Unfortunately I have no experience measuring big heavy speakers in spinorama form and I'm not in a hurry to start!
That said, maybe something like this setup from
audioholics if you can measure outdoors?
@hardisj also had a similar setup with a rolling scaffolding thingamajig
at one point before the NFS saved his back:
(How coincidental that both of these images are for the same speaker too!)
Seems like getting it up there is still going to be a pain, but at least such a setup should provide a stable enough surface.
Thank you for a very informative thread.
Here is some more details for beginners, that you probably already told:
1. Its good to see that a 50 dB window is used for the measurements, you often see people measuring with 80-100 dB that makes everything look flat. The professional standard is 50 dB.
If using smoothing, 1/6 oct is about the same as the ear will hear. Always save unsmoothed measurements.
2. The mic-holder can change the measurements result - one can use a long 1,5 metre plastic tube instead with the mic and cable attached. This is also the cause why Dayton imm6 shows innacurate results about 4 kHz - both the iPhone and the mics shape is causing diffractions with a bump at around 4 kHz .
3. When starting measurements as a beginner, its also good to read about the basics : psycoacoustics and the different laws of acoustics. Meaning:
*The precedence effect. The brains starts to select sounds at certain distances while the mic monitors all the sound.
*The HAAS effect and the law of the first wavefront.
*Critical distance.
*The speed of sound and wavelenghts of frequencies and the connection in time. This will help you measuring the right thing.
4. Read and learn about the differences between a rooms fundamental resonances and reflections.
5. Always measure only one loudspeaker at the time , the other turned off- read about the reason why.
6. Also read ”measuring loudspeakers ” by John Atkinsson at Stereophile. Its free to read on the net.
7. Read Dr. Tooles book ”Sound reproduction”.
Without this basic knowledge about acoustics a newbie can get seriously lost in the measurements.
I myself did those steps while measuring at the same time , the best thing to learn for real.