SaintPeter wrote: 
Glad I could help.  Feel free to ask as many follow-up questions as you want.  Setting up RTP for the first time can be a little tricky, so don't be surprised if it doesn't work the first time, even though it looks fairly simple.

 dmax wrote: 
This is the second vote for the Express.  I love my Apple gear and I have little doubt that one of these devices would set me up nicely.  One benefit of the Express compared to the other suggestions is the ability to stream to a non-computer (like the Sansui receiver mentioned before).  My specific case involves computers that are already networked so it seems a little redundant.  And I am a cheapass and am trying to keep the cost to zero if possible.

Thank you for your input. 

 Servo wrote: 
Wow Servo!  Great information and descriptions for the semi-geeky.  Thank you for your time and effort.  I will spend a little time researching and digesting all of this, but it sounds like what I have been looking for.

 SaintPeter wrote: 
I use an Apple laptop connected to some good speakers, playing RP or my music via iTunes. Using AirTunes, the signal goes to two Airport Expresses, which playback through good big speakers in other parts of the house. They're all (as best I can tell) in sync.

 

 SaintPeter wrote: 
Now you're talking my language.  During my careers in pro audio and TV broadcasting, SMPTE time code was the standard way to keep everything in sync.  The problem with using a common time base of any kind is that you're going to end up running cables or purchasing outrageously expensive radio equipment.  If you're going to go to that length, the simpler solution is to just run the baseband audio around the house.

If you want to keep it all on your existing network without any extra wires or radios, two standard network protocols may help: Network Time Protocol and Real-Time Transport Protocol.  NTP can synchronize computer clocks with millisecond accuracy under the right conditions.  You'll probably never get anywhere close to this level of precision over a Wi-Fi network, but it's a good start.  There are free NTP clients for just about every operating system; see the link above for more information.  RTP is more technical, and something that you're not likely to see mentioned in conjunction with the software that uses it.  Fortunately the free VLC media player supports RTP, and is available for just about every operating system.

VLC has the ability to play a stream and do other things to the same stream at the same time.  That means that you can play a RP stream on your Mac, and stream it directly to your PC over your home network in real time.  You might be asking why you should do it this way when you could just "tune in" RP without installing VLC or setting up a RTP connection.  The answer is that "tuning in" to RP directly makes a separate Internet connection that travels back and forth from far away.  The way that the Internet is designed, you have no control over the path that each stream takes.  But the biggest problem is that "tuning in" to RP uses Internet protocols that must talk in both directions.

Since you're not a geek, I'll try to make an analogy:  Imagine the guy in the Verizon Wireless TV commercials inside your computers, saying "can you hear me now?" over and over.  The RP servers will send a tiny chunk of music, and then wait for your computer to answer back "I got that piece, please send another" or "I didn't get that piece, please send it again".  This happens constantly.  You usually don't hear any interruption in the music because your media player program stores up enough of the music so that it comes out continuously.  But all of the action that happens in the background makes it nearly impossible to have two separate streams from RP to play in sync on any two computers.

By using only one stream from RP, you save a stream for another RP listener, and you have a much shorter path for the second stream to travel: from one part of your house to another instead of cross-country.  Using RTP helps your two home computers sync up better because it doesn't use the Verizon guy.  The RTP server sends the music in perfect sync, and doesn't wait for a reply.  On your small home network, there's usually no need to have the 2-way conversation because there are far less possibilities to lose any of the music stream.

RTP works best on wired networks, where signal quality is close to ideal.  On a Wi-Fi network, signal quality can be degraded by distance, obstructions and interference.  The good news is that the digital radios that Wi-Fi networks use talk back and forth, just like the connection to/from RP, so the Wi-Fi should prevent drop-outs.  It all depends on the quality of the wireless connection, which can change.  By using RTP, you eliminate a redundant 2-way conversation, and have a much better chance of keeping your two machines in sync.

The technical term for storing up the music so that it comes out in a continuous stream is called "buffering".  VLC has fully adjustable buffer settings, so you can fine-tune the timing.  With a little patience, you should be able to tune the VLC software to the point that there is no noticeable delay between your two computers, without any extra hardware.

Since you're on a wireless network, your results may vary.  But since it costs nothing to try, that's where I'd start.

Glad you recognized my av, SaintPeter.  I like to go to whatever lengths are necessary to prove how old I am.  You're probably not referring to RCA cables for the FM transmitter app, because there aren't any.  Just the device itself.   And JrzyTmata, you're quite right ... poor quality can be a problem.  There are lots of low-power transmitters out there; some of them are only effective if they are 4-5 feet from the receiver.  They're made for vehicles, and not much else.  Mine is a HiFast HFM7F, and it's goes a lot farther than that.  It also doesn't hurt being out in the sticks where there are no interfering signals.

 SaintPeter wrote: 
Oh, okay. I'm pretty sure my Sansui receivers predate any digital music devices, since they were built around 1970. Ten years before MIDI was created (1982, according to Wiki.) These old beasts are about the only music technology I'm qualified for anymore.

Sorry I didn't have a more sophisticated answer. I was hoping they had rigged up some kind of 'music server' to keep everything synced, but apparently that's not it. Oh well.

c.

 cc_rider wrote: 
Digital musical devices sync up with each other using a code to keep all the parts together.  That technology has been around for years.  I am very dangerous with my teaspoon of knowledge concerning all of this.

"I did not step forward, Sir.  All the other soldiers stepped back."

Thanks again for looking into this for me.

 SaintPeter wrote: 
I have no idea what any of that means. We don't have an 'IT guy', just one of the mech. engineers we suckered into admin duty. See what happens when you miss a meeting?

 cc_rider wrote: 
MIDI equipment was using SMPTE(?) back when that Sansui was wrapped in smelly plastic and styrofoam!

Thank you for your time.  Tell your IT guy he needs to adjust the rabbit ears.

 cc_rider wrote: 
I had a lot of problems with the FM transmitter solution. static, interference and not that great sounding. worth a try if you already have the equipment or if you can return the equipment if it doesn't work out to your satisfaction.
.
the Airport Express works for me, but you have to stream using iTunes.

 BillG wrote:  Okay, here at work they used a low tech brute force sort of approach. One guy found a cheap-ish 'headphone amplifier' with four outputs. Those are wired into the speakers on other desks. Not exactly what you're looking in for, in fact nothing like what you're looking for!

BillG obviously knows far more about this sort of thing than most folks: if he says it's a big problem with no easy solution (if at all), I'm going with his advice.

I sure like the FM transmitter idea: I have several old (60's-70's vintage) Sansui receivers, and they are perfect candidates for such a setup.

c.

 JrzyTmata wrote: 
That is very helpful.  I do not want to buy more stuff if it will not fix my issue, but it sounds like that would work.

 530ferry wrote: 
A good reply and a Ship Arriving Too Late avatar!  Frank would be proud.

I was hoping to do this without buying more gear or wiring the house with RCA cables.  Thank you for a good option.  And I promise not to Google ubiquitous next time.

 SaintPeter wrote: 
I am playing the stream right now through my mac and through the living room stereo (connected to express) works perfectly.

 JrzyTmata wrote: 
I do not.  The router is wireless, but of a Qwest variety.

If your objective is to have ubiquitous RP (see how I used that big word like I do it all the time?), I have solved that problem in a different way.  I bought a HiFast FM transmitter (about $30) that plugs it into both my USB port and my Audio Out jack.  It picks up RP and re-broadcasts it via an FM signal over about a 60' radius.  I have 3-4 FM receivers all through the house, all tuned to the same frequency, so I can get RP (or any other internet audio signal) wherever I have a receiver.  It's synchronized, wireless, and inexpensive.

 JrzyTmata wrote: 
I am still researching this idea but am unclear if it will present the syncing problems that Bill addressed. 

The Mac's output is the input on a separate stereo.  RP through little plastic speakers?  NEVER!

Thank you, JrzyTmata.

 SaintPeter wrote: 
do you happen to have an airport express?

 BillG wrote: 
You are not the first to tell me this.

Thank you for your input.