Been looking for a small sub and the Grotto is still a bit big. I would like to demo this against the Rel Q108e, the DefTech Supercube II, and the Velodyne SPL-800 II. I think that it only goes down to 25Hz @ -3dB. Do you know if it is magnetically shielded?
Are you using it to hold up your monitor, if not, then the issue of shielding is moot. The magnetic field of any magnet drops off at the inverse square of the distance, double the distance the field is 1/4 its original strength etc.
Just read a review on Audio Review on the Dynamo.. "there is only one" and it was very positive. I can't figure out why the reviewer gave it 5 out 5 stars for value, and only 2 out of 5 otherwise... he says nothing but good things about the unit and DOES NOT say anything bad, go figure. Maybe you should read it.
I haven't given up on the Dynamo. I was sick (had the flu) so I wasn't able to check it out at Magnolia Audio-Video. I can't do it this weekend either because of other commitments. Maybe the week after. I'm not really in a hurry to get a new sub, plus i'm still debating with myself which one i'll get.