February 22nd, 2009
My brother recently emailed me this question, and I thought I’d share my answer:
Are there any wireless surround speakers that don’t completely suck? I don’t need something great, but just want to avoid triumphant crapitude.
Unless something has changed dramatically in the last couple years:
(a) There aren’t really “wireless” speakers in the first place, and
(b) They all still mostly suck, in principle, unless you’re willing to blow serious coin, and even then they aren’t going to be as good as decent wired speakers.
It turns out this is a more complicated thing to accomplish than you might think. Remember, to drive a speaker, you need two things:
1. Analog audio signal
2. Amplification for said signal
Getting an analog signal to a speaker not using a wire means you have to either use some kind of analog broadcast like RF, which will be crappy from a noise perspective, or something digital—newer systems use Bluetooth, I believe. While this will preserve the signal, this has two implications:  Your receiver either needs to send a digital signal to the speaker, which your current receiver doesn’t do (though some new ones designed specifically to work with wireless speakers will), or you hook your receiver up to a transmitter which has an analog-to-digital chip (ADC) inside, and probably not a good one unless the system is very expensive.  Something in the speaker has to covert back to analog. This means each speaker needs its own digital-to-analog conversion (DAC) circuitry, which again will either be expensive or suck (choose only one option).
Then, once you have an analog signal, you need to amplify it before running it through the actual drivers. This means each “speaker” also has to contain an amp, which requires power, meaning… wires. You’ll need to run a power cord to each speaker. Also, there is no such thing as a good power supply that is also small, meaning the amp part, to be any good, can’t be little. The upshot of this is that you’ll need somewhat big surrounds which require plugs. (The actual amp inside the speaker can be reasonably small if it’s a digital amp, but I bet whatever $200 option Sony has instead uses the worst analog amp in the known universe, but at least it’s a small one.)
So, every wireless speaker will need: signal receiver, DAC, amp (requiring power), and then drivers, and the thing that takes what would normally be your speaker out needs an ADC and a transmitter. That’s a lot of components, and doing all of these pieces reasonably well can’t be especially cheap. Or rather, if it is cheap, that means that there is a lot of opportunity for really crappy components, which doesn’t bode well for sound quality.
The other problem here is that all of these steps take a little bit of time, meaning you’re probably going to have phase lag. That is, the sound coming out of your surrounds won’t be in phase with the sound coming out of your wired fronts, center, and sub. You might be able to mitigate this a little by setting appropriate channel delays all around, but that’s a tricky calibration problem. Newer and more expensive receivers will do this for you (they come with microphones that you move around and the system sends test signals to ensure good calibration), but I suspect you don’t have one that does.
Thus, a lot of reputable speaker companies won’t even bother trying to do this; your entry-level audiophile companies like Paradigm, B&W, Mirage, etc. don’t. Of course, I’m sure all the mass-market companies (e.g., Sony, Panasonic) have such things, but I’d be stunned if they don’t all produce triumphant crapitude, as you so colorfully put it (great turn of phrase, by the way).
It’s probably easier to just hide the wires.