The Building of a Pure Digital System

Welcome audiophiles!

In setting up this blog, I hope some of you can find the information here useful. It took me many hours of work to get the information here and create what I believe a reasonably good system. Of course, what is reasonable to me may be rubbish to others. But compared to many so called high end system with millions of dollars on expensive equipment, my setup will not be embarrassed.

In summary, this system involves the use of digital crossover with linear phase filters, properly time aligned drivers with room correction. Crosstalk cancellation with Princeton invention – BACCH filter. The subwoofer is integrated into the system with the same principle described in TACT. (Since 2012, I have ditched the W210 subwoofer as I found it can no longer keep up with the speed of the rest of the system). The speaker is specially designed with sealed box for all drivers. The reason I chose sealed box is so that I have direct control over the driver via DSP. A ported response will rely on the port resonance to get the lower bass and I have no control over for room correction, pre-filtering etc. A sealed design has ab disadvantage of “not getting low enough”, well, not with 8 pcs of 10″ drivers! This system can go down to 30Hz daily. Also, with a Qtc or 0.5 for both the sub and the woofers, the bass is very clean and fast. “Fast” is another keyword in the current design, the drivers chosen has been known to be fast. With DSP for room correction, I need a fast drivers to deliver the inverted signals without delay.

I would describe the sound of my system as “real”. It has a wide soundstage, ultra high resolution with excellent micro and macro dynamics. The timber, the texture and layering of each musical instrument are the best that I have heard. Violin sounds like real violin and piano sounds like a piano. In orchestral musical piece, I can hear each individual equipment clearly in their own location in space. Much of this is brought about by the use of linear phase filter and phase alignment. With minimal phase filter, (typical passive crossover) you feel that all instruments are blended together and their relative position is not as defined. You can only hear roughly different sections, the individual instrument within each section cannot be defined. But if you have the experience in attending life classical concert, you will notice that this is not the case. You close your eyes and you should be able to tell exactly where is the instrument. Think about it, the conductor definitely knows which player is off the pace and the recording microphone is frequently placed just above him!

Setting up a perfect system is the goal of all audiophiles, but it is more a journey than a destination and this insane passion is what keep us, at least myself, sane!

Ackcheng 2015