Webinar Replay - Meridian DSP Loudspeaker Design

Introduction Hello, good afternoon! Thanks for taking some time out to join us, as we're gonna take you through Meridian's DSP loudspeakers and the inside story of what goes into Meridian DSP loudspeakers and why we make them. And so a few bits of housekeeping before we get going, I'm going to wait a moment or two to make sure that we've got everybody joining in in the room. So a couple of things... replay. So if you want to replay this webinar... just go back to the same link that you registered and that will then take you to the replay of the webinar. Now there is a short time delay and that's just because of the platform that we're using. Before it really composites the video together and creates it into a replay that you can watch again. So I don't know what time it is with you. It's 3 o'clock in the afternoon here, so I got myself a cup of tea. We've got Des with us, we've been in here all day and we've had a bit of an early start... so if I'm looking a little tired already it's because we did our first broadcast this morning at 6:00 a.m. our time. So I'm guessing if you're tuning in from the states it's gonna be good morning to you... if you're in the UK/Europe good afternoon and if you're in some other place in the world it could be good evening! So other things, points to note... so if at any point your audio drops out... which some people do get. If all your video drops out this is probably most likely because you've got other stuff going off on your computer. So I really strongly suggest that at this moment you want to shut down all the other things we've got going off in the background. So if you've got stuff that's constantly refreshing, like social media stuff, Facebook all those kind of things... if you just shut those down while you're watching this then you can hopefully guarantee that you're not going to lose video or audio. So without further ado we'll get cracking. Now I'm going to be about half an hour... we know that you guys are all busy and so we thought we'd just... you know, get to the meat of it in half an hour and let you get on with the rest of your day. So let's crack on with this slide presentation we've put together for today. Here we go... so Meridian DSP loud speaker design. Why do we do something that's Why do we do this a little bit different from everyone else? So I think it'd be fair to say that Meridian... since since our inception really, it's been about performance and that has stayed true throughout the whole of Meridian's existence. So how do we create the best performance... because what we're really trying to do with a pair of speakers is... or any amount of speakers... is create virtual reality. We're trying to recreate something happening that hasn't... or maybe that has happened but we're trying to recreate it in a way that's convincing to us as people, tuning in and listening to that audio. What does a speaker do What does a speaker do? Let's get back to the absolute basics and think about why we have got speakers. Now speakers... the technology of electromagnets to move pistons with cones on the end of it. That technology is around 100 years old. Yeah sure we've improved the materials that things are made out of, but the physics behind it hasn't really changed massively and the reason that we make speakers is because we were wanting to reproduce sound. Now that sound could be music, your favorite music that you want to listen to, it could be films, movies, it could be live, so it could be something that's being played across the... you know played on radio or across the internet, it could be recording that you want to playback or artistic creations. So it can also be stuff that has been created from scratch. So electronica, those kind of genres... where yes... there's guys in their bedrooms with laptops actually creating music these days... it doesn't have to be from live instruments, so we need to be able to recreate faithfully all of those things and the more accurately we can do it the more convincing it is. Now how does a speaker make sound? How does a speaker make sound Well our hearing systems are reliant on picking up the changes in pressure of waves in the air. So sound waves - what's the best way to really create those sound waves in the first place? Well this is actually moving air. Now the traditional and standard and best way of doing this really... that technology was invented about a hundred years ago which is to have something that's going to vibrate and cause waves in the air and then our ears are going to pick those up and the more accurately we do it the more convincing it is that it sounds like an original event and a natural sound that's actually occurring. Now as far as moving air goes we're gonna use drive Drive units units. So drive units... you can see a picture here of three different drive units. So the small one at the bottom is a tweeter and this is going to do really high frequencies. Now human hearing is 20 Hertz to 20,000 Hertz. Now I can pretty much guarantee you that my hearing won't be anything like 20,000 Hertz anymore. As you get older your ability to hear pitch tends the tail off but that's a story for another day. Your ability to perceive things happening in time doesn't really diminish as you get older it's just your pitch that rolls off. So 20 to 20 kilohertz... we need to reproduce that audio, so a tweeter that will do the high range frequencies really well... a base driver that will do the base frequencies very well. Now if you put base energy into a tweeter you'll blow it up. I know this because I've done this... you create a small fire. It wasn't intentional but yeah... so that will burn the thing out the other way around if you put high frequency energy into a bass driver it just won't really reproduce it and the reason for that is that a bass driver has more mass and more inertia and it's hard to get it to actually move quick enough to produce those high frequencies. So what we do is we use specialised drivers for the high stuff and for low stuff. Now stuff that's in the middle we can also have a third driver, a mid-range driver. So we've got high, mid and low. Now a lot of Meridian designs use three sets of drivers, so that makes it a three-way speaker. Some speakers that we make are a two-way design and that's to say that they have a wide range driver. So our in-wall speakers being a prime example of this. We use a wide range driver which will go from 200 Hertz up to about 22,000 Hertz and then we'll have a base driver which will supplement that to cover off all the low frequencies. S o there's two main ways that we go about doing it. Now there are some speakers and passive speakers out there in the marketplace, which just use one driver... which seems cool because you haven't got to deal with some of the other problems that we've got. But one of the downsides of that is it doesn't reproduce the ends of the spectrums of frequencies very nicely at all. So that's how we move them there... we use electrum, electrical signals and electromagnets to move Pistons backwards and forwards. Electronics So when it comes to putting all those together in this being our DSP 7200 SE speaker we actually need to use multiples of these and we have a tweeter for the treble, a mid-range for the mid and then we actually... in this pod we have two bass drivers and so what has to happen is we have to actually split those frequencies up to send them to the individual drivers and the way that we do that is by using a crossover. Now crossovers... the key to making speakers Crossovers work. Now the the diagram that we've got here... we have just got, it's just a two way design so that means we've got a low driver and we've got a high driver. Just because it's a bit simpler... I'm ready to show you on a on a diagram. Now frequency across the bottom. We've got bass on the left-hand side and we've got treble on the right-hand side. As far as magnitude goes we have got loud at the top and quiet at the bottom. Now the other things to note on here is we've got the high band as the redline... so that is the audio that's going to be going to the tweeter and then we've got low band which is the blue line and that's the information that's going to be going to the bass. The other thing that we've got on here is we've got two green areas. Now the green area on the left-hand side is where the bass driver is only playing bass energy. On the right hand side we've got the treble and we've got a green section there and that's where the tweeter is only playing that treble energy. The centre section is where both drivers are working together to create those frequencies in that range. Now before I got involved in audio I thought that how this would work would be that bass would come along, it would stop and then the next driver would take over. So in this case the tweeter and that would play the next bit of the audio. The problem is actually getting the two interfaces together and so the way that we have to do this in all speakers is to have a point at which the two combine and they cross over together to actually create those audio frequencies in the middle and you can see it's by a varying amount as well. So what we have to try and achieve and this picture here incidentally is a textbook crossover... this is how a perfect crossover would look. Now with analogue components... so we use capacitors and we use inductors to split the frequencies and split the energy so that we can direct energy to the bass driver and energy to the tweeter independently. Now those two split the frequencies and split the energy but we're using passive components over which we have a limited amount of control. The way that you design crossovers with passive components is by using something called the cookbook method. Now the cookbook method... what you do is you will calculate the performance of how this is going to work, you will then have to listen to it and then you keep having to just change and adjust the recipe until you get the kind of desired result. So it's very, very difficult to design a really good passive crossover. You absolutely can't design a perfect one and people have made some incredibly good passive crossovers... there's absolutely no knowing that at all. Now you can imagine how this picture gets more complicated when we have a freeway design and we're having two sets of crossovers in this. So it's clever but it can be done. It's very technological but it does have some major limitations. So one of the limitations of using a passive crossover is that you can also induce phase shifts. So what do we mean by phase shifts? Well it means that the the audio waves are slightly out of time with each other. Now you can imagine if the base... the section on the green... the green section on the left, if that base was out of time with the stuff that's on the right in the green section it wouldn't matter quite as much but the section in the middle where there's two knitted together... if they're at live phase with each other you can have boosts in frequencies and you can have nulls in frequencies as well. So there is absolutely a better way of doing this and this is the way that we do it. We use a digital crossover. Now DSP technology... Digital Crossover digital signal processing technology is used to create a crossover with textbook performance and you absolutely cannot do this with traditional analogue components. We're essentially doing maths to work out what those frequencies are going to be and redirect them appropriately. Now because we can't do this with analogue components what we've decided to do is adopt a system approach. Now what is a system approach? Well it's looking at the bigger System Approach picture, it's looking at the whole thing. Now a great example of looking at the bigger picture is and this is right from from the beginning of Meridian. We've got a pair of speakers downstairs from 1977. Now these are analogue active speakers. Even back then... what we were trying to do was incorporate everything together, so we got control of the whole system. Now I spent some time working in a Hi-Fi shop and one of the skills I used working in the Hi-Fi shop was matching the speakers with the different electronics... because you'd have a manufacture who would make speakers and a manufacturer who would make electronics. The two didn't actually know there were different manufacturers of electronics different manufacturers of speakers and the art was knowing which would go with which to give the kind of results that you want but nobody had control over the whole system they just had their own different parts of the system. So what we wanted to always do is look at the bigger picture, look at the whole system to have control over all of it, take a proper engineering approach to the problem. We've never been really wedded to the status quo here... it's you know, it's quite clear you know even in 1977 having an active loudspeaker for the home was something that was a bit far out. Quite frankly we've definitely been prepared to be different and we're absolutely nailed on to doing what ever achieves the best solution. So if we look at the whole thing and we take into account the engineering solutions and look at what the engineering problem is and understand psychoacoustics we can deliver the best audio. Now a traditional system... what is a traditional Traditional System system? Well, I had a little look on the internet and I was trying to find something that wasn't brand specific and this is what I managed to find, which essentially as far as I can work out is it's got a 1970s low end - what we've got going on here with our passive speakers on the left-hand side we've got a record tape deck, an integrated power amp, sort of an integrated amplifier at the bottom and then something that no self-respecting hi-fi enthusiasts would ever be seen dead with... a graphic equaliser. Now there's definitely been a resurgence in record decks... you know it's quite a lot of fun putting a record on and playing it... there's talk of tapes coming back, people keep muttering about that. I'm not entirely convinced myself... I'm not sure that I want to go back to the days of being on the school bus with the Walkman, the tape coming out, tape spinning out everywhere, having a pencil and winding the tape backing down... I'm out. It's digital streaming for me... it's definitely the way forward. So that's a traditional system's architecture, now what I'm going to do is I'm going to show you how does this wire up. How does this Wiring all go together. Now I'm gonna try and use my best drawing skills with a mouse on the Internet and we are going to hook this system up. So first of all what we're going to do is we are going to hook up the analogue connectors in the traditional LAN speaker. So we've got a passive crossover and that is going to split our frequencies into base frequencies. So the base we connect up to the base driver and then we're going to use the passive crossover to split out the energy to go to the tweeter and that's not going to have any base energy in it. So that means we're safe and we're not going to set off a fire. Now we have got an analogue source and a digital source that we want to play into this speaker. Now I don't know if anyone's tried plugging directly from a line level source into a speake. The results are pretty disappointing. You don't really get a lot of sound out of that, so what you actually need to do is you need to use an amplifier. So we go unsurprisingly from the amplifier into the passive crossover. We could hook the analogue source straight into the amplifier and it would play loud, but we'd have absolutely no control and turning the volume down is definitely a thing I have been told many times in my life, to turn the volume down... so volume control... we need to hook that into the amplifier and then this again. It's an integrated amplifier that we're showing on the screen here, so we've got volume control, we've got a couple of sources... so the other thing we're going to need and you saw it on the front of the SE and it's on the front of many integrating amplifiers... it is a source switch, which makes the world a better place... being able to pick what thing we want to listen to. See, analogue source into the source which source which into the volume control and we're sort of nearly there. So the digital source... how are we going to get that into the system? Now in the modern world you will probably find that most of your sources are in fact digital. So digital is an amazingly good way of transmitting data. It's why we use it for almost everything these days. Mobile phone communications are digital, the internet is digital, we've got digital radio. The reason that we transmit data using digital is the fact that we convert whatever signal it is into a series of Norton ones and these are represented by a high or a low signal on a cable. We send that down a cable and at the other end we can have a receiver chip which looks at that signal and goes is it high or is it low and it can then work out whether it is a nought or 1. Now as the signal goes down the cable it will be subjected to interference , inductance, capacitance and that will change the shape of the wave. So we can imagine that it started off as a very sharp sawtooth kind of signal going down the cable at the end. It will be a little bit more waving, a bit more rounded off, but what we can do is we can actually look at that signal and work out whether it's noughts or ones and we can recompose it. All of the information that's owing that, you absolutely can't do with analogue signals and this is why there's such a market for analogue cables, because analogue signals are subject to the same things that we have with a digital signal. So they're subject to the capacitance of the cable, inductance interference that you might pick up along the way as well. So if we look after our analogue signals very carefully, we can make sure that there's the minimal of effect from all of those things on the signal but what we absolutely can't do is we cannot guarantee that we've got the same thing at the beginning as what we have at the end. So for me, the best way of transmitting any signal has to be digital and you can look at how the rest of the world is transmitting data, then digital is absolutely the way to go. So if you've got a digital source and we want to hook into this amplifier we are going to need something to convert those digits into analogue. So we have a DAC... a digital to analogue converter, now we take the analogue from the DAC into our source switch and then the next thing we need to wire our do is we're going to need to go from our digital source into our DAC and that is that... really that's the picture of how a traditional system hooks together. Now you can see we've got lots of analogue cabling involved in this and for me one of the ironies is really that we've got... you know, this digital source... could be a digital streamer, streaming information across the internet from servers the other side of the world and then the first thing we're going to do in this kind of system is actually convert to analogue and run the risk of it picking up interference. So the other way of doing this is I'd clear this off. Now we'll have a look now at how a Meridian system Meridian System Architecture wires together and why we've got the Meridian system architecture. So first of all you can see that we have got a Meridian DSP speaker and it's got DSP at the heart of it. Now we need something to convert the digital signals from that DSP to get the audio to the base drivers and the tweeters and if that speaker has a mid range too, that as well. So what we need to do is we need to add DAC. Now in a Meridian speaker we have a DAC per driver, so what we'll do is we'll hook these up together now. So we're going cables into these into the tank then once we've got analogue... now the analogue coming out of the DAC isn't going to be enough to drive the drivers so we need amplifiers. So we'll now go to these. These are now analogue signals so one colour... got to make it colour coordinated. Alright, so from the DAC into the amp we've got an analogue signal and then that's being amplified and sent to the base driver. So now we've got amplified bass from that DAC in to that base driver. So we've got a DAC, an amp and the driver, same again for the tweeter. So from the DAC into its own amp and then from the amp to the tweeter. Now the thing about having a design like this means that we don't have any passive components between our amplifiers and our drivers. That's hugely advantageous because what it means is that we're not at any point converting our music into heat because passive crossovers are very inefficient and they spend a lot of their time converting the energy that we wanted to be music into into heat. Now the amplifiers that we have for these drivers are matched... so we can match our amplifiers to our drivers and we know the characteristics of all of those parts. An amplifier and a Meridian speaker they're generally how much... how many watts again Des? Yeah so it's usually around about 100 watts. Now a common question is how many watts is this speaker? Well, in a Meridian speaker if you add up the watts it doesn't seem like a very impressive amount, if I'm being honest but that's because we're using those watts very efficiently we're actually just driving the drivers what we can absolutely tell you is the performance of the speaker we can tell you this, the sound pressure level at 1 meter genuinely measured in our anechoic chamber. That's really important when you are putting experiences together for your clients so if you've got a home theater that you're creating and you want to hit THX reference with our design service, we can actually help you make sure that you're going to hit that level for your climb. So this is the brilliant speaker, now all hooked up together inside of it we've got an analogue source and we've got a digital source and we need to get those in some way into the Meridian speaker. Now we could hook straight from the digital source into the speaker but we wouldn't have any of the convenience of control in a particularly easy way. So in Meridian what we have is what we kind of call a digital / amplifier so it does Digital Amplifier the same kind of thing it appears from the outside to do the same kind of jobs as a traditional preamplifier except it's all working digitally on the inside of it. Now inside the digital preamplifier we have got a source switch. On that source switch hooks up straight to the DSP speaker so we're transmitting your audio information digitally to the speaker and if we've got digital source unsurprisingly we can come straight into the source, switch and then straight to the DSP loudspeaker if we've got an analogue source. So if you've got your record... that kind of phono stage or if you feel like getting re involved in tape then you are going to be able to plug that into a Meridian system as well because in a lot of our products we have analogue to digital converters. Now these analogue to digital converters work at 24 96 so that is so CD is 1644 so that's 65 thousand steps that we can measure the audio in an CD we've a 24-bit and we are more like 11 million 13 or 4. No I don't like to exaggerate things... no, but I mean a lot... an awful lot. So our analogue to digital converters are unbelievably transparent so these really aren't going to impart anything into the signal. We're just going to change that into noughts and ones which we can robustly and accurately transmit. So we're gonna hook our ADC into a source, which then we'll have to go back to the analogue color and hook that into our analogue to digital converter. Right, well that's pretty cool. So we've got the whole system working... the only thing that we're lacking really at this point is volume control. Now how do we do volume control in a Meridian system? We actually turn the amplifiers in the Meridian speaker up and down. The digital audio that gets sent to a Meridian DSP speaker is always sent at full bit depth... we don't do any bit truncation to reduce the volume because that also reduces resolution. So the way that we do this is we actually send control signals to the speaker . So what we'll do is if we've got a digital parameter file with a volume control on it, it will send the control signal to the speaker and then say, hey turn your amps up! Easy! Now the Meridian DSP loud speaker. A lot of them have infrared receivers on them, so if you point a remote control at the Meridian DSP speaker it can turn its amps up but it also needs to tell the digital preamp while it's done. So we have control signals that go back the other way. So at this point we've got digital audio going and we've got control signals hooking up in both directions. So we've made it for the end user absolutely transparent to them as to what's going on. They just turn the volume control up and down on the preamplifier and that will actually control the Meridian loudspeakers' amplifiers. I mean they don't necessarily know what's going on but they get the performance from the system. Now if we were to add... we talked about the Meridian system approach. We can also add a Meridian source. Now a really good example of a Meridian source that we've got coming is the 210 streamer. Now the 210 streamer has got a digital output, so we're going to hook that straight into our digital preamp, into our source which it has also got control signals with it as well so we're going to be able to do exactly the same thing as we did with the speaker. So when we control the volume on the Meridian source... so for example if I'm streaming to a 210 from my phone I use the volume controls on the side of my phone it will send. It won't send... it won't change the volume of the digital audio it'll send the control signals through to the digital preamp and then they'll get sent on to the Meridian DSP speaker. Conversely if I get my remote control out and I want to skip track or I want to change the volume then we send that to the speaker potentially and that will send the information back through the digital preamp and it'll send it back to the Meridian source. So all of the system knows what's going on all of the time and you can control the system from any point and it all acts together as one seamlessly to the the end user. Now having three cables between stuff isn't hugely convenient so what we can do is I'll show you actually how this hangs together. I'll just delete these little cables out here now using the old eraser... leave those out so what we've got is we have speaker link. Now speaker link is our system connection and what we've done is we have used the same thing that pretty much everybody else uses in all of the custom install world and that is a cat cable. So we're using a point-to-point category cable to connect our stuff together. So why is that useful? Well, that means that we can have every signal going down one cable... so we can have the digital audio goes down this cable and the control signals in both ways in both directions go down this cable. And we can do the same from the Meridian source into our digital preamp as well. So most the Meridian digital preamps will also have a speaker link connector on it. So it's called speaker link but it is also for extending the ecosystem and using with Meridian sources and Meridian preamps as well. So that, in essence is how the Meridian system architecture hangs together. So let's move on. Now that we've got DSP because we've decided that that was definitely the way to deal with crossover problems... we can solve other problems as well. Like I said we can have digital connections throughout the system we can also do some cool stuff as well with base protection and base extensions. So you might be familiar with small boom box type speakers. They get an amazing amount of sound out of a small speaker. They do that using DSP technology. Now we are able to do that at a higher level with Meridian speakers. We get bass extension... so we get more bass from the cabinet volume and we also have protection as well, because we have that amplifier driving that driver we know the parts of all of the system and we know how much energy we can put into it to make sure that it doesn't clip. So we know that we can send so much signal to it before it starts clipping. Now why is that important? Well if you're in the moment of watching a movie or you're in the moment of listening to some music the speaker stops clipping and making odd noises that takes you out of that moment. So it's really really important that we can do that... it also means that you know, your speakers are gonna live longer. Speaker position. So you may be familiar with the concept of boundary gains so this is where if we put a speaker against the wall or we put it in a corner then we're gonna get an increased amount of base from that speaker. Now to compensate for that... because we understand that you can't always put speakers in places where you absolutely like to... real life gets in the way of your speaker placement usually. So we have boundary compensation. So what we can do is if you're putting it up against the wall, we've got a setting so that we can just cut away some of that base so that you get an even response from the speaker. So it delivers the same level of performance as if it was sucked out in the room. We can also do tone controls transparently because we're doing that digitally and we're using DSP cleverly to do with the bass and the treble. We can also do balance controls in a way that you cannot do with anything else, so classically balance control works that if I've got a speaker that's closer to me it's gonna be louder... so I need to turn it down. If i've got one that's further away I'm gonna have to turn it up. So this appears to me to be the same volume. The other thing that we are missing from that picture is the fact that if this one's closer the audio is going to get to me quicker than the one that's further away... it's going to get to me later. So what we can do with Meridian DSP speakers is we can actually adjust the timing. What that does and you'll have to have a player a pair of Meridian DSP speakers to actually experience this is you can be off the center of where the two speakers are and you can steer the audio image to the location that you're sitting in. So if you have got Meridian speakers... have a play around with that. It's a really powerful function. I drive my wife mad with it because I will tend to sit on sofa and then adjust it to where I'm sitting and not her which is possibly unfair of me. But anyway, it's a really cool feature. The other thing that we have is EBA. Now if you haven't heard of EBA... EBA is Enhanced Bass Alignment and what this allows us to do is to align all the frequencies that are coming out of a speaker. So a cabinet has a thing called group delay. Now this is just inherent in speaker design that you have this problem called group delay. What it means is that different frequencies take different amounts of time to get out of the speaker and what we can do with DSP is we can realign all of those. We can get the bass frequencies moving ahead of the mid and treble frequencies and can ensure that all of those things are delivered to you as a coherent way. The upside of that is it means that it sounds more natural and it sounds more convincing and if we're trying to create virtual reality then that absolutely helps create the whole picture. Well if DSP is so bloody marvelous why Why DSP doesn't everyone do DSP? Well the truth of the matter is lots of people do. Portable speakers like I was saying about... sound bars, another great use of DSP is to get more out of the... you know... smaller units that they're in. Cars! Loads of DSP used in cars and we know about that because obviously we do the engineering for Jaguar Land Rover. So plenty of people do, we've just been the pioneers of using it in speakers that you can install in your home. So DSP solves everything. No it Does DSP solve everything absolutely does not solve everything at all... you cannot cheat physics with DSP. It can't perform a miracle and it's always much better to start with a good solid design. We know how to make amazing cabinets. We might be known as, you know, as the DSP speaker company but actually we have to make an amazing cabinet because we don't want any... we don't want a cabinet joining in with a conversation, we want the drivers to do all of the speaking. We have less control over how a cabinet would react, whereas we've got huge amounts of control over those drivers that are in the cabinet. So one of the tests that I tend to like to do, is just... you know, the old knuckle test on top of a speaker, just to see how inert it is. So that, you know that then it's just going to be the speaker that's doing all the work... the speaker drivers. So better to start with good design, good amplifiers and good electronics. So we need... you know, good DSP. In good DSP... you know DSP I think is a term which is just thrown around willy-nilly. Digital signal processing, that's all it means. You have to know how to implement that... you have to know how to use that tool, because in the wrong hands you know it can have disastrous effects. It's a heavy weapon it needs to be used carefully and intelligently. So we've got high quality digital to analogue conversion, we've got excellent amplifiers, we've got class-leading cabinet design and we use high performance drive units, because again, we can't cheat physics. We have to put something good in there in the first place. So all those bits come together to give the kind of performance that we're trying to achieve. So in conclusion... why DSP loudspeakers? Well, we take a system approach which Conclusion means we've got control over the whole eco system. We can use standard cabling so we use the cat type of cabling. You run power to your speakers and you run a cap cable to the speaker and that works point-to-point, delivers that pristine digital audio and it delivers the control systems as well. I personally would say it's a logical way of doing it if you stand back and look at what we're trying to achieve, a look at the engineering solution - this is absolutely a logical way of solving this problem and the thing that is has been at the heart of Meridian since the very beginning is performance getting back to that original performance... creating that emotional connection with the content for people to enjoy. So I hope you found that useful and interesting. Now Housekeeping just to fullscreen. So yeah I hope you found that interesting and useful and I don't know if you've had any... Des have we had any questions coming in the chat? I appear to have completed the answering of questions already so that's good, that saves some time afterwards. Now, if I do it for anybody that has missed the beginning... I was doing a bit of housekeeping. If you watch this again it's no problem. There will be a replay of this available if you just go back to the same link that you got to this webinar with you, it will then take you to the replay. So that's really easy. The other thing is that I'm going to do a small amount of shameless plugging... it's in my contract or some such. So we have got... so if you're tuning in in the UK right now we have got UK event coming up which is Meridian Live... where we'll be showcasing obviously Meridian stuff but also our distributed brands that we do in the UK. So this should be Barco projectors, we distribute DT screens and cinema acoustic treatment systems as well. So if you're interested in that have a look on our events page which is www.meridian-audio .com, forward slash events. If you go on there, that's got all of our upcoming events. In fact... so it even has things such as our next webinar. So if you enjoyed this one which I hope you did... I've enjoyed talking to you about it. Anyway, our next webinar we're gonna be talking about DSP in-wall and in-ceiling loudspeakers, so talking about the architectural range of loudspeakers and that's going to be on Wednesday the 27th of March. Again, if you go to meridian-audio. comm forward slash events you'll find the link there and you can go through and register for it. So we're gonna be doing and continuing this series of webinars. The plan is to do them at the end of every month on a Wednesday. Now the other thing that I'd quite like to know as well from you guys is whether this has been a good time for you or not. But we'll come to that in a second so finally if you're in the UK we're gonna be exhibiting at EI Live - Essentail Isntall in Farnborough and that is on the 30th of April - 1st May. Again, it details it on our events page. I'll be talking there about streaming and how you can use streaming and multi-room audio to create more profit for your business. So if you're in the UK welcome along to that... so I have probably rabbited on enough... so it's been really great talking to you and I'll look forward to talking to you again next month about the same sort of time. So we'll look forward to seeing you then!