This is as good a time as any to have some discussion on woofer sizes. Along with the Anti-Mixed Driver Gestapo, there is also a rigorously enforced notion that all a driver size tells you is what size hole to make. How and why such closed mindedness became TalkBass Gospel is beyond me.
All woofers of all sizes are designed differently purposely to sound different! All 10's do not sound the same, and neither do any of the others. Every driver must be approached individually.
I want to use 12" woofers for this example. Some of today's modern designs actually will go lower than most 15's and higher than most 10's. My V2 Rumble 112 Neo contains a custom tweaked Eminence Deltalite II 2512. GK's 112 Neo cabs and Aguilar SL 112 do too! The cabinets are all about the same dimensions. If you listened to the three in a blind test in a studio what differences would you hear? I've not done it, but I'd bet it would be damned little. @honeyiscool went to an Aguilar Tone Hammer 500 and a pair of SL112's. He later changed to a pair of V3 Rumble 112's because he thought they sounded better! Likewise
@bdplaid loves his V3 Rumble 112 stack.
Fifteen inch woofers have always been a popular size for bass guitar cabinets with good reason. 15's exhibit a super smooth dispersion of the entire midrange that is difficult to beat. It's very ear pleasing. In the 60's & 70's 15's gave low end grunt that you just couldn't get with 10's or 12's.
As far as 10's vs 15's go it can be said the generally today's 10's will go as low and sometimes lower than most 15's. 10's will typically go up to 4kHz+ while 15's typically go up to 3kHz. You can take a peek at various driver specs here
Bass Guitar | Eminence Speaker
You really do have to listen to each woofer individually and not size or by numbers on a spec sheet because cabinet design and tuning always comes into play. We Rumblers are most fortunate in having such great designs in both cabinet and Eminence custom designed ceramic-ferrite driven woofers.
"If it sounds good and feels good, then it IS good!" ~ Duke Ellington