The best questions we hadn't answered - Until now!
When we do Ask the Expert episodes, we have our experts on borrowed time (they gotta get back to developing new technologies for our speakers). So, once in a while we don’t have enough time to answer every question. But, we still hang on to them in case we get the chance to steal away Jan, Otto or Andreas. Now that time has come.
This episode's questions
Watch the entire video above or skip directly to the question you find interesting by clicking the links below:
We kick off this episode by asking Otto a question from Michelle Wang: “Are some speakers better for movies and others for music?”
The next question is from Joe Sbonbetti. Joe wants to know why Dynaudio speakers are light (but are they though?).
We get this one quite often. This time is from Krishna: “What are ohms?”
The last question is from Boy: “Why don’t you use waveguides?”
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We want to thank all of you who posted questions on our Facebook posts. We didn't have a chance to answer all of your questions, but we'll keep them in reserve - just in case.
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All the best,
Otto and Christopher
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Christopher Kjærulff, Content Manager: Hello, my name is Christopher. And we are at the High End show in Germany. With me I have Otto. We've already done some LIVE this… the past couple of days. This time we are trying to catch up on some of the great questions that we got in the past for Ask the Expert but just didn't have the time to answer. So, Otto, let's jump right into it and start with the first one. This one is actually a more recent one but I think it's a great question from Michelle and she wants to know if there are any speakers that are fundamentally better for movies and some that that are just better for music.
Otto Jørgensen, Product Manager: Yes it's a very popular question that we get quite often actually. But when you think about it what is a movie - a very big part of movies is music. So, if you don't play music well how are you going to play movies well. If it's not good at playing music it won't be good at playing movie sound - movie soundtracks. An interesting thing is, actually, if you have a surround sound system and you remove the cable to the centre speaker, you’ll only hear the left and right speaker, you will notice that you're basically hearing music and sometimes a few sound effects. Most of that it is actually music. So if the left and right speaker doesn't play music well, I wouldn't call it a good speaker for movies. So that being said, there are low frequency effects in many movies that has higher requirements of the output in the lower frequencies than what the demands are in music. So that's why you more often see a subwoofer in a movie setup compared to music setups.
Christopher: But fundamentally it's about getting a great pair of speakers.
Otto: On a fundamental level, the job is the same. It's about conveying the audio. It is about playing back the audio that's in the track. Whether or not that is music or movies doesn't actually change the loudspeakers job it's more important how large is the room how loud do you want to play that would make some differences to the compromises that that you're eventually going to take but the basic requirement of a loudspeaker is the same. To playback sound.
Christopher: Then it's all about going back to - to the basics I guess and figure out how big is my room? How far from the TV or the music am I? and just getting all that sorted out and perfect…
Otto: Yeah… Yeah…
Christopher: Great. The next question is from Joe and he's wondering why our speakers are so light as he writes.
Otto: Yes. Well, our speakers have very different range in weight and if you look at our Evidence or Consequence but also our Contour line, if you have a Contour 20 which is a semi-big bookshelf speaker. But it's still more than 20 kilos. That's a very heavy speaker. So some of the ranges are more heavy than the others depending on the trade-offs we are taking. We are always trying to get very high quality drivers into our speakers and sometimes have to make compromises to get the best possible drivers into a cabinet. So the higher the price the more we're able to put more bracing into the cabinets and they give a bigger more dead cabinet. So yeah…
Christopher: But what are the - what are the advantages of having a more… or a heavier cabinet?
Otto: Basically what you want is to avoid the cabinet from adding any sound. The drivers are playing and that puts force into the cabinet. If the cabinet is vibrating that is in itself making sound and that's a distortion to the sound - so you want to get rid of that distortion.
Christopher: And the weight helps…
Otto: …and the more dead the cabinet is the less distortion you get. And a dead cabinet is generally more heavy. You can also make it with different kinds of materials. But actually sometimes it can be more beneficial to tune the resonant frequencies in the cabinet rather than simply making it heavier. It can be a bit of a better trade-off to figure out a way to make it less intrusive to sound without necessarily putting more money into making it heavier, if we're trying to reach a specific price point.
Christopher: So what I hear you say is that it also really depends on what kind of loudspeaker you're developing - if you make it lighter, heavier or put bracing in or out…
Otto: Yes it's always a deliberate decision. It's not an accident where we are ending up. We're always looking at the end result. Like when we were discussing drivers; We're not trying to make the best possible drivers, we're also not trying to make the best possible cabinet - We're trying to make the best possible complete loudspeaker! And the trade-offs are some sometimes different but the goal is always the same.
Christopher: …and it is deliberate choices?
Christopher: Yes and another question that we get quite often is people asking what they… About what kind of Ohm they should go for with the amplifier, I think.
Christopher: But I want to reframe it a little bit and then ask you to start by kind of explain to me what it is.
Otto: I'll do my best this can be become a very big topic and could be a topic for other experts so I'll try to keep it brief - but in short if you have lower impedance, if you have a lower Ohm number, you'll draw more power from the amplifier. So that makes the loudspeaker sound - play louder. Simply because you are drawing more power from the amplifier. But that also requires that the amplifiers actually capable of sustaining that power and delivering that that power. And also there's also a very big difference to how this impedance curve actually works. Because this is where you're looking at a number but that numbers actually an average. So if we're saying we have a 4 Ohm speaker two 4 Ohm speakers can behave completely different and be a completely different load to the amplifier. If you have an impedance curve that goes various - a lot of up and down - you can have a curve that goes down to 2 Ohms in some frequencies but still the average is 4, then it will be a really difficult load to the amplifier. Our speakers generally have a very smooth impedance curve so we don't have large dips. For instance, the Special Forty is 6 Ohm.
Christopher: And that makes it easier?
Otto: Yeah that makes it a lot easier. The Special Forty is a 6 Ohm in average but the lowest dip is 4.8 and that makes it quite an easy load - because these dips where you have very low impedance curves - that's actually what is difficult to drive for the amplifier.
Christopher: Can you say anything you mentioned now that our Special Forty is 6 Ohms. Are we… Do we try to go for a specific Ohm number or is it really what suits the loudspeaker the best?
Otto: In general we try to balance it so that -like you said- get us a smooth curve. We have in the past generally tried to reach 4 Ohm impedance because that is a good balance between how much you're actually drawing out of the amplifier and what most amplifiers are still able to drive - provided it's a smooth curve. So that is actually a fairly easy load for most amplifiers. What we've been seeing is that some types of amplifiers - digital amplifiers sometimes struggle, if you have even close to 4 Ohm loads. So as soon as you go much lower than 4 Ohms they can have problems. So it can be an advantage to go slightly higher. But again as I said, it is an average so and just historically you would always call it a 4, 6 or 8 Ohm loudspeaker but many of them in reality - maybe it is 5.2 so we are calling it six because it's just the way it has been rounded up historically… So if we wanted to do it completely accurately we would be showing all kinds of curves which most people wouldn't understand anyway that's why we're basically putting it down to this basic level - most of our loudspeakers actually isn’t the problem for the amplifier to drive. We basically have to look at put more power if you want to play it loud. But most amplifiers don't actually struggle with…
Christopher: …And as you said they're easy to power because they have the smooth impedance curve.
Otto: Yes… Compared to other products.
Christopher: Let's move on to the next one. It's from Howie. It’s a guy we have talked quite a lot with on Facebook so it's nice to be able to answer a question here in live… for him. He's already checked out the Special Forty and he's curious to know if we're going to use any of the drive units in other loudspeakers.
Otto: Yes, in general we don't really comment on unannounced products. But you can say we have already announced that the tweeter in the Special Forty - which we're calling the Esotar Forty - actually is a unique driver for this speaker. So the current plan is not to use that in other products and we're not expecting to change that. For the woofer, who knows?
Christopher: Who knows? Great… Last question for you Otto. It's from Boy Griffioen and he wants to know why we don't use a waveguide.
Otto: Yes that's a interesting question because the answer actually is that we do use a waveguide. It's just a very small one.
Christopher: Could you start by explaining it to me what it is?
Otto: Good idea. Well, if you look at a tweeter like this - what we have - the domes basically playing the sounds. Then you have the shape of the plate around - around the dome. And that shape is what we basically call a waveguide. So the shape of this guide is crucial to the sound. It actually makes a very big difference to the sound how you make this shape. If you put the dome further back and you have a more steep shape then you kind of pull the sound in. You will put - send the sound more directly forward so less sounds to the sides - then you'll have a louder sound to the listener. You can also steer the sound if you don't want as much sound up and down. You can basically steer the sound in the direction you want and increase the SPL along the way.
Christopher: So we actually use waveguides…
Otto: We use waveguides. If you look at the front plate of ours - this shape here which looks really simple - that is acoustically a waveguide. And this shape is actually - if you change the shape it changes the sound of the tweeter quite a lot and we have been experimenting a lot with this shape and this is the one we've been using for a long time. All of our domes have the same shape. That shape physically dictates the shape of the waveguides. So this is the waveguide that works for this particular dome. So if we change the dome, we would also have to change the waveguide. But if you look at our products whether it's from the smallest Emit speaker or the Evidence Platinum. All of them have exactly the same shape around the dome, so that's because it's not a matter of better or worse - it's a matter of this acoustically works with this kind of dome for what we are trying to achieve. Some may choose differently to get like higher SPL for instance - we believe that have a balanced sound between the direct sound and the sound directed to the sides is what gives the most accurate sound quality in the end. And we're not actually striving to get the highest possible SPL. We want the correct natural sound at a reasonable SPL. So Yeah.
Christopher: Is it… Is it unusually small waveguide or just…
Otto: Don't know if it's unusual. I guess that depends on what you're comparing to. This is a physical property that basically most people have it - just think that most people don't think of it as a waveguide because it looks so small and many waveguides can be very big. In the end, if you look around the High End show you can see waveguides that are several meters for a similarly small driver. It is also a waveguide. It is just a completely different design and a complete different different choice. So it gives a different aspects. This means even if it's half a centimeter it is still a waveguide. One interesting detail is that if you look at the consequence which is basically an evolution of a very old design - but the original came out in in 1983 - that actually uses a different wave guide that is more like a traditional waveguide but that's a bit deeper and there’s a difference but that's basically a question of going in a different direction where the consequence is a celebration to the old Dynaudio design. So that's why we've never changed it in that one. But currently we believe this is…
Christopher: …this is the best design for our purpose.
Otto: This is also why officially the Evidence Platinum is our top-of-the-line speaker. Not specifically why. One of the points where the Evidence Platinum with the - consider that’s a newer better design - although the Consequence does have its fans.
Christopher: I think that we have to stop now. Otto… It sounds they want to do a live demonstration of the Special Forty and…
Otto: That’s why we are here for.
Christopher: Yeah it is. It became a little loud in here so… But the good thing is we got all the way through the questions - so thank you so much for joining us again and thank you for joining us as well…