Question on small bass drivers in tower speakers


I noticed that many speaker manufacturers have been offering tower speakers with a multiple array of smaller bass drivers in their latest designs. I understand that having a series of smaller bass drivers in a cabinet can provide very fast and accurate bass response but I often wonder how these smaller drivers fair when it comes to reproducing the lower registers of the frequency range at louder volume levels (95+db).

I've seen claims of bass response down to the low 20hz range using two 6.5" woofers from some manufacturers like Proac as an example.

My question is this, how can these small drivers be capable of reproducing such low frequency when stuffed into a box when if you look at the manufacturer website of the speaker drivers themselves and see a listed Frequency response that shows the woofer only being able to play down to 40hz at best when taking a speaker of no more then 7" in diameter into consideration?

If someone was in the market for an almost "Full Range" speaker how likely are they to be happy with a tower that only uses 6.5-7" drivers at most that claim low 20hz capabilities verses some other manufacturer who uses 8" or larger drivers with similar advertised capabilities?

Even if I take into consideration the most inert cabinet designs available for these small drivers I still find it difficult to grasp the idea that they will be able to play bass that low on the scale with any real authority.

Please add your thoughts and experiences with small driver tower speakers and if you were impressed or disappointed with their capabilities of playing low and loud despite the advertised claims ..Thanks
eniac26
A compromise in design for increased sales, hi WAF ,less shipping, construction, packing,and material costs for manufacturer, distributor. Lastly the multiple smaller woofers are needed to approach the bass of a proper sized transducer. Which they do not really do.
Agree with Johnk - it is entirely WAF cosmetic, cost and footprint driven.

There is NOTHING true about the MYTH "can provide very fast and accurate bass response"

Most of these woofers use voice coils that are no bigger than a tweeter!!!!!

There is a place for small woofers - small near-fields.
Well designed small woofers like the 3.75" magnesium/aluminum ones in my Silverline Preludes (second/current series woofers with slightly larger woofers than the original series) can sound amazing...d'Appolito amundo! Proper porting/box loading and crossover design are the key...with great (and I mean GREAT) midrange being the primary benefit with fast bass that almost goes as low as advertised. Might have something to do with the huge double woofer magnets and long throw of the woofers. I recommend a small decent sub (I use an old REL Q150E) with any small woofed drivers and you get the best of both worlds.
The best bass can be obtained from dual, freestanding sub woofers. All else is suspect.
Shadorne - It seems logical from a physics perspective that smaller drivers would be easier to control resulting in a more accurate bass response. The problem being that small drivers cannot move as much air and that's more related to volume that quality. Obviously, driver design is very important, but all things being equal it seems that the smaller driver should distort less.

My current Focal 836v speakers have three 6-1/2 inch bass drivers and can reproduce frequencies down to about 30 hz on a test CD, though at a very low volume. They will play organ music in a satisfactory way. If I compare these speakers to my Infinity IL50 that had a built in 250 watt 10 inch woofer/subwoofer they certainly can't reproduce the same volume levels, but when the IL50s were adjusted to music levels on the subwoofers they wouldn't go any lower than the Focals do. For music, the Focals have an equal low end and much higher sound quality. For home theater, the Focals require a subwoofer to be used if I want the house to shake. Most people that hear my speakers assume the subwoofer is on when listening.

It's possible to put larger drivers in a side firing configuration that maintains a lot of the WAF of the small forward firing drivers so I'd think that would be the better solution IF the large drivers were the goal.