Why Synergy horns?

In another thread I was asked, if I would provide more details about my speakers, so I thought why not?

I have played on active 4 way horn systems since 2016. First iteration was front loaded bass horn, midbass horn, tractrix midrange horn and tractrix tweeter horn. I worked nicely, with all the attributes associated with well implemented horns. Clarity, dynamics, realistic live sound etc.

However some problems will arise, with such horns. First of all, the center to center distance between the different horns is big, compared to the crossover frequencies. We need to be within 1/4 wave in distance at x-over for a seamless transition. For instance if you x-over from the midrange horn to the tweeter horn at 3 KHz the c-to-c distance would have to be 340/3000/4= 2.83 cm (1.11 inch). This is virtually impossible with "normal" horn configurations. This problem rears its ugly head, at every x-over throughout the audio frequency range. As frequency decreases, the wavelengths gets bigger, but so does the horns in the specific bandpass and then c-t-c also increases. It is a linear problem, that can't be solved with the regular approach, aka stacking horns on top of each other. This creates interference problems and lobing in the vertical response curves, that will color the reflection from floor and ceiling. Secondly a large column of vertically stacked horns, will push the sweet spot (SS) further back, for the horns to be perceived as more coherent and integrated, with one another.

But the biggest problem is that almost all horns beam with increasing frequency, it's their way of nature so to speak. What that means, is that the off-axis FR will not be similar to the on-axis FR. This translate into a poor power response, which is not considered a good thing, in terms of best sound quality.

Luckily we can circumvent all these problems with clever engineering and have our cake and eat it too, so to speak. Enter the Synergy horn.

 

You are welcome if you ever come to Denmark But these Synergy horns are getting more attention within the DIY society, so maybe you can find someone near your location. Or look up Danley's new speaker for the home market The Hyperion.

You mention Danley has a new horn system for the home market which I find very interesting. The pro audio world has much to teach us! Can you send me a link to the Danley product for the home? Thanks for your insights. DSP, especially to address bass room modes in an incredibly powerful tool. Also for more finite time domain correction for complex multi-way loudspeakers.

 

Can you send me a link to the Danley product for the home?

You need to contact Danley at https://tomdanley.com/contact-us/ and get a password. But there is lots of info on the web on The Hyperion.

 

I had the chance to hear an expensive system the other day. Air Tight ATM-3211 Mono Power Amplifier alone is 80.000 $. Speakers are DIY from quality drivers. Stage Accompany ribbon tweeter is 1.500 $ each. Can't remember the turntable but it is around 20.000 $ in total. Took the owner more than 1 one year to fine tune the passive filter, using expensive components. The room is well treated with absorbers and a thick carpet on the floor. The picture below is an older one, the system I was listening to, was setup a bit different.

The sound, well it was ok, but nothing special. Why? First and most importantly, the sound was not neutral, due to room interaction and perhaps filter implementation. So what I heard was a skewed FREQUENCY RESPONSE and some of these faults could easily be remedied using EQ and get a much better result.

 

Please allow, an objectivist, for a second to be a bit subjective, to describe what I’m hearing in front of my synergy horns.

Like most, I find it a bit difficult to express words reflecting the sound that I’m hearing. But I can best describe it as neutral, precise, dynamic, which render it realistic and lifelike. The benefit from being a controlled directivity phase linear point source, allows them to have high intelligibility even in a large room, so they “sound the same” over a large span of distances and listening positions.

The CD horn gives a reduced early reflection pattern, resulting in a precise soundstage and pinpoint imaging between the speakers. What arrives at the LP is much more like the original wave front leaving the horn, than a wide dispersion loudspeaker can provide. There simply is less splash from walls and other surfaces so SNR is higher. If you have any doubt, please measure your loudspeakers response from the listening position and evaluate how much it has changed, compared to a nearfield measurement.

The Synergy horn reduces distortion over other designs because the bass and midrange goes through acoustic band pass ports, which reduce upper harmonic distortion. This gives an unmatched clarity and detail resolution, almost like electrostats, leaving most other speakers sound colored and distorted.

All these clever engineering attributes that goes into a synergy horn, allows the listener to gain more insight into the reproduced recording. Remember that your room will leave a sonic imprint, superimposed on all sound coming to your ears. Taking more of your own room out of the equation simply leaves more of the recorded venue ambient sound to your ears.

I any practical home situation these horns are limitless in terms of SPL and with dynamics only horns can deliver. This brings well recorded music to life with musical engagement and reveal how radically most speakers, even large ones, miniaturize the dynamics and scale of recordings.

Reaching this level of neutrality and precision render every CD production, to stand out as different from one another, revealing their true nature, still leaving bad recordings listenable.

To sum up the Synergy horn, it is having the imaging precision as a small 2-way monitor, the clarity and transparency like electrostatic speakers and the dynamic and lifelike sound of horns.

To my ears the Synergy horn is a paradigm shift, but call me biased

 

Reaching this level of neutrality and precision render every CD production, to stand out as different from one another, revealing their true nature, still leaving bad recordings listenable.

This is exactly how I feel about my system as well and it's a good place to be !

Now are there any aspects of your system that you feel could be improved upon ?

 

I don't believe that a system/room can't be improved upon, but diminishing returns, so in reality, nothing really Maybe get bass below 20 Hz, working on that at the moment.

 

Please allow, an objectivist, for a second to be a bit subjective, to describe what I’m hearing in front of my synergy horns.

Like most, I find it a bit difficult to express words reflecting the sound that I’m hearing. But I can best describe it as neutral, precise, dynamic, which render it realistic and lifelike. The benefit from being a controlled directivity phase linear point source, allows them to have high intelligibility even in a large room, so they “sound the same” over a large span of distances and listening positions.

The CD horn gives a reduced early reflection pattern, resulting in a precise soundstage and pinpoint imaging between the speakers. What arrives at the LP is much more like the original wave front leaving the horn, than a wide dispersion loudspeaker can provide. There simply is less splash from walls and other surfaces so SNR is higher. If you have any doubt, please measure your loudspeakers response from the listening position and evaluate how much it has changed, compared to a nearfield measurement.

The Synergy horn reduces distortion over other designs because the bass and midrange goes through acoustic band pass ports, which reduce upper harmonic distortion. This gives an unmatched clarity and detail resolution, almost like electrostats, leaving most other speakers sound colored and distorted.

All these clever engineering attributes that goes into a synergy horn, allows the listener to gain more insight into the reproduced recording. Remember that your room will leave a sonic imprint, superimposed on all sound coming to your ears. Taking more of your own room out of the equation simply leaves more of the recorded venue ambient sound to your ears.

I any practical home situation these horns are limitless in terms of SPL and with dynamics only horns can deliver. This brings well recorded music to life with musical engagement and reveal how radically most speakers, even large ones, miniaturize the dynamics and scale of recordings.

Reaching this level of neutrality and precision render every CD production, to stand out as different from one another, revealing their true nature, still leaving bad recordings listenable.

To sum up the Synergy horn, it is having the imaging precision as a small 2-way monitor, the clarity and transparency like electrostatic speakers and the dynamic and lifelike sound of horns.

To my ears the Synergy horn is a paradigm shift, but call me biased

Thanks for the subjective comment. Adds a dimension to all the maths and measurements.

I have a question. For all the concrete benefits, some might say that such a full range controlled directivity system will always sound a bit 'dry' due to low reverberant room energy, possibly to the point of 'robbing' the brain of late reflection location cues. Hence why some add rear or up firing drivers as an adjustment.

Do you compensated in any way to add these cues in? Or fine without them?

Thanks again for your time and thoughtfulness in all these posts.
( I have always been an admirer of Danley and the many others advancing horn design )

 

As you might be aware, I have a similar system to yours. I have horns, and I have modified my speakers so that they are controlled by DSP. I use Acourate instead of REW.

What I am curious about is whether you have taken any off-axis measurements of your horns to demonstrate that it really is constant directivity.

I would love to do the same with my horns except that I am having measurement issues at the moment (follow the link in my sig to see the thread in my system showcase), and that I would have to dismantle my speakers and take them outside. That is no small feat, they weigh 110kg each.

 

Thanks Solypsa for your comment.
If you come from a more traditional cones and domes setup, you will for sure have a more lively sound. What CD horns provide is minimizing early reflection but still allow later reflections to the party, so the sound will be focused by not dry per se, in a normal listening room. So no, I don't use extra "reflective drivers" and I have never seen anybody with CD horns do that. What I have spend quite some time focusing on, is finding the right room curve tilt. That tilt depends on different factors such as speaker pattern control, room acoustics, room size, listening distance. Even small increments as 0,1-0,2 dB tilt makes a big difference when we are talking 20 Hz to 20 KHZ. This room curve tilt is greatly missed by the audio community at large.

 

Keith, I don't have any measurements at hand and I'm rebuilding the room right now, not at total change just adding a second system to the room But I remember when I did measurements in and around 3 listening positions, during the setup period, they were practically identical. Straight sided (conical) horns will have CD, they are bound to, due design.

I finished the build of the Synergy horns in my garage and now they are too big, to get out through the door for taking some proper measurements LOL.

 

At what angle off axis did you take those 3 measurements, and at what distance?

I am curious about how my "normal" spherical horn performs compared to yours. When I get my measurement setup working again I will try to get some sweeps.

 

Thanks Solypsa for your comment.
If you come from a more traditional cones and domes setup, you will for sure have a more lively sound. What CD horns provide is minimizing early reflection but still allow later reflections to the party, so the sound will be focused by not dry per se, in a normal listening room. So no, I don't use extra "reflective drivers" and I have never seen anybody with CD horns do that. What I have spend quite some time focusing on, is finding the right room curve tilt. That tilt depends on different factors such as speaker pattern control, room acoustics, room size, listening distance. Even small increments as 0,1-0,2 dB tilt makes a big difference when we are talking 20 Hz to 20 KHZ. This room curve tilt is greatly missed by the audio community at large.

Makes sense.

For 'tilt' are you using a Niveau filter? I recall Danley speaking of a a slight lowering n response from ( 1k iirc ) on up...

 

At what angle off axis did you take those 3 measurements, and at what distance?

About 2,5 to 3 meter horizontal 3 meter from the speaker, mono left and right . Other speakers can also perform well under this condition it's when we get further out in width it gets interesting.

 

For 'tilt' are you using a Niveau filter?

Don't know what that is, haven't heard of it. I have -1 db/oct from 0 dB 20 hz to -10 dB 20 KHz. You can see that on FR measurement somewhere here.

 

About 2,5 to 3 meter horizontal 3 meter from the speaker, mono left and right . Other speakers can also perform well under this condition it's when we get further out in width it gets interesting.

Why did you measure them so far away? If I am not mistaken, the Klippel NFS measures them 1m away. At 3m from the speaker, your measurement is going to be heavily contaminated by reflections, such that even windowing might make it difficult to remove. Not challenging you here, I am curious.

If I understand what you said correctly, you are measuring at an equilateral triangle, meaning that your off axis measurement is 30deg with respect to on axis, and it still looks the same? That is wonderful performance. What is the vertical dispersion like?

BTW, here are some on axis measurements of my horn, taken from different distances from the throat. Ignore the falling frequency response, that is some kind of anomaly with my measurement setup which I am trying to solve. The important thing to see is what those curves look like with respect to each other at various distances. I also took measurements from 1m and 2m away, but they look similar to the 60cm measurement, and are even more contaminated by reflections, so I did not show them. With my horn, there is no benefit from measuring further than 60cm away.

 

Why did you measure them so far away? If I am not mistaken, the Klippel NFS measures them 1m away. At 3m from the speaker, your measurement is going to be heavily contaminated by reflections, such that even windowing might make it difficult to remove.

I use Frequency dependent window (FDW) in REW to filter out reflections and and smoothing a bit, we want a general trend in FR, when comparing FR in a room especially at 3 meters.

If I understand what you said correctly, you are measuring at an equilateral triangle, meaning that your off axis measurement is 30deg with respect to on axis, and it still looks the same? That is wonderful performance. What is the vertical dispersion like?

Yes, thanks to the nature of CD horns it measures pretty well, kind of one of the big deals about them
My CD horn is a 90 degree horizontal and 60 degree vertical, which translate into that the FR at 90 H and 60 V is -6 db from the on-axis FR.

 

A lot have happened since the year 1925. Man has been on the moon (or so they claim ), we invented the nuclear bomb, computers and internet. We have equipment to look billions of light years out into space. The list goes on with rapid technological advancements. 1925 was the year Edward Kellogg and Chester Rice invented the moving coil loudspeaker. Speaker driver development doesn´t exactly fits into this category of rapid development.

Hifi enthusiasts live with the deficits of that fact. Loudspeakers are by far the least accurate component in a hifi system. Even the cheapest electronic gear, surpasses speakers by magnitudes, when it comes to things like distortion and frequency linearity. Speaker drivers also have breakup resonances, limited frequency band and narrows dispersion with rising frequency. Transforming the electrical signal into an acoustic signal introduces a whole range of problems.

Some speaker companies use vast resources to minimize these inherent shortcomings and try to make speakers that measure well under controlled conditions. The most serious speaker manufactures even builds expensive anechoic chambers to measure their speakers in. When they finally get a nice frequency response, often by noodling and tweaking the speaker crossover design, then what happens? The end user puts the speaker in a room and then, this nice frequency response is totally altered. Granted, the speaker with the neutral anechoic FR, will still sound better in a room, than a lesser design, with a more impaired FR. However, that does not exempt the neutral speaker from being substantially sonically degraded by the room impact. Most audio enthusiasts accept that fact, knowingly or unknowingly.

Using acoustical treatment, which can never be a bad thing provided it’s done correctly, can to some extent remedy the room impact. In the end, it is a question of how much boss you are and how dry you like your sound.

 

When they finally get a nice frequency response, often by noodling and tweaking the speaker crossover design, then what happens? The end user puts the speaker in a room and then, this nice frequency response is totally altered. Granted, the speaker with the neutral anechoic FR, will still sound better in a room, than a lesser design, with a more impaired FR. However, that does not exempt the neutral speaker from being substantially sonically degraded by the room impact.

Isn't that a strong argument to go with speakers that are CD with a uniform power response?? It helps for sure!

Rob

JBL Technical Notes Volume 1 Number 11

Courtesy of Robh3606

www.audioheritage.org

 

CD horns helps to take more of the room out of the equation, but under the transition frequency (300-500 Hz) we still get cancellations and summations of frequencies, that results in an uneven FR. So we still need to do something about this problem, if one strive for best sound quality. That is just the basic physically facts, that we all are subjected to.

Firstly, we have to clean up what really matters, which is FR. Once we have achieved that, we can focus on other sonically problems as time domain etc. But most people are satisfied as long as the worst mistakes are rectified. Such room FR errors normally sums up to somewhere between 10 and 20 dB and that is actually what most people are accepting and used to listen to. So isn't it an enticing thought to build a system with components that can be transparent and then use DSP to make it sound "right" in the room?

 

If you have to harvest the benefit from measuring at home, you should probably genuinely think, it is so much fun and interesting, that you invest some time in learning and understanding. Nevertheless, rest assured that you could potentially save huge sums of money, instead of swapping equipment and try to tune the sound through system matching. I recommend using tech tools for reference instead of senses. But I get it. The result will be SO much better if you take it in stride, because then it will be real needlework with a personal touch!

The "take it by ear" approach does not ensure that the sound is accurate. Most often than not it won't. Accurate sound reproduction is the one and only objective goal, that can be directly translated to High End sound, not shiny boxes with astronomical price tags. Try setting up a turntable without measuring.

Measurements say a whole lot more than audio analogies as airy and dissolved treble, better bass, the blur disappeared etc.. and the best, an octave lower bass after a cable change (from people who don't actually know what an octave is ).

A frequency sweep measurement shows all the peaks and troughs, and you quickly get a picture of what the problem is. It can be difficult to hear the difference between 500 Hz and 600 Hz by ear, with a mic you can at least see a clear difference and then quickly get better control over the sound. If there is something that stands out in the sound, it is difficult for most people to put their finger on what exactly it is.

In the end you get further with measurements, facts and good knowledgeable friends, than tenacious audio myths and glossy magazines.