Subwoofer driver optimized for sealed cabinet vs. for reflex cabinet

[ZolaIII]

Get a normal sized driver and don't skimp on box either buffle or depth. There are quadratic sub drivers which for square 10" size have 12" round one's surface that way you can lower the size for example. Kicker for example and rather good ratio of price/performance. You can't cheat or beet physics it will return and kick your ass. And aim at little bit more sensitive one's then average (86~88 dB), preferably 8 Ohms (or 2x4 that together dosent fall under 7 and you will need two amplifier chenels to feed it). Relative low Fs and good linear X max. Also take in consideration linearity trough SPL. You probably won't get there regarding sensitivity if you don't go with bigger ones (13~15") that are tough reinforced on cone side (and otherwise including cast basket) so that it can keep such behaviour (higher mass of the cone is the price and directly in sensitivity).

 

[J.M. Noble]

I know how you must feel ;-) As Boris Vian, the highly esteemed pataphysicist, said: “I hate wear and tear!”

But what would you do?

(Squints at the tiny box in the corner of my listening room) I'd evidently buy a Dynaudio Sub250 Compact and make do with modest SPLs down to the high 20Hz range.

But if I was designing something for home use, wanted to shake the room, and was willing to deal with a box that would fit (2) 15" drivers I'd make physics go to work for me and build a 10" tapped horn with a very low frequency tuning. I'd need drastically less amplifier power and/or would be able to achieve insane SPLs for a home subwoofer. I work as a live sound engineer, so these things are relative ...

The alternative is therefore closed with a maximum diaphragm area. Although the resonance is then very high, this is not a disadvantage compared to the same sealed speakerbox equiped with a smaller driver. This is because the efficiency depends practically only on the volume, not on the alignment. Above the low bass, the larger cone surface always has an advantage.

Well, the larger cone doesn't just move more air--below the frequency at which the speaker cone's diameter is equal to one-quarter of the wavelength, the speaker cone must double its excursion for every octave decrease in frequency to maintain the same sound pressure level. For a nominal 15" driver the key frequency is 225Hz, for example; 12" is ~280Hz, 10" is ~338Hz, 8" is ~420Hz, etc.

From a practical perspective, there don't seem to be many drivers 15" or larger that get low enough for me. Speakers that size tend to be aimed at the sound reinforcement market, where anything below the low "E" of a bass guitar (~41Hz) can usually be ignored.

 

[Heinrich]

(Squints at the tiny box in the corner of my listening room)

Also looking back to the o/p's question, better to have a single driver in a given sealed volume X, or, two of some other type in the same speaker box?
If I had the two already, and would need to buy the single one additionally, I would keep the two.

If there's something special about a driver designed for sealed enclosures, that doesn't count when equalization is available.

 

[ppataki]

Again, thanks everyone for your contribution
I guess my personal conclusion is that what I am doing now (putting PA subs in sealed cabinets (DOS) and applying DSP) is OK
I will not pursue any other ways for now - anyway I am really happy with my setup