Newbie Q: How do small woofer speakers reach 32Hz?



I starting thinking about this after reading several Totem Hawk and Forest reviews and after seeing their specifications on the Totem website.

How on Earth do those speakers dig down to 32Hz? It just doesn't seem possible, especially with the 5.5" woofer in the Hawk. I suppose speaker design and driver selection has a lot to do with the overall frequency response, but those are such small woofers.

I own a set of Snell Type J/IV's that are very close in size to the Totems (full spec's of both the Hawks and J/IV's below). They have an 8" woofer and I'd say the bass response is quite good, maybe better than the manufacturer's specifications indicate. But why is there such a huge difference in the manufacturer specifications? Maybe Snell is conservative and Totem liberal with their measurements? Do the Hawks really get down to 32Hz?

Anyway, here are the specifications;

Totem Hawk
<32 Hz - 21 kHz ± 3 dB (with proper room positioning)
6 ohms
88dB sensitivity
30 - 120 watt recommended power
5.5" woofer, 1" tweeter
6.8" wide x 34.3" high x 9.6" deep

Snell Type J/IV
48 Hz - 20 kHz ± 2 dB
8 ohms
90dB sensitivity
15 - 150 watt recommended power
8" woofer, 1" tweeter
10.5" wide x 32.5" high x 9" deep
alpha220
Earphones with drivers smaller than an inch go lower than that. It's all about loudness. A small speaker may respond at a low frequency, but not at a useful volume.
An 8" woofer can certainly do 48hz with no difficulty whatsoever, in fact it can do 28hz or lower but to get it +/- 3db at 28 hz you'd probably need 2 of them. (I've speakers down 3db at 28hz using 2 8" woofers). Unless it is rolled off the single speaker in the Snell might be down as little as 8db(?) at 32hz which would certainly be usable. A WAG, not a calculation.

The spec's for the other speaker are kind of interesting because of the caveat that the 32hz +/- 3db is "
obtainable with proper room placement". Where would you have to put it, in a corner? But, seriously speaking, I've had two sub woofers that put out fair volume of good tight bass using small woofers. Fair volume for audio down to 32Hz but not with much HT potential.

Good to be cynical when reading equipment spec's.
Great question. All I can say is they are manufacturers specs. You would have to listen to them yourself especially in your room with your equipment. I would suspect when they refer to proper room positioning I think in a nearfield setup you won't anywhere near 32hz. Where in a perfect larger room it may be possible. Remember -3db is half the loudness for that frequency. Also being a small driver they can not pressurize a room to give you the bass you can feel.
Unless it says free standing then the specs are not that meaningful as a wall will give a 6 db boost and a corner can give a 12 db boost...manufacturers make this stuff up in a business that has very little in the way of standards.

The other issue is how loud can it play? You are not going to get much at 32 Hz from a 5.5 inch woofer - perhaps 90 db SPL max if that?
Shadorne has a good point about freestanding. Perhaps they were tested in an anechoic chamber. IMO, if it were that easy to get to 32hz more speaker makers of small speakers would be doing it. When you actually try to duplicate their claims it in a home listening environment it just will not work. It takes a little more than a 8 in driver to pressurize a room at the lower octaves.
Check out this set of measurements on the Totem Staf, which is admittedly a slightly smaller speaker than the Hawk, but in many ways similar.

The -6db point is 36 Hz.

I have had most of the Totem line and they are great speakers and have amazingly nice bass for their size. But physics is unavoidable. Even my Totem Forests required a subwoofer to sound their best.
Sorry here are the measurements:

http://www.hometheatermag.com/floorloudspeakers/1206totem/index2.html
O.K. It now seems pretty clear that the frequency response specification is used by some as more of a marketing tool than a true measurement of speaker performance. Since there is no governing body or uniform standards for rating speakers, manufacturers self select methods. With Snell, apparently they took a scientic approach, using an anechoic chamber (their specs are actually printed as 48 Hz - 20 kHz ± 2 dB anechoic) while Totem, went with agressive marketing, using the unscientic approach (but perhaps more helpful in the real world) of considering placement. Additionally, Snell selected ± 2 dB, while Totem selected ± 3 dB, which also makes a difference. Considering a corner placement can add +12 dB to the low end and the speaker might still be -3 dB in the low end, that would explain how such slim speakers with small woofers put up such heroic numbers.

I suppose, manufactures that use Snell type measurements should add a second specification that shows what their speakers can do with perfect placement in the right room. At least they'd seem competitive as potential buyers glance down the specifications tables.

Totem is smart. Being able to list a bottom frequecy in the low 30's or better, very likely gets them many more auditions, and eventually, more sales.

You would simply have to know a lot about speaker measurements or specific manufacturers to either realize that Snell's sound better than they appear on paper or Totem's may not deliver the goods exactly as promised.

To throw out specifications all together is just not viable, people simply do not have the time to audition dozens of speakers. Furthermore, most speakers (several hundred dollars and up) sound really good. So, if a manufacturer can get you interested and into a store for a listen, they're probably half way home!
Good question. The Merlin VSM have a 6 1/2" woofer and are +/- 2db 33hz to 22khz - how do they do it? With the BAM bass augemntation module, essentially a bass equalizer that provide totally smooth bass response down to the low 30s with no electornic signature. Absent that, I don't how a small driver can possibly provide true 30hz bass output that is balanced in loudness with the mids and highs.
It is not only that manufacturers cannot get bass extension from small woofers but often they don't want to (tuning bass for lowest distortion and not for extension). Paradigm Studio/60 v3 has worse bass extension than previous Studio/60 v2 but sounds better (according to reviews). My Hyperions HPS-938 have pretty large box with two 8" woofers but only 35Hz extension.

For practical reasons I prefer better bass definition over extension since lowest bass string is 42Hz and below that are only pianos (keys seldom used), big drums (mercy for the neighbors) and church organs. Extension can be remedied with a Sub but loss of bass quality perhaps not.