OK, caveats first. These measurements do not represent the actual response anechoic response of the sub, but only a rough approximation in my room, with consumer grade measuring equipment.
The main reason I did this is that I was curious as to why I was getting such good in room extension (-3db at 21.5Hz) given that the published 3db point of the sub is 28 Hz. Normally a sub has a very steep rolloff below port tuning. I would have expected to see the -3db point extended by 3-4Hz.
This first image is how a ported sub usually rolls off. You have about 5db of shallow roll off and then the response drops like a stone.
Here is a measurement taken about 2" from the center of the EP350 driver. it will not include port response. My first reaction was, "What the heck is that cliff at 50Hz!" its a good 8db drop. I have seen a lot of driver measurements and not even the cheapest one has anything like that. The only explanation is that it is the crossover.
Not so good methinks.
The other interesting thing is the shallow roll-off of the sub. The curve looks more like what you would expect with a sealed sub. This design trades off a few DB higher up for a little more extension lower down. I'll bet this is why the 350 v3 has so much more apparent impact than the older design.
The other thing is that this confirms that I am getting a good 20db of gain at 22Hz. Thats Huge! Way more than I would have expected.
Here is a measurement taken at about 1.5' with the meter positioned down towards the port to pick up its output as well. The slope is a little shallower. I am willing to bet that the port adds more to the low end then I am measuring.
OK, I'm all done geeking out now.
