Let me first tell you why I bought a Pioneer A4 and why I'm so happy with it. Then I'll go over its features and do a little nit-picking, which boils down to "this is an RTFM product in a post-RTFM world." All things considered, I love my A4: it's a great product at a terrific price.

What was I looking for? First, I wanted a self-contained package with a big sound that my friends and family and I can beam music to with Apple's Airplay technology over wifi. Second, I wanted outstanding sound and I didn't want to compromise on bass response. Third, I specifically didn't need a battery powered model. (If I did, I could sacrifice the A4's "subwoofer" and get an A3 for the same price with the same features plus water resistance and a rechargeable battery.) The A4 easily delivers on my three wishes, so I'm delighted with it. It sounds simply terrific for a product of its size, and it does exactly what I want it to. As a bonus, it includes an Ethernet port for improved network reliability, and it's capable of being its own wifi access point for use where there's not an existing network (say, at a vacation house). And its USB port, in addition to providing a direct audio connection for iOS devices, charges them too; I mention this because iPads can be fussy about what they're willing to take a charge from. If you're in an analog mood, there is of course an 1/8" stereo input port in the back. And it comes with an itty-bitty remote control that, when lost forever under a couch cushion, won't render the A4 useless. I like that.

But what about Bluetooth? Pioneer says they skipped it because of its limitations: limited bandwidth means reduced audio quality, and limited range means more audio dropouts. I agree, and I'd add that setting up a Bluetooth connection is a hassle. If you're not an Apple Airplay fan, the A4 can receive music over DLNA, a non-proprietary technology that can do similar stuff. I gather there are mobile apps that can leverage this feature. Also there's a connectivity option for HTC phones. Does anyone still have HTC phones in this Samsung/Apple world? Who cares. If you're not into Airplay, this may not be the speaker system for you.

So the Pioneer A4 is a total winner...if you're sufficiently geeky. If not, its setup process is likely to frustrate you endlessly. The "quick start" guide provided with the unit unfolds--no joke--to a wall-sized double-sided 24"x36" poster covered with impenetrable-looking flow charts. I showed it to my mother-in-law and she howled with laughter: there's no way she'd have the patience to make the most of the A4's features, or possibly get it working in the first place. You have to learn the A4's secret codes in order to unlock its features.

For example, other reviewers have complained that when the unit is turned off, you can't start streaming music to it without turning it on manually. They complain that it switches itself off when idle, and that it takes at least 30 seconds for it to start playing music after you turn it on. This is all true unless you learn about "Quick Start Mode" which obliterates all of of these problems. Quick Start Mode is activated by holding the "input" button for a few seconds.

The A4 has no display and few buttons. Wait, how are you supposed to get it on your wifi network? There are a few ways, but again you gotta RTFM.

One way is to power it up, connect an iPhone or iPad and then hold both the "input" button and the rear "network setup" button for a few seconds. Your iWhatever will then ask for permission to transfer its wifi connection details to the A4, which will then reboot and join the network automatically. This is very cool and it works perfectly, as long as you know the code.

Another way is to have the A4 create a temporary wifi network that you join with a nearby computer in order to configure connection settings via a web browser (this is also how you can update the A4's firmware or change its Airplay name if you don't know how to find its IP address on your network). To enter this mode, power up and hold "volume down" and "network setup" for a few seconds, then look for (and join) the new wifi network on your computer, then visit the A4's web interface.

And what about creating an isolated music wifi network where none exists, vacation-home style? The secret code for this is to power up the A4 and hold the rear "network setup" button for a few seconds.

And if after all this you end up in a state where you need to reset everything and start over, there's a code for that too: power it up and then hold the power button for several seconds until it turns back off, tabula rasa.

Pioneer would be well advised to put these cheat codes and a link to interactive online help on a simple 3x5 card, *and* on a sticker on the bottom of the unit, ditching its all-but-incomprehensible "quick start" guide.

So. The Pioneer A4 made its debut at a rather spendy $400. At that price it was a compelling option. Great sound, attractive package, nice features. At its current MSRP of half that, it's a no-brainer if you need a self-contained, great-sounding Airplay speaker, provided you have the inclination and ability to take command of its cryptic but effective setup process.