Separate subs for music and HT/surround

OmniMic or REW are more accurate Measuring devices. Promoting anything other than measuring with instruments is misguided advice. 
While multiple subwoofers are accurate advice, and provides enduser with a smoother response at the LP, this is 2019 and we have software and hardware that are affordable and accurate.

a comprehensive multiple subwoofer array setup scheme combined with proper calibration equipment will get you much closer than archaic “crawl” method.

If crawling around was a conclusive method, Kef and Velodyne would scrap their testing facility and hire professional “Crawlers” :0)

Kg

Actually, on page 25 of the Velodyne Digital Drive Plus User’s Manual under the heading of Optimize for Subwoofer Placement, "you place in the room according to the information in the general section and optionally the "Crawl Test" section in the Subwoofer Placement Recommendation Guide" (where the "Crawl Test" is explained in more detail).
As a multiple DD Plus user I can confirm that DD Plus Room Optimization can compensate for time and phase issues that may arise from less than optimal positioning. Its ability in dealing with any rooms unique modes and nulls is far less effective, if at all, compared to beginning with the suggested "Crawl Test".
Sadly, the Velodyne facility is now used for Velodyne LiDAR.

No wonder SVS is climbing toward the top in subwoofer sales, design, R&D

if i read SVS recommends crawling around rather than a $60 mic and free software and a lsptop, i’ll throw in the towel Lol

   The SVS Ultra appears to be the first affordable subwoofer with an application that offers needed low frequency crossover related adjustments as well as three customizable memory EQ presets within a single frequency band between 20 and 200Hz.
   Velodyne, JL Audio, Vandersteen, Magico, and Von Schweikert, understand the importance of multiple frequency bands of discreet equalization within a higher crossover region without reducing gain and not simply a set point where the subs kick in.
   SVS claims (SB16-Ultra Owners Manual page 15), "in some cases, reversing polarity - can be used to fix bass nulls or overly boomy spots in the listening area". While it may have a minor affect reversing polarity simply restores the polarity of the recording which is most noticeable in the bass drum and can vary as often as from track to track. If the listening position is located within a null or mode the sub will require proper physical relocation. With the sub at the listening position you don't actually need to crawl around to locate a rooms modes.  
   I'd venture subwoofer sales are related to affordability rather than flexible frequency integration. If they've never heard it how would they know what to listen for? After all, almost any sub sounds better than no sub.

kgveteran: " a comprehensive multiple subwoofer array setup scheme combined with proper calibration equipment will get you much closer than archaic “crawl” method."

Hello kgveteran,

I think we both owe a big thank you to m-db for informing us that even a manufacturer of subs containing room correction hardware and software realizes the effectiveness of the timeless ’crawl method’. Thank you m-db.
Sure, individuals are free to buy and utilize expensive calibration equipment and software to determine the optimum positioning of subs in a multiple sub bass system. But the crawl method has proven its effectiveness since ancient times when the Greeks first invented the technique circa 3480 B.C. Aristotle and Plato actually put it best when they stated numerous times in oral and written form, " why bother? Crawles fideles!".
The reason the crawl method has since been used continuously for approaching the last 6,000 years is because it works so well. A bit more recently in this country, it’s a well known historical fact that Thomas Jefferson was observed teaching the method to George Washington in the upstairs living quarters of the White House when George was setting up his system just after his Inauguration. Interestingly, it is recorded that they did so while dining on beer and pizza. Also of note, Jefferson was introduced to the magical secrets of the crawl method by Benjamin Franklin at a clandestine Freemason meeting just years earlier in Philadelphia.
Given its long, proud and extremely effective history spanning centuries, I consider your attempt to abandon, or at least foreshorten the effective lifespan, of such a beloved, archaic and globally respected sub locating tool as the crawl method to be reprehensible, heretical, counter-productive, nonsensical and possibly criminal in most legal jurisdictions world-wide. My god man, Leonardo Da Vinci used the crawl method in establishing his controversial, and humankind’s first, 4-sub DBA system over 500 years ago.
I fail to comprehend your logic in casting aspersions and apparent lack of respect for a literally free technique, that has been so cherished, reliable and effective throughout the long and historic record of sub locating efforts, solely on the basis of not being sufficiently technologically sophisticated enough for your approval.
Well, we now clearly understand you’re not a Freemason.

Tim