As said in the methodology post, enclosure orientation can be a bit tricky with certain subwoofers, Proson Stratego Sub 12+ is one of them. It is a front-firing subwoofer, but has a port in the back. Of course the most reliable and convenient way to find out the best possible orientation is to measure all of them and choose the best one – and that’s exactly how I did it. Graph below shows the measured frequency response with woofer facing the mic (2 m distance measured from the front baffle) and another one with the subwoofer turned sideways (2 m distance measured from the center of the driver/enclosure mid-line). Naturally the input level was kept identical. As you can see, the sideways option gives a slightly better extension, although the response is rolled-off quicker above 100 Hz due directionality of higher frequencies. Sideways option was used with this subwoofer.
