每次看到了Eton 大的這篇單元, 當中有很多學問是小弟要一看在看去研究的, 尤其是空間方面還有數位訊源方面, 謝謝無私的分享
每次看到了Eton 大的這篇單元, 當中有很多學問是小弟要一看在看去研究的, 尤其是空間方面還有數位訊源方面, 謝謝無私的分享
轟聲不是我們要的.....
空間的高度比較沒彈性....建築物規範
在高度尺度的約制下....音響空間合比例就好
至於20hz能否聽到....討論許久....意義不大
能有這發聲條件的系統不多.....音源軟體亦少
務實的把能力所及做好...功德無量
各位的探究精神令人佩服!為了成為更優的音響演奏家,在聲學、材料、電學、音樂、唱片...多長知識,務實的去調整,還能一起分享、探索未知,有所精進,這就是福氣!
人類的聽覺不是線性的 - 有關維基百科的 Equal-loudness contour 相同音壓等高線圖, 真是發人省思,
我們要的是甚麼長像的頻率特性曲線?非常好的一篇參考資料!
http://en.wikipedia.org/wiki/Equal-loudness_contour
Headphones versus loudspeaker testing
Good headphones, well sealed to the ear, can provide a very flat low-frequency pressure response measured at the ear canal, with low distortion even at high intensities, and at low frequencies the ear is purely pressure sensitive and the cavity formed between headphones and ear is too small to introduce any modifying resonances. Headphone testing is therefore a good way to derive equal-loudness contours below about 500 Hz, although reservations have been expressed about the validity of headphone measurements when determining the actual threshold of hearing, based on observation that closing off the ear canal produces increased sensitivity to the sound of blood flow within the ear which appears to be masked by the brain in normal listening conditions[citation needed]. It is at high frequencies that headphone measurement gets unreliable, and the various resonances of pinnae (outer ear) and ear canal are severely affected by proximity to the headphone cavity.
With speakers, exactly the opposite is true, a flat low-frequency response being very hard to obtain except in free space high above ground or in a very large and anechoic chamber free from reflections down to 20 Hz. Until recently it was not possible to achieve high levels at frequencies down to 20 Hz without high levels of harmonic distortion, and even today the best speakers are likely to generate around 1 to 3% of total harmonic distortion, corresponding to 30 to 40 dB below fundamental. This is not really good enough, given the steep rise in loudness (rising to as much as 24 dB per octave) with frequency revealed by the equal-loudness curves below about 100 Hz, and a good experimenter must ensure that trial subjects really are hearing the fundamental and not harmonics, especially the third harmonic which will be especially pronounced as speaker cones become limited in travel as their suspensions reach the limit of compliance. A possible way around the problem is to use acoustic filtering, such as by resonant cavity, in the speaker setup.
A flat free-field high-frequency response up to 20 kHz, on the other hand, is comparatively easy to achieve with modern speakers on-axis. These facts have to be borne in mind when comparing results of various attempts to measure equal-loudness contours.
Kevintran兄所言並不算是吐槽啦, 您的耳機是用來享受高品質悅耳的音樂, 還顧及舒適透氣與安全, 為此, Hi-end 耳機設計應該走此路線
如果要用來量測人類的 相等音壓等高線圖 或 耳科醫師的聽力檢驗 就是另外一回事了, 越密閉, 越貼耳道的耳機是量測儀器的理念, 為求儘量沒有能量損耗, 直接灌入耳道
還是回到這問題 20-20K Flat 好嗎? 無響室的規格如此, 音樂廳就不是了, 真的很想知道最好聽的三大音樂廳 - 維也納愛樂協會金廳、阿姆斯特丹音樂廳、波士頓音樂廳的頻率響應圖, RT60殘響圖長的如何哩?
如果大量看過許多喇叭的頻率響應測試報告
的確可以發現某些廠商的確是依照Fletcher-Munson curves在設計響應的