Hi Justin:
I apologize for the inconsistencies in our website. The STS-01 does indeed use the same woofer as the remainder of the S-series speakers, and there was no intentional deception on our part. We've been trying to standardize all the S-series woofer diameters on our website, and have unfortunately lost several recent changes due to back-up glitches which restored earlier versions without the changes.
We measure and list our subwoofer woofer diameters by the OD of the basket (e.g., a 12" woofer actually has a cone diameter of 9+"), and we're migrating to the same nomenclature for our loudspeaker woofers. The "gotcha" on the S-series is the square type frame, which is shorter in one dimension. Square type frames can be measured across the narrow dimension (5-1/4"), or across the diagonal (6"). The key here is that a round 6" basket has the same woofer cone diameter as the 5-1/4" square basket woofer. In other words, calling it a 5-1/4" woofer implies the cone diameter is smaller than it really is.
The same type of logic applies to our M-series, where the 6-1/2" flat basket woofer has the same cone size as a 7" round basket woofer; so we're migrating to a 7" size rating for the M-series woofer. In summary, the basket size should be determined by the major dimension, not the minor dimension, because that is the only way to compare like cone diameters.
There is no official industry standard on sizing drivers. Due to its unique surround design, our 13.5" Ultra driver (for example) actually has virtually the same effective cone diameter as many standard 15" woofers - so go figure. In any event, we hope this spec-goof on our website won't diminish your enjoyment of the STS-01, Justin; I love the sound and performance of this new tower, and frankly I didn't want to give-up my pair during the product development process! :^)
Ed Mullen, PE
Customer Service Director / Product Development Manager SV Sound, LLC
