- Manufacturer & Model
- Aperion Audio Dual Firing AMT Folded Ribbon Super Tweeter
- $999.00 Pair
Aperion Dipolar Air Motion Transformer (AMT) Tweeter
Six position crossover selector – Off, 8KHz, 10KHz, 12KHz, 14KHz, 16KHz
Six position attenuator selector – 0dB, -1dB, -2dB, -3dB, -4dB, -5dB
Aluminum Alloy enclosure
8KHz – 35KHz rated frequency response
Another Super Tweeter from Aperion Audio using an Air Motion Transformer (AMT/Heil Driver) this time around. Good sensitivity, coupled with a flexible crossover and attenuation adjustments, make this simple and easy to integrate with most speakers. Appears to be extremely well built and is attractive. Dipolar AMT speaker design delivers clear, airy, and open upper frequencies into the room.
Aperion Audio just sent their brand-spanking-new AMT Dual Firing (Dipole) Super Tweeter for review.
It wasn’t that long ago (January 2021) I had the opportunity to review the Aperion Audio MKII Planar Ribbon Super Tweeter. In that review, I found the MKII to be a functional and useful addition to my older BG FS520 speakers. I declared in that review that while the MKII Super Tweeter might be somewhat of a “specialty item,” it was in no way a “novelty device!” What I meant by that is…. it worked! It literally breathed new life into my somewhat treble shy BG FS520 speakers, making an already fine speaker even better and more listenable.
Because of my previous positive Aperion super tweeter experience, I was more than happy to take a listen to the new Aperion Audio AMT Super Tweeters. So, breaking out and dusting off my old BG FS520 speakers again, I prepared for the receipt of the newest super tweeter from Aperion!
The Aperion AMT Super Tweeters arrived via UPS and were double boxed. The plain cardboard box, when opened, revealed a printed product box tucked inside. The speakers were nicely wrapped and snuggly nestled into cut and formed, closed-cell foam, top, center, and bottom pieces.
The only other thing in the box was the two-page instruction sheet.
The packing appeared secure and appropriate for the 3.5lb (x2) speakers.
Construction and Design
In a departure from previous designs, the Aperion AMT Super Tweeter is an all metal (Aluminum Alloy) painted cabinet. Belying their small size, the speakers are surprisingly heavy. The cabinets are two-piece construction with the top piece housing the AMT Tweeter in a metal frame that is open front and back. The bottom piece provides the base for the tweeter and houses the crossover, robust appearing binding posts, and the attenuation and crossover controls.
The controls are heavy duty metal rotary knobs with solid detents in every position. The settings are clearly marked with small, silk-screened numbers at each detent.
The crossover is a Butterworth design with a soft 6dB/octave rolloff. High quality, precision components are used throughout, including custom Aperion precision capacitors and high-purity copper wiring. The crossover has six detents for Off, 8kHz, 10kHz, 12kHz, 14kHz, and 16kHz. For easier integration it is designed with a soft 6dB/octave rolloff.
The attenuation control has detents at 0dB, -1dB, -2db, -3dB, -4dB, and -5db. Measurements indicate the amount of attenuation at each position is right on.
The Air Motion Transformer assembly is tightly held in a rigid metal frame and is open front and back, producing a Dipolar radiation pattern. The actual driver size is 3.19” x 1.34” (81mm x 34mm) and consists of a 20µm aluminum ribbon captured between a 12.5µm Kapton film with a total thickness of 44µm. The resultant pleated (folded) ribbon assembly is ultra-low mass suspended in a high gauss magnetic field created by stacked neodymium magnets.
The AMT speaker, originally invented and developed in the 1960’s by physicist Oskar Heil (1908 – 1994), contains a folded ribbon suspended in a strong magnetic field. The motive force moving this assembly is much like the motive force in a planar (flat) ribbon driver. The interaction of the varying electromagnetic field produced by the current flowing through a conductive ribbon material suspended in a strong fixed magnetic field, causes the thin membrane of the ribbon folds to move laterally in concert with the changing current flow accelerating the air in and out of the folds.
When it is properly designed, this type of driver is very good at reproducing the most rapid of transients and the complex sounds and dynamics of music, with high output and low distortion.
Aperion has a great explanation of what an AMT tweeter is, and how it works. If interested in a greater level of detail go to “What is an AMT Tweeter and How It Works” by clicking on the supplied link.
All said, Dr. Heil was on to something. In recent years the proliferation of the AMT driver has spread through, not only the consumer speaker market, but the professional monitor market (HEDD, EVE, Adam, etc.) as well.
I attached the super tweeters to the narrow top of the BG’s by using a heavy silicone tape on each side, then angling the speakers down slightly by hiking up the backsides with two small rubber equipment feet stacked on top of each other. I aligned the radiating surface of the super tweeter with the front radiating surface of my BG FS520 mid-range/tweeter as best I could in the name of “time alignment.”
As with the MKII set up, connection was an easy jumper from the host speaker to the binding posts on the Aperion AMT Super Tweeter.
I loaded the Audyssey curve pre-stored for my BG’s and made sure the Audyssey correction range stopped at 300Hz, leaving the higher frequencies uncorrected, and unfettered.
Aperion supplies a frequency curve at two crossover points (14kHz and 16kHz) paired with an undisclosed bookshelf speaker with a good roll off around 14kHz as the host speaker.
I set up my laptop and UMIK-1 and ran some additional tests with REW to see how the super tweeters would perform in my room. I also wanted to see if there were any interference/cancellation/artifacts in the region where the “host speaker” and the super tweeter overlap in coverage.
All measurements are right and left speakers, unless otherwise noted, with the microphone placed at my normal listening position.
One more and I promise to move on. The next curve is the AMT tweeter measured at 1 meter from 8KHz to 24KHz. Crossover at 12KHz - 0dB attenuation. It is obvious there is plenty of energy out to 24KHz and beyond.
There has been a lot of debate as to whether this type of high frequency extension, well beyond the range of human hearing, is meaningful or not. I would have to say in one respect…not really! But what is/can be important, is that this extension insures there is a nice flatness and extra measure of energy delivered in the 14KHz to 20KHz range. A range that many speaker systems fall a bit short on.
While there is little Fundamental Musical Content above 14.5KHz there is something to be said for the reproduction of the harmonics and sibilance that do add character, presence, space, and air, to the overall sound. That extended frequency range and energy should also reinforce a system’s innate ability to produce clean, lower distortion, high frequencies in the actual audible range.
Looking at the measurements, nothing jumped out as an issue, and basically confirmed Aperion’s claims and published specs. I could not actually confirm the extreme ultrasonic capabilities due to my equipment limitations. But having said that, the speakers displayed a strong, relatively flat, presence up to 24KHz (REW’s and the UMIK-1 operational limits) with plenty of energy seemingly still available and extending on into the high frequency hinterlands.
Initial informal listening told me the tweeters sounded their best, when used with my speakers, with the crossover set at 12kHz and -2dB attenuation.
I went back to, more or less, the same material, I had used to evaluate the Aperion Audio MKII Planar Ribbon Super Tweeters in January, with a few additions and deletions. The goal, as in the previous review, was to listen for coherent, extended high-end presentation and those sometimes-elusive sound qualities of depth, image, space and… “AIR!”
Of course, these recordings are artificially created spaces that are built and enhanced in the studio using EQ, panning (Placement), phase trickery, delays and reverb to give a sense of space and air. But some recordings (and engineers) are just better at building and presenting those studio enhancements to the speakers and making the feeling of space and air more palpable and believable.
Testing started by listening with the Aperion AMT Super Tweeters on and at my preferred crossover setting of 12K and -2dB attenuation…. then re-listening to the same material with the Aperion Super Tweeters off.
Simply Red – Picture Book – “Sad Old Red”, “Holding Back the Years” 1985 – Elektra (CD)
A great recording from 1985. It is wide open and airy with an expansive studio soundstage.
With the Super Tweeter on, the soundstage was crisp and “airy” with a big diffuse image. The Cymbals and High-Hat were noticeably present and hyper-defined while the snare drum had a good, well defined “snap” and snare sizzle. Subtle cymbal “Bell” work was noticeable and distinct throughout.
Overall, a big, deep soundstage with great imaging, and a marked sense of space…. “AIR!”
Turning the super tweeters off, the sound took on a more mellow and less immediate presentation. The open and “airy” space that was conveyed with the super tweeters on, now became more “rounded” and confined by comparison. The snare lost some of its “snap and sizzle” and became a bit laid back. Cymbals lost some of their attack and crispness.
Dave Grusin and Lee Ritenour – Harlequin – 1985 – GRP Records (CD)
Well produced and digitally recorded and mastered, this recording has a wonderful, open, and big, yet concise sound, with an expansive soundstage.
With the Aperion AMT Super Tweeters engaged, the presentation was “airy” and open with a big image presented. The cymbals and subtle percussion touches were well presented. The “space” seemed big and expansive.
The vocals by Ivan Lin, on the three tunes with vocals, were clear and expressive with a natural sounding edginess and raspy-ness to his voice. Even though the human vocal range is well below the frequency range that the super tweeters operate in, they still added something to the listening experience.
Turning off the AMT tweeters had the same effect as before. The sound now produced, while warm, refined and eminently listenable, had lost something. The sound stage seemed to shrink on itself somewhat, and the sound became less expressive losing a measure of excitement.
Alexandr Misko – Beyond the Box – 2017 (CD)
While this recording itself is not stellar, the final sound is open, atmospheric, and quite full for a single instrument.
With the super tweeters engaged the subtle overtones and harmonics of the acoustic guitar, produced by Alexandr’s unique fingerpicking style, were rich and satisfying. The sound was airy, light, and atmospheric. Percussive effects, all supplied by Misko while playing, were crisp with lots of snap and a sweet woody overtone.
Without the super tweeters the atmospherics shut down a bit and the soundstage became more confined with less depth, edge, and excitement.
Johann Sebastian Bach: 6 Brandenburg Concertos –– Helmuth Rilling Conducting - The Oregon Bach Festival Orchestra – Silva Concert Hall, Eugene, Oregon – 1994 (CD)
Nice clean concert hall sound in a performance center environment.
The Aperion AMT tweeter units added space and air to the soundstage. The super tweeters also added texture and layers of tonality to the strings and high frequency wind instruments like flutes and piccolos. The surface sound of the violins gained a measure of that edginess that is inherent in a violin’s sound while other strings remained pure and woody sounding, even at their top end.
Turning the tweeters off, the sound became somewhat more confined and a bit lifeless for an orchestra in a concert space.
Soul of the Machine - Various Artists – Windham Hill – 1987 – Compilation (CD)
This very well recorded (probably mostly direct) 1987 release featured “New” (at the time) Electronic Music.
In the first track “Rizzo”, by Michael Forman I was struck by the size and depth of the soundstage. The synth lines seemed literally disembodied and floated in the space above the speakers. Tons of air and big soundstage.
The second track, “Time and the River” by Fred Simon was more of the same. Nice atmospheric, floating imagery and a clear, well-defined sound.
When I removed the super tweeters from the equation and re-played the first track, the floating synth lines came back to earth and the breathiness/airiness of the sound collapsed becoming more “rounded,” focused, and mellow. It was much the same with the second track, but less so… The sound just became less diffuse and more focused, more rounded.
I continued listening to a variety of music, in several formats and on different media. In each case the same pattern presented, and the same notes were taken. The sound was more “open” with a nice “airy” character when the super tweeters were engaged.
Television and Movies
Using my AppleTV 4K I perused a lot of TV/Cable and several movies to see how the super tweeter fared with that type of media.
Some of what I sampled was; The Falcon and the Winter Soldier (Disney+ 2021), Monster Hunter (iTunes 2021), Mortal Kombat (HBO Max 2021), The Equalizer (Paramount + 2021)…. I even watched a 1972 Samurai Flick, Lone Wolf and Cub: Sword of Vengeance (HBO Max – 1972 - Stereo).
Unlike when previously auditioning the Aperion MKII Planar Ribbon Super Tweeter, I never felt the need to dial back the AMT super tweeters. Even the somewhat harsh, period sound, of the 1972 Lone Wolf and Cub was perfectly fine and listenable. The AMT super Tweeters consistently delivered very listenable, non-fatiguing sound, regardless of the source or genre.
Summary and Closing Thoughts
I’m brought back to what I had previously written about the Aperion MKII’s… “These speakers may be somewhat of a specialty item, but they are not a novelty item!” They are instead, what can be a functional, real, and worthwhile upgrade to many speakers that are lacking a bit of sparkle on the high end, but are otherwise perfectly serviceable speakers in every other respect!
A good deal of the better sound and imaging I was hearing I attribute to the fact that the BG FS520’s are dipolar speakers, with the mid-range and top-end reproduced by a 50” planar ribbon driver. My feeling is the better imaging and “AIR” I was experiencing, stemmed from the fact, that I was now pairing them with another dipole type speaker in the Aperion AMT Super Tweeter.
The $1000.00 price tag does require a bit of thought and consideration though. At this price point are these a good investment? My thoughts are, maybe, just maybe! But it depends!
As good as I thought the Aperion MKII’s were with my BG FS520’s, the Aperion AMT Super Tweeters were certainly better. Better sounding, easier integrating, better imaging with more “sparkle,” more “crispies,” more “sizzle”… and definitely more of that “airy” quality I value so much. The Aperion AMT Super Tweeters are such a clear step up from the already impressive Aperion MKII Planar Ribbon Super Tweeters previously reviewed, that If I were keeping/using the BG’s as my main speakers, I would now consider the Aperion AMT Super Tweeter as the best value added option.
Wanting to add some “crispies”, “sparkle,” and high-end extension? These super tweeters are worthy of serious consideration!
Specifications: Aperion Audio Dual AMT Super Tweeter
Product Family: Super Tweeter
Placement Location: On top of host speaker
Product Weight: 3.5lbs/1.6Kg each
Frequency Response: 8kHz – 35kHz
Crossover Points: 8K, 10K, 12K, 14K, 16K
Crossover Slope: 6dB/octave
Nominal Impedance: 4 ohms
Recommended Power: 10 – 150 watts
Direct Power Handling: 20 watts
Driver: Air Motion Transformer (AMT)
Product Dimensions: 4.9" x 5.1" x 6.9" / 125 x 130 x 175 (HxWxD)
Shipping Weight: 8.2 lbs/ 3.7 Kg per pair
Shipping Dimensions: 13" x 7.5" x 8"/340 x 190 x 205mm (LxWxH)