(Image credit: Apartment Therapy )

Non-powered acoustic speakers have come a long way since their early, humble beginnings. A lot of engineering and design prowess has gone into making them more effective, as well as portable, and even stylish. Passive speakers are an easy, convenient way of sharing your music without draining your battery. Here are some of our favorites.

(Image credit: Apartment Therapy )
1. DOCK Box Acoustic Speaker for iPhone: This speaker is made out of plywood and amplifies sound so you don't have to put the volume on your iPhone up too high. It and other plywood speaker designs are available at the Etsy store IndexDrums.
(Image credit: Apartment Therapy )
2. Eco-Amp by Eco Made: This acoustic speakers is made out of a sustainable paper-based material, and it folds completely flat until you need it. It's something handy to slip into your bag, when you don't have room for anything powered.
(Image credit: Apartment Therapy )
3. Change the Record Speaker: Designer Paul Cocksedge's passive speaker is quite striking and beautiful. He deforms an old vinyl to get this interesting shape, which works well for passive amplifying.
(Image credit: Apartment Therapy )
4. Passive Non-Powered Speakers for Smartphones: If you like speakers that look like pieces of art, then you'll be happy to see all of the ones we've found for you in this post. They come in all shapes, sizes and colors, and there are plenty to choose from.
(Image credit: Apartment Therapy )
5. Simple Acoustic Speakers for Your iPhone: In this post, find even more speakers that will power your tunes without consuming any electricity.

MORE SPEAKERS & HEADPHONES ON APARTMENT THERAPY:
The Portable Boombox
Loud Luggage: Powered Suitcase Speakers
These Earbuds Always Stay In

(Images: as credited above)