Buchardt Audio S400

[Mads Buchardt]

It will be almost a year since Danny Ritchie said he was designing a coaxial. Maybe you should contact him. http://gr-research.com/

Coaxial can be very good, that im well aware of. But they have one big drawback witch was the main reason we went with a waveguide. When doing a waveguide design with the highest resolution robot measurement scanner available. You notice how sensitive a tweeter actually is to just the smallest changes in the waveguides geometry. This is also the main reason 99% of waveguides are not constructed properly/optimal. It really requires equipment and know how to make an proper waveguide. And this equipment we used for the development was completely new technology that the engineer Kasper needed to rote his own software for in order to utilize so many measurements.

The drawback that he hated was that the contour response on a coaxial is constantly changing as the "waveguide" is moving around the tweeter. And some other things as well that i cant quite remember (im not an engineer). But it also has tons of benefits as well, so its not say that coaxial are bad at all! we would possible do a coaxial design in the future as well.

But like its always in audio, benefits usually comes with drawbacks as well. There are no such thing as the perfect speaker design ;-)

 

[maty]

...The drawback that he hated was that the contour response on a coaxial is constantly changing as the "waveguide" is moving around the tweeter. And some other things as well that i cant quite remember (im not an engineer). But it also has tons of benefits as well, so its not say that coaxial are bad at all! we would possible do a coaxial design in the future as well.

Therefore, I think, the best coaxial are the small ones, up to 5.25" like mines.

 

[maty]

...And this equipment we used for the development was completely new technology that the engineer Kasper needed to rote his own software for in order to utilize so many measurements.

https://www.google.com/search?q=Kasper+Buchardt+Audio

-> https://6moons.com/audioreviews2/buchardt/1.html

When I asked what model he intended to send, "a pair of s300 MkII. It was developed by Kasper Raun, a previous Dynaudio engineer. He is the man behind their new Xeo series, Focus Xd range and many more. He recently quit there to work for Primare... We use Danish drivers developed by Ulrik Smith, the same guy who brought us the popular ScanSpeak Revelator drivers. In fact, our warehouse is in the same building as theirs so we work closely together."

Kasper Raun Andersen (Dynaudio)

[Czech] https://www.hifi-voice.com/profily/osobnosti/923-kasper-raun-andersen-dynaudio

to English: https://translate.google.com/transl...y/osobnosti/923-kasper-raun-andersen-dynaudio

 

[Ron Texas]

Our production is in China actually. Though its a half Danish factory, so its not an cheap factory to manufacture at, but the quality and experience is fantastic there!. Being there and seeing what brands they manufacture for, was an absolutely shock to me! Brands that you would NOT think is made in China is actually made there. The rules of this "made in" are completely broken if you ask me. We could do it as simple as just slap the drivers in the speakers here in Denmark and legally call them "Made in Denmark".

B&W is manufactured in China except for the uber expensive 800 series. Still, the price seems high for a small 2-way with off the shelf drivers. Perhaps the box is built like a tank.

 

[jtwrace]

It will be almost a year since Danny Ritchie said he was designing a coaxial (the driver). Maybe you should contact him. http://gr-research.com/

That's not a good idea.

 

[617]

Mads, I'd be willing to do independent testing on your waveguide. Just send me two of them ^_^

 

[kaka89]

I have a question about Buchardt audio's view on how speaker directivity help in room. On Buchardt's website it claims that good off-axis response will help the speaker to perform better in room.

"Since most research suggests that what we hear in-room is estimated to be around 12% direct sound (from your speakers), 44% Early Reflections (from your room), and 44% Sound Power (how the sound loads your room), we strive to create solutions that'll deliver predictable, consistent, and excellent results both on and off axis – regardless of the living space!"​

My question is, this view is exactly opposite to what Dutch & Dutch's cardioid waveguide design. Here is what they D&D said on their website:

"8c’s adapt to the room they are in and can be placed (very) close to room boundaries without losing performance.​

​

To achieve this (adapt to the room), 8c’s combine a proprietary waveguide tweeter with an acoustic cardioid midrange, boundary-coupled bass drivers and active room matching. The result: superb acoustical reproduction in any room,."​

My understanding is less off-axis energy will reduce room reflection. May I know how Buchardt perceive about the different of two approach?

 

[617]

I have a question about Buchardt audio's view on how speaker directivity help in room. On Buchardt's website it claims that good off-axis response will help the speaker to perform better in room.

There are two acoustic goals which you generally have when you're designing speakers with attention to directivity. The first is to shape off axis-response so that it matches the axial response. The idea here is that a speaker which sounds totally different off axis will create a reverberant field which has a different tonal response than the direct response. Generally, the problem is that there is little upper treble in the reverberant response, and a big suckout around the crossover region where two drivers with different directivity are transitioning to each other. This is the problem with almost all audiophile speakers - they sound 'dark', or 'hollow' despite having a linear axial response. There are a number of conventional solutions - small midrange driver, elevated response at the crossover frequency with the instruction that the speaker be listened to off axis. Dipoles also bring more treble energy into the room.

The second goal is to avoid early reflections. When reflections are sufficiently close to the speaker, they are heard at effectively the same time as the direct sound. This is generally regarded as a Bad Thing, and the explanations for this are numerous. David Griesinger, a famous acoustics guy, believes that these early reflections impede our ability to distinguish between vowel sounds, making listening to a teacher speaking into a blackboard very difficult. The current technological trend for avoiding early reflections is to use a waveguide, which narrows treble response (while also smoothing off axis response, accomplishing goal #1 described above). Other solutions - use a big woofer for the midrange (see GedLee). Dutch and Dutch do something a bit unusual which is to use a cardioid loading of the bass. Cardioid loading is sort of like halfway between dipole and monopole response - you get some off axis cancellation, without the rear radiation. I think Genelec is doing something similar.

So to summarize, we use these technologies to make the off axis response both smooth and narrow. Buchardt's speakers are smooth, and narrower than a conventional speaker. Dutch and Dutch are smooth, but also very narrow.

 

[kaka89]

Thank you for your explanation. Wondering what does conventional speaker's directivity graph looks like.
By looking at the graph, Buchardt is smooth but can't eliminate early reflections (a lot of off-axis energy below 500Hz), I wouldn't consider it as "room friendly" as it claims.

To be directivity is probably as important as frequency response, sadly only very few speakers has such measurement.

 

[andreasmaaan]

David Griesinger, a famous acoustics guy, believes that these early reflections impede our ability to distinguish between vowel sounds, making listening to a teacher speaking into a blackboard very difficult.

It's worth noting that there's also plenty of evidence that early reflections enhance speech intelligibility. On the run now but will post links later.

I think Genelec is doing something similar.

They are firing the woofers through slits at the top and bottom of the baffle to increase the distance between the acoustic sources, narrowing the woofers' frontal dispersion over a relatively narrow bandwidth to bring it into line with the midrange waveguide. Unlike cardioid approaches, however, there is no significant impact on rearward polar response.

 

[617]

Thank you for your explanation. Wondering what does conventional speaker's directivity graph looks like.

This is what a conventional speaker looks like. This is the horizontal directivity sonogram of some cone/dome 2 way, I don't know which. The narrowing of response at 2.0khz is at the crossover, where you're transitioning from a narrow dispersing cone to a wide dispersing dome. In this case it looks like they're using a steep slope crossover, probably 24db/octave. When you transition two very different drivers with a steep slope, while still trying to keep the 0 degree response linear (red) this is what you get.

Think of a passive 2 way box speaker with a flat baffle. This is what they all basically look like. The narrowing at Fc is associated with reduced energy in the power response as well, meaning that at 2khz, the amount of that energy in the room is less compared to other frequencies.

The waveguide of the s400 and other similar speakers widens the lower part of the tweeter response so that it blends with the woofer at the crossover frequency. It also makes choosing a crossover frequency a bit easier in my experience; you can go a bit lower or higher depending on the characteristics of the drivers and how loud you want it to play.

 

[andreasmaaan]

This is the horizontal directivity sonogram of some cone/dome 2 way, I don't know which.

This is an extremely bad example though! Plenty of conventional speakers with a directivity mismatch, but much less pronounced than this

The waveguide of the s400 and other similar speakers widens the lower part of the tweeter response so that it blends with the woofer at the crossover frequency.

Typo I think? It narrows the lower part of the tweeter’s response to better match to the woofer’s response around the crossover point.

 

[617]

Typo I think? It narrows the lower part of the tweeter’s response to better match to the woofer’s response around the crossover point.

My mistake Andreas. As for how bad this looks, you are correct that this is unusually bad, but it's also not that unusual. I'm sure the vertical response is even worse!

I really need to look into cardioid midbass. I have no idea how to start.

 

[andreasmaaan]

My mistake Andreas. As for how bad this looks, you are correct that this is unusually bad, but it's also not that unusual. I'm sure the vertical response is even worse!

The verticals are likely worse, but the same would be true of any waveguide-controlled tweeter. And really, that directivity mismatch you posted is the worst I’ve seen! Where did you find it?? But yes, it can get pretty bad when no thought is put in...

I really need to look into cardioid midbass. I have no idea how to start.

It’s not too hard I have a good practical guide I can send you, just need to find it. I lost all my bookmarks a couple of weeks ago so it may take some searching...

 

[Ron Texas]

Has anyone laid hands on one of these? It appears a lot of thought went into the design. However, cabinet integrity is a major part of the value calculation.

 

[Cortes]

Has anyone laid hands on one of these? It appears a lot of thought went into the design. However, cabinet integrity is a major part of the value calculation.

Then, go to the European made Genelec

 

[Ron Texas]

Then, go to the European made Genelec

Are their cabinets rock solid? (Unfortunately the nearest place to audition them is 250 miles away.)

 

[Cortes]

Are their cabinets rock solid? (Unfortunately the nearest place to audition them is 250 miles away.)

Most rocks would dream to be as solid as the Gennies. You'll change of hobby before seeing the gennies broken.

 

[Ron Texas]

Most rocks would dream to be as solid as the Gennies. You'll change of hobby before seeing the gennies broken.

That's a cool video. I had no idea the cabinets were made out of cast metal.

 

[617]

It’s not too hard I have a good practical guide I can send you, just need to find it. I lost all my bookmarks a couple of weeks ago so it may take some searching...

It wouldn't be Kimmo Saunisto's website would it? What I'm looking for is a measured design using a reasonably normal hifi type driver. Really interested more in cardioid for 100-500hz more than anything.