hickups while streaming HD tracks

Hi Arno, for most hidef bit rates you are asking rather a lot for it to reliably work without droputs on wifi. Its best to use conventional wired ethernet leads between the upnp server and the network player, and if you are streaming hidef this starts to become more of a neccessaity apart from the odd situation where wifi will work without interuption on some hidef.

Wait a sec... does the airport even stream hidef?

If not, it is probably taxed trying to covert it.

I have experienced MANY dropouts using it with iTunes and MP3s AND on a robust network.

I can stream 24-96 over wifi without breaking a sweat.  Standard fare gigabit netgear rangemax.

I would blame all of your problems on the Airport.

Airport Extreme is a wifi access point as well, and from the context of the OP that is what it understand he is using it for.

Back to wifi... One has to be very careful in interpreting wifi speed with effective throughput.. Probably an area where the marketeers are even more mis leading than usual.

With 802.11a/b/g at higher data speeds effective throughput  efficiency can drop to 15~20% under good signal conditions.. A lot less for poor conditions. Therefore a 802.11g 54Mbps wifi link will under good conditions in the real world will be giving you around 7.5Mbps to 10Mbps, and that will away significantly if anything else is on the wifi network or conditions ate poor.

Now 24bit 96kHz stereo hidef signal has a raw data rate of 4.6Mbps. With application overheads, encryption and data encapsulation this is going to increase (I was going to typically work this out but ran out of time so let's say 10% ) so we have an effective load of around 5Mbps. So we can see quite easily it's possible to stream this hidef rate over 802.11g but very easily this becomes not possible without pause interruption.

With 802.11n at both sender and receiver, efficiency is massively increased, and throughputs of upto 10 x 802.11n appear possible.... But I am not sure Naim is supporting 802.11n yet.

Simon

Thanks for your reply's.

The remark about airports capacity to stream hd, made me think. I use a Imac to store the music. Then it is wirelessly connected to an airport extreme, with an airport express in between to get a better signal. The airport extreme has a wired connection to the nd5xs. So, for iradio i have a complete wired connection from router to Naim. But to get digitallt stored music on the Mac it's partly through wifi with airports.

I just found some internet fora. There is found that the express doesn't support hd, and the extreme does support it but wireless not bit-perfect.

There you go, it'not about some hickups: i didn't even get hidef. (and still thought quality was much better than before)

I am afraid i have to rebuild the house a bit, or buy a decent nas and put it close to the nd5xs.

Arno, thanks for clarification. I am sure you realise the comment about the express not supporting hidef refers to its TOSlink output rather than the data it can handle via its wifi link / Ethernet port.

Simon

Thanks Simon, that helpful as it clearly explains why I can wirelessly and reliably play 24/96 stuff but 24/192 isn't possible. I've just moved house and no longer have a wired network and no real prospect of it either. 24/192 does start but the buffer slowly depletes and empties after about 5 minutes - this suggests to me that my wireless g is only just not capable......so I have a plan!

Since Naim doesn't support N wifi yet, I'm going to get an Apple Express and plug it directly in to my ND5. I'll link the Express to my main ASUS RT-N66U router using the higher capacity 5Gb n wifi. The server and NAS are wired in to the ASUS. 

Do you think it's more likely to work with the 24/192 stuff?

Chris

Hi Chris

I think you will find that Your ND5 does have wireless N - my Superuniti definitely does.

If you have a wireless network with both G and N spec devices it may default to G speeds. I have a dual band Netgear router and have separate N and G networks to avoid this. 

Hi Pev - yes you are right I have checked the specs and ND5 supports 802.11n. However only on 2.4Ghz band if I read corectly - which means if there are any g,b or c  networks in your reception then the the n is going to downgrade to standard size channels, rather than the double size spectrum channels so bandwidth is still reduced from the full 802.11n potential - althoguh there is some improvement in overhead management. As you have a 802.11g network runing alongside your 802.11n, the two are going to have to share the radio spectrum to work using the g channel spacing - so performance improvement will be marginal.

You might find - assuming you have no wifi zones nearby just running 802.11n gives a better performance.

Chris - so .. your ND5 can run 802.11n - but it looks like you have non 'n' radios in your vicinity or your performance is marginal.

Simon

I also have a dual band router but the ND5 doesn't "see" the 5Gb network.

Hence my little scheme to use an Express in conjunction with my dual band router - to force the use of 5Gb N.

Hi Simon

thanks for this - I didn't realise the SU only worked at 2.4. I set up a separate G network for my Squeezebox Boom in the hope that would stop it dragging down the overall network performance, now it seems the SU is likely to be doing the same . Looking at the wireless signal on my laptop in the next room from the router it shows 54mbps so you are right as ever, I actually run the SU on ethernet off a switch wired to the router so I don't have a streaming problem and I must admit that as I haven't had any network problems since junking the BT hub for the Netgear I leave well enough alone.

I mainly answered to let Chris know he probably did have N level wireless but now I've learnt something for myself - cheers.

Pev, thanks,

Chris, I am not sure your scheme will help unless you are able to position the antenna of your express in a more advantageous place.

If you can see other wireless networks, then assuming they are 802.11b/c/g then you will only get marginal throughput increase in usung 802.11n. 

However if there are no networks visible including Openzone etc then lock your sender to 802.11n and you should get a significant increase in data throughput.

There are two frequency bands that can be used 802.11n to help this. Naim from what I can see only supports the lower band. The upper band is shared with 802.11a which is less common these days so the upper band is less populated with oldner protocols and so is less likely to have to downgrade.

You see the radio spectrum around you has to shared and 'downgraded' to smaller channel sizes if an older wireless  protocol is present on its band otherwise nothing would work.. Old or new.

Simon

I can see no other networks apart from my own - one of the benefits of a very rural location.

My ASUS router has two SSID - one is exclusively for the 5Gb 802.11n. So, I propose to use the Express as the other end of a wireless bridge and only give it details of the 5Gb SSID. That way should force a connection at the higher capability shouldn't it? The ND5 will be connected to the to the Express with Cat5. 

Chris, give it a go and see how you get on. It sounds like it should work. BTW I found the signal strength of my express on 5GHz somewhat attenuated, and so I went back to 2.4GHz.. Your results might vary. 

 2.4GHz travels through walls better than 5GHz.

Simon

I enabled both 2.4 and 5 GHz here at home on my Airport Extreme and Time Capsule, and found that in some places in the home the 2.4 actually was better.  I'm pretty sure it's a thru-the-walls issue.

I can get the express to within 1 meter of the ASUS with just a floor between them; I suspect the floor will be of solid construction since I can hear nothing in the room above when the system is playing. My IPad appears to get 100% on the 5Gb in my proposed position and so I am optimistic. Of course, I should really take a drill to the floor but I have a feeling there are some central heating pipes somewhere in the vicinity and I don't want a crisis just as winter-proper comes to the Czech mountains where we live!

Ahh central heating pipes. Been there, done and got the collapsed ceiling to proof it.. Thank goodness for insurance 

Of course if it's wooden floorboards on joists it's easier to manage .. It's easier to unscrew and lift. I guess you could get one of those metal pipe/cable detectors?

You could also try routing on the outside of your house. I manage additional telephone, satellite coax,radio antenna coax that way.  Once you paint to match your house colour it blends in well.

Simon

Simon, your knowledge of wireless networking is amazing. It's a subject which Ihave some difficulties in understanding to any level of depth.

may I ask a question, coming from a slightly different angle?

What impact, if any, would fitting the higher gain antenna to our boxes where there are issue with

wi-fi as discussed above?

In my case, a Uniti.

Just curious whether it would in fact make any/much difference or whether it simply makes more sense to pursue the wired ethernet solution.

Hello Arno, I had a similar problem with a wireless HD connection to my ND5 XS, it worked well with standard and even 24/96 but couldn't cope with 24/192 tracks. I bought a homeplug kit (TP-Link £38 for 500mbps - whatever that means!) and now it works well.

Good luck.

Matthew

Hi Chris, higher gain antennas may work, but here are considerations.

Antennas trade gain for directional coverage. So typically the less directional gain variance an antenna has the more effective it is at being omnidirectional assuming its as  efficiently close to its unity gain as it can be. The more gain you apply the more directional the antenna becomes. It's a bit like focussing a beam of light or using a telescope to look at a star as opposed to looking at the milky way across the sky with your eye.

Also 802.11n uses mutipath technology so there may be Mutiple directional peaks, which may be hindered by a higher gain directional antenna.

Therefore if your higher gain antenna is a more efficient omnidirectional antenna then go for it. Otherwise keep a high gain directional antenna for point to point links and typically you would point the mini beam antennas at each other. However on the latter I am not totally sure of the licence free limitations of doing that in the UK.

Hi Matthew yes Homeplugs can work if your mains was clean prior to its use, but they are horrendous RFI polluters that actually radiate and have field strength nodes (as Ofcom demonstrated to me ) that will cause intermod distortion in audio circuits and digital clock circuits. Non revealing systems might not show this up or have other colourations, but high end equipment will be affected.. It's then a lottery whether you brain/hearing notices or not. The high bandwidth Homeplugs can cause intermod with phono amp, FM tuners and I have seen affect DAB radios and broadband. RFI pollution is a damaging thing. From a network point of vie they are single collision domains at full bandwidth as well and therefore are not ideal for garenteed uninterrupted higher bandwidth media.

If you want proof switch a SW radio on, walk a 30~100 feet away from your house, get someone to do a file tranfer .. What do you hear? Do be careful if you use  earplugs however.

Simon

Simon already answered, but I will give an additional answer . . .

Given all the variables of home construction and layout, buy the antenna from a vendor where you can return it if it doesn't help.  Try it and see if it works   Simple and effective and you need not worry about the theory, just the results (or lack thereof).

Bart, perfect... Myfinal twopennence worth, it the antenna has a load of marketing hyperbole attached to it.. Give it a miss. I would really stick with the vendors own devices... If the vendor offers it .. Try it.. If its a third party be careful. RF at these frequencies is very sensitive to precise impedance matching. If the antenna is not perfectly matched you are bouncing the RF back from the antenna which won't help on transmit.

Simon

Thanks Simon & Bart.

It was the Naim higher gain antenna I was thinking about.

Good suggestion. I'll check it out with my local dealer who have always given me excellent service.

Im sure they would let me have a trial with one to see if it works for me.

Geeh, I thought i raised a simple question on a dito topic

But this debate has gone far above my understanding

Arno