Bass Driver Size - how much better is an extra inch?


Have older b&w speakers and bass drivers are 7 inches vs 804 d3 speakers that are 6 1/2.

the larger drivers seem to really open the sound stage, more open and less constrained.  Imaging of older speakers not as good but a very enjoyable listen.
Not sure why driver sizes tend to be smaller these days unless you pay a lot more.  Hear that most consumers want more compact mains so drivers are smaller.  Kinda sad.
emergingsoul
Why not fill in the low end with a pair of REL S2 SHO subwoofers.  You can dial them so they don't over power the bass and with their high level connection they will act more like woofers.  Be curious to hear what this group thinks about this.  These really helped to broaden the sound stage.  Trick is to make sure you do not over power the bass.  I noticed my mid frequencies and higher frequencies seemed to clean up.
I've been using a pair of Velodyne HGS-15s crossed at 40 Hz with KEF Reference 1s.  Today I raised the crossover to 80 Hz, still using a 24 dB/octave slope, and ran acoustic room correction.  I was surprised how much that enlarged the sound stage.  My concern about the setup being suitable for large orchestrations vanished.

db
I don’t have a lot of experience with different speakers, but I can tell you there is a big difference in bass between my current Klipsch Cornwall IV’s and my Goldenear Triton 5’s. On paper the Tritons went deeper into the 20’s while the Cornwalls only go down to 38 however the sound is bigger. When I added two JL Audio Dominion D108 Subs with the Goldenears the Sound was great but still not as powerful as my Cornwalls. I’m actually thinking of adding my Subs back into my system to see how they’d sound with the Klipsch. But is it useless to use two 8 inch 500 watt subs with big 15 inch woofers? So in my experience albeit limited bigger woofers can provide bigger sound but not always deeper bass. 
@bigjohn1995,

"So in my experience albeit limited bigger woofers can provide bigger sound but not always deeper bass."


Mine too. My 15 inch Tannoy DC drivers certainly have a big sound but I don’t think it goes down as deep as the slimline floorstanding Tannoy R3s with their twin 6 inch drivers.

It’s not always easy to be sure as most of the music I listen to hardly features much, if anything below 40Hz. Besides it’s a common misconception to think that 60Hz is where real deep bass is. That's why a lot of small speakers seem to give perfectly adequate bass without disturbing the furniture.

Horn loading like your Klipsch Cornwall’s will result in a different bass sound than ported designs which will sound different to sealed boxes.

As @mijostyn said earlier, real deep bass (sub 40Hz) is where you start to feel it rather than hear it. A key difference I think between live and reproduced sound.

Live sound is often equally felt as it is heard.
@cd318 --

Horn loading like your Klipsch Cornwall’s will result in a different bass sound than ported designs which will sound different to sealed boxes.

The Cornwall’s 15" bass driver is ported. The sibling La Scala’s on the other hand are using a 15"-loaded folded bass horn, and yes that’s certainly a different bass presentation vs. a ported, or even a direct radiating sealed design.