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Mattresses Buying Guide
Simmons Motion Separation Index
The Simmons Motion Separation Index
What is Motion Separation Index?
Motion Separation Index, or MSI, is a measurement of the transfer of motion from one sleeper to another across a sleep surface. A mattress with a high Motion Separation Index will prevent one partner from unintentionally disturbing the rest of another.
What is the purpose of MSI?
If undisturbed rest through motion separation is important to you, then the MSI rating of a bed is the perfect way for you to simplify the purchase decision of your new mattress. The index puts a quantifiable measurement on how much motion will be eliminated when one partner tosses, turns, gets into or out of bed.
What do the numbers mean?
The Motion Separation Index is actually very simple. It uses the lowest-priced Simmons Beautyrest with 825 coils (the Tyler) as the base, or 170 points. From that point, it compares the other major mattress manufacturers and the other Simmons mattresses to the Tyler. Some other leading Brands can only suppress 28% of the motion that the Tyler can suppress. At the high end of the index, the Simmons Beautyrest World Class Exceptionale, with a MSI of 210, will suppress the most motion transfer.
Which MSI rating is right for me?
Take our quick test to determine how many of the following questions can you answer yes to:
- Do you sleep with a partner?
- Do you go to bed before or after your partner?
- Do you or your partner get up in the middle of the night for any reason?
- Does your partner’s tossing and turning wake you?
- Do you and your partner wake up at different times?
To how many of these questions did you answer 'Yes'?
||Recommended Sleep System
|1 to 2
||Simmons World Class or Exceptionale
||180/2 or 190/3
|3 to 5
||Simmons Beautyrest World Class Exceptionale
Note: Simmons has changed the numbering system for MSI. The new 2007 models now have an MSI of 1, 2, 3 or 4. These new models still give you the same motion seperation; the only thing that's changed is their numbering system!