High Frequency Horn Resonator - 1st Class

Recently I was introduced to this device, supposedly known in the market as a “Passive Super Tweeter” and sold by Sky Audio and his resellers here


I first tested the device, lets have a close up look

The entire piece above :point_up:

There appears to be a small hole if u observe the horn

The diameter of the horn measures about 6cm and the length of the horn 11cm. These numbers are specifically calculated to the designers intent. A wider hole yields supremacy in the high frequencies whilst a smaller hole is better for controlling Low frequencies. These are quite similar to the helmhotz resonator. The diameter of the horn, it’s length, cavity and air movements etc all changes with sound. Requires a lot of study and experiment to get it right. I think this should be known as a high frequency horn resonator instead of a passive super tweeter. Nowhere it is doing the job of a super tweeter .

A quick guide on the science behind below :


You can observe with helmhotz , the openings are smaller. Which works well for Low frequencies . A whole lot of science behind which is available le on Wikipedia.


Real life application & listening test… below….

Very very poisonous :skull_and_crossbones::skull_and_crossbones::skull_and_crossbones::skull_and_crossbones:

Yesterday I had the opportunity to host one member for demo session. Together, and with the distributor, we had our listening test session. Combining various options and rinsing and repeating the various different genre music to find the best balance.

It was a fantastic demo session yesterday. I really enjoyed the session from the demo yesterday and learnt lotsa stuff in the process. I ended up with the following placement for 2 pairs of HF Horn resonator

On mains:

Behind MLP

Wow!! Just Wow! Only 3 letters… the music and vocals did the talking…. Super solid!! It transformed the entire listening experience and I was absolutely stunned and thrilled on the quality it brought to the set up!

The realism is scary good and we could feel the emotions from the singer. We took it out from speaker location and tested behind MLP, different impact. Leave on speaker location and took out behind MLP, another different impact took out both, the song becomes normal song. Put it back, wow again… the music sounds so different and pleasant. I’m really not very good at describing it. But what I can tell u is that, whoever we put it in front, vocal clarity improved a few folds with a sense of realism and you can feel his emotions. The horn at the back of MLP, improves the sound stage and creates a sense of “spaciousness” as if the back wall doesn’t exist. In his voice, with the horn placed behind MLP, the transition of sound is a lot smoother with very nice high frequencies decay… we can feel him using every ounce of breath singing at the top of his lungs…. That final oomph for the high notes until he can no longer go higher and then he grasps his breath… that decay…… 1st class man!

Then comes the layer of instruments… speed of the instruments from the ribbon tweeters in layers… wow so damn nice the quality….it doesn’t mask out the details ….

Along the way, Steve from sky audio did some tweak, this guy has magic hands when it comes to stereo, whatever he touches seem to make things sound right. He realised that the placement of the horn was not aligned to the tweeter, immediately he fixed it and we had another listen,

This time it was aligned and instantly, our friend who is a pianist, could tell, “bro, this piano sound now sounds right” fantastic! And we were all stunned !! Some minor tweaks here and there and boy, so satisfying….

So as we found out, the placement makes a big big difference as well.

Above all, the experience was fantastic for me, I’ve learnt so much yesterday. What’s suppose to be demo to pass on knowledge, turns out to be a learning experience for me, and I enjoyed and loved every moment of it.

This is the best thing in this hobby, you always have something to learn from each other. But sometimes, it’s important to learn the right things and apply them.

Some would argue that this resonator , is actually colouring the sound. Whilst I cannot disagree, I would argue that in a home set up, any speakers we are listening to is also “coloured” :sweat_smile:, but coloured to the “room sound” . Now my concept of thinking is, since the sound is already coloured, how about we “colour it in a nice way that we like”?. One has got to understand, the moment you put in the diffusors in the room, you are already colouring the sound. U put too much absorptive material, the room sounds dead. None of us are listening to music in an anechoic chamber. So I come back to the sentence, we “colour it in a nice way that we like”? that is key takeaway….

It turns out there are a few many others who are already using it. For me, it was a game changer, it brought the biggest improvement to my set up, the upgrade of the AVM90 and the divini silver XLR didn’t come close to this

This one is absolutely :skull_and_crossbones::skull_and_crossbones: Confirmed, I guarantee once to in not coming out type…

Be warned…

Moral of the story… acoustics still has the most significant impact to sound quality… time and again I have established this fact… no doubt about it….

Very very happy man, haven’t been so happy in a long time! It’s like I have finally nailed it

Ps:// side note to bro Hillviewer and Bro Kingajit who are both on the GX300, u need to get this !! U will be stunned !! Take my word for it and thank me later. Not very expensive but very very satisfying

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My Mrs and kids came back in the evening after a day out with friends yesterday whilst I hosted the demo session.

She asked:” what is this horn? U bought new stuff?”

Looking guilty, I had to think quick…

“ this horn thing works to amplify our love :heart: for each other” … good fengshui … :rofl:

Ram out of options and answer …

Then she winked at me and walked away… but didn’t ask me how much I spent for it… :joy:

Oh yes, prior to purchasing this stuff. I wanted to actually see what it is doing to the various frequencies. So I wanted to pull up the measurements with and without. Using RTA to look for differences in mid to high frequencies and their fluctuations and changes in spectrum, with vs without . I also wanted to look at the impulse on broadbanded time delay but haven’t had the time.

Based on what I’m hearing, I can conclude the effects mirror those when I first used a SMT Wings diffusor.

The “spaciousness” effect is scary good when placed bottom top exactly behind MLP.

In acoustics, we all know that if the speakers are placed equidistant in front, the late reflections will always… always end up behind MLP.

Using the same theory , we placed this horn thing exactly behind the MLP. We are essentially turning these late reflections into something that “activates” the brain to expose different time masking. If I put my hands on the device, I can feel it resonating (sort of tony vibrations). The results are then our ability to hear the instruments and vocals better, because of how the late reflections resonantes with the horn, delays those frequencies and amplifies it in a nice way. Too much of those delays and we enter the region of “echo”, which becomes detrimental. So I guess this designer got it bang on with the acoustical delay.

I’m suspecting if we pull out the reverb time, we should see a very “even” looking delay… otherwise I wouldn’t be hearing this type of improvements

I guess I didn’t want to go through the hassel of bringing the gear out to measure again.

For me, it worked wonders, and the sound is so beautiful… I don’t have more words to describe. The last time I had this type of improvements was when I discovered the SMT wings diffusor. Some years back, that was one helluva solid built temporal diffusor that works very well in space and time

This is going to rock for many audiophiles. Because it’s not an electronic device that alters the sound , it’s more of an acoustic device. Either you are hearing more of your room, or more of your speakers being amplified by this in frequency and time domain.

Damn it sounded fantastic for HT as well.

This takes 2022 upgrade of the year for me! It beats the AVM90 anthem upgrade and divini silver XLR cable hands down ! So much impact this HF Horn Resonator and I have to say I’m so in love :heart: With the ribbon sound from monitor audio…

Nice. Is it suitable for HT LCR use?

Ya it is. It sort of works with the acoustics in the room. Unlike super tweeters that emanate sound, this thing sort of get the acoustics in the room to sound nice….

Try… once u try it no turning back type… you can place it on top the speakers to try…

But if your speakers are like this below then can’t

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Thanks Ronildoq for the detailed review of the 597 Horn Resonator. I have linked it on my facebook page https://www.facebook.com/LoveSanctuaryStereo/posts/pfbid0iNaGg9Uxn2of6B1HotAXtwG7PZUU82RLUaRaFMJSLGu1GMcuMAuVY3z9g7Fq2fHgl

Steve and I will also be holding a demo of the product on 17 Sep 2022 2pm-3.30pm. I welcome everyone to join. Details can be found at https://www.facebook.com/LoveSanctuaryStereo/posts/pfbid02YbZ7gfzwFWLbTdegU3yTFbA9ALVDZnGowjUos8QJE8gSsjtv9BuD4aucbAKg8tE6l

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Let me share further my experience with the horn resonator after some months of using…

The set up at home at the moment, actually has a laminated timber floor. I covered it with mass loaded vinyl for bass absorption and a layer of carpet above that. MLV absorbs any bass produced by the subs resonating with floor and doesn’t disturb my neighbours downstairs. The results are satisfactory air borne vibrations only. The floor is not part of the “subwoofer system” and it does not transfer any type of vibration produced from the subs since these have all been absorbed by MLV, if any. It removes any form of distortion and none of the equipment or windows rattles , there is hardly any harmonic distortion as a result of heavy bass produced from 4x 18” subs with dual 12x10” line array.

The carpet on the other hand, absorbs high frequencies and what follows is very accurate sound from the speakers.


One massive problem is, the decay in upper frequencies is shortened. Because of the absorption from the carpet. Making all high frequencies sound much more dull and less extended. This is obvious in many set ups when carpets are used.

Enter the horn passive radiator.

Notice how it is placed above the ribbon tweeters? With the first reflection pointing upwards going through the horns, the extended decay in the high frequency is now being “restored” and in a much more pleasant way. The way in which instruments sounded was way more precise and extended with layers compared to how it bounces off the wooden floor. It sounds a lot more precise and “controlled” with these extended decaying times in high frequencies . They sound really pleasant and musical, the ee now sounds like eeeeeee. The Ahh sounds a lot more ahhhhhhhhhhhhh

I now have a situation whereby the unpredictable floor bounce is eliminated, with decay at higher frequencies being restored through this passive radiator.

Does it sound good for HT? Yes it does as well. Especially the way in which it decays, doesn’t mask out any information. When a car accident happens, it goes bangggggggggg…. You have got the gggggggggg extended rather than just bang. And stops. So the extended ggggggggg blends in really well with vibrational energy rumbling from the subwoofers. So it’s really pleasant sounding for both HT and music. When the creature walks in “ a quiet place movie”…. The grrrrrrrre R sound, extends longer and supplements the rumbling energy from the subs , it feels a lot more natural.

All in, quite happy I got this passive horn radiator. Such a delight to have it in the system for both HT and music

Highly recommended !

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Today tested at my uncle’s place….

Wah this cd big big difference so much difference . A lot easier to tell compared to the Chinese YouTube

Once go in…… not coming out !! :rofl:

Fuu we tested this Indian song, damn good man !!

Wah damn solid sound , the instruments all coming out naturally

My uncle said : wow so beautiful…

Hahahahaha…… jialat go in not coming out at his place…

I got back home, then still fresh on my mind. I still cannot forget the looks on my uncle’s face after testing the horn resonator. For so long I didn’t see that big happy smiley face of his, it made me so happy to see him happy. He said only this to me :” beautiful sound” . I told him he can keep it as I bought 2 pairs . So I temporarily removed the pair placed at the back of MLP at my place

Initially when I first tested, I played this Chinese music from YouTube

He couldn’t tell much difference with the above track, it was only after repeating 3-4x he started to experience the difference with vs without. I suppose he wasn’t familiar with the soundtrack. Can’t blame him.

Then once he started playing those familiar sound tracks from Prem Joshua, then he started enjoying it. I could see the 360 degree change from his expression

It goes to show that the source material used for testing and playback plays a huge role too.

The mastering had so many types of instruments in it, it had the

  1. tabla (some drum)
  2. sitar
  3. Flute (bamboo)
  4. Tanpura
  5. Saxaphone
  6. Santoor
  7. Percussion

OMG so many types of instruments I couldn’t believe what I was hearing from that CD. Magnificent disc to see how good the horns were with all sorts of instruments playing at the same time

This time, it was a game changer. With so many different types of instruments playing at the same time, we could tell much more easily how accurate the layers of the instruments were placed within the soundstage with the horns in place

So I was in charge of adding them back on and taking them out as we rinse and repeat the same track to listen to its impact.

When I removed it, he looked at me and said :” oh it sounds so flat” that was his exact words when I took the horn out. I believe he was experiencing a much more musical presentation from the speakers when the horns were in use. Without the horn, the presentation was monotonous and plain. Yes there was sound out from the speakers, but it lacked the spark, clarity in layers and the Rhythm. They were gone when we took it out. The overall presentation was so so dull without the horn, very apparent

Suddenly, we came across some section with bass, and even with bass we experienced a tighter sounding upper midbass. It was so good and even I felt the improvement whilst being seated at the side and not the main listening position.

Finally we tried vocals, and we played Justin Bieber. Wow the emotions from the singer, was so obvious with the horns on. We could feel his emotions when he started singing. The extended high frequency decay was superb…. So airy and gives you that spaciousness effect, very immersive. I was absolutely stunned his Dali opticon $1.8k speakers sounds better than the $20k speakers I have heard. It is not easy to hear this part of the sound from the recording , the emotions. Very difficult. The horns brought out the emotions, it was a super upgrade for his system. This is something you and I will not know if we do not A B it with vs without. Only after you complete the A B will you understand and know what is missing and what not

I explained to him, this horn thing, is really good. Unlike cables or clean electricity where it improves the details or changes sound signature, this one does something different. It brings out the musicality from the speakers and the ribbon tweeters really sing . For the first time, he was experiencing solid music, from a simple $1.8k speakers. Worth it ? Absolutely !

Will changing to a higher end model speaker bring out the musicality? Definitely not. It cannot give you that type of quality that the horns bring to the system. The horns doesn’t altar the signal, nor does it add noise or change the sound signature of the speakers. It brings out the best from the speakers using the theory of acoustic . The designer is a true genius! I think he got it absolutely right with this design.

BEAUTIFUL SOUND…. That is how I would describe it too with the use of The Horn Passive Radiator . Another happy man….

Oh yes, and I came across this article recently , a review done by an audiophile well known to many in the industry…

He knows how good the sound ! And he appreciate the quality. Was it a reference speaker well measured speaker? Absolutely not. It was just a simple pair of bookshelf speaker


The sound, however, deserved to be praised. The Divini Reference 8 bookshelf speaker was the most natural and smooth sounding speaker of the entire floor. Surely they do not have the highest resolution or the strongest bass impact, but the sound is smooth and welcoming. They made music, not bells and whistles. And they really had to rub it in, the gentleman told me repeatedly that they were only playing low-res files from YouTube, running off of their iPhones!

Hang on a sec ! Did he just say cheapest on that floor ??

Quote :slight_smile:

The Davini Audio speakers were a rare exception to the entire International Sound & Sight Exhibition, as they are likely one of the cheapest setups on the floor – yet they presented one of the most inviting and “musical” sounds.


Little did he realise, the rest of gear used in the set up and how it pairs the speakers plays a huge role in the final presentation. How the speakers were able to sing! The addition of the horns very evident not only at my place but my uncle’s! He was so delighted that it had to stay in the set up

Do you also see something familiar from the pictures above paired with the divini bookshelves?

Yea ! That is the Passive horn radiator pairing a pair of simple inexpensive bookshelves. I’m sure there were other well measured speakers on demo , but none of it got mentioned in his article…I suppose it didn’t leave an impression ……

The funny part he mentioned this …

I liked the sound so much I went back to the room again and again over the next two days.


Wah 3 days show, next 2 days also go back same room listen and listen again ! It shows he was really really impressed with the sound.

I was definitely, my uncle was mesmerised…. Some of the other kakis were too…

Worth it ? That’s for you to find out… YMMV. this audiophile uncle found out recently during the Hifi show …

Today again :point_up_2:t2:

Last week after using it :point_up_2:t2:

Straight from the horse mouth…. Not from me, from my uncle using it

Kao lat kao lat poisoned with Passive Horn Resonator…. :rofl:

So far I know 5 person who tested, all 5 got it ! They love the sound….

What magic u ask? I have no clue. It’s so musical and clear, without it the presentation was so dull and monotonous… lacking in rhythm ….

Actually very happy to see that the system has improved and the user loves it… hard to achieve this type of quality …

Stunning beauty!

So nice I’ve just had a chance to listen to my friends set up, it sounded fantastic pairing the audio control amplifier…

Beautiful sound from divini Reference 18

Saw something familiar ? So so nice midrange and upper frequencies, very very good !!

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When I have the time, I’ll dive into the measurements to see what this horn thing is doing…hopefully I’m able to see what’s going on on the impulse, Energy time curve and amplitude, will also check out the RTA response as the music plays with and without… just to have an idea of what it’s doing…