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Synchronizing Music Players? 64

orn asks: "Lots of people now have MP3 players in the living room. Some people have players in the kitchen, bedroom, garage, and so on. They are great when it comes to getting to your music from multiple places, but when you walk from room to room, it's almost impossible to get the music aligned. Are there software packages or techniques for synchronizing multiple networked music players? One thought is to use streaming software to stream to all players — but is there any streamer that will let you account for the different delays in different hardware to create a single synchronized whole?"
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Synchronizing Music Players?

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  • SlimServer (Score:4, Informative)

    by jad4 ( 87988 ) on Friday May 04, 2007 @07:28PM (#18996811)
    SlimServer works for me. []
    • I second that. Open Source, Runs on any platform supported by Perl, can synchronize multiple squeezeboxes and softsuqeeze players. supports a boat load of formats, mp3, flac, aac, ogg, you name it. Plenty of plugins and modifications from an active user and developer community, and the CEO of Slimdevices has even been known to posts on the forums, answering user questions, on the weekends.

      The Squeezebox is a solid piece of hardware and even when it's turned off it's useful for using it's VFD as an informati
  • Simplify (Score:5, Insightful)

    by pintpusher ( 854001 ) on Friday May 04, 2007 @07:30PM (#18996847) Journal
    So, I know this doesn't answer your question, and I'm all for technology, but why not just run a multi-output speaker control box. Then just pipe the same signal to all the rooms over plain old speaker wire. I'm sure you can get lovely remote control panels (or fab some up) to control the device too. Its just so much simpler, IMO.

    • Re: (Score:3, Interesting)

      Indeed. And if one really wants to have other additional computers in control of the music, they can just use vnc or some similar app to control the music server.
    • Re:Simplify (Score:4, Interesting)

      by simcop2387 ( 703011 ) on Friday May 04, 2007 @07:51PM (#18997067) Homepage Journal
      similar in line with this you can get a low power FM transmitter off ebay, and use that and some radios, much simpler if you don't want to run that much wire. my parents do it like this.
    • Re:Simplify (Score:5, Interesting)

      by blhack ( 921171 ) on Friday May 04, 2007 @08:03PM (#18997189)
      I came here to suggest the same thing. We have a setup very similar to this in our house. There is a room with a rack that has 4 Amps on it. Each one is individually controllable as far as volume goes (remotely). So that i can be in my bedroom with the music on VERY low, and the kids can be out in pool with the music on very LOUD. With this setup, you can also run different sources to different amps too. Its pretty slick. I'm still at work so i can't look at who makes the stuff. If this is something like what you want, i'll go look at who makes everything for you when i get there. :)

      BTW, everything is controlled either from little panels that look like light switches in each room, or from a wireless tablet.
      • Re:Simplify (Score:4, Informative)

        by Jah-Wren Ryel ( 80510 ) on Saturday May 05, 2007 @02:38AM (#18999623)
        If you don't know who makes it (which means it wasn't a DIY project), and it has both a wireless tablet and on-the-wall controls, chances are it is Crestron and costs a boatload.
        • by blhack ( 921171 )
          The Controllers are intellinet, and the amps are knoll......if that helps at all. I would pull one of the panels off the wall, but i'm assuming they're just some basic serial devices.
          • Re: (Score:2, Informative)

            by blhack ( 921171 )
            sorry about the double post, but this website shows pretty much all the stuff you would need to do a setup exactly like mine.

            Click []
    • Re: (Score:3, Interesting)

      by _Sharp'r_ ( 649297 )
      My favorite trick is that with the right adapter you can use the cable TV coax already throughout your house as digital coax. That will generally get digital audio piped from one source to any device in your house that accepts a surround sound input.

      Pre-existing cables and a couple of $70 Theater in a boxes (for the amps inside and the multiple speakers to scatter about the house) with that solution gave me whole house audio sourced from the one expensive tuner (Denon 3806) that runs my real theater, which
      • by FLEB ( 312391 )
        Can you still run your television cable on the same lines through some sort of filter, or is that disconnected?
        • I didn't need to, because since my Theater equipment was already at the "hub" of the cable plant, but I'm pretty sure that with some careful planning and knowledge of what frequency ranges you needed for what you could feed it all through.

          I say that because I do know that you can backfeed various combinations of cable/satellite/over the air broadcasts in different directions over the same RG6 cable as long as you pay attention to the frequency ranges they use and use the right combiners/filters.

          The only iss
  • I am not sure if this is quite what you want, but wouldn't it be easier to just add more speakers? That way, you'll only have one player to worry about.

  • by YrWrstNtmr ( 564987 ) on Friday May 04, 2007 @07:34PM (#18996897)
    but when you walk from room to room, it's almost impossible to get the music aligned.

    That's what the volume knob is for. I assume you have an '11' setting on it? Problem solved. You can hear it in all rooms simultaneously.
    • Re: (Score:3, Funny)

      by orkysoft ( 93727 )
      Another easy solution:

      MP3 players are portable, are they not? Simply carry the one you're listening to with you, and the only delay you'll get is relativistic, which (1) is negligible at the velocities of typical slashdotters, and (2) nullified by carrying the player with you.

      I believe Apple makes a suitable device for this purpose.
  • Simple. (Score:5, Funny)

    by harrkev ( 623093 ) <> on Friday May 04, 2007 @07:40PM (#18996947) Homepage

    First, figure out what your slowest player is. Then, delay the others to match. Note that a lot of cat-5 cable might be useful -- about a mile or two should do it.

    Use an osiclloscope to compare two different devices, and figure out how much delay you need. Figure that eight inches of wire is about a nanosecond delay. Note that you might have trouble driving a mile or two of cat-5, so you might have to throw in a switch or hub along the way -- which will introduce additional delay. Simply measure the delay and use less cable.

    See, simple!
    • You sound like a knowledgable guy, so maybe you'll be able to confirm if this could help: We all know that sound travels slower than light and other forms of electromagnetic radiation, so the /. askee could do some clever positioning of wireless network receivers around his house from his AP to adjust the delay of the music over a wireless LAN!
      • by cskrat ( 921721 )
        Too much jitter. Wi-Fi latency is known to fluctuate every time a large organic mass with a high iron content moves across the room.
  • AirPort Express (Score:4, Informative)

    by Anonymous Coward on Friday May 04, 2007 @07:47PM (#18997019)
    Buy AirPort Expresses []. iTunes will drive multiple units in perfect sync. If you don't like iTunes or need to play from some other source, the Mac version of Rogue Amoeba's Airfoil [] can also drive multiple units in sync using any application on your computer as the source.
  • by Zadaz ( 950521 ) on Friday May 04, 2007 @07:49PM (#18997037)
    Standard Network latency and timing is not precise enough to reliably sync audio between rooms in such a way that you won't hear an echo. At least that was what I found when I researched this a couple of years ago.

    Buy a Sonos [] and forget about it. It's an amazing set of hardware that's worth twice the price.
  • Not particularly useful/applicable in this situation, but I thought I'd mention it as tech that can do what you want to do.

    I don't know how it works, but it does...

  • Instead of trying to sync music across multiple rooms (which can be a hassle -- if not a near impossibility), why not simply wire the speakers to every room and install a motion sensor attached to the speaker line. The music is always broadcasting, but only if there is movement. The bonus to this method, is if someone is upstairs, and someone else is downstairs, both can listen to the music without worrying about latency. It also saves a bundle in hardware since all you need is a decent soundcard and some h
    • Most motion sensors wouldn't detect, say, someone sitting at a computer, reading slashdot.

      Having the music cut out unless you wave your arms around every 5 minutes might be a touch obnoxious.
      • Most motion sensors wouldn't detect, say, someone sitting at a computer, reading slashdot.

        Use your webcam with motion-sensing software. A number of "security" apps will let you trigger an external program that could very well fire off an X10 [] signal upon a sense event [or lack thereof.]

        I know most of us are mouse potatoes, but I'm also fairly sure a large percentage make some form of perceptible motion within 5 minutes time.

        • by FLEB ( 312391 )
          Use a light beam/sensor between the arms of the office chair. Or, for that matter, a pressure switch wired to the chair.
    • The music is always broadcasting, but only if there is movement.

      And so when they sit down to listen, the music stops? Brilliant!

  • 1. Low Power FM Transmitter hooked to a central player, FM receivers elsewhere in the house. Check ebay for some cheap, stereo FM transmitters

    2. Use a stream server on your network to "stream" your mp3's to the other players. This should be pretty close to real time synchronization.

    3. Run speaker wire to each room from a central location

    I've actually tried 1 & 3, they work great!
  • > it's almost impossible to get the music aligned

    OMFG! Life is so hard!

  • I have a related situation for which I'd love to hear you Slashdotters' input.

    In these few months, I am going to be out-of-town for most days out of the month. My wife and I miss each other very much and we've gotten the old Unlimited-Talk-To-Each-Other-On-Your-Cellphone plan, etc. But one of our favourite activities is watching movies or TV shows together. We already know how to play them on the computer when we are at home together (got the ol' bigscreen and hi-fi hooked up to my Linux box), but it wou
    • You're going to run into a problem with latency in the handsets. There's a noticeable delay on most cellular networks even inside the same city (it's actually pretty remarkable how many times your voice signal is decompressed and re-compressed as it hops from node to node on the network, and each hop adds latency and lower quality). So, if both movies actually were started at exactly the same time, you would both hear each other's reactions anywhere from a 1/10th to 1/2 after the movie you were watching.
    • One way I'd solve this is, you can start the player and movie, and hit pause at a certain point, e.g. when the movie logo shows up. Then you can tell your wife to load it and hit pause when the logo shows up. This makes sure loading latencies don't affect anything. After you're both paused at the same place, you can just do a countdown and unpause at zero.

      But as the other poster said, the cellphone network might have other ideas of latencies...
    • I've done the same thing thing
      but personally i still think there is no real answer
      maybe go and find out what the real definition of VLC media player is about but i dont think that would help really
      if you find an answer let us know...
  • Centralized unit (Score:2, Interesting)

    by ZipR ( 584654 )
    I have a system from these guys ( in my house. Each room has its own set of built-in speakers, with a separate volume and source control too. I serve music via my computer (in the basement), and can skip from song to song in the living room (on the first floor) with an ATI remote wonder (works through walls.) I also have my main TV audio hooked into the system as well as the DVD/CD player. When the big game is on, I can turn it up in all the rooms.
  • A few ppl have already mentioned it, but I actually use it and it works wonderfully. I have a set of speakers upstairs, in the living room, on the patio, and in the downstairs den. I can run iTunes from any machine in the house and send the stream to any of these Airport Express-connected speakers. It's a fantastic solution that really works. Of course, you need to consider your network layout, but these small basestations are able to extend existing networks, and can do B and/or G. They also do printer sha
    • by mrfett ( 610302 )
      just to clarify, I said "any" speaker, and should've said any/all. You can use as many speaker as you have hooked up, at the same time, in-sync.
    • I'll chime in on this too. I use two Airport Expresses, one in the basement and one in the living room. I can (and regularly do) have music playing from my desktop machine (PowerMac G5), living room, and basement all at the same time, all in sync. It works great, and as picking the alternate outputs is done with dropdown in iTunes, it's wonderfully easy to switch around where the music comes from.
  • by ArchieBunker ( 132337 ) on Friday May 04, 2007 @10:51PM (#18998331) Homepage
    Not to sound like Jerry Seinfeld, but who are these people? Who needs music piped into every room of their house available constantly? Who needs an ipod to get through the day at work?
    • And what is the deal with streaming music? You need music everywhere you go? Do you listen to music in the bathroom? etc. etc.

      I always thought Kramer was the funniest anyway.
    • Who needs music piped into every room of their house available constantly?

      Who needs music?

      Who needs an ipod to get through the day at work?

      I do. I work on a trading floor as a quantitative analyst. When I need to concentrate, music is a hell of a lot less distracting than the conversations I can hear otherwise.

      Incidentally, this is what you get for asking rhetorical questions on Slashdot. Some nerd will always take you literally anyway.

  • Get some sets of good wireless speakers. Use one transmitter and tune all the other speakers to it. Voila, you have the same music all through the house, no delays, no extra wiring, little expense.
  • You're probably not using a Mac or you'd already have an airport extreme...

    If you're linux compatible you should check out mpg123 as it can take a playlist on standard in, and it can buffer n bytes of music. In the man page they suggest that a one meg buffer is about six seconds of delay, so that's one way to give yourself some tuneable delay...

    mpg123 will also let you send the output in pcm or wav to standard out... and then you could make your own software based buffer before handing the music off to the
  • Of course, if you don't want to run audio cables throughout your home, you could also consider sending the audio signal over the unused wire pairs that are in the ethernet cable. Unless you use gigabit ethernet, only two out of the four wire pairs in the UTP-cable are used. It's twisted pair, so it's reasonably immune to interference.
  • vlc ( has a network sync feature, allowing you to synchronise playback on several computers.
    • I have to second the VLC reccomendation.

      best of all, its handles multiple OSs

      it handles varying latencies pretty well, i've had it sync two desktops over a 10/100 local and a 802.11b and a 802.11g laptop at opposite ends of the house... and it sounded pretty decent.

      anything more is excessively costly, complicated and a pain in the ass.
  • by cybereal ( 621599 ) on Saturday May 05, 2007 @06:21AM (#19000397) Homepage
    Apple's iPod + iTunes + Airport Express covers all of your needs.

    One iTunes installation streaming to several AirPort Express base stations (connectable via wifi or ethernet) provides just what you need, including synchronized output. I was really surprised when I discovered the output was synchronized, despite being streamed as data and decoded at the express device itself.

    Furthermore, if you have several iPods it's trivial to synchronize them all with the same iTunes installation, in fact, it's kind of the entire point and reason behind the iPod's success isn't it?

    It's not like the iPod is that great of a player, and people can quit pretending the scroll wheel was a good idea because it's not (my sore thumb joint...) but the software to manage the things, that's the golden feature right there.

    I'm sorry to be the one that pimps Apple on this, but son... they've got you pegged.
  • PulseAudio, which is a cross-platform audio server/proxy. Is supposed to have very good synchronization across different' sound cards and across the network. I havn't gotten to play with it much, but it might be the solution you are looking for. []
  • Obvious (Score:2, Funny)

    by triso ( 67491 )
    Put a MP3 player in your pocket, with the tunes you want, put some headphones on and the music will follow you around, magically, without phase or synchronization problems.

  • I have 4 Squeezebox III players all over the house. They can be synchronized. In fact the living room and kitchen players are permanently synchronized. Whenever I turn on the kitchen SB it starts playing what the living room SB is playing.


Don't sweat it -- it's only ones and zeros. -- P. Skelly