Barra.... Just downloaded and tried the Sonarworks software. Installed the vst into JRiver and set it up with the ssbb tweak. Selected the hd800 setting and it does make a big difference. Have to figure out how to make the ssbb tweak a little more blended. Have to try it with the 650's next, thanks for the heads up.
The HD650 is a no brainer as it is already dialed in for you with its own SonarWorks plug in. There are also unlimited curve versions of the plugins that add more frequency response to both ends adding more to the equation. @johnjen is the the expert and is responsive on his cookbook thread that I linked earlier if you have any questions.
One more thing. The phase reversal technique is a big deal and the hardest part as it requires a special phase reversed cable. But it is a huge upgrade even without the other two tweaks that is obvious in an A/B situation that we had tested in mini-meet conditions many times. This was the first tweak that the Seattle group adopted, again thanks to @johnjen and @atomicbob and it was eye opening to say the least. Not an expert here and it is better explained by @johnjen , but in a nutshell - an amp has a + and a - voltage swing that both channels use together in the same phase. The reverse phase allows each channel to use the opposite voltage rather than the same so that their is more headroom during dynamic or big bass moments providing huge dynamic improvements. The result is an Abyss like bass and faster transitions for more clarity.The difference is easy to hear.
If you have any soldering skills and time, @johnjen can instruct the assembly of the cable or you can have one made through your favorite cable maker. The requirements is a balanced four wire cable to your HP and possibly a balanced to SE adapter if your amp only accepts SE.
If you find any tweaks that help the HD700 sound better with SonarWorks, please share them here or in the cookbook thread so I can try them too. The nice thing about the Jrivers/SonarWorks combination is that it becomes a laboratory that you can make changes and instantly A/B the differences to check their value. If only I had more time in my schedule to play with it.