Moderately sound-proofing a backyard theater set-up
June 29, 2020 9:45 AM   Subscribe

I recently put together a pretty budget-friendly outdoor theater set-up that consists of a projector, 92" portable screen, and a single 28" soundbar. My backyard is relatively small and located on a corner lot with one nextdoor neighbor, separated by a 6 foot wooden privacy fence. How can I limit the speaker noise that carries over into the neighbor's yard?

My neighbors are friendly, reasonable people that I can discuss this with. Our movie-watching is limited to Friday and/or Saturday nights and begin when it gets dark around 9pm and ends by 11:30pm at the latest. My neighbors tend to eat late dinners in their backyard, starting around 9pm. We can hear general conversation noises from them, but I'm only concerned with limiting the noise our speaker produces for this one neighbor to the left of our house--not to soundproof our theater experience. We live in a semi-urban neighborhood with standard ambient sounds like traffic/fireworks/dogs barking. I currently have the speaker bar placed directly behind the projector, and the projector is aimed at a fence facing our back alley, perpendicular to the neighbor's yard. It doesn't need to be soundproof, but something like a 50% reduction in the volume heard next door would be great. All gear is brought into the garage when not used so weather-proofing isn't important. Would it work to move the soundbar closer to the fence we share and hang an acoustic blanket from the fence? Or hang acoustic panels from something like a portable clothing rack and place the soundbar directly in front of the acoustic panels, with the acoustic panels acting as a barrier between the neighbor's yard? The soundbar is pretty robust and I feel like even if it's placed at the side of the yard all theater-watchers could still hear properly. Any other solutions that would cost less than about $100 to set up?
posted by shornco to Home & Garden (5 answers total) 1 user marked this as a favorite
The biggest way you can reduce the sound to them is by turning the sound down. The best way you can do that is by moving the source of sound closer to the watchers and further from the neighbors. Ideally, you would give each guest headphones, putting the sound very close to everyone's ears. However, second to that, move the soundbar as close to the people watching as possible. Then yes, put a piece of wood also near the sound bar to avoid it going toward your neighbors.

Then just test it out. Sit there, ask yourself if it's loud enough for yourself as a viewer, then walk to the fence and ask if you can hear it.

Acoustic Panels/cloth barriers would be better used on reflective surfaces from behind you than a barrier between you and them. So, if there is a fence or wall behind you, you'd probably be better off putting the sound dampening there.

|||||||___h_h_h_ -\____[__]___|___
(House) (Chairs) (spkr) (screen) (Neighbors)

So to try and illustrate it - move the speaker toward the chairs, put dampening onthe house behind you/fence behind you, and just try it out a few different ways.
posted by bbqturtle at 10:03 AM on June 29 [3 favorites]

i think the most compassionate thing to do is to use earbuds. Hearing my neighbor’s TV outdoors at any volume would feel intrusive and stressful to me.
posted by HotToddy at 12:18 PM on June 29 [9 favorites]

Agree on the advice to put the sound bar as close to you as possible to minimize the overall volume required to be output.

Can you install the sound bar up high, facing down? Imagine it was suspended above and slightly in front of the audience, facing down towards the audience (who may be on sound-absorbing grass?)

You could also hang your acoustic blanket a few feet behind the sound bar, blocking some of the sound that would otherwise spill outward towards the neighbors.

By keeping the sound bar close to the audience, and aiming it at the sound-absorbing ground, you'd go a long way to reducing how much the neighbors would have to hear.
posted by reeddavid at 3:58 PM on June 29

bbqturtle pretty much has it.

Nthing that you want the soundbar as close to your audience & as far away from your neighbors as possible, because sound (very generally) is subject to the inverse square law - for every doubling of distance the sound power is reduced by a factor of 4. And the closer you get the sound source to your audience, the lower the initial output has to be.

Another factor to consider is that sound is "directional" to some extent depending on frequency - the higher the frequency/tone/pitch, the more directional it is, and the lower the frequency the more the sound tends to travel in all directions. As in, when a speaker is facing you, you hear all the sound, a full range of tones & pitches. As you start to move around a speaker you will start to hear a reduction in higher sounds as you get out of the "direct" throw of the speaker - things will start to sound "muffled."

Couple of possible wrinkles: 1) sound reflecting off surfaces (like your house) can cause all sorts of unpredictable behavior in the real world and 2) most "acoustic blankets" are not really meant to "soundproof" anything - they're meant to absorb reflected sound in order to change the acoustic response of a room, and due to the inherent nature of sound - higher frequencies are smaller sound waves and thus easier to "capture" with soft materials - they mostly do this by absorbing higher frequencies. "Blocking" low/bass sounds outside is pretty much impossible - all you can really do is turn it down (says the man who has had many conversations with the police/authorities about why teh bass from the band is rattling the neighbor's windows.) I dunno how much bass you're really going to get out of that soundbar, but low frequency sounds are most likely where you're going to run into problems, and there's not much you can do about it besides volume and maybe position.

If your neighbors are copacetic enough to deal with a little experimentation, I would start with the screen up against their fence, and the soundbar as far back away from it as possible with your family as close to the soundbar as possible. That way you have lower volume + distance + direction all working in your favor. If that's not enough it's worth seeing if they're getting some reflections off your house and/or fences behind or beside you and hanging a blanket or two against whatever walls might be reflecting. (You don't even need to really buy pricey acoustic blankets to try this, regular heavy blankets or cheap packing blankets would be fine for a trial run.)

You could maybe add blankets against the fence, and you might need to experiment with keeping the same orientation but moving the whole shebang further away from their fence.

Barring this, though, there really isn't much to be done - hopefully they'll be OK with one or two nights a week of indistinct movie sounds. Or you could always (if you all feel safe about it) just invite them over for social distant movies - it's not unusual to feel less annoyed by a thing that they can participate in (says the man who has had lots of interactions with people who come up to complain about the noise who then go "Oh, hey this is cool I think I'll stick around and party" when they discover the noise is from a neighborhood event that's free and open to the public.)
posted by soundguy99 at 9:11 AM on June 30

Assuming you are all going to work please give them one weekend night, where they don’t have to listen to your movie night. Enjoy your garden in a less intrusive fashion the other weekend night.
posted by koahiatamadl at 8:25 AM on July 1

« Older NYC in the 80s, yuppie person edition?   |   How can I switch between two different usb-c... Newer »

You are not logged in, either login or create an account to post comments