Speakers can connect to an iPod in a couple of different ways. One is through the iPod's proprietary 30-pin docking connector (on the full-size iPod, iPod Touch/iPhone and iPod Nano, including the latest models). Speakers that include a built-in dock usually, but not always, will charge your iPod's batteries if the speakers are connected to a power source. This type of speaker usually allows you to use a bundled remote to control your iPod and other functions, such as overall volume. Some even have video pass-through, which sends video from a video-capable iPod to your television or another display device.
However, not all iPods (such as the iPod Shuffle) have a docking connector, and not all docking connectors are identical. Most iPod speakers also have a 3.5 mm auxiliary input, which can be used to connect non-docking iPods and other MP3 players via the headphone jack.
Some newer iPod speakers offer wireless streaming, so you can play music from your iPod (and other streaming-capable devices) with either Bluetooth or Apple AirPlay. Always pay close attention to the manufacturer's specifications for streaming; some speakers require you to purchase an extra dongle for streaming, while others offer optional dongles if your iPod isn't already Bluetooth-capable. Also, take note of whether the manufacturer uses a lossy or lossless streaming protocol. Lossless protocols, such as AirPlay, typically deliver better sound quality than lossy connections.
Clearly, making sure which speakers are compatible with your iPod is a key step in selecting a speaker system. The best way to determine compatibility is visiting the manufacturer's website; most clearly list which iPods their speakers are compatible with, including older iPod models.
Although the wide array of iPod speakers can feel overwhelming for a first-time buyer, it's fairly easy to separate your numerous speaker options into a few broad segments. While there is certainly some crossover between varieties, concentrating on the type of speaker system that best fits your needs and budget will make the buying process much simpler.
Budget speakers: If all you want is to untether from your earbuds and generate enough sound to fill a small room or office, budget speakers (under $100) are a reasonable option. Although you shouldn't expect top-notch sound quality from all budget speakers, reviews say that the better models do a surprisingly good job.
Portable speakers: Portable speakers are designed for the traveling iPod user. Some are truly tiny, small enough to fit in a briefcase or large pocketbook. Larger models fit better in a suitcase or backpack. Remember that making a speaker small and light enough to be portable usually involves some sacrifices in sound quality. That said, reviews indicate that a few portable speakers can hold their own with their stay-at-home brethren. Higher-end portable speakers usually have a rechargeable lithium-ion battery so you can listen to music anywhere, but you may need to provide batteries -- ranging from AA to D, depending on the speakers -- for lower-end models.
Bookshelf speakers: These larger, heavier (and usually more expensive) iPod speakers have no battery, and are clearly intended to stay in one place. In most cases, audio quality is excellent (for an iPod speaker). Many bookshelf speakers also feature innovative and attractive styling, making a statement beyond the sound they produce, and may include detachable components, such as a wireless subwoofer. Your biggest decision in this price range may be deciding whether you want the ability to wirelessly stream music from your iPod, computer or even the Internet; some higher-end wireless speakers even allow you to network multiple speakers throughout the house. Wireless-compatible iPod speakers are usually (but not always) significantly more expensive than their wired counterparts.
iPod clock radios: IPod clock radios combine an iPod/iPhone dock with a regular alarm clock, and usually include an AM/FM radio too. IPod cost more than traditional clock radios ($75 and up), but allow you to play (and wake up to) music from your iPod. Audio quality isn't the best, but reviewers say these types of speakers are fine for casual listening at moderate volumes.
Here are some points to think about when shopping for iPod speakers: