有意思 , 很不錯想法算我一份
可列印查看
andychu買一台最貴的捐出來
我們出資買一台簡單隨身的....
Testing LoudspeakersHOME/SOLUTIONS/LOUDSPEAKERS
Speaker testing is challenging because extraneous noises and reflections from surrounding walls and floors interfer with the acoustic measurements. The ideal testing setup is a dedicated acoustic tester in an anechoic chamber (or a remote, windless location such as a desert), where there are no reflections or other disturbances. However, the cost and time for this kind of setup is impossible to justify for the vast majority of engineers, especially if the need is only occasional.
Most engineers who want to make acoustic measurements wish to do so in their lab, or even on a noisy production line. For these situations, two main techniques have been developed to negate the effect of reflections: MLS and time gated log chirp (continuous sweep).
Setting up an acoustic test
Setting up an acoustic test is the biggest challenge in measuring loudspeakers because it's hard to determine exactly when the first reflection hits the measurement microphone (and thus pollutes all subsequent signals). The latest APx software uses drag and drop cursors on an Energy Time Graph to define where the time gate should start. APx also automatically calculates distances to double check the measurement correctly. Measurement results are recalculated based on the new time window and regraphed in real time.
Common speaker tests include frequency response, sensitivity, maximum SPL, phase, group delay, and impedance. The APx Series and 2700 Series both feature extensive programming capabilities for automated production line testing, including advanced reporting, pass/fail limit setting, and control of turntables and other external equipment.
Cello Acoustic Recordings By Mark Levinson 想这器材必是用Cello直接錄的8)
http://img413.imageshack.us/img413/6326/img0034jr.jpg
http://img412.imageshack.us/img412/2339/img0033ym.jpg
Audio system do not reproduce music they reproduce "recording of music"
這是CD內付的資料------
http://img716.imageshack.us/img716/4923/img00341u.jpg
http://www.my-hiend.com/vbb/picture....ictureid=11397
這張我還是會三不五時拿出來聽......