TCP/IP Speakers

Fallen Kell writes "From the anouncement, "Polk Audio LCi-IP Ultra High Performance In-Wall/ In-Ceiling Loudspeakers are the world's first active Internet Protocol-ready Loudspeakers. They were created for IP networked systems such as the ground-breaking NetStreams DigiLinx system but also provide vast convenience and performance benefits when used in analog systems. Integrated digital amplifiers eliminate remote amplifiers connected via hundreds of feet of lossy, performance-robbing speaker wires." I had the great pleasure of having a demo on September 16th, 2005 of these speakers. The ability of connect to a wired network for sending the audio stream is simply amazing and wonderful innovation in the audio world."

Comments

Caveats

[dada21]

I couldn't load TFA from my PDA, so take with that knowledge:

Remote digital speakers are a great solution for lowfi and mid i systems, but true audiophiles will not accept them.

Integrated amplifiers greatly reduce customizing, additional ADCs and DACs reduce resolution, increase the noise floor and change the sound.

Also, IP isn't my favored priority stream transport. I'd recommend a separate network for sound and I'd be weary of any delays incorporated in the IP transport. Think ping times! Also, encoding with the ADC does not include encapsulation into an IP packet, which can lead to worse lip-sync problems. Even 20ms delay makes me crazy (~1 frame). Of course, if its digital all-the-way, things can look brighter.

But a start is a start. Here's to hoping it continues to improve. Polk has a decent hifi range and a great R&D team. If anyone can find a better solution, its them.

Speaker Hacking

[wenck]

Just wait until these things become common, and their owners connect them to a wifi network ...

IP will give these no advantage at all.

[fishnuts]

They'll be heavier than non-powered speakers because they'll need to contain an integrated power supply, an amplifier, and a microcontroller to do the interfacing. It's completely useless to bring up the "lossy speaker cable" argument, because if you were going to spend the extra money and waste an extra power cable for powered speakers, you might as well just use standard analog speakers with XLR cables (which have been VERY well established as nearly noiseless and lossless for point to point audio distribution). You can reliably have a couple double-shielded XLR cables ran from your pre-amp to your self-powered speakers for less than having speakers that speak IP.

having multiple IP speakers on a network in the same room may also introduce phase offsets, since there's ALWAYS an inherent delay between receiving the network packets, decoding them, and sending the data off to DACs before the signal gets to the amplifier. Even a 2ms difference difference in delay/phase between two speakers in the same room is noticeable, and WILL screw up accurate stereo imaging. 2ms is not uncommon as a delay on an ethernet network.

Of course, mixing analog and IP speakers in the same room is right out.

Want the best audio quality, distance, noise-resistance for your speakers? fiber optic digital audio paths. end of story.

Nothing special

[commanderfoxtrot]

I built a networked DAC a few years ago at university. Not too hard- the complex bit is making the timing and sync accurate, with the limitations of tiny chip controllers and rather unaccurate ethernet chip documentation!

Due to TCP/IP delays e.g. switching, you need some sort of buffering, which ends up meaning expensive memory on small chips. Once you have buffering e.g. 0.2 seconds, you should be fine. I ended up using a couple of little Burr-Brown PCM54 DACs, but the system was designed to feed digital into a decent professional DAC.

Disneyland Japan has had audio over ethernet for years as well; the setup there is huge, with hundreds of speakers over a large area.

Re:Latency?

[theonetruekeebler]

Ethernet-level would have better latency than an IP stack, sure, but ties to back a platform-dependent transmission medium---you may as well use a speaker wire. And you have to write your own underlying network layer. If each speaker is running the same stack, it's going to have pretty much the same latency anyway---the worst problems arise combining digital and analog speakers.

The advantage of TCP/UDP/Music-Transport-Protocol is that the medium suddenly becomes less relevant. Take wireless, for example. Imagine being able to cart your Big Speakers outside for a patio party without running a single audio wire. Or just to install speakers on the other side of your house (or in your shed) without having to grovel through the attic or crawlspace.

Imagine how useful this could be for concerts: the sound board now has one wire running to it---the power line. Likewise with your front, middle and back stacks, and your monitors.

Another plus is that we have a nice bidirectional protocol, as well as a chance for side-channel data: speakers can report their health back to the control panel, or to other speakers in the same stack. And since each speaker is doing its own DSP anyway, getting the equalization right for a given speaker is a matter of sending it a message.

You know what? Forget the speaker---sell compact, portable, one-speaker wireless-enabled amplifiers and let people convert their existing speakers into packet-switched audio devices.