Small drivers vs big drivers

@twoleftears

+1. A 12” or larger woofer can pressure up the room much like a real kick drum would do. The difference is very noticeable. The tendency of speakers with smaller woofers is to generate the lowest frequencies through port tuning which gives a muddy sounding kick drum, as the transient response is smeared by group delay. The frequency response on small multiple woofer speakers can be sometimes equaled to that of a large woofer by clever use of ports to plumb the subsonic depths but the time smearing from porting leaves one with the impression of a kick drum that sounds a bit like a bass guitar - it hums or resonates rather than sounding explosively punchy.

Large woofers really make a kick drum sound realistic and much more distinctive from bass guitar despite sharing similar frequencies.

@shadorne

Did you mean sound realistic, or feel realistic?
I ask because I am always curious how much we actually listen through our skin than our ears.

@erik_squires

I think we hear it but you are right in the sense that it isn’t really a change in the sustained note of the kick. It isn’t because there are more lower frequencies present - more a time coherence thing - the slap of the head with the kick pedal is matched by a very low frequency room compression that the ears “feel” more than hear - like descending in an aeroplane but infinitely faster. It is very useful to clearly distinguish kick from bass guitar. A timbral effect caused by a time coherent transient.

You won’t get this effect from a ported subwoofer but you can get it from a sealed one like a JL sub.

There is a huge amount of detail in the bass range - most bookshelf ported designs can sound enjoyable but fail completely at conveying this detail or texture. All Headphones fail too. Maybe feeling does have something to do with the effect - our bones would pick this pressure or LF up too.

Good point fellas. The inability of home playback systems to recreate the physical sensation of live music is one of the most serious remaining failings of the recording/playback process. Reproduced music sounds too cerebral, the brain being fed information mostly through the ears, not the largest organ in the human body---the skin. I wonder if future centuries will look back at this period of hi-fi development as we do the Edison cylinder.

The question is a bit broad and could cover a large response with respect to the advantage and disadvantage of large vs. small driver. 

First I don't think the OP was interested in line array.  It's a different class of speakers all together.  I think he was referring to for example having 2x7in drivers vs. one large 10in driver.  I don't think the reason of using line array is because one needs that many drivers to replace a single 15in. driver.  Line array is not meant to compensate for low end response.

In general a large driver will have more bass response but lacking the transient speed of a smaller driver.  So what you would do is having two smaller drivers to get the same bass response of a larger driver, but retain the transient of a smaller driver.  Also in general, a small mid range driver (2in or 3in) will have better midrange transient speed compared to a 5.5in or 6.5in driver, but the larger midrange driver will have more weight in the lower midrange especially on the male voice reproduction.

Large drivers also have the benefit lower distortion since it does not have to move a lot to generate the same amount of pressure vs. a smaller driver but of course you need to mix and match driver size since there is no single driver that can play the entire freq. range.