Plugging the ports is a parameter for exploration, with both positive and negative effects. If the 626s are close to the wall, experimenting with materials of varying densities (from loose fiber, loose nylon stockings, all the way to foam plugs) may improve tuning and prevent excessive bass, but the tonal and dynamic quality of the bass will change. There is no one answer, but I would get the best room position first, then experiment with the ports. Your own ears and taste will tell you if it works. I'm using a VMPS NOS sub, with soundcoat and megawoofer, driven by a Hypex HS200 amp (x-d at 50 hz.) with 626s which for decor reasons are only about 8" from the rear wall. I have settled on foam plugs after over a full year's trial and error. More space behind the 626s would be a better arrangement. This sub and amp replaced my Legacy Impact sub, and is a match made in heaven, as well as a total steal at under $1k. I would not consider any sub but VMPS for a VMPS system, unless space is at an absolute premium. The blend is perfect, and the quantity and quality of the bass is SOTA for a real world price. Have fun!
