Low Bass Outside By The Pool

[BigBassLover]

Hello

We enjoy home theater out by the pool and for my birthday, the wife is allowing me to buy some subs. Since there will be water I want to tune the box as LOW as possible, like 5 hz low. I think it will be cool to see and feel the bass!

I would like to stick with 21 or maybe even consider 24 inch subwoofers. Since they will be outside I want to do a tapped or folded horn or something to protect the driver. Also I am thinking that pro audio drivers would be best suited to handle the outside heat?

Stereo Integrity HS- 24 - These look nice but very expensive and a 2 month wait! FS 16.2
HTS545HE-4 Kraken 21 - Nice the price is right - not pro audio - 18hz - FS 26.3
LaVoce SAN214.50 21" Neodymium - pro audio - fs 30
Eminence NSW6021-6 21" - nice pro audio - expensive - fs29
B&C 21DS115-4 21" - another pro audio - fs30
Really I am open to any set of woofers.

One last thing, I have neighbors that are not TOO close but I would like to keep the bass as directional as possible.

Can someone please recommend and help me with the box design since I am not so great with software?

Thanks in advance for your advice

 

[Audio>X]

https://aespeakers.com/shop/td/td18h/#

 

[rayma]

Low bass is not directional. For example, a 10Hz bass waveform has a wavelength of 40 meters, or 131 feet.

 

[BigBassLover]

Well I meant as directional as possible.

What scares me the most is the software modeling part of this equation. I am pretty handy with building enclosures but not great when it comes to computers. I will take a look at the acoustic elegance

 

[AllenB]

I'd consider aiming to use the ground and maybe a wall to increase the output into a reduced space.

 

[Circlomanen]

One last thing, I have neighbors that are not TOO close but I would like to keep the bass as directional as possible

A large 221 ROAR, based on standard plywood dimentions and tuned for sub-bass duty is probably the most directional design except for large full sized horns. It takes two B&C 21DS115-4 and two kilowatts to reach 123 dB at 13 Hz in a 2 pi radiation space (free field outdoors).

 

[Circlomanen]

I'd consider aiming to use the ground and maybe a wall to increase the output into a reduced space.

It is a huge beast, but a solid 101 dB/1.5w/m @ 13 Hz (1.0 Pi radiation angle) is nice to have.

 

[Circlomanen]

Here is the difference in efficiency between my ROAR design and the same two B&C 21DS115-4 in a 600 liter bass reflex with a 800 cm2 port, 100 cm long (grey line in the graph).

 

[tmuikku]

In pro-audio they seem to use very special equipment, moving magnet linear actuators, for the very low sub https://www.powersoft.com/en/applications/oem-solutions/m-force-sub and even those are tuned from 20Hz up for realistic applications. I could be wrong but 5Hz extension is not needed, or it's so expensive to achieve no-one has it and thus there is no content produced for such low frequency, it would not be audible on 99,999999% of playback systems and just eat headroom which is critical for loudness war. I'd say ~20Hz could be realistic goal, doesn't mean you couldn't try 5Hz, just quadruple cost of getting to 20Hz to get to 10Hz, and quadruble again to get to 5Hz.

 

[abstract]

How about a spinning fan where the blade pitch is modulated, helicopter style? Erect a small building to get the right tuning frequency and hey presto!

 

[Brian Steele]

You just described a "rotary subwoofer". They are available. And expensive 🙂

 

[turk 182]

Hey Big Bass Lover!

your goals might be best achieved by a bass array....not just two big drivers pumping oodles of power at ultra low frequencies....think multiple smaller drivers focusing that pound power at YOU and not your neighbors!

but that does come with a lot of math and a butt load of computer/software shite to control your array...

be careful what you wish for...

 

[mattstat]

as directional as possible

You could look at cardioid prosound setups for examples of one way it can be done. This pattern is produced with a time delay between two (or more) spaced subwoofers.

Dave Rat has multiple interesting videos on Youtube dealing with bass arrays. This one does a quick cardioid overview.

Dipole is also an option. It puts out equal sound front and back, but minimal to the sides. You also lose progressively more output at lower frequencies, but it can be equalized out - just keep in mind it typically requires a lot of excursion/volume displacement to make up for the cancellation.

You didn't say where your neighbors are located, so I'm not sure which one is more applicable.

 

[weltersys]

Since there will be water I want to tune the box as LOW as possible, like 5 hz low. I think it will be cool to see and feel the bass!

One last thing, I have neighbors that are not TOO close but I would like to keep the bass as directional as possible.

Forget about achieving any directionality in the two octaves below 20Hz, if it's loud enough for you to feel it outdoors, any neighbors within 1000 feet will hear their windows rattling.

If you use tactile transducers like the EarthquakeSound Quake 10B you could rattle your eyeballs in their sockets and have enough "feel" to make you sick without any complaints from neighbors.

This thread has reviews of the QB10 and links to videos:
https://www.avforums.com/threads/q10b-vs-svs-pb13u-tactile-sound-infrasonic-test.1201626/

"If you look carefully at the first clip, with PB13U running, although it is not obvious in the clip there were very slight ripples in the water. I could feel the infrasonics from the sub, the room groaned and the vibrations could be felt in the sofa. Then take a look at the second clip in the video with the Q10B. The effect of the much stronger infrasonics from the Quake is clear to see ----- as they say a picture is worth a thousand words... The Q10B isn't even at full throttle 😱 "

 

[Audio>X]

https://www.heynowhifi.com.au/products/ascendo-smsg50-active-seismic-50-inch-infrasonic-subwoofer

 

[Audio>X]