You can't predict subwoofer behavior in a room at 40Hz, but you can test it
COMMUNITY W2-112 Subwoofer, 40 Hz - 700 Hz, LF 1 x 12" carbon fiber
Amazon.com: Earthquake Sound FF6.5 6.5-Inch Front Firing Subwoofer black : Electronics
RCF L15S801 15" High Efficiency Woofer 1400 Watts 8-Ohm 95dB / 40 Hz – 1.5 kHz
Amazon.com: Ported Sub Enclosure Box for a 12" Rockford Fosgate T1 Subwoofer - 4" Aeroport - 40 Hz - 1.75 CF : Electronics
SUB-4K / SUB-5T Active Subwoofer High Quality LowPass Filter Freq. 40Hz~250Hz+Bass Boost+Phase - Motronix
Audiopipe Csl-4102 Speaker - 2-way - 2 Pack - 40 Hz To 20 Khz - 4 Ohm - 4" X 10" (csl4102) - Walmart.com
RCF L15S801 15" High Efficiency Woofer 1400 Watts 8-Ohm 95dB / 40 Hz – 1.5 kHz
Bose Sub1 Powered Bass Module 120V NA Delivers Low-End Performance Down to 40 Hz
BlastKing ROCKET15 15" 2400 Watts Woofer 4.5" Voice Coil 40 Hz - 2500 Hz 96.3 dB | Reverb
Binnifa Live-2s Speaker Stereo Bass Karaoke Home Theater Ktv Audio Sound Bar 40hz Subwoofer Wireless Microphones Bluetooth 5.0 - Speakers - AliExpress
ELX20018SPUS Electro-Voice 18 inch powered subwoofer/40 Hz - 145 Hz/US cord
18 Inch Ferrite High Power Subwoofer 18Ah-400X Frequency (Mhz): 40 Hertz (Hz) at Best Price in Guangzhou | Guangzhou Shengguang Electronic Co.,Ltd
![RCF L15S801 15" High Efficiency Woofer 1400 Watts 8-Ohm 95dB / 40 Hz – 1.5 kHz | eBay](https://i.ebayimg.com/images/g/j~sAAOSwuYZhEZ53/s-l1200.webp "RCF L15S801 15" High Efficiency Woofer 1400 Watts 8-Ohm 95dB / 40 Hz – 1.5 kHz | eBay")
RCF L15S801 15" High Efficiency Woofer 1400 Watts 8-Ohm 95dB / 40 Hz – 1.5 kHz | eBay
Crown 500W 12" Woofer Pro Sound Audio Speaker with 40Hz-2KHz Frequency – JG Superstore
40 hz horn with bass reflex - The Paper Horn by Inlow Sound
velodyne-dd-18-plus-subwoofer-40-hz - HomeTheaterHifi.com
JBL Professional 4642A Woofer - 2400 W RMS - 40 Hz to 500 Hz - 4 Ohm
RCF HDL12-AS Active Flyable High Power Subwoofer – Sonic Circus
40Hz Bass Test - YouTube
SVS 3000 Micro Subwoofer | Dual Active 8-inch Drivers | 800 watt RMS
Subwoofer Frequency Test - Apps on Google Play
DAYTON AUDIO DS175-8 Designer Series Speaker Driver Woofer / Midbass 70W 8 Ohm 88dB 40Hz - 4500Hz Ø16.5cm - Audiophonics
Subwoofer - Wikipedia
VORDON TB-16R+ Active subwoofer 6 Inch, 350 W, 200, 40 Hz | ML Performance Car
200w Bass Speaker 40hz-400hz Subwoofer Frequency Divider Home Theater Hifi Stereo Diy Car Audio Woofer Crossover Filter - Speaker Accessories - AliExpress
![ROCKFORD FOSGATE P3SD2-10 / PUNCH P3 SLIM SHALLOW 10" DVC 2-OHM SUBWOOFER *NEW* | eBay](https://i.ebayimg.com/images/g/uO8AAOSw8nxbBup8/s-l1200.webp "ROCKFORD FOSGATE P3SD2-10 / PUNCH P3 SLIM SHALLOW 10" DVC 2-OHM SUBWOOFER *NEW* | eBay")