I got started yesterday on actually completing the review of the Buchardt S400. For now, I am using my "manual" turntable to get measurements indoors until I have time/money to finish the motorized platform. The stand height is about 42 inches off the ground with the ceiling at 10 feet. With Klippel's ISC module you can use an anechoic "reference" measurement with an indoors measurement and subtract the room out of the result. You can read about it here:
http://www.klippel.de/products/rd-system/modules/isc-in-situ-compensation.html
I will be using the outdoors ground plane measurement as my "reference" and getting anechoic data for the DUT. It's really impressive. The reason why I chose to go this route instead of using the ground plane measurement for all is due to a few things:
1) Accuracy in aiming. I showed in an earlier result that the difference in just a couple degrees can equate to relatively significant "errors" in the measurement. For instance, if the tilt of the speaker isn't lined up perfectly with the microphone the Buchardt S400 measurement was off as much as 3dB within a 5 degree tilt window. This issue is more trivial but it's something to keep in mind. Measuring on a stand in my garage allows me to laser-align the mic position relative to the location I want to measure (i.e., tweeter axis, between waveguide/mid, etc).
2) Noise. Ground plane measurements are subject to wind in high frequency. Aligning my available time with no wind and perfect weather isn't really feasible. So, using the GP method for lower frequency response helps alleviate this issue.
3) Temperature. High frequency drift is common in extreme temperatures. My garage is insulated and I also have a 220v heater that warms the garage quickly in the winter months. So as long as the doors are closed the garage stays within about 10-20 degrees of the house temperature which is enough to keep drift from occurring.
4) Comfort. With the ISC module I can create a room compensation curve and conduct additional tests such as distortion measurements indoors. No need to stand outdoors and conduct additional measurements and sweat/freeze.
Without Klippel's ISC module I would likely conduct my tests outdoors in the ground plane method only. But with the ISC module I am afforded some additional flexibility without loss in accuracy (actually, potentially better accuracy) which makes my life a bit easier.
Here's some shots I took of the measurement rig with the Buchardt S400 being tested. And, yes, there is a rear leg on the stand; it's just blocked in this angle.