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.

 

Solypsa, that is a good question. I would say that the room is a bit of a the show stopper and as I'm not willing to relocate or rebuild, I have to go with the room I have.
The room is L-shaped, the listening area is 3,6m W, 6,5m L, 2,2m H, and is well acoustic treated. A bigger room would probably sound slightly different. But I have more direct sound, than what is the norm, so in my situation, the room has a smaller impact soundwise.

Let's forget all cables, USB/SPDIF, DSP as a factor of SQ. What about amps then. Right now i only play on class-d. Some years ago I had a whole stack of SS amps running, but with all things in place, FIR/EQ, same target curve, I can't say that I hear any notable difference. That of course, is a very "unscientific" statement, but after hundreds of listening hours in the room, you kind of know how it normally sounds and I can't say there is any significant change. What if I changed to amps with 10 dB better SNR and 10% less distortion and another distortion pattern, would that make a difference? A cautious maybe. I actually have a Topping PA5 in the house. It should have slightly better specs, than my LJM L20D amp modules. I could test with that.

 

Sure, one involves the eyes and the other the ears, but they are indeed linked. You see, there is great correlation between a frequency response and how that FR is perceived in terms of SQ.

There is obviously a correlation - no one is going to be stupid enough to argue against that, and I am surprised you would think that I would - but there is (much) more to sound perception than frequency response.

Digital audio is like a giant (four dimensional) puzzle with millions of pieces that have to be assembled. If your vision is poor, and you put glasses on, you will see the puzzle better, but if the puzzle has not been assembled correctly, then what's the point ?

I think the fundamental problem is that no one has really seen the puzzle assembled, so we can all go to the ophthalmologist and get the best (measured) eye correction we can get, we are all arguing about a heavily distorted picture in the first place.

Enjoy...

 

What about speaker drivers? I use Fane PRO 15" for front loaded horn subs and long throw JBL-GT5 12" for tapped horns. As long as you use drivers that suits it function all are good, especially for bass duty. All driver except tweeter horn, are paper cones, with some sort of composite fiber treatment. We all know those drivers. When horn loaded in a synergy horn, the harmonic distortion is acoustically filtered out. Harmonic distortion in speaker drivers are mainly 2. and 3. order. Any break up modes, will potential happen way out the bandpass. Any frequency deviation are minimum phase and are easily corrected for. Maybe changing to other drivers with hard cones, could potential give a bening change in sound, EQ'ed to the same target curve. But on the other hand, light cones with strong motors, and is what a horn loaded system wants.

The horn tweeter is an old but goodies BMS 4550. What if I replaced it with a very expensive TAD or other exotic brand, with beryllium diaphragm. Would it sound different to the same target curve, maybe. Would it sound better, potentially maybe. I'm not willing to put down that kind of money to find out. But I have heard exotic drivers in a number of systems and for many hours, and did not find them particularly better than good but cheaper alternatives. As I see it, it's about implementation.

 

There is obviously a correlation - no one is going to be stupid enough to argue against that, and I am surprised you would think that I would - but there is (much) more to sound perception than frequency response.

Digital audio is like a giant (four dimensional) puzzle with millions of pieces that have to be assembled. If your vision is poor, and you put glasses on, you will see the puzzle better, but if the puzzle has not been assembled correctly, then what's the point ?

I think the fundamental problem is that no one has really seen the puzzle assembled, so we can all go to the ophthalmologist and get the best (measured) eye correction we can get, we are all arguing about a heavily distorted picture in the first place.

Enjoy...

No has said here that frequency response is everything. Quite the opposite if you have read the thread.
But frequency response is fundamental and needs to be within a certain limit in order to have a correct tonality. After all, it decides how much level you have at different frequencies and there needs to be a balance. If this is off too much, it's never going to sound right.

I think the problem is rather people continue to avoid the fundamentals, and don't understand much about speaker design and room interaction. And they tend to look at non existing problems.

 

No has said here that frequency response is everything. Quite the opposite if you have read the thread.
But frequency response is fundamental and needs to be within a certain limit in order to have a correct tonality. After all, it decides how much level you have at different frequencies and there needs to be a balance. If this is off too much, it's never going to sound right.

I think the problem is rather people continue to avoid the fundamentals, and don't understand much about speaker design and room interaction. And they tend to look at non existing problems.

I think we can stop discussing this point. We can both continue our "journeys" and see where they ultimately lead. Perhaps some day we will get the best of both.

 

hopkins & co. I would go out on a limb a say that frequency response is more than 80% responsible for perceived sound quality. The time domain and decay are also important if the sound reproduction, is to sound as the producer intended.

A horizontal response will sound thin and anemic. In a blind test, most people would prefer a smooth but falling response down towards the treble. I have repeated this to the point of boredom (and probably annoying for some).

The old German DIN standard says +/- 4 dB from 40 - 16 KHz, but that was the time before advanced EQ. Today something like +/- 1.5 dB is obtainable. So in reality, most audiophiles who are reluctant to use EQ, won't even live up to the minimum standard for High Fidelity, in terms of frequency response and without an even FR, chances to have a good time domain will diminish.

 

hopkins & co. I would go out on a limb a say that frequency response is more than 80% responsible for perceived sound quality. The time domain and decay are also important if the sound reproduction, is to sound as the producer intended.

A horizontal response will sound thin and anemic. In a blind test, most people would prefer a smooth but falling response down towards the treble. I have repeated this to the point of boredom (and probably annoying for some).

The old German DIN standard says +/- 4 dB from 40 - 16 KHz, but that was the time before advanced EQ. Today something like +/- 1.5 dB is obtainable. So in reality, most audiophiles who are reluctant to use EQ, won't even live up to the minimum standard for High Fidelity, in terms of frequency response and without an even FR, chances to have a good time domain will diminish.

Hi Schlager,

I'm going to go out on a limb also and suggest that the 40.000 people who watched this video of my system and the many who "liked it" did not find the sound to be anemic

They probably had no clue that they were watching a system video!

Of course it is "only" a video, but if the sound was so boring because of some hypothetical limitation in the frequency response, I think it would transpire...

I would not even mention this, with some humor, if I myself did not find the sound of that system highly engaging and enjoyable in spite of its limitations.

 

Sorry hopkins, my remark about anemic sound, was not specifically aimed at your system, more an objective remark of what is generally perceived as a natural sounding FR.

 

Sorry hopkins, my remark about anemic sound, was not specifically aimed at your system, more an objective remark of what is generally perceived as a natural sounding FR.

I did not take it personally (and even so I would not get offended!) but responded as Bjorn gave some comments along those lines after seeing the FR curve I posted in my thread some time ago.

 

So why is an even FR so damn important? Two acoustic phenomenon plays a role. Let's look at an example of a FR measurement I found online.


In the bass and upper bass, we see a couple of peaks followed by dips. These tend to be room induced and being low in frequency the are predominantly a minimum phase issue, so we can to a certain extent smooth these out.

In terms of how our ears perceive this, we will hear 60-70 hz and 100-150 hz quite a bit louder than the surrounding frequencies due to masking. Play some music relatively loud and then have a person talking to you (or turn on the tv) and you won't hear what the person is saying, that is masking. MP3 codec is based on how our ear/brain masks lower sounds relative to high sound.

Higher up at 1500-5000 hz we have a broad dip (BBC dip) and then a rising response up to 10 KHz. This will be perceived as a tonal coloration.

At 400 hz we have a sharp dip, but our ears are quite insensitive to sharp dips and much more prone to high peaks, because of the masking effect.

Another way to determine if a frequency deviation is a potential problem, is to look at the total area the problem occupies. Again from the example we can draw a line and have a quick estimation of how big a problem a deviation will be. In this example the problems ain't so bad at all. But fixing the issues in the example will definitely give a very different tonal balance, which is very important if high fidelity is the goal. Of course it doesn't have to measure perfectly to sound good, but a very uneven response simply ruins the music completely.

 

A little story from the real hifi life. About a month ago I had several audiophiles visiting me. One of the guys played some of his selected music on my system. After that he approached me and said, that what he heard had to make him rethink his own approach to audio. He told me that he was into cables and interconnects and could not understand the overall sound quality of my system, all with DIY cables. We talked for a while and he asked me to help him setup his system and dial it in. You see, even that he was into cables he also had a miniDSP 2x4HD that he wanted to integrate his subs with, but he had not been successful.

So I went to his place the other day. His room was about 35 m2 (377 ft2) and well treated with acoustics, a blend of diffusers and absorbers, so far so good.

The picture is with his old Tekton speakers, when I was there he had shifted to Magnepan LRS+, as he wanted to try some dipole speakers. The rest of the system was 2 REL s510 subs and Pre, DAC, CD, from Holo Audio and amp from PS Audio BHK Signature 250 Stereo with tubes in the pre-stage + streamer, some power conditioners/cleaners.

After taken some initial measurements, we found out that the Magnepan dropped as a rock below 50 hz, no surprise there but it had a nasty high spike at 50 hz, probably some membrane resonance. Now, the speakers was fairly new and probably not fully broken in, yes I do believe in breaking in speakers especially panel speakers. But he was surprised to see that his subwoofers had no output, whatsoever, below 30 hz. The specs says -6 db at 20 hz and with room gain you should expect some output, but no, nothing there.

I showed him my process of sewing the subs to the Magnepan, using some delay, gain and then add global EQ to the bass. Then I did some EQ on the Magnepan between 150-700 hz and it was time to give it a listen. He said that it sounded wastly better in the bass, than what he had been able to achieve. To me, it sounded okay in the bass department and the overall sound of system was decent to my ears. Now again, the Magnepan was quite new, so I offered him to come back and give it another go, when the speakers was fully broken in.

 

Yup, people need to get the eyes (or ears!) open by getting such experiences and starting to focus on the major contributors and leaving the nonsense on the side. So many in this hobby has been lead astray.

I visited an older gentleman this weekend who had Burmest speakers and electronics. The shop had convinced him to buy an expensive Burmester conditioner and Nordost cables with the setup. When I explained to him that this does make any difference and that a conditioner has very cheap parts in it that can purchased from a pro brand at a very low price, he was very upset that he had been fooled. And he agreed that couldn't hear a difference between his Nordost cables and cheap ones. Obviously selling him something like a subwoofer with a DSP for crossover and integration would have made a huge audible difference compared to the conditioner and cables who didn't do anything. It even would have been cheaper.

And the almost funny part was that hifi store, who had connected everything for him, had connected the signal cables with wrong polarity.

 

Hi Audiophile friend. Listen, I got it! To some degree I have been there too. You have spent a lot of time and hard earned ressources, through the years, grinding and plugging away through the dirt of audiophilia. You have read all the reviews, you have watched all the youtube videos. You have visited all the other forums where everything always makes a difference. You bought the cables and the little bridge thingies for them to sit upon and the benefits were magical. You have bought speakers that need exactly 200 hours of breaking in, for truly to sing. Not 175 hours or 225 hours...no 200 hours! It must be that for the magic to appear!

You converted your entire music library to super high res and enjoyed the blissful new details that never were revealed by the awful, kludgy red book mess that was 16/44 cd. Never have your ears been assaulted by the likes of bluetooth audio or lossy mp3. You searched endlessly for the perfect dac...the dac that truly brought the magic. You bought one after another, each more expensive than the last, searching for the one true dac, that sounded better than all the rest...

Probably, during your long audio journey, someone told you that a dac shouldn't sound like anything at all. Unwavering in your own almost religious beliefs and subjective convictions you lash out angrily. Why shouldn't a dac sound great?? Why would expensive dacs even exist if they all sound the same??? It's idiocy! It's retarded! People saying this have dead ears! Their systems aren't good enough and expensive enough!

I understand, it's been a long time in audiophilia land and you've spent a lot of money, all for nothing. But here is a free advice, from me to you (you can thank me later ). Instead of locking your eyes shut against the bright light of objectivity...just try to open them up a little. Just a squint! Let a bit of that light in and bask in a warm tubey glow that actually means something! Perhaps, as happened to me, a weight will begin to lift off your shoulders. Perhaps there is freedom in this new reality. You might discover that there is a different way...a way that wields real magic. A way that actually answers questions and reveals truth while at the same time leaving your wallet fat and happy.
Welcome my friend. Peace

 

Hi Audiophile friend. Listen, I got it! To some degree I have been there too. You have spent a lot of time and hard earned ressources, through the years, grinding and plugging away through the dirt of audiophilia. You have read all the reviews, you have watched all the youtube videos. You have visited all the other forums where everything always makes a difference. You bought the cables and the little bridge thingies for them to sit upon and the benefits were magical. You have bought speakers that need exactly 200 hours of breaking in, for truly to sing. Not 175 hours or 225 hours...no 200 hours! It must be that for the magic to appear!

You converted your entire music library to super high res and enjoyed the blissful new details that never were revealed by the awful, kludgy red book mess that was 16/44 cd. Never have your ears been assaulted by the likes of bluetooth audio or lossy mp3. You searched endlessly for the perfect dac...the dac that truly brought the magic. You bought one after another, each more expensive than the last, searching for the one true dac, that sounded better than all the rest...

Probably, during your long audio journey, someone told you that a dac shouldn't sound like anything at all. Unwavering in your own almost religious beliefs and subjective convictions you lash out angrily. Why shouldn't a dac sound great?? Why would expensive dacs even exist if they all sound the same??? It's idiocy! It's retarded! People saying this have dead ears! Their systems aren't good enough and expensive enough!

I understand, it's been a long time in audiophilia land and you've spent a lot of money, all for nothing. But here is a free advice, from me to you (you can thank me later ). Instead of locking your eyes shut against the bright light of objectivity...just try to open them up a little. Just a squint! Let a bit of that light in and bask in a warm tubey glow that actually means something! Perhaps, as happened to me, a weight will begin to lift off your shoulders. Perhaps there is freedom in this new reality. You might discover that there is a different way...a way that wields real magic. A way that actually answers questions and reveals truth while at the same time leaving your wallet fat and happy.
Welcome my friend. Peace

Howard Roark as Audiophile hehe.

Joking aside interesting thoughts to consider.

 

As in life as in audio we read, we study, we listen to other peoples advice, we do, we fail and try again, we learn. Along those lines we get experience and some pointers and perhaps and hopefully a direction to which path to follow. We get an audio habitus of some sort.

Most of us have been to hifi shows and probably and hopefully visited others audio buddies, with whom we exchange experiences and get an insight into their way "of doing audio". Through that whole process I got ideas of do's and don'ts.

Attending to numerous hifi shows, with High End Munich being the most prominent, was in the beginning an event, build up with excitement. As me and my regular audio buddies expanded our knowledge and audio systems, these shows today merely stands as a little audio holiday in good company, with no expectations whatsoever, to hear anything groundbreaking. Most of my audio epiphanies comes from private audio visits and resorting to letting reason reign over magic as a model for explanation and correlation. Brain over bling of some sort

Without further ado and with no strictly chronological order I'll go through some of my audio experiences.

Here is a private setup in 2017 of Magico Q7, D'Agostino Momentum mono amps, Jeff Rowland DAC. This speaker room combi had a huge suckout at 60 hz, so we advised the owner to get some extra subs. Luckily for this fellow, he was very open to suggestions and advices for improvements, instead of having his audiobrain locked in a vice. A couple of 24" subs was added + EQ. I heard this system numerous times and one time we brought some amps to test against the Momentum amps. A very unscientifically test, that would be, but even the owner admitted that if there were any difference they were benign. He just fancied the look of the Momentum amps, a very honest man, I'll give him that
This system is pretty expensive and it sounded good. Without the extra subs and EQ it was nothing special. Go figure!

 

That's a really challenging acoustical space. Especiall if the cathedral ceiling also comes down behind the listening position. That type of rear wall is called "rear wall of hell" in expert acoustical circles. Creates a lot of comb filtering and frequency deviations which is very difficult to properly treat.

And his speakers don't have neither vertical constant or narrow directivity, plus there's polar lobing between the drivers. Probably good that he's using amps with higher distortion to avoid those issues becoming to evident.

 

The room only has that angled front wall, the back of the room is a straight wall.

Even that the speakers costs north of 200.000 $, they are still submitted to the physical laws, so they operate like most monkey coffins. And yes, I believe that Dan D'Agostino doesn't care much about distortion numbers in his amps. The number he probably cares most about would be the pricetag number

 

Another private setup with Usher D2 "upgraded" with 2 x diamond tweeters. Pass Lab amps, DIY subs. Playing in a big room of a total of +150 m2 (+1600 ft2). With a very uneven frequency response, I did not enjoy this system at all.

In the other end of the room there was a second system. Dutch Stage Accompany M-59 , big studio monitors in an exclusive hifi version with ribbon tweeter, in an MTM configuration with 2 x 12" JBL mid bass and 2 x 15" for low end bass. Amps from Viola Audio Labs in a dual mono configuration (horizontal bi-amping). One amp driving the tweeter/mid bass and the other the low end bass. A "special" feature is added to these amps, as they have a big cobbercoil on the AC input side, said to function as an integral choke input filter, reducing the peak current. Another audiophile gimmick? You decide!

The sound was much more balanced compared to the Usher system and actually sounded pretty good, probably due to the amps . These speakers cost "only" around 30.000$ and I would take them anyday over some of the overpriced garbage, we see on hifi shows.


Yours truly, with some pretty big speakers coming in at 200 kg (+400lb) pr. side.




In the basement we find the little brother of M-59, the SA M-57. Some room modes were very prominent and difficult to "listen through". I have heard these speakers many times as one of my friends have them. They sound ok together with a multiple subwoofer setup, as they drop like a stone at 40 hz. But in this particular setup, not so much.

 

Attending to different hifi shows, through the years, have given me a pretty good insight into "The Audiophile World". Especially all the tweaking auxiliary equipment, that is said to improve the sound quality. One of the more bizarre example would be a showroom with small wood boxes with a bell on top. They were placed strategically along the walls and on top of the speakers, said to improve the treble region, but even more bizarre seeing all the +middle aged men in the room nodding, as in agreeing, to the preposterous claims made by the salesman. If you are not prepared for such "experiences" and caught off guard, it can be quite disheartening.

Another experience would be the Avantgarde room, from a show in Copenhagen in 2018. A very important part of the sound quality, we were about to experience, had to do with the power cleaner, inserted in the system.



The "benign" power cleaner, costing tens of thousand of dollars, could of course not help the very boomy bass in the room. Or the shrill midrange that blew off your ears at louder SPL and needed to be padded down a bit.

 

These speakers cost "only" around 30.000$ and I would take them anyday over some of the overpriced garbage, we see on hifi shows.
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Only 30.000$? What a steal!

Wonder what we should price our horn speaker system or a CBT where the cost of production is much higher.