Sub output: Is it the woofer size or the rated RMS

Excuse me , but that is ridiculous. Some of the best and most expensive speakers made use 10" or smaller bass drivers. In the 60s no self respecting speaker had less than a 15" woofer, they now are extremely rare. Look at the DIY speaker sites and see what is for sale there. They are hardly affected by marketing considerations. If you do not understand speaker design I can recommend some good books, starting with HIGH PERFORMANCE LOUDSPEAKERS by Martin Colloms. What part of my statement about cone linearity did you not understand?

Stanwal

Hummm, I wonder why all the best subwoofer designs, that have more than one size (10"/12"/15"/18"...charge more for the larger subwoofers?, if the smaller subwoofers are better?

You should quit reading, and get some practical experience.

The subwoofer drivers of yester year, were very large for a reason...more bass, with less power. The box design for the old 30" subwoofer you mentioned was huge (around 5' tall), and required only limited power supply....more in line with the technology of the day.

Dave

It stands to reason that for a given cost it is easier to design and manufacture a smaller driver that will be more accurate than a larger driver, with respect to the inevitable tradeoffs between cone resonances, stiffness, transient response, overhang (the ability to stop quickly when the music stops), various forms of distortion, etc.

It is also true, of course, that a larger driver in a larger enclosure will provide more bass for less power, everything else being equal. But so what? I don't think that Dave's insulting response to Stan's well intentioned comment was called for, and I don't think that "no other reason for doing it, purely marketing" tells the whole story.

Regards,
-- Al

More power in a sub can probably never hurt, but just be overkill perhaps.

Generally, a larger driver, properly driven, will facilitate better low end response but size alone is not enough. Its the quality of the driver and soundness of the overall design that matters most.

There are many things I could say to socalled sogood but will stop with saying that I have been in audio 46 years, some of it as a Krell dealer, have 4 pairs of subs, none of which I would trade for any of his, and will end with what my wife told me to tell him, " its not the size of what you have but what you do with it."