The SEVEN Value when calculating RMS:
The value used when calculating RMS (Vrms =Vp*) is .707.
.707 is typically for the sine wave only, and determined by taking the integral of V(t)2 over a full cycle, dividing by the time of the cycle, and then taking the square root of the answer (hence the name "root mean square", RMS).
Some Quick Facts about SEVEN products, materials, research, design & development:

-We use dual voice coils @ 2/4ohm impedance with an outstanding "Mechanical Q" (QMS), such as 4.01. A lower Qms means tighter suspension (the spider and the surround working together).

-High Efficiency FEA optimized motors (Finite-Element-Analysis based optimization of structural mechanics in engineering). We also use the NEO motor system in research and design but have not released any NEO subwoofer models yet (if).

-High performance oversized double stitched foam (polymer infused) surround that sits one full inch tall; a stiff but light weight design.

-The only Ten Inch Subwoofer model we will ever make, the ss1000, was newly designed in 2016 using a Satin Black (powder coated) Die-Cast Aluminum Alloy Rigid Frame, with six flared out vents surrounding the spider and coil (six forced-air vents that each flare out). These vents together provide open air of 33 squared inches.

-Each ss1000 subwoofer has a supporting top plate three quarters of an inch solid allowing for the "Ten's" open air design. Notice in the pictures, six (6) four inch long rails surrounding the basket. This creates additional rigidity creating a reinforced super structure!

-The ss stands for many things such as Seven Speakers, a.k.a. Seven Subwoofers, or Seven Series. For example, Seven Series 1000w would be the ten inch, 1000w nominal power rated ten (ss1000). These names help keep Seven Simple, clear and concise. In addition to "The Simple Seven", ss pertains to SEVEN also as "Sonic Shock". This ss tag actually came later on after the name of the company, Seven. Today there exist two domains for Seven; and (one website, here). "Sonic Shock" is a term derived from lighting and thunder and was an alternative name before "Seven". 

-One of Seven's parts manufacturers designed and introduced the "Neodymium Magnetically Powered Motors" into subwoofers. This same manufacture has been in business over 20 years.

-"The number 7 is the seeker, the thinker, the searcher of Truth (notice the capital "T"). The 7 doesn't take anything at face value -- it is always trying to understand the underlying, hidden truths. The 7 knows that nothing is exactly as it seems and that reality is often hidden behind illusions." QUOTE CREDIT OF
What does this have to do with speakers or car audio; nothing, so what...?

-Any purchases made online on the Seven Website are through a secure socket (https). You may also find our products on Amazon and occasionally on eBay. Both, also, being secure locations to purchase online.

This is the inside of a box using SEVEN'S Moldable MDF (Patent Pending - only so no other company takes the product, and then tells us we can no longer give it away for free), part of our Research and Development:

Understanding even the smallest differences in subwoofers unlocks the door to engineer a better sounding, better looking and more efficient product for our customers.

For example, here are specs on the only TEN inch subwoofer we need, the ss1000 (Ten inch High Performance Subwoofer by SEVEN):
fs/fms: 31.6hz
Qms: 4.01
Rms: 12.7 - kg/s
Nret: 0.16%
VAS: 15.1 L
RES: 180.9 ohm
Qes: 0.28
Cms: 0.10
Rp: 54.0 ohm
Le: 2.98 mH
Re: 4.0 ohm
Qts: 0.26
Mms 256.5gr
SPL: 84.1 dB
Lp: 77.6 mH
Below are specs on the white twelve inch subwoofer, the wss2000 (Twelve inch High Performance Subwoofer by SEVEN, white basket):. This speaker may be discontinued - TBD
fs/fms: 38hz
Qms: 4.931
Qes: 0.360
Cms: 68.451u M/N
Fo: 38.440 HZ
Sd: 51.071m
MMd: 198.000g
BL: 25.916 T
No: 0.387%
Krm: 70.176m ohm
Kxm: 206.028mH
ERM: 0.638
EXM: 0.544
Qts: 0.336
MMD: 280.244m kg
Mms 286.881g

         (3.5sf if underpowered)
Below are specs on the black twelve inch subwoofer, the ss2000 (Twelve inch High Performance Subwoofer by SEVEN, black basket):

fs/fms: 36.1hz
Qms: 3.51
Rms: 18.6 - kg/s
Nret: 0.23%
VAS: 19.3 L
RES: 137.3ohm
Bt: 23.4 N/A
Qes: 0.48
Cms: 0.06
Rp: 35.5 ohm
Le: 1.62 mH
Re: 4.0 ohm
Qts: 0.42
Mms 266.1gr
SPL: 85.7 dB
Lp: 42.1 mH
We maintain a high level of quality in our products and work to do the same with our customer service. If you are experiencing any difficulty with one of your Seven Products please use the following form to open a support ticket.

Turn around times vary depending on the time of day, day of week...

    Thank you for your understanding.
©2017 SEVEN, LLC  - ALL RIGHTS RESERVED,  Subwoofers | Car Audio and Apparel
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product in question:
Like small practical subwoofers? Neither do we... We have one however! Its the ss300 subwoofer (Six n' half inch Subwoofer by SEVEN):
fs/fms: 66.4hz
Qms: 5.93
Rms: 5.0 - kg/s
Nret: 0.15%
VAS: 2.3 L
RES: 69.2 ohm
Qes: 0.43
Cms: 0.08
BL: 16.6
Rp: 41.1 ohm
Le: 1.69 mH
Re: 4.0 ohm
Qts: 0.40
Mms 70.8gr
SPL: 83.9 dB
Lp: 28.5 mH
Click here for the specs on the ss5500 (5,500w RMS 15" subwoofer)