Interview with Dynaudio chief engineer Stephen Entwistle

[abdo123]

So where is this proven that “you need to alternate quickly, and seamlessly. Otherwise you would NEVER be able to tell which product is subjectively better”?

That’s just like your opinion man.

Give me a set of speakers for 2 weeks. Then give me another set of speakers for the next 2 weeks. I could tell you which pair I thought were subjectively more enjoyable.

I don’t need to eat a mouthful of entre then a mouthful of main course and continue with alternating mouthfuls to know whether I preferred the entree or the main. I can tell you whether I enjoyed a meal more at one restaurant than the restaurant I went to a week earlier. I couldn’t say “the level of salt on the palette in restaurant 1 was slightly more pronounced than restaurant 2”. But I could say subjectively which I preferred.

Their are many here who seem more interested in measuring speakers than enjoying music. You don’t need to listen to 2 pairs of speakers side by side to know whether you enjoy the sound of one of them.

I can't think of a situation where i would want a meal based on the method A instead method B, method B is just far superior and is meticulously detailed.

We're talking about manufacturers that make their money and living off making speakers, i rather that person takes that job seriously instead of being another hobbyist listening hours on end while scrolling down their phones because 'that's the typical use case'.

 

[Schollaudio]

People need to remember Dynaudio built devices in the mid 80s with distortion levels many companies are just starting to match and only a few are consistently beating. That excludes prosound devices of course.

 

[MattHooper]

In stereo reproduction it is always a compromise, closer you get a smaller (less envelopment) but sharper representation.

That’s weird; my experience is exactly the opposite. The closer I sit the more immersion
but less sharp/dense imaging.

 

[abdo123]

That’s weird; my experience is exactly the opposite. The closer I sit the more immersion
but less sharp/dense imaging.

People are going to describe the experience differently, but i can understand what you mean if when you sit closer and the speakers would border your visual boundaries.

Either way the closer you sit to speakers the more like headphones and less like the room they will sound, that could mean different things to different people.

 

[MattHooper]

People are going to describe the experience differently, but i can understand what you mean if when you sit closer and the speakers would border your visual boundaries.

Either way the closer you sit to speakers the more like headphones and less like the room they will sound, that could mean different things to different people.

Yes and I'm sure it will depend on the speakers/room.

I'm able to slide my sofa easily forward and backwards (it's on coasters) and I often play with seating distance. I actually just nudged my seating distance closer again. When closer I get a more nuance in to the recorded acoustic and a sense of being more immersed in the recorded space (even if artificial). However when further away I get more sharply focused and dense imaging, and a livelier sound (which I attribute both to becoming slightly more on axis to the speakers and the contribution of room reflections). It's always a trade off between a more lively energetic sound and more subtle timbral/spatial nuance.

 

[SpanishPassion]

On one hand, a narrow directivity means hearing less of the room and more of the recording... on the other hand, the reflections can create a wider soundstage that can be pleasant.
It's a hard life

But if you are listening near field, is this point about reflections still valid?

Give me a set of speakers for 2 weeks. Then give me another set of speakers for the next 2 weeks. I could tell you which pair I thought were subjectively more enjoyable.

I want to emphasize that my statement was not about whether you can subjectively tell which set of speakers is better after listening to them for weeks separately.

It was about a valid development methodology for a product. It implies developing substantial improvements that vast majority of your customers will perceive as an improvement comparing to the previous version of your product or to your competitors.

So in order to develop an improvement you absolutely have to not just listen to a speaker, but also to compare it against a reference, be it the previous version or your competitor speakers. If you don't do this, you may be just running in circles instead of improving your product, because some of the changes you make may improve it, but others may actually make it worse without you noticing, because you think it sounds better while in reality it just sounds different.

As an example, https://www.audiosciencereview.com/...io-core-47-review-professional-monitor.25113/

This speaker is just a mix of right and wrong design choices which result in a product that's clearly inferior to its competition.

So I don't know how Dynaudio actually performs their listening sessions, but I wouldn't be surprised if they do exactly what you described and it results in what I have described.

Their are many here who seem more interested in measuring speakers than enjoying music.

Actually in order to notice narrow directivity you don't have to measure it, you can hear it perfectly. And this affects my enjoyment quite negatively.

Not necessarily a deal breaker, but you also have to take into account that Dynaudio doesn't seem to have the flattest frequency response either even on-axis, so the question is what do they honestly offer that's better than their competition?

Like "we know how to do speakers, good according to some other opinions, but we are doing models from 80ies just because we have a company image and our marketing deprtment doesnt's allow us to"?
I think even accepting something like this is not very comfortable for decent engineer.

Typically, audio companies are just trying to make profits. If their products still sound "right" it's nothing more than a luck.

You are absolutely right, of course.

Then on the other hand, it's not like Dynaudio doesn't do some innovation. They do DSP, they do wireless active speakers, their speakers are honestly very convenient to use... So after the news about the Jupiter I hoped they will definitely improve their sound.

People need to remember Dynaudio built devices in the mid 80s with distortion levels many companies are just starting to match and only a few are consistently beating. That excludes prosound devices of course.

This is great (no irony). I just hope their directivity and frequency response would also be so good that the other companies would be just starting to match them.

I'm not against Dynaudio, it's a brand that I really liked (and still like despite my very mixed feelings at this moment) and I hope they would make great products. But if they don't deliver, I'd rather change the brand. I don't want to be a fanboy who buys products just because of the logo.

 

[lowkeyoperations]

Yes the room will have a big effect. when moving your sofa you are sitting in a different frequency response due to nodes and nulls (unless your room is a really well treated studio space, but even then).

They can have a big impact on how the rest of the frequencies are perceived. A node will often mask your experience of higher frequencies.

 

[lowkeyoperations]

“So I don't know how Dynaudio actually performs their listening sessions…”

Therefore you cannot conclude that their listening tests are not a valid methodology. To suggest so is simply assumption based on bias.

 

[Alice of Old Vincennes]

We do need to be aware of design process to be able to judge it. I'll address only first two.

1. If you listened what Stephen said, he mentioned Jupiter system. You can find pics of it on the web. It is a measurement system that uses over 30 microphones mounted on an arc picking up log sweeps. So they can sample 30 measurements at 30 different angles in one sweep. Of course they spend only 30% of design time doing measurements. Measurements are straightforward job, precise and simple to do. Our ear/brain combo, on the other hand, is much more complicated. Few minutes listening to the familiar music and i can hear tonality with regard to frequency amplitude response. But i need at least a week or more of listening to be able to hear if there are flaws that aren't too obvious.

2. Sound power is not one of those things that can't be measured but can be heard. He says that Sound power is more important to them than directivity curve - and it matches my experience. Directivity curve shows if a loudspeaker will react good to equalization. Sound power shows all of the sound produced by the loudspeaker in all directions which is averaged to a single curve. If there weren't things that can be heard but can't be measured, no company would conduct listening to their products or blind A/B tests. They would just make a crossover in simulator, measured it in a chamber to confirm it and ship the loudspeakers to dealers.

Unmeasureable sound power? Sounds like a crock.

 

[Ilkless]

After hearing this interview, as a Dynaudio customer, I can say, that I am disappointed.

Unfortunately, I didn't take notes while I was listing to it, but what I got from it essentially is the following:

1. Dynaudio doesn't really follow a proper engineering process or methodology when designing the speakers. This is evident by the statement that they spend around 30% of their time doing the measurements and 60% of their time doing subjective listening in the listening room. He didn't describe any methodology that they follow when performing this subjective listening, so this activity probably is just wasting time when it comes to a tangible outcome.
2. They claim that there are characteristics of the speaker that can't be measured and can only be heard. As an example, he gives something like the sound power that speaker produces in the room, I didn't really understand it. Apparently, this is supposed to affect the sound quality a lot.
3. Poor vertical directivity is intentional. Apparently when it's that way, there are less reflections from the floor, so the sound on axis is better. This decision is derived directly from their subjective listening "tests", not from the measurements of any kind.
4. According to him, you can't really hear the "anomalies" in the vertical directivity. Well, I don't know about the "anomalies", but I sure can hear that it is extremely narrow.
5. In general, the Dynaudio's (narrow) directivity gives better image, according to him. I assume that in some rooms this can give you less reflections, but seems to be very room-dependent.

Overall, what I got from this interview, is that we shouldn't expect any significant improvements from the upcoming Dynaudio speakers. They don't want to address the technical issues like poor directivity. Even on-axis, I don't think they want to have a very flat frequency response, because apparently a luminary that performs the subjective tests there doesn't like it that way.

Personally, I don't see any reason to buy those speakers anymore. They are not bad, they are surely reasonably flat on-axis, but given that they have these technical drawbacks which are built-in intentionally, this is just wasting money when compared to competition. And that's a shame, because their speakers are extremely convenient to use and Dynaudio as a company clearly can produce state of art speakers.

I wonder why did they invest in Jupiter (which I think is a very fine tool) if they rely on it 30% of the time when designing a speaker? Seems like a rather poor investment to me.

Narrow vertical directivity can indeed reduce reflections but not when it is the haphazard result of driver cancellation and varies wildly with frequency. The way they spin a deficiency as an intentional feature based on a plausible explanation, but one that requires significantly higher performance in the metric in question to be justified, perturbs me. Strikes me as quite disingenuous.

 

[Zvu]

Unmeasureable sound power? Sounds like a crock.

Do read what you've quoted, please.

 

[Alice of Old Vincennes]

Do read what you've quoted, please.

Help me.

 

[fluid]

After hearing this interview, as a Dynaudio customer, I can say, that I am disappointed.

Unfortunately, I didn't take notes while I was listing to it, but what I got from it essentially is the following:

I think you may have interpreted some of the things Stephen Entwistle said in a way that I didn't after listening to them.

The amount of time spent on measuring vs listening does not place a value on the data that is obtained from either. The real question of which he considered more important wasn't asked only how much time was spent. Perhaps to someone who has never designed a speaker the questions seem the same, but they are definitely not.

A measurement rig like Jupiter costs a lot and for Dynaudio to invest that money means they value the measurement data. The fact that they chose to build an arm with 30 odd microphones on it rather just rotate one speaks to how time efficient the process would be.

Whenever any engineer speaks the truth and says that there are things that came out of listening that weren't evident from measuring it sparks the objective subjective debate off when it really shouldn't. There is no company of any standing that designs speakers only through measurements. A speaker is a big bunch of compromises that have been chosen one way or anther. At some point they have to be listened to to see if it all worked out the way it was meant to, and if not, the change, measure, listen process will start again. Due to the variability of program material it is inevitable that it takes quite some time to evaluate a speaker properly in listening tests before being released to market.

There are still many things about a speaker that are very hard to tell even from a full suite of measurements. It doesn't mean that the answers aren't in there, more that so far no one has worked them all out and published them.

Sound power curve contains data on amplitude and some data on directivity of a loudspeaker, but a directivity curve has no data about real amplitude of a loudspeaker just a hint if it can be equalized or not to obtain a good sound power reaponse.

I'm not sure I understand what you mean with this.

"The directivity factor (index) spectrum is typically defined as (ten times the base-ten logarithm of) the ratio between the on-axis power spectrum and the average power spectrum,1 which is approximately computed by averaging measured power spectra over many directions [2]."

https://www.princeton.edu/3D3A/Publications/Tylka_3D3A_DICalculation.pdf

In a flat on axis system the DI is pretty much the inverse of the soundpower, it might be easier to look at one or the other to interpret features of the speaker but they are tied together closely, one exists because of the other.

 

[tuga]

Unless they're very different I don't think i would be able to form an opinion that i would personally trust.

I on the other hand find quick AB of a single speaker a worthless exercise.
I find that for preference assessment both speakers have to be adequately positioned in my own room and long term listening with known, diverse musical programme is paramount.

 

[lowkeyoperations]

^exactly

 

[Schollaudio]

But if you are listening near field, is this point about reflections still valid?



I want to emphasize that my statement was not about whether you can subjectively tell which set of speakers is better after listening to them for weeks separately.

It was about a valid development methodology for a product. It implies developing substantial improvements that vast majority of your customers will perceive as an improvement comparing to the previous version of your product or to your competitors.

So in order to develop an improvement you absolutely have to not just listen to a speaker, but also to compare it against a reference, be it the previous version or your competitor speakers. If you don't do this, you may be just running in circles instead of improving your product, because some of the changes you make may improve it, but others may actually make it worse without you noticing, because you think it sounds better while in reality it just sounds different.

As an example, https://www.audiosciencereview.com/...io-core-47-review-professional-monitor.25113/

This speaker is just a mix of right and wrong design choices which result in a product that's clearly inferior to its competition.

So I don't know how Dynaudio actually performs their listening sessions, but I wouldn't be surprised if they do exactly what you described and it results in what I have described.


Actually in order to notice narrow directivity you don't have to measure it, you can hear it perfectly. And this affects my enjoyment quite negatively.

Not necessarily a deal breaker, but you also have to take into account that Dynaudio doesn't seem to have the flattest frequency response either even on-axis, so the question is what do they honestly offer that's better than their competition?


You are absolutely right, of course.

Then on the other hand, it's not like Dynaudio doesn't do some innovation. They do DSP, they do wireless active speakers, their speakers are honestly very convenient to use... So after the news about the Jupiter I hoped they will definitely improve their sound.


This is great (no irony). I just hope their directivity and frequency response would also be so good that the other companies would be just starting to match them.

I'm not against Dynaudio, it's a brand that I really liked (and still like despite my very mixed feelings at this moment) and I hope they would make great products. But if they don't deliver, I'd rather change the brand. I don't want to be a fanboy who buys products just because of the logo.

The directivity of a 6.5" two way crossed at 2000-2500 has a very good chance at good directivity, frequency and phase response for household listening with minimal engineering.

 

[Ilkless]

The directivity of a 6.5" two way crossed at 2000-2500 has a very good chance at good directivity, frequency and phase response for household listening with minimal engineering.

Not without a waveguide or very unusual drive units like the Bliesma tweeter.

 

[ctrl]

But wouldn't directivity affect this direct sound field much more than the total sound power?

I'm sorry, but I just don't see what is the benefit of this approach. I guess having a narrow directivity can have some benefits, but so far I don't see any data supporting this assertion.

You have misunderstood me there. Below the critical distance, the direct/free field is dominant. In an ideal free field there would be no reflections and the sound character of the loudspeaker would be determined solely by the listening axis - e.g. the on-axis FR when the loudspeakers are directed towards the listener.

In this case (ideal free field) the directivity of the LS would not matter at all, only the FR on which the listening is done would play a role.

In an ideal diffuse field, the sound source direction could no longer be determined, since all reflections would be equivalent. Since this can never be realized in a normal listening room, there will always be a mixture of direct and diffuse field at the listening position, with the diffuse field being dominant over wide frequency ranges (see also the calculation of the critical distance).

So you need a measure that describes the behavior and the sound character of a loudspeaker at the listening position including the room reflections.
This is where "sound power" SP and "predicted in-room amplitude response" PIR come into play. In the calculation of these two curves the radiation outside the on-axis FR of the speaker is included.

Historically, the SP curve has been used in loudspeaker design for a very long time - I come from the DIY field and there the SP (calculated from measurements +-90° horizontally and, not always, +-90° vertically), has been used for over 15 years.
The PIR reproduces the behavior of the LS at the listening position even better. Whereby the weighted average of 44% SP also flows into the PIR (see CTA-2034a definitions).

Why is SP and PIR important?
It helps to explain why, for example, Amir found the Wilson-Audio tunetot tonally not bad and with a little EQ even good.

Especially with the PIR, you can see that the LS does not show sudden or wide humps (when we ignore the ugly bass hump).
SP/PIR can help explain why even poorly designed speakers can still sound good in the listening room if they are tuned properly with SP or PIR in mind.

The better a loudspeaker is designed, the more the on-axis, listening window LW, SP and PIR curves converge:


For a loudspeaker that is nearly SOTA, the various curves are nearly parallel (ignore FR >15kHz) because the radiation is so uniform that the off-axis FRs hardly change. You can then focus on small details, for example, and use different XO designs to strongly influence the vertical radiation around the crossover frequency. Same LS with two different XO:

In both cases on-axis FR (black), LW (green), SP (blue) and PIR (orange) >700Hz are nearly parallel (DI is red).

However, since very few loudspeakers are SOTA, it is important to look at SP/PIR, or to consider these curves when designing and tuning a loudspeaker, and to value a smooth SP/PIR response more highly than a flat on-axis frequency response - at least that is what Stephen Entwistle probably wanted to say, and with which I strongly agree (I am more skeptical about other statements in the interview).

It is important that a uniform SP/PIR response is present regardless of wide or narrow directivity.

With a narrow directivity it is usually easier to achieve a uniform SP/PIR response and the curve shows a steeper drop.
Therefore horn loudspeakers can often be corrected quite well via EQ (if the directivity is even, which the DI shows us). Example without and with EQ:


Source

That was another annoyingly long post, but it try to show that not every LS with a (slightly) wavy FR has to sound bad.

Conversely, you can say that a classic 2-way LS (6.5'' woofer and 1'' tweeter) in a normal cabinet with classic XO around 2kHz with an optimally flat on-axis FR will not sound optimal in a normal listening room (too aggressive at high SPL).

 

[markus]

I on the other hand find quick AB of a single speaker a worthless exercise.
I find that for preference assessment both speakers have to be adequately positioned in my own room and long term listening with known, diverse musical programme is paramount.

Not really. Sighted listening is full of bias. Also, our auditory memory is pretty bad. This has been shown over and over again. Toole, "Sound reproduction" for a primer. Or this example from Olive: https://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html

If you want to compare two different sound fields in an objective manner you have to design a blind listening test that controls all possible bias. That's pretty hard to do. Probably involves doing binaural recordings.
But don't throw out the baby with the bathwater and expect that what you're proposing above would be worthwhile. I mean it is what audiophiles are doing and have been doing since the beginning of audio reproduction. It's just human to believe our individual perception would let us experience the world in an objective way. Hardly useful though if one wants to learn something objective about the real world. That's why we haven't made as much progress as we could have in the last 100 years or so in the field of audio reproduction. More or less it's all just been driven by business interest and listener confusion.

So where is this proven that “you need to alternate quickly, and seamlessly. Otherwise you would NEVER be able to tell which product is subjectively better”?

That’s just like your opinion man.

No, it has been scientifically proven over and over again how cognitive bias renders sighted listening tests, or any sensory testing, rather useless – see my avatar. Just because you're not aware of the research that has been done this doesn't mean it wouldn't exist. Your following statement shows the full extend of confusion which is common amongst "golden ear" audiophiles:

Give me a set of speakers for 2 weeks. Then give me another set of speakers for the next 2 weeks. I could tell you which pair I thought were subjectively more enjoyable.

I don’t need to eat a mouthful of entre then a mouthful of main course and continue with alternating mouthfuls to know whether I preferred the entree or the main. I can tell you whether I enjoyed a meal more at one restaurant than the restaurant I went to a week earlier. I couldn’t say “the level of salt on the palette in restaurant 1 was slightly more pronounced than restaurant 2”. But I could say subjectively which I preferred.

Their are many here who seem more interested in measuring speakers than enjoying music. You don’t need to listen to 2 pairs of speakers side by side to know whether you enjoy the sound of one of them.

Speakers are sound reproduction devices. They are not part or should not be part of a recording and the process of making artistic decisions. You're confusing the pizza oven with the pizza.

 

[markus]

That’s weird; my experience is exactly the opposite. The closer I sit the more immersion
but less sharp/dense imaging.

Depends largely on the recording. Different miking techniques have a huge impact.