Welcome to Ask the Expert. Hello. Today, we're going to do a quick-fire round. We have a bunch of questions, and I'm only allowed to use 30 seconds or less for each question. What's a two-way speaker? In a two-way speaker you have basically a tweeter and one or more woofers. So the crossover divides the signal into two ways. And what's a two-and-a-half-way speaker? In a two-and-a-half-way speaker, you have typically two woofers that are not playing exactly the same thing. So the upper woofer will play midrange and bass, and the lower one will play bass only. What’s impedance? Impedance is how much the speaker impedes the flow of electrons from the amplifier. So a lower impedance allows more power to go from the amplifier into the loudspeaker. Why does impedance matter? Impedance matters because it determines how much power you're drawing from the amplifier. So a lower impedance will draw more power. But if it's too low, the amplifier might struggle with delivering that power. What's a voice coil? A voice coil is basically what makes a loudspeaker work. It's a coil of wire that, when you put alternating current into it, it will create a magnetic field that goes back and forth between plus and minus. Put that in a magnet and then it moves, which we can utilise to make the speaker move. What's resonance? Resonance is... Any sort of material or space has a resonant frequency – a frequency where it would like to vibrate. So at that frequency you're going to be vibrating more. So in a cabinet, for instance, you want to avoid exciting that resonance because then you're adding frequencies you don‘t want in the sound. Which speakers need space around them? Which speakers need space around them...? Basically, any speaker that‘s designed for it! In the optimal situation, any speaker needs space around it, but you can design the speaker to be like an on-wall or in-wall speaker where you take that into account in the design to try to, you know, amiliate the situation. Is that the right word? What's the word for it? Ameliorate! Ameliorate... Yeah. Why do speakers need space around them? The... The reflections from the walls will affect the sound. So if you have the sound from the speaker hitting the wall and coming back, it will be out of phase with the sound from the speaker. So it cancels out the sound for the speaker itself. So a larger distance to the wall means that effect is minimised. What's a three-way speaker? In a three-way speaker, you typically have tweeter, a midrange and a woofer. You can have more woofers, but essentially the crossover was designed to have three ways of splitting out the sound. Why do speakers have ports? Why do speakers have ports...? In a normal box, the woofer will roll off at some point. You reach some frequencies where it can't really play any lower than that. So to extend the response from the woofer, you're adding a port that has a resonance below that point of roll-off. So you're extending the roll-off of the speaker. What does chuffing mean? Chuffing is normally used in when you're talking about ports. If you have a port that doesn't have like a flare, if it just ends like a tube, like the end of a tube, you will have the air rolling around. It will create some turbulence around those edges and you'll hear that as a chuffing noise. So it's a port noise, chuffing. Yeah... I don't know... It‘s just my ending was kind of fluff. Maybe that's fine. In the big scheme of things. That's how I talk... Do the chuffing sound. No. Do the chuffing sound... Well. It depends on the port. No. What's a crossover? A crossover is a network that divides the signal into typically tweeter-woofer, maybe tweeter-midrange-woofer, into different segments so that the tweeters only tweet and the woofers only woof. What is a first-order crossover? In a first-order crossover, you have a very shallow roll-off of the slopes of that crossover. So you basically have the tweeter gradually rolling into the woofer. So it's actually playing a lot of low frequencies as well. And the same with the woofer would play high up in frequencies. So they have a lot of overlap between them. What's a Hexis? Hexis is a small piece that we have underneath the dome in our soft domes so that we kind of divert the the back waves of the dome into the rear chamber. But instead of trying to dampen them – which you can't do fully – we try to steer them around into the rear chamber instead, where we have much more efficient damping. That increases the resolution of the tweeter. Why do speakers have cabinets? If you didn‘t have a cabinet, the woofers when they're playing, send sound both forward and back. So the sound from the back would kind of 'short-circuit' around and cancel out the sound going from the front. So you basically have no bass. So you have to encapsulate the sound coming from the back of the woofer. That's what you do with the cabinet. Where should I sit when I listen to music? Optimally, the best listening position is in an equilateral triangle. So the distance between the two speakers is the same as the distance between one speaker and you. Maybe a little bit further away than that, and preferably somewhere at the same height of the speaker. Grilles... On or off? Grilles off! It’s basically what sounds best. The grille is mainly there to make the speaker look good and protect the drivers. So in most of our speakers you can remove the grille when you are doing serious listening. What's the difference between active and passive? So active versus passive... In an active speaker, you basically have the amplifier built into the loudspeaker. But what we consider true active, you have an electronic crossover before the amplifier channel. So we have one amplified channel per way of the speaker. So you might have one amplifier driving more woofers, but you will have a separate amplifier driving midrange and tweeters. Was that still below 30-? Do you really listen to glue? Yes, we actually do listen to glue. In our development processes, we do all sorts of measuring and analysing and simulating. But in the end we do listening tests for all of the different components that we can change in the speaker driver – including the glue. What is damping? Damping basically means that when you have some sort of vibration, you try to remove that vibration. By adding, for instance, weight can add damping. So you're stopping that vibration. You can do that in various ways depending on what you're trying to damp. Cut away my 'errs' and 'aahhs' there... Essentially, when you're damping something, you're converting energy into heat. So instead of a vibration that‘s causing sound, then you're converting it into heat so it doesn't make a sound. So you make the sound cleaner, basically. What is MSP? MSP is Magnesium Silicate Polymer. That's the material that we use for essentially all of our woofers and mid-woofers. So it's a material that has a very good balance between lightness and weight and damping. So it's not ringing but has a very natural, clean sound. Why do our tweeters have domes? The dome tweeters that we use in our speakers, they essentially have a very natural sound. The way it disperses sound into the air is quite natural, especially in all frequencies. It's very uniform across frequencies – so it sounds natural both in the high frequencies and the low frequencies, and that makes it easier to do a good crossover with the woofer. Just making a natural sounding speaker. Do you like Christmas songs? Do I like Christmas songs? Would you like my top-three Christmas songs? Chris Rea, 'Driving Home for Christmas'. Because obviously... Bing Crosby 'White Christmas'. (I'm just a sentimental guy.) And Danish one, Mads Langer, 'Stjerneregn af Sne'. No Slade in there, I notice? Slade? No. No Slade... Runner up: AC/DC, 'Mistress for Christmas'. No Christmas without it.