I tought quite efficient vented 12" subwoofer. I would use about 50-100W amp (AV-receiver zone2). I found SB34NRXL75-8 driver. 80 liters enclosure would make possible to use reasonable length 100mm diameter tube at about 20-25Hz tune. Looks like there is not many drivers like this. Is it so or should I search better?
shrub0 has tested quite a few:
https://www.diyaudio.com/community/...fers-distortion-and-15-dollars.360855/page-12
Post #236 has a spreadsheet of IMD results including the SB34NRXL75-8.
https://www.diyaudio.com/community/...fers-distortion-and-15-dollars.360855/page-12
Post #236 has a spreadsheet of IMD results including the SB34NRXL75-8.
You definitely won't find many subwoofers with high SPL at 1w/1m. That's because the sub-bass area isn't really related to the 1w / 1m measurement. The sub-bass physics are different than the physics where these drivers define their efficiency rating. Consider the WinISD modeling of 3 drivers driven at 1W with >6dB difference in "efficiency" in your proposed 80 liter box with tuning from 22-25Hz... They're completely on top of each other below 50Hz, then separate as frequency rises.
So efficiency is not really relevant for subwoofers in the traditional sense. However, there are discussions on how that efficiency rating may affect sound signature... There is a lot of good discussion on this in the thread that weltersys linked, but it's a lot of reading to get there.
So efficiency is not really relevant for subwoofers in the traditional sense. However, there are discussions on how that efficiency rating may affect sound signature... There is a lot of good discussion on this in the thread that weltersys linked, but it's a lot of reading to get there.
You're asking for things that are nearly mutually exclusive these days. Higher efficiency is typically achieved with lower moving mass, which often produces a higher free air resonance. While this can be overcome, doing so can create the need for a large enclosure. Think in 1960's large speaker terms, not today's idea of a large speaker. There aren't many people looking for woofers like that anymore.
Large excursion, lower sensitivity, and small boxes are the norm now, especially since high powered amps have gotten cheaper/more common.
High sensitivity drivers often have smaller Xmax/excursion capabilities as well, which is also at odds with what most expect from today's subwoofers.
There are high sensitivity woofers around, but asking them to play down to 20 Hz is usually not going to make them happy.
My typical problem is lot of toughts not coming out as text. I dont mean dB/W rating. Idea is bigger than minimal enclosure and low Fs driver. Trying to avoid low frequency lift with amplifier power. Strong motor for good sound quality in vented box.
I almost used term old school, but wasn't sure is it one. Mattstat you describe it well.
I almost used term old school, but wasn't sure is it one. Mattstat you describe it well.
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If you aren't as concerned about driver sensitivity, then there are more options. Here are two I found quickly. I haven't modeled them, so I'm just going by the optimum cabinet size Parts Express provides.
This one needs a very large enclosure, but it's cheap and looks more like an older style woofer overall.
https://www.parts-express.com/Goldwood-GW-412D-12-Poly-DVC-Subwoofer-290-367
This one is a more typical modern high excursion subwoofer.
https://www.parts-express.com/Dayton-Audio-UM12-22-12-Ultimax-DVC-Subwoofer-2-ohms-Per-Co-295-512
If you haven't looked at their offerings, here's a link to the 12 inch subwoofer category at Parts Express. There might be something else here you like.
https://www.parts-express.com/speak.../subwoofer-drivers/nominaldiameter/12?show=72
If I'm still not getting what you're after, let me know.
This one needs a very large enclosure, but it's cheap and looks more like an older style woofer overall.
https://www.parts-express.com/Goldwood-GW-412D-12-Poly-DVC-Subwoofer-290-367
This one is a more typical modern high excursion subwoofer.
https://www.parts-express.com/Dayton-Audio-UM12-22-12-Ultimax-DVC-Subwoofer-2-ohms-Per-Co-295-512
If you haven't looked at their offerings, here's a link to the 12 inch subwoofer category at Parts Express. There might be something else here you like.
https://www.parts-express.com/speak.../subwoofer-drivers/nominaldiameter/12?show=72
If I'm still not getting what you're after, let me know.
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Not sure I agree with the 'physics difference' part, but we are more concerned about the base efficiency part since we're always trading efficiency for BW, i.e. its mass corner frequencies, so the lower we go the narrower the BW for a given speaker system efficiency means the effective motor strength (Qts') must become weaker and raise its compliance (Vas) to offset its loss.
In short, we need a super low Fs, high Qts', Vas, Xmax driver for true sub/woofer duty, which de facto means a fairly large cab with corner loading or huge and/or uses multiple drivers and/or uses DSP + amp power to optimize in room.
upper: Fhm = 2*Fs/Qts'
lower: Flc = Fs*Qts'/2
Qts': 2*Fs/Fhm
[Qts']: [Qts] + any added series resistance [Rs]: http://www.mh-audio.nl/Calculators/newqts.html
[Rs] = 0.5 ohm minimum for wiring, so may be higher if a super small gauge is used as a series resistor and/or there's other series resistance.
Seems like someone posted somewhat suitable Visaton sealed/IB/OB drivers recently, so try them and/or similar quality/priced, though assume you'll need multiples to get the desired performance.
TTBOMK, the 'physics' I posted are the most correct ones to use and ideally over a fairly narrow BW to keep any 'ringing' out of the > ~120 Hz BW, though of course you can use whatever has a low enough Fs, most correct Qts' to get the desired LF base efficiency (~0.403 for flattest response) and as many as it takes to get the desired system efficiency and DSP them flat in room.