Right, I'm in disagreement with most of his opinions as mentioned on this thread.
A miniDSP has many many times the proper bandwidth for applying PEQ to bass frequencies. Much of his criticism might have more warrant if we were discussing full range. I might not recommend A MiniDSP for a full range active speaker application that you plan on using for critical listening, but even then it's not terrible.
Dismissing a mic response for bass tuning is ludite speak. Beliving you can best that with just using your ear is chumpish at best. An omnidirectional mic is more than capable for bass frequencies, and presenting a visual graph of response is quick and easy. Humans aren't that sensitive to bass frequencies so a fair response might still sound good. However, the excellent response you never heard tuning by ear, will sound better.
and HDMI is fine... but oh boy, here we go...
"What type of sub is it?"
The impact of the topology of the subwoofer, if there is any, will be reflected in the measurements. A secondary consideration could be sealed vs ported, for determining room gain, but again measurements will reveal that impact as well.
"Is it a downward facing reflex speaker or is it a forward facing reflex?"
Every subwoofer creates bass from a focal point within the cabinet of the subwoofer. The position of the woofer has tertiary effect on performance. But if it did, see measurements.
"Is it carpeted or hard floor?"
This almost certainly never matters,, but room dimensions matter a lot. A secondary concern could be if on a slab, or crawlspace floor, but again, mic measurements will reveal that impact as well.
"All these things will create a different sound"
Ehh... Your primary concern are the room dimensions, and again, simple mic measurements will reveal the room's impact.
"It would be best to ask others what experience they have had with the different materials used."
It would be best to use your own quantitative date via mic measurements instead of folks opinions.
"This even goes to raising a sub further away from the floor to alter the tone."
Yes, moving a subwoofer in any of all three dimensions will change it's presentation at the listening position.