I’ll do my best here not to tout on competitor’s products, but I saw this and got intrigued:
According to this Gizmodo article the promise is more bass and loudness when you attach an empty soda bottle to the portable speaker - which can work without the bottle.
I’m not sure about how this works, but it’s intriguing nevertheless. Maybe it’s something @AnkerTechnical should be looking into?
Hope there is nobody here who is drilling such a big hole in an ANKER speaker 
Adding more air (the air in the bottle) yields more power. Just like a car engine, which is basically a large air pump, increasing it’s displacement (a 2.0 liter engine vs. a 5.0 liter engine for example) gives you more power.
The bottle is also acting as a passive radiator.
Interesting, thanks!
i bet it works. When I worked overnights in a warehouse we weren’t able to use ear buds and this was before portable speakers. We use to take our cellphones and play music over the speaker and put the phone in a large plastic cup to boost sound loudness and quality. It worked well enough we could hear the much over the equipment
Interesting. Thnanks for posting
The problem with this is that soda bottle or not it still wont make up for low powered crappy internal speakers. Sure it will add bass,but not nearly enough to do it justice. Decent concept that I think is poorly executed
Hahaha. Imagine having to carry an empty bottle with you too. No thanks.
Yes funny!
As I never drink any soda or coke I wonder if it works with one of my favourite bottles! 
Emptying is quite easy as you see! 
im hoping its only a gag 
I believe the idea behind it is something like this: you are at the beach, or on a park, and you already drank a soda, or a bottle of water you purchased onsite and you can use the now empty bottle to increase your music experience even with a tiny speaker.
The glass is too dense and it’s resonant frequency is too high. It wouldn’t work very well although it’s contents would work just fine cheering you up! 
I would say this in a nut shell was the most likely reason 
This reminds me of some old Unbox Therapy video, there was a similar product that used empty wine and glass bottles to amplify sound. Seems pretty cool.
Edit- Here’s that video, it really does seem to improve the sound quality. https://youtu.be/-_boNMWC-fg
Using a CLEAN DRY pint glass, place mobile phone inside with speaker towards the bottom of the glass… This will amplify your sound n give some extra bass tone (especially if like the glass @fhassm is showing, nice n thick)… Try it, you’ll be surprised at the boost‽
But you need to empty the glass first!
Not possible with the glass I show at the photo.
If not doing this, the speaker needs IPX7
And what a waste of good AUGUSTINER if not emptied. 
Funny, Lol
Can always slice a slit in an RMPTY tube of pringles, just big enough for your phone.
Remove lid from pringles, and play music.
Better be extra specific then having someone blaming you for putting their phones into beer, right? 
Very interesting might have to try one of these out.
