Rerurn to Romy the Cat's Site

Romy,

Regarding your first illustration:

Some time ago I intentionally made two different boxes for my ScanSpeak drivers to see what will happen, because I do not believe in theories and trust only to my ears. The boxes had exactly the same internal volume and front baffle width, so the only difference was in their actual proportions (height and depth). The first one was very tall and very shallow, the second one was little in height but very deep.

There was HUGE difference in sound. The deep box sounded much more articulated and with ease at the dynamic peaks. The improvement in sound was most remarkable in the upper range of the driver. The only reasonable explanation I have for that is that the back wave form the driver bounce back to the cone and interfere with the front fired wave, adding delayed signal with high amplitude. If the back wall is very far from the driver’s diaphragm, the energy of the reflected wave is very low thus the sound is more clear and better defined. In comparison the sound of the shallow box was some kind of polluted at MF, loosing definition and dynamics (micro and macro), the midbass was quite excessive and unlistenable, although SS is quite nice driver.

So I think the depth of your box is of much greater importance than the exact location of the ports at the bottom and I definitely think the design “B” is going to have better sound.

My thoughts about your second illustration:

I’m not sure if my interpretation of the picture is right, but the port of speaker “B” seem veeery long to me. That means the tuning will be extremely low and the acoustic system should behave more like sealed box rather than typical bassreflex design. It is true if you tune it below approximately 20Hz but I hardly see any sound benefits from this kind of bass loading. The longer the port is, the lower the Fb will be and vice-versa (if the port area is the same). What is your motivation to use so long port?

Rerurn to Romy the Cat's Site