embedded room correction行不行？

http://www.computeraudiophile.com/content/Room-Correction-without-downside
這老兄真是有錢啊...用的系統是
dCS Paganini 3 box front end, ASR Emitter Exclusive 1 integrated, and B&W801ds
整套應該要三百萬以上吧...
他說搞了十年的空間校正，用過
three generations of Tact correction, two Lyngdorf units, Rives (not really room correction), Logitech Transporter (with Inguz) and cheaper Behringer units
全都不行...
Tact與Lyngdorf都不便宜哪...至少要NT$十幾萬...

Lyngdorf DPA-1 Room Correction Processor

這隻機器做的就是RRC囉～
這段video解釋怎麼操作

http://www.lyngdorf.com/downloads/Video/Lyngdorf_RoomPerfect_Presentation.wmv

測試不只聆聽位置這一點，至少還要空間中任意三點
這篇有細節 http://www.lyngdorf.com/downloads/product_descriptions/roomperfect_productdescription_english.pdf

Therefore the challenge is not to remove the room and the reflections – but to adapt to them.

Lyngdorf的Class D擴大機

這篇裡談了不少細節 http://www.lyngdorf.com/index.php?option=com_content&task=view&id=69&Itemid=35

Most PWM amplifiers today are self oscillating which means that the amplitude of the ANALOG input signal decides the switch frequency. This means that the switch frequency is high (> 300k Hz) when the audio input signal level is low, and that the switch frequency is low (= moving towards the audible frequency range) when the audio input level is high = when the output from the amplifier is high.The advantage of this topology is that it is cheap and simple to design since it uses well proven feedback from the analog output to the analog input partly to create the oscillation and partly to create a low THD amplifier. The disadvantages are that it requires an analog input signal (= it is really an analog amplifier!). So, the PCM (Pulse Code Modulated) signal from your CD player is converted to analog and then the analog signal is converted to the PWM signal. Also, the feedback loop typically isn't linear which is why distortion often increases towards higher frequencies.