comprehension is the technique called SQ3R: Survey, Question, Read, Recite, and Review that was introduced by Francis Pleasant Robinson in his 1946 book Effective Study.[9]

Between 1969 and to about 2000 a number of "strategies" were devised for teaching students to employ self-guided methods for improving reading comprehension. In 1969 Anthony Manzo designed and found empirical support for the ReQuest, or Reciprocal Questioning Procedure, it was the first method to convert emerging theories of social and imitation learning into teaching methods through the use of a talk rotation between students and teacher called cognitive modeling.[citation needed]

Since the turn of the 21st century, comprehension lessons usually consist of students answering teachers' questions, writing responses to questions on their own, or both.[10] The whole group version of this practice also often included "Round-robin reading", wherein teachers called on individual students to read a portion of the text. In the last quarter of the 20th century, evidence accumulated that the read-test methods were more successful assessing rather than teaching comprehension.[citation needed] Instead of using the prior read-test method, research studies have concluded that there are much more effective ways to teach comprehension. Much work has been done in the area of teaching novice readers a bank of "reading strategies," or tools to interpret and analyze text.[11]

Instruction in comprehension strategy use often involves the gradual release of responsibility, wherein teachers initially explain and model strategies. Over time, they give students more and more responsibility for using the strategies until they can use them independently. This technique is generally associated with the idea of self-regulation and reflects social cognitive theory, originally conceptualized by Albert Bandura.
Vocabulary

Reading comprehension and vocabulary are inextricably linked. The ability to decode or identify and pronounce words is self-evidently important, but knowing what the words mean has a major and direct effect on knowing what any specific passage means. Students with a smaller vocabulary than other students comprehend less of what they read and it has been suggested that the most impactful way to improve comprehension is to improve vocabulary.[12]

Most words are learned gradually through a wide variety of environments: television, books, and conversations. Some words are more complex and difficult to learn, such as homonyms, words that have multiple meanings and those with figurative meanings, like idioms, similes, and metaphors.[13]
Three tier vocabulary words

Several theories of vocabulary instruction exist, namely, one focused on intensive instruction of a few high value words, one focused on broad instruction of many useful words, and a third focused on strategies for learning new word etc...
Broad vocabulary approach

The method of focusing of broad instruction on many words was developed by Andrew Biemiller who argued that more words would benefit students more, even if the instruction was short and teacher-directed. He suggested that teachers teach a large number of words before reading a book to students, by merely giving short definitions, such as synonyms, and then pointing out the words and their meaning while reading the book to students.[14] The method contrasts with the approach by emphasizing quantity versus quality. There is no evidence to suggest the primacy of either approach.[15]
Morphemic instruction

The final vocabulary technique, strategies for learning new words, can be further subdivided into instruction on using context and instruction on using morphemes, or meaningful units within words to learn their meaning. Morphemic instruction has been shown to produce positive outcomes for students reading and vocabulary knowledge, but context has proved unreliable as a strategy and it is no longer considered a useful strategy to teach students. This conclusion does not disqualify the value in "learning" morphemic analysis - prefixes, suffixes and roots - but rather suggests that it be imparted incidentally and in context. Accordingly, there are methods designed to achieve this, such as Incidental Morpheme Analysis.[16]
Reading strategies
.
Reciprocal teaching

In the 1980s Annemarie Sullivan Palincsar and Ann L. Brown developed a technique called reciprocal teaching that taught students to predict, summarize, clarify, and ask questions for sections of a text. The use of strategies like summarizing after each paragraph have come to be seen as effective strategies for building students' comprehension. The idea is that students will develop stronger reading comprehension skills on their own if the teacher gives them explicit mental tools for unpacking text.[11]
Instructional conversations

"Instructional conversations", or comprehension through discussion, create higher-level thinking opportunities for students by promoting critical and aesthetic thinking about the text. According to Vivian Thayer, class discussions help students to generate ideas and new questions. (Goldenberg, p. 317). Dr. Neil Postman has said, "All our knowledge results from questions, which is another way of saying that question-asking is our most important intellectual tool"[citation needed] (Response to Intervention). There are several types of questions that a teacher should focus on: remembering; testing understanding; application or solving; invite synthesis or creating; and evaluation and judging. Teachers should model these types of questions through "think-alouds" before, during, and after reading a text. When a student can relate a passage to an experience, another book, or other facts about the world, they are "making a connection." Making connections help students understand the author's purpose and fiction or non-fiction story.[17]
Text factors

There are factors, that once discerned, make it easier for the reader to understand the written text. One is the genre, like folktales, historical fiction, biographies or poetry. Each genre has its own characteristics for text structure, that once understood help the reader comprehend it. A story is composed of a plot, characters, setting, point of view, and theme. Informational books provide real world knowledge for students and have unique features such as: headings, maps, vocabulary, and an index. Poems are written in different forms and the most commonly used are: rhymed verse, haikus, free verse, and narratives. Poetry uses devices such as: alliteration, repetition, rhyme, metaphors, and similes. "When children are familiar with genres, organizational patterns, and text features in books they're reading, they're better able to create those text factors in their own writing."[18]
Visualization

Visualization is a "mental image" created in a person's mind while reading text, which "brings words to life" and helps improve reading comprehension. Asking sensory questions will help students become better visualizers.[17]
Multiple reading strategies

There are a wide range of reading strategies suggested by reading programs and educators. The National Reading Panel identified positive effects only for a subset, particularly summarizing, asking questions, answering questions, comprehension monitoring, graphic organizers, and cooperative learning. The Panel also emphasized that a combination of strategies, as used in Reciprocal Teaching, can be effective.[17] The use of effective comprehension strategies that provide specific instructions for developing and retaining comprehension skills, with intermittent feedback, has been found to improve reading comprehension across all ages, specifically those affected by mental disabilities.[19]

Reading different types of texts requires the use of different reading strategies and approaches. Making reading an active, observable process can be very beneficial to struggling readers. A good reader interacts with the text in order to develop an understanding of the information before them. Some good reader strategies are predicting, connecting, inferring, summarizing, analyzing and critiquing. There are many resources and activities educators and instructors of reading can use to help with reading strategies in specific content areas and disciplines. Some examples are graphic organizers, talking to the text, anticipation guides, double entry journals, interactive reading and note taking guides, chunking, and summarizing.[citation needed]

The use of effective comprehension strategies is highly important when learning to improve reading comprehension. These strategies provide specific instructions for developing and retaining comprehension skills. Implementing the following instructions with intermittent feedback has been found to improve reading comprehension across all ages, specifically those affected by mental disabilities.[7]
Assessment

There are informal and formal assessments to monitor an individual's comprehension ability and use of comprehension strategies.[20] Informal assessments are generally through observation and the use of tools, like story boards, word sorts, interactive writing, and shared reading. Many teachers use Formative assessments to determine if a student has mastered content of the lesson. Formative assessments can be verbal as in a Think-Pair-Share or Partner Share. Formative Assessments can also be Ticket out the door or digital summarizers. Formal assessments are district or state assessments that evaluates all students on important skills and concepts. Summative assessments are typically assessments given at the end of an unit to measure a student's learning.
Difficult or complex content
Reading difficult texts

Some texts, like in philosophy, literature or scientific research, may appear more difficult to read because of the prior knowledge they assume, the tradition from which they come, or the tone, such as criticizing or parodizing.[citation needed] Philosopher Jacques Derrida, explained his opinion about complicated text: "In order to unfold what is implicit in so many discourses, one would have each time to make a pedagogical outlay that is just not reasonable to expect from every book. Here the responsibility has to be shared out, mediated; the reading has to do its work and the work has to make its reader."[21] Other philosophers, however, believe that if you have something to say, you should be able to make the message readable to a wide audience.[citation needed]
Hyperlinks

Embedded hyperlinks in documents or Internet pages have been found to make different demands on the reader than traditional text. Authors, such as Nicholas Carr, and psychologists, such as Maryanne Wolf, contend that the internet may have a negative impact on attention and reading comprehension.[22] Some studies report increased demands of reading hyperlinked text in terms of cognitive load, or the amount of information actively maintained in one’s mind (also see working memory).[23] One study showed that going from about 5 hyperlinks per page to about 11 per page reduced college students’ understanding (assessed by multiple choice tests) of articles about alternative energy.[24] This can be attributed to the decision-making process (deciding whether to click on it) required by each hyperlink,[23] which may reduce comprehension of surrounding text.

On the other hand, other studies have shown that if a short summary of the link’s content is provided when the mouse pointer hovers over it, then comprehension of the text is improved.[25] "Navigation hints" about which links are most relevant improved comprehension.[26] Finally, the background knowledge of the reader can partially determine the effect hyperlinks have on comprehension. In a study of reading comprehension with subjects who were familiar or unfamiliar with art history, texts which were hyperlinked to one another hierarchically were easier for novices to understand than texts which were hyperlinked semantically. In contrast, those already familiar with the topic understood the content equally well with both types of organization.[23]

In interpreting these results, it may be useful to note that the studies mentioned were all performed in closed content environments, not on the internet. That is, the texts used only linked to a predetermined set of other texts which was offline. Furthermore, the participants were explicitly instructed to read on a certain topic in a limited amount of time. Reading text on the internet may not have these constraints.[citation needed]
Professional development

The National Reading Panel noted that comprehension strategy instruction is difficult for many teachers as well as for students, particularly because they were not taught this way and because it is a very cognitively demanding task. They suggested that professional development can increase teachers/students willingness to use reading strategies but admitted that much remains to be done in this area.[citation needed] The directed listening and thinking activity is a technique available to teachers to aid students in learning how to un-read and reading comprehension. It is also difficult for students that are new. There is often some debate when considering the relationship between reading fluency and reading comprehension. There is evidence of a direct correlation that fluency and comprehension lead to better understanding of the written material, across all ages. However, it is unclear if fluency is a result of the comprehension or if this a separate learned task.

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נושא שלא נקרא #27 

הבאתי טקסט באנגלית יותר ארוך ולכן גם ניצחתי בוויכוח.
חחחחחח חחחחחחח פחחחח.


ngold7
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נושא שלא נקרא #29 

PolarBear

עזוב, הוא לא יפרוש, הוא תמיד יבוא ויגיד מה לא טוב, מה לא נכון, ומה לא לעשות. אבל לתת עצה שבאמת אפשרית לביצוע, בעולם האמיתי הוא לא יודע לתת.
אותי לימדו, ליפני המון שנים, שאם אני רוצה להתלונן, אני חייב להציע פתרון. אם אין לי פתרון אז אסור לי להתלונן.
הפורום הזה נועד, בין השאר, לעזור לאנשים מתחילים בתחום ולמנוע מהם לקנות דברים שהם לא צריכים. חברינו אכן עוזר מידי פעם ונותן עצה טובה, לרוב לגבי הספק וואטים שאנחנו לחלוטין לא צרכים, או כל מיני כאלה, אבל בצד השני הוא גם לא מסכים אם המון דברים שאנחנו עושים, כגון שמיעת מגברים ליפני קנייה, מסיבות מדעיות שעדין לא ראיתי ולו קישור אחד לכתבות האלו..
אפשר וגם רצוי להיות סקפטי, אבל, בזמן שרבים מאיתנו "נילחמים" כנגד תעשיית הכבלים, חוטי החשמל וכבלי HDMI "אדיופילים" ושאר שמני הנחשים, הוא מנסה "להלחם" כנגד התחביב עצמו.
הוא אומנם מסכים שיש הבדלים בין מגבר אחד למגבר שני במצבי DSP דומים, אבל מייד מבטל את זה כי לא כך צריך לבדוק מגבר(לדעתו).
כאשר כולנו, אבל כולנו, שולחים את החברים לשמוע, הוא שולח אותם לבצע בדיקות "מעבדה" שאין שום אפשרות אמיתית לביצוע.
אני לא מבין מה הוא רוצה שהקונה כן יעשה, הרי הדרך היחידה לבצע בדיקה אמיתי היא:כל אחד יכנס לחנות מתמחה עם מכשיר מדידת SPL וידרוש מהמוכר להיזיז את כל הרמקולים הנבדקים לנקודה אחת, השוואת SPL, ביצוע מבחן ABX עם החלפה מהירה מספיק בין מגבר למגבר ורמקול לרמקול.
אחרי הבדיקות אנחנו צריכים לזכור שגם זה לא מושלם כי האקוסטיקה שונה, אז אפשר אולי לקחת הביתה, אבל כדי שיהיה מבחן אמיתי ההמלצה היא לקחת לפחות 4 רסיברים, 4 זוגות רמקולים, חיבורם לממתג, שוב בדיקת SPL וביצוע מבחן ABX ל 16 המשתנים, בזמן אחד.

לסיכום, אתה מנסה לעזור, אולי בדרך נכונה ואולי בדרך לא נכונה(לגיטימי), הוא מנסה רק להפריע.
.He who knows the past controls the future
.He who controls the future conquers the past

PolarBear
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נושא שלא נקרא #30 

צודק בכל מילה, אין מה להוסיף.

שלח תגובה

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