Hi all
In my opinion the a7 cabinet reconances are somehow inherent to this system. The big box allows the air to resonate in various fequencies, to make the box out of stone would not help this. The compromise to let the A7 act as half bass reflex and half backloaded horn is the trick to make the A7 as eficient as it is down to about 40Hz. The drawback are these bothering resonances. I was not able to ignore them, so I sold my pair of A7's. I prefer the 9846-8A studio monitors. The resonances I'm talking about in the A7 cabinet could be stopped with a lot of damping material, but the bass power would then be lost too! To make two chambers in the A7 and add a sub in the lower part is an often discussed way to solve this problem. I tried that with adding a 411-8A to the lower part of the A7. Sounds ok, but the sound is not as nice as it is if 40 Hz to 500 Hz is done with one speaker alone. And it is complicated too, the 411-8A cannot keep up with the efficiency of a 515 or 416 speaker, so it needs biamping& electronic xover. But actually still.. I miss the bright mids of the A7. In switzerland they say "you can't have both the penny and the bun!"
