Sreten did indeed know about such things. Before the thread is derailed, is the OP not intending home/room applications, rather than tiny sealed automotive spaces?
Home use ……100db dynamic peaks. What’s better?……bandpass?…..BLH?……..footprint can be no more that 11” wide and 16” deep.
For home use with only 100dB peak requirements there is no need to use resonant assistance for clean output.
As far as dynamic transient response, bandpass and BLH are at the bottom of "what’s better" .
As far as dynamic transient response, bandpass and BLH are at the bottom of "what’s better" .
Looks like your size constraints will make almost imposible to hit HT (home theater) freq range with authority, picowrecker is an option but idk of the size match what you want.
depends on the bandpass type.
But as mentioned sound quality / accuracy is a tradeoff.
meaning less quality.
and longer vents just means more resonance.
for home use, and loud home use.
Normal everyday reflex.
and if not limited by space.
Large sealed.
One 12" is fine.
For loud listening with dynamic bass heavy genres.
just use 2x 12" for little more.
lot more.
If we are talking " sub" meaning actual crossover
100 Hz to 80 Hz
if its just a woofer at 300 to 600 Hz crossover.
guess you need 2x anyways.
But as mentioned sound quality / accuracy is a tradeoff.
meaning less quality.
and longer vents just means more resonance.
for home use, and loud home use.
Normal everyday reflex.
and if not limited by space.
Large sealed.
One 12" is fine.
For loud listening with dynamic bass heavy genres.
just use 2x 12" for little more.
lot more.
If we are talking " sub" meaning actual crossover
100 Hz to 80 Hz
if its just a woofer at 300 to 600 Hz crossover.
guess you need 2x anyways.
Vents at low frequencies need to be quite large diameter to avoid chuffing noises through excessive port velocity, which then means they need to be long which takes up even more space and the length also risks port/pipe resonances in (or close to) the frequencies of interest. Things like this can be mitigated with skill, there are (of course) successful bass-reflex and band-pass subs. But for similar tuning a shorter/fatter vent usually wants a bigger chamber, which goes against requirements for small size, which you wanted. I've reached the conclusion that if you can't make the box big enough, vents are going to be more of an uphill struggle. Horns also tend to get quite big at low/subwoofer sizes and frequencies.
So unless you need the extra SPL, then IMO there is a strong argument for a small sealed box. It avoids vent/port issues regardless of frequency, and has a potentially nicer transient response. One down-side (other than lower SPL) is potentially cost; to offset a small box, extra amplifier power and EQ is needed to achieve the same excursion (and of course the driver needs to be able to take that power too, without excessive distortion or power compression; though music peaks are thankfully quite short in most cases).
I'm not sure if you need such extra SPL, or not. 100dB peaks are not in themselves difficult, but get much harder as frequency drops and as listening distance increases and as box size reduces. As it happens I'm deliberating a similar question, but only for music so to be pragmatic I'll settle for say 27hz at 110db at 1m (which will give me at least 100dB at 3m, likely more depending on room modes and effects). That can be achieved sealed with two 12" subwoofer drivers.
Though it is the room modes that I've been wrestling with most, since they can have a huge affect on SPL at any given point - including the listening position. The best way to address this is by positioning the subwoofer (preferably more than one) where it is most acoustically suitable for the listening position. Which might not be where one would like it or where there is the most space for a big one. So IMO better to have subwoofers that are small enough to give flexibility on location, rather than go as big as you can manage if it'll then only fit in one place (unless you're lucky about that one place being acoustically good, anyway).
Room position is critical as is separation of woofers in the room. 8 ft spacing leaves multiple 45hz dead zones in the room.