Originally Posted by Ricci
Let me guess. Port is too close to the internal walls, the exit is compromised due to such a tiny worthless flare and proximity to the edge of the baffle also compromises it. How about since both exits are asymetrically loaded? Not enough baffle surrounding the port too.
If you can keep turbulence down in the port, then the corner placement might allow you to make it slightly shorter since it'll get extra internal loading...same goes with the floor actually. The downside is that the Q of the port is going to get a bit more narrow since you've effectively got more mass, but less inductance. This may not be a bad thing though because the Q of the port gets wider as it starts to overload.
Also, turbulence generated at the exit of the port essentially comes down to the ratio of circumference to the port area. Going to two smaller ports increases the total circumference for the same area, which will introduce more turbulence than the one larger port.
The reason flaring works is that the transition to a smaller circumference/area ratio is slow enough that the air doesn't pull apart as quickly, making it easier to suck it back in on the rarefaction. However, flaring a 4" port to a 6" mouth is going to have more turbulence than a tube that is 6" the entire length. The reason is because the extra 2" of diameter acts like a soft flare, or at least that's how I've been led to understand it.
The biggest downside I see to having the port in the corner of the cabinet is that it guarantees the mouth is at a pressure maximum for all the internal standing waves...basically the same effect of standing in the corner of your room. This just means you'll need more stuffing inside the cabinet to keep the resonances sufficiently damped. The downside to stuffing is that it lowers the Q of the box capacitance, which makes the overall system less efficient...and combined with the higher Q of the port you're likely going to see a small dip in the frequency response just above the tuning point.
Btw, you can model all of this in WinISD by doing some manual manipulation. One saving grace might be the fact that heat on the voice coil might compensate for the dip above the tuning point when the system is driven harder. I personally like to adjust the tuning frequency and the box volume to minimize the amount of change seen between linear and fully non-linear operation. Sometimes you can keep it within a few dB and I've found that these boxes behave more consistently when EQ'd and tend to sound better overall because of it (it's easier to voice when things are more consistent).
Anyways, just some thoughts I had...I hope I'm not spreading any misinformation.