For those that want data for mods of the 1.6, Danny provided before and after response data. Have anyone noticed that Danny’s modification lowered the SPL to get flatter base response? The efficiency is already low. My 1.6QR were rebuilt by Magnepan due to some delamination. I had upgraded the capacitors to Claricaps and Magnepan left them alone during the rebuild. For $675 I ended up with a practically brand new 1.6QR. Selected a new color for the sock and new wood trim. A few months ago I bypassed the fuse and removed the metal panel and tied the bi-amping posts together. An audible difference for those simple changes. The speakers sit on 2” maple slabs and the nylon washers are removed to eliminate the tilt.
My opinion is that if there are simple modes that make a difference, enjoy the process of tweaking your system. I don’t think you can find a speaker measuring tool to demonstrate an increase in clarity or an improvement in the focus or imaging. So if it sounds better to you, go for it.
Thank you to all who take time for these discussions.