GIK Vicoustic and others

Would double dry wall be sufficient or do I need insulation such as rock wool ? Has anyone tried both? 

I have both GIK and Vicoustics. Vicsoustics is >>>> GIK. They are expensive, but worth it. If not anything, get multifuser DC3 in between the speakers on front wall. That will be the biggest change. Rest you can manage based on budget and preference.

Not sure about the dry wall/ insulation: Waiting for other replies to learn from them. 

Use the long axis ( placement on room width ). 

Find out what the radiation pattern is for the Sonus Faber Ellipsa and you will have some idea where to start.

No Loudspeaker should overload ( be unusable ) for a reasonably sized room.

Work out how to treat for low end response and the rest will be less of an issue.

Once low frequency is addressed moving out of close field is possible.

I’d insulate because it’s the basement, but no need for double drywall. Another place to put insulation is in the ceiling, it will definitely cut down on the noise complainants from upstairs 😁

All the best.

JD

I ordered from GIK and was not pleased.  It took two months for the products to arrive. And when they did, they were poorly packaged and all four pieces were damaged. Took close to another 2 months to get replacement pieces for the damaged pieces. I could have overlooked the delays if the products had arrived in good condition, but based on my first experience with the delays and damage, I am unlikely to go back to them for any future purchases.