First Ever Website

Qrius: The first website ever made. http://google.com/newsstand/s/CBIw5ejv2jU

Ikea's Smart Lighting gets Smarter

Ikea’s smart bulbs are finally compatible with Siri, Alexa, and Google Home. http://google.com/newsstand/s/CBIw5rn52TU

VPN Setup on DrayTek using L2TP/IPSec

Layer 2 Tunneling Protocol is a secure method of creating a point to point user based VPN. It relies on the Internet Protocol Security standard of encryption which individually encrypts each packet. This is preferable to the main VPN alternative PPTP (Point-to-Point Tunneling Protocol) which has optional encryption which applies to the connection as a whole as opposed to each individual packet making it PPTP more vulnerable.

To configure L2TP on a DrayTek Router go to VPN and Remote Access >> Remote Access Control Setup and make sure that IPSec and L2TP are ticked.

Then go to VPN and Remote Access >> IPsec General Setup. Here we will setup a Pre Shared Key (PSK) to use alongside our L2TP User Name and Password, so type you desires PSK into the fields and make sure the Security Method boxes are ticked.

Finally go to VPN and Remote Access >> Remote Dial-in User and open a user to edit. Input a User Name and Password and make sure that the LT2P box is ticked, the the IPSec Policy is set to "Must".

That's the router configured now we need to set up the VPN connection on a remote computer. The following instructions are for Windows.

Go to Network and Sharing Center and click "Setup an new connection or network"

Then choose "Connect to a workplace" and click next.

Choose "No, create a new connection" and click next.

The choose "Use my Internet connection (VPN)".

Input the WAN IP or DynDNS details of the remote site in the Internet Address field and give the connection a name so that you can identify it in the Destination Name field. then Click create.

Before we can connect for the first time we must first set the security protocols to be used and input our IPSec PSK.
To do this open "Network Connections" by pressing "Windows+X" (Windows 8) or by clicking "Change Adapter Settings" from the "Network and Sharing Center" (Windows 7). Right Click on your new VPN connection and choose properties. You will need administrator privileges to do this.
Click on the "Security" tab and from the "Type of VPN" menu choose L2TP/IPSec, then Click "Advanced settings".

In the "Advanced Properties" window choose the "Use pre-shared key for authentication" radial button and type your IPSec PSK into the Key field then click OK to all of the property windows.

Now you're ready to connect. Simply click the network icon in the bottom right of the screen and choose your remote site from the list. The first time you connect you will be asked for your L2TP User Name and Password. You can choose to save these for future connections or input then each time depending on you security policy.

How to Setup Wi-Fi Like a Pro

These days Wi-Fi networks are all around us, so how do we go about setting our Wi-Fi up so that we can get the best from it?

First a few basic concepts

1. Most Wi-Fi networks use the 2.4GHz frequency as manufacturers do not need to pay a license fee to use the frequency. For that reason the airwaves can get pretty crowded as just about any domestic appliance that is wireless will also be using the 2.4GHz frequency.
2. Some new Wi-Fi devices can use the 5GHz frequency as this has recently been made free to use. At the moment 5GHz is virtually devoid of any Wi-Fi as very few people will have the brand new equipment required to use this frequency.
3. Both the 2.4GHz and 5GHz frequencies are subdivided into channels. There are 12 (13 in Europe) channels in the 2.4GHz frequency and 24 in the 5GHz frequency.
4. Ideally we should avoid overlapping channels. In 2.4GHz only channels 1, 6 and 11 don't overlap each other. In 5GHz all channels are non-overlapping.
5. Each device that transmits a wireless signal is referred to as either a Wireless Access Point (WAP) or Access Point (AP), each device that consumes Wi-Fi e.g. laptop, phone, tablet etc. is referred to as a Client.

There are also two general methods for deploying a Wi-Fi setup, Managed and Unmanaged. Simply put a Managed Wi-Fi network will have a processor which can automatically make performance adjustments to the Wi-Fi transmitters, including channel changes. An Unmanaged Wi-Fi network will stay exactly as originally set up but can have the ability to change channels automatically (though this feature is usually disabled). I am only going to deal with Unmanaged Wi-Fi here as Managed Wi-Fi is quite an in-depth topic.

Ok now let's get down to business.

Setup Unmanaged Wi-Fi

First of all you are going to need some Wi-Fi analysis software, my favorite is inSSIDer from MetaGeek (www.inssider.com), you can find some others here (Free Wi-Fi Tools).

When you run your chosen analyser, you will see  all of the Wi-Fi networks that are in range of your computer; it is best to use a laptop for this as you will need to move around. You will notice that many of the wireless networks overlap and signal strengths move up and down. The more interference there is on a given channel the more the signal strength as perceived by your laptop will fluxuate. Here is where it would help to understand a little about how devices communicate on a Wi-Fi network. If we imagine that the devices are all having a conversation: 

• Those on different channels are having a conversation in a different room, therefore there will be little to no interference from other devices and performance will be best.
• Those on the same channel are having a conversation in the same room but will wait their turn to speak. This will slow down performance but limit interference. This is referred to as Co-Channel Congestion.
• Those on overlapping channels are having a conversation in an adjacent room, with thin walls. They will attempt to speak at the same time and this will reduce performance for both networks. This is referred to as Adjacent Channel Congestion.

A more thorough article on this can be found on the MetaGeek website (Choosing a Wi-Fi Channel). 

Single AP Environment

If you have a single AP environment, i.e. you only have your router transmitting wireless and no other WAP's, then select a channel that is least congested since we don't have to worry about overlap. Dial into your router, choose manual channel selection and choose your desired channel.

Multiple AP Environment

If we have many WAP's then we will need to set each up individually and manually optimise Channels, Security Settings and Signal Strength. This is where it would be best to keep notes so you can refer back later.

Channel Selection

This is where we want to use channels 1, 6 and 11 exclusively. First sit close to the router with your laptop and using your Wi-Fi analyser select which of these three channels is least congested, this will be our starting point. Then start moving from one WAP to another assigning the least congested channel to each one. Try to avoid putting two WAP's on the same channel, if you must put two on the same channel try and select one where the signal from the co-occupying WAP is weakest. Once you have assigned channels to all of your WAPs you may want to go back round ad adjust signal strength to further reduce congestion.

Some WAPs will allow you to select the 20MHz and 40MHz bandwidths, these are great in an single AP environment but in a multi AP environment it will cause interference so it is recommended that you select 20Hz only.

Security Settings

To make your devices or Clients automatically move from one AP to another set the SSID on all of your Access Points to be the same. The SSID (Service Set Identifier) is the name of the wireless network. Try to avoid symbols and spaces as some older devices don't like it; they will still work but my randomly drop their connection.

Next decide on a password or Pre-shared Key (PSK), this should be easy to remember but hard to guess and at least 8 characters long. Some good tips can be found here (How Do I Create a Strong Password?)

Now we need to consider what security protocols to choose. These must set up the same on all WAPs and it is best to use the highest security settings that are compatible with all of your Clients. again MetaGeek have a really good article if you want more information on this topic (Wireless Security Basics). My go-to settings are WPA2/AES and I always switch WPA off.

Other Performance Enhancements

There are several Wi-Fi standards, 802.11 a/b/g/n are the most common. 

• 802.11a has an indoor range of up-to 35m and a max speed of 54Mb/s. It uses the 5GHz range and given recent advances it is not very common to find new devices that are 802.11a compatible.
• 802.11b has an indoor range of up-to 35m and a max speed of 11Mb/s. This the most basic standard to make use of the 2.5GHz range. As most devices these days are 802.11g or better I disable this standard so that i can maintain better speeds.
• 802.11g has an indoor range of up-to 38m and a max speed of 54Mb/s. It is by far the most common standard and makes use of the 2.4GHz range.
• 802.11n has an indoor range of up-to 70m and a max speed of 150Mb/s. This standard can use both the 2.4GHz and 5GHz ranges. To make best use of the speed WPA2/AES must be selected and the security protocol and the 40MHz bandwidth must be enabled. When this standard is used as part of a multi AP environment either setup all WAPs on either channel 1 or channel 11 and avoid channel 6 or disable the 40MHz bandwidth. If you choose to disable the 40MHz bandwidth then the max speed will be limited to 72.2Mb/s.

Some WAPs may allow you to set a Client Limit, this should be left off unless you are in the sort of environment where lots of people may be trying to connect at once (e.g. a Café, free Wi-Fi). Set a limit to avoid one particular WAP becoming clogged up with lots of Clients.

Water + 24Hz in slow motion.

Check out @SciencePorn's Tweet: https://twitter.com/SciencePorn/status/437774437996593152

Living Room Acoustics for Beginners

I would like to start by saying that although I have some knowledge on this subject I am by no means an expert. I covered acoustics whilst at Uni but in a very specific way, aimed purely at room acoustics and recording studios. There is much more to this ‘dark art’ than what I covered, however I do know enough to write this article.

I write this because in my line of work I come across people who claim to know about acoustics, room treatments and in particular how to make a cinema “sound good”. I aim to dispel some of the myths and give a simple guide to ways in which you can go about improving the acoustics of you living room to suite a surround sound system or hi-fi.

So, lets start at the beginning.

How does sound behave in my Living Room?

To answer this we need to consider the room itself and what we have in that room. We of course have four walls, each of which will reflect sound. Very simply two parallel walls reflect low frequencies, these are known as Axial Modes, and are the most powerful and troublesome echos we have to deal with.

The simplest solution is to have no parallel surfaces, however we all know in our living room this is impossible. The ceiling and the floor will always be parallel even if the walls are not. The next best thing is absorption, acoustic specialists will tell you to invest in “bass bins”. They are absolutely right technically, but this is your living room not a recording studio, the best thing to do is add as many soft furnishings as possible, not leather sofas but plush deep carpets, heavy curtains big cushions etc. This will be no means cure the problem, but it will help.

Sound does not just bounce in one direction, it can bounce of at angles. If the sound remains on one plane, i.e. x or y or z then we say these are Tangential Modes. These are made up predominantly by mid frequencies and are less problematic than Axial Modes but can still influence the overall sound in the room. 

If the sound bounces randomly across all planes, i.e. x, y and z then we say they are Oblique Modes and are generally high frequencies. These frequencies generally are so low in power that they dissipate very quickly and are therefore the least problematic. 

This is of course highly simplified, but the basic principles still apply. The best way to deal with problem frequencies around is absorption, things like canvas paintings are good for mid frequencies as well as light curtains, blinds and even some fabric wall papers. The other option is to use diffusers, these scatter the Tangential Modes into the least problematic Oblique Modes, some diffusers can be made to look quite nice. If you want to go down the diffuser route, hunt around but don't forget, you still want your living room to look homely or your wife will kill you!

I wouldn't worry too much about Oblique Modes as they scatter and die out very quickly.

The next question to ask is; does it make a difference where I put my speakers?

The short answer is yes. The long answer is it depends on what speakers you have and what you hope to achieve.

If you are looking at setting out your Surround Sound have a read of one of my previous posts How to Setup Your Surround Sound. If you are setting up a Hi-fi or are creating a listening environment then you need to place your speakers at about ear height and 30 - 40 degrees apart as viewed from the desired sweet spot. You should also bring them away from the wall slightly; if they are too close you get something called comb filtering (for the super geeks follow this link to Wikipedia). The best way to check if you have got it right is to have a listen, if the music sounds muddy move the speakers further from the wall. Another tip; if your speakers sound a little weak in the bass area, put them in corners as this will give a 3dB boost to bass frequencies. If the speakers have a reflex port you can also experiment with putting different kinds of foam inside, this will change the way air flows in and out and consequently how the speakers respond to bass.

As far as setting up the room goes that’s it! Remember to listen to your work as you go and try to use your EQ only for minor tweaks.

How to Setup Your Surround Sound

We’ve all been there, having just bought an all-in-one DVD/Blu-ray with surround sound, complete with speakers, got it home all excited and can’t wait to get it going. Most of us will have just spent a few hundred or even a few thousand pounds on our new exciting purchase, but how do we get the most out of it?

The first thing is to take things slow, don’t rush into anything, make a cup of tea and get out the instructions. Yes guys I know, instructions are for losers, but trust me, if you new system has a handy button for setting up the surround sound you’ll want to know about it.

Once we’re au fait with our new systems features we can start to consider our setup. I’m sure we are all aware that a surround sound system has three front speakers, two rear speakers and a sub woofer, though some may have a pair of side speakers as well. Before we consider placing our speakers we must first consider the room in which they are going. Where do we want the “sweet spot” to be? Will the system be setup around the room or will the room be set be around the TV? For best results I recommend setting the room up around the system.

Now to business...

First lets consider the fronts, assuming that the television is all setup (I recommend 1400mm from floor to screen center by the way) we can place the center speaker. When placing speakers be aware that for best results the tweeters should be at about ear height when seated, generally this will be about 1400mm from the floor (see how that matches the TV?).

The center speaker is where the dialogue comes from and so should be unobstructed or speech will sound muffled. Place this either above or below the screen, this can be hard up against the edge of the screen or a little distance away, but remember if it is too far from the screen then it won’t sound like the actors are talking from the screen but from somewhere else.

Now lets look at the front left and front right speakers, these create the stereo effect. They play a small amount of dialogue, but predominantly are for sound effects. As with setting up any stereo system these should be about 30 - 40 degrees from the center speaker measured from the sweet spot, the further they are placed from the sweet spot the further apart they will need to be. You may wish to adjust the angle of these to get a clear sound at the sweet spot, generally pointing the tweeter towards the sweet spot will achieve this.

Now the rears, these create the surround effect and are only rarely heard. The thing to consider here is that you want the sound to wash behind you, in other words fill the space behind the sweet spot with a wide stereo effect. These can be placed at about 100 - 120 degrees measured from the sweet spot when facing the screen, pointing the tweeters at the back of the persons head. Di-pole speakers are ideal as surround sound rears, however these rarely come in the kits. Mounting a conventional speaker on the ceiling just behind the listening position can create a similar effect, though not many of us will go to that extreme.

The Sub woofer fills in the low frequencies that the surround speakers cannot produce. Sub frequencies are omnidirectional and so it is not hugely important where the sub is placed. Some will tell you to be wary of null points, though for most of us this isn’t a huge issue. The human ear can her frequencies as low as approximately 20Hz, as this has a wavelength of 17m it is unlikely that most of us are going to fit this in our living rooms. However this can still be heard as we feel the vibrations created at these low frequencies, this is called psychoacoustics and we can use this to our advantage. If the sub is placed say under a seat or downward firing then less volume is required for us to hear these sub-frequencies as we will feel them more readily. This has the added advantage of not pissing off the neighbours.

Finally the sides, if you have these in your system i.e. 7.1 they go parallel with the ears of the person sitting in the sweet spot.

Think we’re done? Not quite!

Now we have to set up the levels (relative volume of each speaker) and if possible distances. Setting the distances is easy, measure from each speaker to the sweet spot and put in the values, this helps prevent sound cancellation. When setting levels you will want the centre speaker to be slightly louder than the left and right so that dialogue will be clear, also the rears and sides will want to be a little quieter than the fronts so that they can be heard but are not distracting. The best way to get this all sounding great is to put on a film that you love with lots of surround sound action in and experiment. Personally I do not recommend boosting (amplifying) any speaker channel by more than 3dB, if a speaker is too quiet turn the others down to suit rather than turning the quiet one up. This will help to improve audio quality as sound will distort less as the volume is turned up.