In one of the linked reviews for the SMS-1
[http://www.hometheaterhifi.com/volume_13_4/feature-article-two-subs-10-2006-part-2.html]
was the following statement: "At CES 2006, Velodyne showed a new product they call the MIC-5, or Bass Management Hub, priced at $799."

The reviewer then goes on the use and describe the system.

Have any of you used this or a similar multi-mic setup?

I seems to me that it would help to get "good sound everywhere" in the listening room instead of "great sound only in a 8 cubic inch sweet spot".

Whaddya'all thionk? "Great", "Snake oil", "We never move our heads from the sweet spot", other?

Empirical evidence? Anecdotal evidence?

Multiple microphones for EQ certainly aren't snake oil, as the idea of sampling more than one location is a pretty widely used one. Lexicon uses it on their MC-12 (connections for four microphones if I remember correctly) and Audyssey's MultEQ can do something similar (one mic, moved from place to place), to name just two examples that come to mind. I haven't used the MIC-5, but I don't doubt that it can provide benefits when setting up the SMS-1 for a space with multiple seating positions.

$800 to save you time. You could just move your one mic around a lot and tweak a bunch and get the same result.

What follows is all my personal opinion...

I think that just because one uses multiple microphones for EQ it does not mean that it changes the characteristics between one sitting position and the next. To me, this method seems designed only to produce a pretty curve. Unless a listener's ears are 5 feet apart, he will never get to hear the sound as it was sampled. It may be a good measure of the overall characteristics of a room (dead, bright, etc.) but, IMHO, not of the listening experience.

I don't have any experience with multiple mic setup but to me it seems like letting the air out of three tires to fix a flat.

I would just buy another sub instead of spending $800+ on microphones. I agree with lanion, I think it is better to take a couple of samples at two or three positions and tweak. If one position is drastically different than another, we might need to apply some sound treatment or adjust the sub's settings (or move the microphones closer together - I am kidding on that one).

With the 990 as is, or with an SMS-1 or similar item involved, one could go through the setup procedure for any number of positions, writing down the results after each one. This might be painstaking, I know, but you’re an enthusiast, right? If I had a couch with three primary seating positions, I’d average those three results at adult seating height and enter the average values manually. They should be fairly close to begin with. If I had a couple other seating positions substantially different from my primary area, I wouldn’t create a poor listening experience for the primary positions just to make it better for the outlaying seats.

If a problem existed, such as much more bass response for seating near a wall of the room when compared to other positions, I’d might add room treatment (bass traps?) then go through the averaging setup again for the primary seats. One might still check the values obtained for primary versus secondary positions to see if room treatment helped create less of a differential, but I'd still favor an average of the primary seating area.