- It's not fair.
I told you my wifi was fixed.
It worked perfectly for a week.
Then right after we uploaded this video,
it made a big liar out of me.
I hate it when that happens.
Intermittent problems are the worst.
Thankfully, now I have this.
That's right, three cheap wifi adapters and a USB hub.
Okay, admittedly, it's not that impressive.
But the software behind it is.
Through the power of spectrum analysis and packet capture,
we're gonna be digging deeper than ever
into what causes wifi to randomly lose performance
or drop out, and even though it wasn't our intention
we're gonna be exposing some of the BS marketing
that Sony uses to sell their wireless home audio systems.
BS marketing that I unknowingly spread
when I did a sponsored video on the very product
that has been causing me all this trouble.
Just like I'm about to spread this segue to our sponsor.
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(upbeat music)
- First up, I need to show you guys how I got bamboozled
into thinking that I had the solution last time.
Every wifi card is constantly looking for wireless networks.
It can do this passively
just listening for different networks
to announce their presence
or it can do it actively by sending out a probe request
and then looking at the replies that come back.
Surprisingly, the active method
is actually a lot more power-efficient
so that's what most devices do by default.
That means that when I was going around
pointing my Wi-Spy antenna
at anything and everything in the house,
the wifi card in my laptop was happily probing away
in the background blasting out enough power
that even my very high-tech directional antenna
was able to pick up the signal.
The only thing that is hard to explain at this point
is why sometimes it didn't seem to pick anything up,
'cause that's what led us to believe
that the source of the interference
could be malfunctioning light switches.
I mean, I should have dismissed this theory
as quickly as I dismissed the 2.4 gigahertz microwave.
Only a grossly malfunctioning 900 megahertz device
should be capable of emitting
any kind of 5 gigahertz interference, like so defective
that it wouldn't even pass compliance testing.
But in fairness to me,
with everything I've been through with these switches,
nothing would surprise me at this point.
- [Phone Representative] That is correct.
- It's still my bad though.
I should have dug deeper.
And a good place to start digging
would be the hidden wireless SSID
that we determined is associated with the base unit here
on Sony's HT-A9 wireless audio system.
Last time around, we took Sony at their word
when they claimed that they were using
wireless sound specification 4.0 to deliver wireless audio
to the speakers distributed around my family room.
But looking back on it, if both the freebie wifi analyzer
on my phone and the paid Chanalyzer software on my laptop
saw a hidden wifi network,
then maybe wireless audio specification 4.0 is just wifi.
To check our theory,
we'll be using MetaGeek's Chanalyzer again
with the Wi-Spy Adapter and we'll be looking for
that familiar shape that we know is the Sony base unit.
It looks like it's around channels 44 and 48 today,
although that does tend to vary from day to day,
which is part of the reason for my problems.
We can see though there's a hardware address
associated with this, so let's remember that
as we peel back the next layer of this problematic onion
with a new piece of software from MetaGeek called Tonic.
Wait, that's Wireshark.
Tonic.
Tonic works by capturing spectrum information
also from the Wi-Spy, but at the same time by capturing
all of the wireless network traffic
that is bouncing around in the house
using off-the-shelf USB wifi adapters.
Following MetaGeek's recommendation,
we went with three of these Edimax EW-7833UAC units
that retail for about $50 each.
Each of these has three antennas
and supports three by three spatial streams,
which means that they're able to take advantage
of multi-path transmission
to significantly improve throughput, and more importantly
it means that it's extremely unlikely
that they're gonna miss anything
when we start capturing traffic.
Just for transparency,
we're probably gonna do a little bit of movie magic here
and show you guys a mixture of live and pre-recaptured data.
We got a ton of audio dropouts and other artifacts
when we were testing this out a few days ago.
But I think it's a law of the universe
that the second to camera starts rolling,
your product demonstration will fail.
All right, the first thing that we're gonna do then
is limit our view to the 5 gigahertz spectrum.
Then we're gonna click on Show Hidden.
And sure enough, there's a hidden network
with the Mac address that we noticed in Chanalyzer.
That is our base unit that I hid
on top of the other base unit.
Get it?
That's a subwoofer.
Sorry.
Anywho, when we click on that network,
we get a list of access points, which is just one,
because even though I did gesture
to one of my RUCKUS APs, they are not the problem.
It is entirely this.
It's on channel 44 and it has 5 clients,
which makes sense because we've got 4 wireless speakers
around the room and then also the subwoofer.
When we click on the access point,
we get some more detail about it
and we get some graphs and charts
that summarize the traffic that's being transmitted by it.
If it can show us all this information about the AP's radio,
that means according to our contact at MetaGeek,
there is pretty much no doubt
that Sony's wireless sound specification
is just a typical wifi 4 network,
rather than some special technology they've invented.
Though, I mean that does kind of make sense,
since getting some new wireless technology certified
for 5 gigahertz globally would be a monumental task.
But then from my point of view,
they should just say it's wifi.
That would've made troubleshooting this a lot easier
from the start.
Looking at the airtime distribution now,
it's interesting that basically all the traffic
sent out by this base unit is broadcast,
rather than being sent to a particular client.
What that means then is that this base unit
is just blasting wifi signals out into the air
for any device that's listening without any regard
for whether the signal actually gets to all of the speakers
or some of the speakers or the speakers and something else,
and then it's just up to each speaker to take that data
and sort it out into which channel it's supposed to play.
I suppose every speaker just gets all the data
for every channel, which might explain
some of why they are not able to make efficient use
of the spectrum.
I mean, I can kind of see why they took this approach
since they need to keep latency low enough
to keep audio synced to the picture.
But clearly it's not working.
A little weird, but not super weird yet.
Yet.
When we switch over to the client list here,
we're gonna see a pretty high percentage
of remitted packets.
Remember, these are going from these guys
back to the base station.
This Retry column here means
that when the speakers are sending some kind of data
back to the base unit, maybe it's timing information
or related to the room correction, I don't know,
whatever it is, it has to resend that data quite often
because the base unit isn't receiving it
on the first attempt.
Normally, you would wanna see
less than about 10% retransmission on your wireless network
and less than 2% if you're dealing with something
like voiceover IP.
Anything higher and you're gonna start to notice
an impact on performance.
In this case though,
I don't think that's the source of our problems,
because if we click through
and look at the number of packets
being sent by the speakers,
it is such a tiny amount of traffic
that even if all four of them
had to reattempt 100% of the packets they sent,
we'd only be looking at a few hundred packets
spread out over 10 minutes.
I don't think that's the issue.
So then, we've determined
that this Sony surround sound sound bar
is using plain boring old wifi
and that it is basically just spewing audio data out
for the speakers to pick up and turn into sound
with very little communication going back
from the speakers to the base unit.
Just the occasional acknowledgement and little bits
of what Tonic classifies as quality of service data.
That still doesn't tell us what's wrong.
We're gonna have to go even deeper.
Let's take this data and put it into Wireshark,
which is a free network capture and analysis tool
that will let us go through each individual frame
to try to determine what's happening.
Wireshark uses the exact same data as Tonic,
but it's not quite so user-friendly.
Where Tonic organizes things into networks
and graphs and charts that we can easily explore,
Wireshark is more like standing in front of a fire hose
of raw data.
In the default view, we get every bit of traffic
from every device on every network
that our wireless interfaces can see
over the same 10 minutes that we were looking at in Tonic.
I think it might take 10 minutes
just to scroll to the bottom of this thing.
Nobody wants to watch me do that, right?
Luckily, Wireshark has a powerful filter system
that we can use to turn the fire hose into,
well, a smaller fire hose.
We know we're interested in what's happening
on channels 44 and 48,
so we'll start by narrowing our view down to those.
Okay, we're on the right track here.
It looks like almost all of the transmissions we see here
are multicast data coming from the base unit.
It looks like it's sending out a couple of frames of data
every 2 or 3 milliseconds.
We'll just scroll down a little bit,
see if there's anything interesting.
Ah, right here it switches the channel of the multicast
to channel 48 and if we look in the Delta column,
we see that it was 74 milliseconds
since the previous transmission.
That is pretty significant.
We mere mortals don't typically perceive LEGs
shorter than 8 to 12 milliseconds,
so when we see the deltas of 0 to 3 milliseconds
leading up to this switch,
those would pass us by totally unnoticed.
74 milliseconds, though?
That's a lot.
What's weird though is that there is nothing else happening
on these channels at this time,
so while it's normal for a wireless network to jump around
from channel to channel in order to reduce interference,
if there's nothing else going on, why does it switch?
Maybe we'll see something if or when it switches back.
At 3996, it goes back to 44 with another 76 millisecond LEG.
There's also a huge jump in the frame number here
so that means that there's a bunch of other traffic
that we're not seeing because of our filter.
Let's turn our filter off for a minute.
There's a bunch of traffic on other channels at this time,
but it looks like it's mostly access points
talking to other devices and mostly on channels
that are at the other end of the spectrum
from the Sony base unit.
Let's change up our filter again
and see if there are any other long delays on our channels.
Let's say anything more than 50 milliseconds.
Wow.
Some of these are more than 100 milliseconds,
a 10th of a second.
That is a massive delay, which could totally explain
the audio dropouts that we got when we were testing.
So now, okay, we're gonna take this
and we're gonna jump down to a period
where we know that the audio had serious problems.
And what in the world is going on here?
This thing is changing channels
more than once a millisecond, and it looks like, yeah,
it's sending out more data more often
so it goes from sending 2 frames
on one channel every 2 to 3 milliseconds,
to 4 or more packets
on 2 channels as often as every millisecond.
Let's check the whole lower end of the 5 gigahertz spectrum
just in case something else is making it behave.
No, there's nothing,
like, there's bits and pieces of other traffic,
but it's not much and I'm not seeing anything
on 44 or 48 other than the Sony gear,
which means that our Ghost Hunter episode
looking around for the source of the interference
was pretty close to a real episode of "Ghost Hunter",
meaning we were looking for something that didn't exist
and misinterpreting the data we collected.
The true culprit then is just Sony,
who has no reason to be shifting channels
or sending out more frames like this,
at least not one that's obvious to me
or to our friends at MetaGeek, unless it's ghosts.
No, I'm just kidding.
Which means that unless Sony re-engineers
how this thing works, I'm going to keep having this problem
and so will many other owners of this wireless setup.
I'm gonna have to append both the last video that we did
searching for the source
as well as the sponsored video that we did on these,
because obviously I don't want anyone buying them now.
I wanna give a massive shout out to MetaGeek though
for providing the tools we needed to diagnose this today
as well as their software.
We're hoping that our labs team
is gonna make excellent use of that relationship
in the coming months and years.
The path forward for me then is what?
I guess just to do what so many of you suggested
last time around and put an AV receiver in here,
and then find a wife-approved way of running wires,
I guess, over to the surrounds.
I'm gonna miss the room correction from these Sonys,
that's for sure.
Like that was the cool thing that sold me on them
was A, they sound really great,
and B, you could kind of put them anywhere
and you get a really convincing surround experience.
But I mean, who knows?
Maybe in the grand scheme of things, that sucks too
and I'd be better off with some basic distance correction
and EQ from an AVR.
With some help from the labs team,
we're gonna find the answer to that, and while we're at it
hopefully we can shed some light
on who has the best mainstream room correction.
'Cause darn it, I wanna stop fighting with this
and I want to do it right this time,
like I do my segues right, like this segue to our sponsor.
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- If you guys enjoyed this video,
why don't you check out the first time
we worked with MetaGeek?
It was a long time ago,
but it was a really good look at their Chanalyzer software
and how it can be used
to find non-wifi sources of interference,
which if you'll recall was what I thought I was looking for.