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View Full Version : Woeful sync SB3 & Boom - just me?



moley6knipe
2010-03-20, 02:47
I've had two SB3s for ages, one wired, one wireless. Have never had *any* sync issues at all, ever, under any version of SqzCtr.

Now, having added a wireless Boom, sync is awful. Using LAME to go to 192kbps from apple lossless, always have done to the wireless SB3. Up to three seconds out, all three devices refusing to lock together. Tried with clean installs of 7.4.3 and 7.4.2. And oh what fun it is spending another evening putting all my settings back in. Yes, I back them up but I've yet to upgrade versions without needing to do a clean install to get it working properly.

Sync returns when I unplug the mains on all three devices.

By the time I've unplugged all the devices and waited for them to boot, it would be quicker to find the disc and play it. Which puts me back about 10 years.

But, surely that's not the solution? Anyone else have this, before I start pulling my network to pieces?

XP Pro SP3, wireless G network with WPA-PSK. 66% signal on Boom, 70+ on SB3. PC is dual core 3Ghz 4Gb DDR3 ram so it can certainly run all this.

moley6knipe
2010-03-20, 03:05
The Boom is only a few weeks old, so it can always go back as unsuitable.

Oh, and I'd try contacting Support, but they've never responded to me yet, so I'll save the RSI...

I realise I'm moaning, but I just want to listen to some music.

pippin
2010-03-20, 03:15
What kind of server do you use?
Do I understand correctly that you transcode to mp3 on the fly? Why? Please try to transcode to flac instead, should use much less CPU and give you better quality at the same time.

I think your sync issue could be due to the server simply having too much load.

toby10
2010-03-20, 03:20
I'd first try (temporarily) a couple of simple Boom tests to rule out WiFi issues:
- move Boom much closer to your router
- try wiring Boom (arrow back to setup, select Ethernet)

moley6knipe
2010-03-20, 04:16
Hello. Thanks for replying even though I'm whining. I'll stop whining now.

@ pippin
My server is a PC running WinXp Pro SP3, dual-core E8400 chip (3Ghz), 4Gb DDR3 RAM.

I transcode to mp3 for the devices connected via wireless simply to extend the possible range of coverage for my Boom. The wired SB3 is set to stream in flac (obviously it transcodes to mp3 when it's sync'd). I know mp3 transcoding uses some juice but surely not enough to defeat my server?

@ toby10
Problem is that the sync issues are random. Sometimes they happen, sometimes they don't. I'll wire the boom and see if they persist. If they don't, what tips can I try to improve my wireless network? Have tried changing frequencies, problem persists. Any tools to check for interference?

I'm not convinced it's that, though, have never had problems with 2+ years of syncing sb3 wireless with sb3 wired with lame transcoding, but I appreciate that adding the boom increases network traffic.

toby10
2010-03-20, 04:31
I presume your XP server is wired to the router?

Many use a free program called NetStumbler to see the various WiFi's around them which may be causing interference.
Haphazardly picking different WiFi Ch's is as good as rolling dice to pick your WiFi Ch.

Basic WiFi troubleshooting:

WiFi Network Tweaking and Performance Enhancements:
- Perform a Site Survey (very simple to do) where you are looking for any/all WiFi networks near you and within range of your WiFi devices that may be interfering with your WiFi. Click on the little WiFi terminal on your computer, go to “View All Networks”. Make note of any/all other networks with a 50% or better signal strength. You want to note for each of these stronger signal networks the Name and Channel #. If the Channel #’s are not available you can try a free program called NetStumbler to view such info (it is very simple to use).

With your Site Survey information you can now do some very simple WiFi performance enhancements:
- log into your routers Administration functions and……
- Change your routers name to something unique (i.e. not Linksys or DLink): This will ensure you are always connecting your players to YOUR network and not your neighbors network. This will also prevent accidental connections to your network from your neighbors devices.
- Change your router to use only “G” mode: Most WiFi routers can use A or B or G modes, or all three. Unless you have much older WiFi devices you likely do not need A or B modes.
- Change your Channel # to either 1 or 6 or 11 (or 13 if in Europe): Choose the Ch # based on which one is NOT in use near you. Ex: If Ch’s 1 & 11 are strong signals near you, choose Ch 6. If Ch’s 6 & 11 are in use near you, choose Ch 1. If all three 1-6-11 are all in use near you, choose the Ch # that shows as the weakest nearby. Ex: Nearby networks show Ch 1 at 70%, Ch 6 at 80%, Ch 11 at 60%, then choose Ch 11 (the weakest nearby strong Ch).
NOTE: When you change your routers WiFi Name and/or Ch # *all* devices connected via WiFi will disconnect from the router. Don’t panic, this is what you want. 
Changing Name: You will have to manually re-connect all devices by selecting the new router Name on your devices WiFi setup
Changing Ch #: All devices should automatically re-connect within 60 seconds if only changing the Ch #

Further WiFi Enhancements:
- Move the router: Higher, lower, away from electronic devices (particularly computers and cordless phones), more centrally located in the home, orientating router and antennas for maximum signal strength to the troubled player

pippin
2010-03-20, 04:59
Please try turning off mp3 transcoding. You won't extend anything through that any WiFi coverage will be good enough for a single flac stream.

Scheduling on windows isn't particularly good and while transcoding to mp3 will not bring your server down it can be enough to kill sync timing.

Mnyb
2010-03-20, 06:41
And also you are doing both mp3 trans-coding and flac trans-coding simultaneously, it must make life harder for the sync algorithm ?

pippin
2010-03-20, 07:55
And also you are doing both mp3 trans-coding and flac trans-coding simultaneously, it must make life harder for the sync algorithm ?
Really? If that's the case it would explain it altogether since I don't thing you can reliably sync mp3 and flac streams. I was assuming that as soon as you sync all the SBs would play the mp3 stream.

rgro
2010-03-20, 08:35
I presume your XP server is wired to the router?

Many use a free program called NetStumbler to see the various WiFi's around them which may be causing interference.
Haphazardly picking different WiFi Ch's is as good as rolling dice to pick your WiFi Ch.

Basic WiFi troubleshooting:

WiFi Network Tweaking and Performance Enhancements:
- Perform a Site Survey (very simple to do) where you are looking for any/all WiFi networks near you and within range of your WiFi devices that may be interfering with your WiFi. Click on the little WiFi terminal on your computer, go to “View All Networks”. Make note of any/all other networks with a 50% or better signal strength. You want to note for each of these stronger signal networks the Name and Channel #. If the Channel #’s are not available you can try a free program called NetStumbler to view such info (it is very simple to use).

With your Site Survey information you can now do some very simple WiFi performance enhancements:
- log into your routers Administration functions and……
- Change your routers name to something unique (i.e. not Linksys or DLink): This will ensure you are always connecting your players to YOUR network and not your neighbors network. This will also prevent accidental connections to your network from your neighbors devices.
- Change your router to use only “G” mode: Most WiFi routers can use A or B or G modes, or all three. Unless you have much older WiFi devices you likely do not need A or B modes.
- Change your Channel # to either 1 or 6 or 11 (or 13 if in Europe): Choose the Ch # based on which one is NOT in use near you. Ex: If Ch’s 1 & 11 are strong signals near you, choose Ch 6. If Ch’s 6 & 11 are in use near you, choose Ch 1. If all three 1-6-11 are all in use near you, choose the Ch # that shows as the weakest nearby. Ex: Nearby networks show Ch 1 at 70%, Ch 6 at 80%, Ch 11 at 60%, then choose Ch 11 (the weakest nearby strong Ch).
NOTE: When you change your routers WiFi Name and/or Ch # *all* devices connected via WiFi will disconnect from the router. Don’t panic, this is what you want. 
Changing Name: You will have to manually re-connect all devices by selecting the new router Name on your devices WiFi setup
Changing Ch #: All devices should automatically re-connect within 60 seconds if only changing the Ch #

Further WiFi Enhancements:
- Move the router: Higher, lower, away from electronic devices (particularly computers and cordless phones), more centrally located in the home, orientating router and antennas for maximum signal strength to the troubled player


Plus, NetStumbler can be configured for an almost real time continuous graphing/readout of both signal strength and S/N ratios that you can display for each wireless signal being received by your wireless card...good diagnostic tool for both your own equipment and to see what how much your neighbors' signal is really doing....Install it on a laptop and move around with it, you might be surprised with what you find. Lastly, it may look like one of those slightly dodgy things when you go to their website, but it's completely safe to download and use.

Mnyb
2010-03-20, 09:26
Really? If that's the case it would explain it altogether since I don't thing you can reliably sync mp3 and flac streams. I was assuming that as soon as you sync all the SBs would play the mp3 stream.

He is using alac -flac in general

Then bit rate limiting is a per player setting, the boom has it set at 192kBps

Bandwith should be plenty if the network is ok.

The bandwidth test in squeeboxserver can fool you a bit, for example an SB3 or Receiver starts to choke at 3000k over wifi, the radio at 2000k controller at 500k, but it's the player that is the bottleneck.
Start the network test on all players at the same time and see you can probably stream more than you think, because it bottoms out on one player don't mean that's the max for the whole network.

pippin
2010-03-20, 10:24
Yes, I understand that. I just thought that if you sync players it uses the smallest common denominator for all of them. For example, if I sync SB3 to Touch and play AAC, both play the transcoded stream even though the Touch can play AAC natively because otherwise sync would not work.
Same with 24/96 material, if I sync Transporter and SB3, both play the downsampled stream.

Mnyb
2010-03-20, 10:33
Yes, I understand that. I just thought that if you sync players it uses the smallest common denominator for all of them. For example, if I sync SB3 to Touch and play AAC, both play the transcoded stream even though the Touch can play AAC natively because otherwise sync would not work.
Same with 24/96 material, if I sync Transporter and SB3, both play the downsampled stream.

They do ? that's not so fantastic, I understands if it would not work with mp3 and flac as they are internally different ,but flac vs flac where the only diff is the 1/2 sample-rate.

moley6knipe
2010-03-20, 10:38
Hi everyone, thanks for all the tips, I'll have a play. Can't use NetStumbler as have no wi-fi card in my PC but have only scanned thru docs so far so I may be wrong.

Yes, when streaming to all 3 of my devices in sync everything streams to all players as 192 mp3 at the moment.

@ Pippin
Please try turning off mp3 transcoding. You won't extend anything through that any WiFi coverage will be good enough for a single flac stream.
Scheduling on windows isn't particularly good and while transcoding to mp3 will not bring your server down it can be enough to kill sync timing

...thanks for that, will try. I'd assumed that the lower the bitrate the less signal strength needed to transmit it and therefore further distance possible.

Transcoding to flac shows on my devices shows as "converted to 700ishkbps ABR". I'm presuming that alac>flac takes less work than alac>mp3 thus more chance of the server getting it all right in time to stream, thus less problems in streaming over wi-fi - is that about right?

pippin
2010-03-20, 11:10
Transcoding to flac shows on my devices shows as "converted to 700ishkbps ABR". I'm presuming that alac>flac takes less work than alac>mp3 thus more chance of the server getting it all right in time to stream, thus less problems in streaming over wi-fi - is that about right?

Muuuch less. Don't know about ALAC but you need to decode that anyway, and you can do flac encoding completely on an integer basis, this takes way less load than mp3.

You are correct that you can theoretically get a higher range with lower bandwidth but I don't think there are any modes below 11MBit/s in modern WiFi networks so plenty of capacity left. Plus if you need that your coverage will probably be spotty causing trouble with streaming at any bitrate,

The biggest issue I could see is that the server has to do a bit of real-time processing to get the sync done right and if it transcodes in the same process this can get spotty. I also don't think lame is optimized for real-time operation.

moley6knipe
2010-03-20, 11:35
Thanks, makes sense.

So, now streaming in flac. Changed router to switch it to G only. Changed channel to 9. At the moment, that's an arbitary guess, yet to investigate network traffic properly. Seems ok so far, boom seems snappier to use to.

toby10
2010-03-20, 14:46
pippin likely has your solution. He has forgotten more about SB players than I'll ever know in a lifetime.

But, when time permits, I'd still spend 20 minutes investigating your WiFi and possible surrounding WiFi's.
Years ago just changing my router to G only and changing to the least crowded ch around me (ch 11 in my case) gave me an instant 20% signal boost.

moley6knipe
2010-03-21, 04:22
Ah, spoke too soon. Streaming in sync, transcoding alac>flac, wired SB3 and wireless Boom.

All rock solid *until* I skipped forward a couple of songs on the SB3. Then sync went out. I then switched the Now Playing info to just "remaining time" (was "spectrum analyzer and Remaining time") and I think sync improved, but wasn't perfect (of course, the only tool I have available for this, my ears, is also not perfect!).

No amount of power on/off, pause/unpause, skipping tracks would restore sync. In the end I had to pull the plug on both devices.

Anything else I can try?

pippin
2010-03-21, 05:59
Anything in server.log?

moley6knipe
2010-03-21, 07:21
Nope, not a thing. Have set (player.sync) - Multi-Player Synchronization Logging to "Debug". Will post back when it's played a few tracks!

moley6knipe
2010-03-25, 01:26
Just happened again, same set-up as before ie SB3 wired, Boom wirless 53% signal, alac>flac, sync'd, but wouldn't play in sync until I pulled the power out of both devices. Server log attached. Both Boom and SB3 hadn't been disconnected from the mains at any time; my server was woken from sleep by the SB3.

At this point I did have the baby monitor on; I wonder if that could interfere? Never has in the past with the wireless SB3 though. Problems only started when I added the Boom. Does my server log point to any problems, anyone? It does mention "bailing"!

On the attached, I've replaced the MAC addresses for my Boom and SB3 with the words --------------SB3 and -------------BOOM.

toby10
2010-03-25, 04:24
And when you take Boom out of the setup (un-sync or turned off) the problem goes away?
Tried with Boom wired?
Tried with Boom WiFi but much closer to the router?

awy
2010-03-25, 08:32
On the attached, I've replaced the MAC addresses for my Boom and SB3 with the words --------------SB3 and -------------BOOM.
It looks like your server cannot keep time. This is a requirement for successful sync. The clue is the following:


[10-03-24 19:52:18.0127] Slim::Player::Player::trackJiffiesEpoch (951) -------------BOOM adjust jiffies epoch +0.005s

[10-03-24 19:52:18.2352] Slim::Player::Player::trackJiffiesEpoch (951) --------------SB3 adjust jiffies epoch +0.005s

occurring every few seconds.

You need your server clock to run at proper clock time +/- 2ms/minute.

I'm not sure how best to achieve that with Windows XP. You probably need some sort of NTP service running.

moley6knipe
2010-03-26, 00:49
Thanks awy. Some Googling found this http://support.microsoft.com/kb/314054 from MS - is that the sort of thing I'm after?

Just checked and WinXP system time is set to update from time.windows.com but if I attempt an update I get "sync failed". So it looks like this could be worth pursuing!

awy
2010-03-26, 01:13
I don't really know how this stuff works under Windows.

The main issue seems to be that your server clock does not seem to run at the correct rate.

Under Linux, there is a mechanism whereby an NTP daemon can detect this and use a kernel mechanism to adjust for it. This is separate to the use of NTP to correct the clock time using an external clock source in the first place, or periodically.

I have no idea if something similar is available for Windows, nor why your clock would run at the wrong speed in the first place. Perhaps someone else here knows better.

moley6knipe
2010-03-26, 10:32
Pardon my ignorance, but we're not talking about CPU clock speed here, are we? Coz PC Wizard shows this for my CPU, which is nominally a 3Ghz dual core...

Frequency : 3000 MHz - (current : 1999.83 MHz)

General Information :
Real Frequency : 1999.83 MHz
Multiplier : 6x
Low/High Multiplier : 6x / 9x
Multiplier Locked : Yes
Marketing Frequency : 3000.06 MHz

...or am I barking up the wrong 'un?

Phil Leigh
2010-03-26, 10:34
Pardon my ignorance, but we're not talking about CPU clock speed here, are we? Coz PC Wizard shows this for my CPU, which is nominally a 3Ghz dual core...

Frequency : 3000 MHz - (current : 1999.83 MHz)

General Information :
Real Frequency : 1999.83 MHz
Multiplier : 6x
Low/High Multiplier : 6x / 9x
Multiplier Locked : Yes
Marketing Frequency : 3000.06 MHz

...or am I barking up the wrong 'un?

No this is about the actual "time" that your PC thinks it is, nothing to do with how "speedy" your CPU is...

moley6knipe
2010-03-26, 10:37
And when you take Boom out of the setup (un-sync or turned off) the problem goes away?
Tried with Boom wired?
Tried with Boom WiFi but much closer to the router?

Hi - seems not to make a difference! Sync failed a moment ago (in fact SB3 refused to play an apple lossless file that it's normally ok with) and even after power cycling both devices (but not the server) it still failed to sync but at least it played.

Another server log attached. Lots of mention of "Playpoint too old" and "Bailing" which can't be good?

Phil Leigh
2010-03-26, 10:47
have you rebooted your router recently?

NikolajC
2010-03-26, 13:32
I use Dimension 4 ntp client to update my clock every 1 minute on windows. Sync finally works. You should try it too.

herbman
2010-03-26, 13:40
I can't recommend this NTP server enough:
http://www.meinberg.de/english/sw/ntp.htm

It disables the (crappy) windows time service, sets up a port of the real NTP, and its own user, and comes with a great list of pre-defined server pools.

moley6knipe
2010-03-26, 14:20
Genius, thanks guys - I'll give them a go when I've not had so much ale. C'mon, it IS Friday. I'll post back with my results!

moley6knipe
2010-03-26, 15:52
have you rebooted your router recently?

Haven't Phil, but will. It's only been up a couple of weeks at most.

General question if anyone can help - I'm curious; why do my Squeezeboxen care if the time that they're getting from Windows is wrong? Come to that, how do they know - what do they compare it against? Or don't they? And I'd thought to adjust sync you'd just count + or - milliseconds against the other network stream; so my brain doesn't understand why the time of day being accurate is important.

I think it's fair to say I don't understand why wrong time as in the time-of-day could cause a sync problem with my Squeezeboxen, but I'm prepared to accept that it is!

I'm in need of enlightenment!

awy
2010-03-28, 03:38
It is not the wrong time of day that is the issue, but the rate of change of that time of day.

The synchronization process works by calculating, every second, the apparent start time of the track for each player, based on the report from each player of amount of the track that has been played (in milliseconds) and the timestamp of that report. That timestamp is converted to clock time by using the time epoch of the player, which is tracked separately. When two players in a sync-group have different apparent start times (by more than 10ms), the server tells one of them to make an adjustment (usually by skipping a very small interval).

The algorithms use various smoothing and hysteresis functions to avoid false adjustments. A system (server) clock that runs at a sufficiently different speed to the clocks of the players will mess up this process.

moley6knipe
2010-03-28, 04:33
Ah, I see. Sadly almost impossible to Google for more information on how to correct, if indeed I can, as CPU clock speed is all that turns up.

Does anyone have any links for further reading?

moley6knipe
2010-03-30, 10:41
Well, tried installing Dimension 4, no effect apart from making the RSS ticker on the SB3 pause every time Dimension 4 updates the time! I set it to 45 seconds. Same sync problems, sometimes I can correct them by rebooting PC/SB3/Boom, sometimes not.

So I'm off to some hardware forums to see if anyone can shed any light on how, if at all, one corrects the fact that my computer doesn't know how long a millisecond should be...

elziko
2010-04-08, 07:49
For anybody running Windows who want needs to increase the NTP update frequency look here:

http://blog.basteagow.com/2009/10/30...tion-interval/

It isn't necessary to install another client if you don't want to. I have my Windows 7 updating once per hour now (instead of the default once per week) and my sync problems seem to have gone away.