Waterfall Audio, Iguasçu Evo Floor-Standing Speakers


I’m hoping to not be the minority when it comes to design and audio equipment. Far too often you hear of audio and videophiles mentioning that a piece of gear has a high WAF (Wife Acceptance Factor). All too often this denotes it’s not a boring slab of black electronics or a monolithic boring speaker. Why is it only the spouse who has high aesthetic requirements? Here, we review Waterfall Audio’s Iguasçu Evo floor-standing speakers that have glass enclosures.


  • Design: Three-driver, 2-way Floor-standing Speaker
  • Drivers: One 0.8″ Silk Dome Tweeter, One 6″ Woofer, One 8″ Passive Radiator
  • MFR: 48 Hz – 28 kHz, ± 3 dB On-Axis
  • Sensitivity: 88 dB
  • Impedance: 8 Ohms Average, 4 Ohms Minimum
  • Dimensions: 34″ H x 10″ W x 10″ D
  • Weight: 31 Pounds/each
  • Finish: Clear Glass
  • MSRP: $4,499.95/pair USA
  • Waterfall Audio

I for one am very design driven. Sure, often the aesthetics of a product don’t enhance its performance (though often the aesthetics can improve performance) but we live with these objects in our homes and studios, they should enhance the spaces they occupy. To that extent I am often willing to spend more to get a product that is as beautiful as it is functional.

Waterfall Audio has chosen to use glass as their design statement. After seeing the Iguasçu Evo in person there’s no doubt in my mind that they chose a wonderful material. The sight of drivers floating mid space is a sight to behold.

Waterfall has chosen to name the speakers in their Evo line after prominent waterfalls. Iguascu being a large waterfall on the border between Brazil and Argentina.


Waterfall Audio is a new player in the North American market but the company was established in Northern France in 1996. It took several years for Waterfall to perfect their technology and produce a commercial product. The engineering team had two areas of technology to develop. One, manufacturing tight tolerance enclosures from glass. Two, controlling vibration and energy in what is essentially a non damped material.

In order to make the cabinets out of glass Waterfall had to find a partner that would be able to cut and finish glass to a tolerance not typical for most glass applications. A 6 x 3 meter glass sheet is roughly cut to the various panels required to build the cabinet. These rough panels are then further machined by CNC equipment to get exact dimensions to +/- 150 microns.

While glass is a very dense material and not prone to transmitting vibrations throughout the cabinet, it can resonate. To control the resonant properties of a non damped material like glass, Waterfall developed several technologies. The main innovation is the Acoustic Damping Tube. This applies to the woofer. The ADT is part of the rear section on the woofer, and helps to limit the energy from the back wave of the cone. It dampens the Medium to High Frequencies with an integrated damping chamber. There’s also a hydraulic damping mechanism for low frequencies which also assists in controlling excessive cone movement, which reduces distortion and increases power handling. Last, the ADT uncouples the bass drive from the glass structure and controls the amount of energy transferred to the enclosure.

One very unique aspect of the Iguasçu is a passive radiator at the base of the speaker which can be tuned for extension or bass output. The passive radiator has the option of attaching one of the two weights provided to tune bass response.

The product documentation is a bit vague in that it defines the adjustments simply as; extension to 60hz +2b for no weights, 55hz +1db with the smaller M7 weight, and linear to 50hz with the M27 heaviest weight. It’s hard to verify the curve of the boost without proper measuring equipment and a anechoic environment. By ear it does seem to tune bass for greater extension versus bass output. The extent to which I suspect is highly determined by the room acoustics where the speakers will reside.

The towers are relatively short in stature and in my listening environment it put the tweeters almost 2 feet below my ear level. Keep in mind I’m a very tall individual at 6’6″ and the tweeter may be closer to ear level for the average listener. This is one reason I’ve never been a big fan of tower speakers. With monitors you can use stands to get the right height based on your seating situation. I find solutions for doing this with towers to be cumbersome and less than aesthetically pleasing. In practice this proved to not be a real issue.

The towers have substantial aluminum bases with a single set of binding posts. The base has threaded recesses for spikes which were not supplied. The lack of supplied spikes or feet prevents angling the speakers upwards to compensate for their low tweeter height. Purchasing threaded spikes will remedy this, though in practice I never felt the image was too low in space. Experiments to raise the front of the speakers resulted in minimal lifting of the soundstage.


Since the tower is essentially a sealed box I did not find it very sensitive to corner or wall loading. It did tend to thicken up the bass response in my room around 100-180hz when moved closer to the wall and much more so in a corner. Yet compared to a bass reflex (ported) speaker it was a much milder bump. By ear I would guess only a 2-4 decibel boost. I settled on having the speakers about 2 feet from my back wall. Toe adjustments yielded very minimal results in terms of treble energy or imaging. From my experience this is a sign of having a very broad and even dispersion, which proved to be correct once I began listening.

I hooked up my speaker cables via banana plugs and broke-in the speakers for 4 days playing nonstop out-of-phase white noise. Afterwards I repositioned the speakers back at the original location 2 feet away from the wall and played with side spacing. In my room they seemed to work best about 8 feet apart, my listening position at 10ft away, and with just a tad of toe in. As time went by I experimented further with toe in and came to the conclusion it didn’t affect imaging or spectral balance much. These are fairly easy speakers to set up.

Attaching the optional weights is a simple affair requiring a hex key to attach the weights with a bolt. Using the weights to tailor the bass in my room proved very useful. With no weights the bass had a hump somewhere around 55hz. It wasn’t objectionable and actually made kick drums sound fantastic, giving music a nice driving rhythm. I went to the other extreme and attached the heaviest weight. It removed the hump but also all the bass energy below 60hz was now too weak to feel the attack of bass notes. They were more heard, not felt. I suspect this had more to do with my room than anything else. My space isn’t able to sustain notes much below 40hz. Using the middle weight flattened out the bass response and increased bass extension slightly. This is the setting I used for the remaining months of auditioning.

For all gear I will review from now on I will list what support equipment was used in development. In the case of Waterfall they use Naim and Bryston amplifiers, with Atohm(the company which also builds the drivers to Waterfall’s specs) and Wire World cables. I feel this is important information for getting a feel for what electronics will work exceptionally well with speakers or vice versa.

In Use

After setting up the speakers and letting them break in, I sat down for my first initial impressions. Keep in mind I had several prejudices going into this review. One, I’ve never been a big fan of soft dome tweeters for home use. Two, I tend to prefer monitors with a subwoofer over tower speakers. In my experience soft dome tweeters always sound sweet on female vocals and string instruments, but lack sheen and air with cymbals and brass. With those biases and with the passive radiator with no weights attached, I sat down and played a movie. I had just received the Apollo 13 Blu-Ray and rather than listen to music I felt inclined to watch one of my favorite movies yet again.

Hooked up to a Naim Supernait and letting the Naim provide both the power and DAC I sat down for a night of movie watching in stereo. I find watching dialog heavy movies in stereo to be a good test of spatial depth for speakers. Most good speakers will image a nice center image, most will present on-screen voices several feet in front of the screen. Usually the speakers will sound 1 foot or less behind the front of the speakers. In my case the speakers were 4 feet in front of my plasma TV. The Waterfall speakers had so much depth that at times it felt like the voices and other on screen events were happening inside my TV! I took a note stating “can’t wait to hear music with this much depth resolution!” The other aspect that really impressed was the absolute clarity and pin point imaging of the speaker….with a very wide sweet spot. I’ve owned many speakers with super precise imaging (my own B&W 805s come to mind) but usually they require you to place your head in a vice. Move so much as 4 inches in either direction and the center image is destroyed. Not so with the Waterfall speakers, the sweet spot was feet wide, very similar to the JBL and Genelec studio monitors I use professionally.

Another great aspect of the Iguascu speakers was their bass delivery. During the launch sequence of the Saturn V booster, the bass of the five F1 engines never overwhelmed the speakers. They handle excess bass very gracefully. Definition was always tight, snappy and with good extension. Not as deep as a good sub but I never felt the need to add a subwoofer. The score to the film was rendered with superb detail, timing and space. The tweeter was superbly detailed though it sounded a bit dry compared to a metal dome. Or so I thought. In later listening with my Myryad integrated amp and Benchmark DAC, the tweeter really came into its own. The Naim SuperNait turns out to have a rather dry treble. With my own electronics the tweeter was as good if not better than the aluminum B&W tweeter in my 805s or the titanium tweeter in my JBL pro monitors. This is the best fabric tweeter I have ever heard and left we wanting for nothing.

Once I switched to music my initial impressions of the Iguascu were multiplied three fold. As good as the speakers were with a movie they were simply stunning with music. They are so inherently natural sounding. Neutral without being lean, highly detailed, articulate, fast and with superb timing. I’ve heard enough Hi-Fi speakers in my life that the truly good ones are instantly recognizable. Many “good” speakers require some time to become acclimated with, they exhibit many good or great characteristics but somehow don’t end up sounding whole. Not so with great speakers. They are from the start natural sounding. The oddity is that this “right” sound is actually a lack of character. Many speakers sound very warm or detailed in the presence region with tradeoffs in the bass or treble. Or they are very bright (without being harsh), or have great bass definition. Yet they almost always focus on one aspect to generate a sonic signature. What really impresses about the Iguascu is that lack of a signature. They’re much like good professional monitors. Neutral, honest, and with good macro and micro dynamics. They impress without jumping out at you. They are just a pleasure to listen to.

Feed the Iguascu’s good power, a great source, your favorite recordings, and be prepared to sit down for a late night of listening pleasure. They are that good. Whether listening to heavily processed rock and pop albums, or hip hop albums, what the speakers are fed is what they give. It’s a mixed bag with recordings of mainstream and electronic music. The quality of the recordings varying wildly. The Waterfall speakers won’t polish a flawed recording.

Switching from countless music albums such as La Roux, Massive Attack or Hifana that are studio albums I heard exquisite details in all good, bad and ok recordings. The Iguascus instantly rendering electronic reverb as being artificial and allowing also allowing me to distinguish real room reverb. They’re not so revealing as to completely make poor recordings unlistenable. Poor recordings lack sparkle and substance but are still listenable.

I switched to some older classic Jazz and Rock albums. Beatles 1 was stunning through the Iguascu’s. I could clearly hear the cabinet resonances of the guitar amps in Day Tripper. More amazing was being able to hear the subtle changes in tonality as McCartney or Lennon would move closer to or further away from the vocal mics. This is detail and spatial resolution I’ve only heard in speakers costing twice as much. My own B&W 805s speakers couldn’t match that level of spatial detail, yet alone my JBL studio monitors.

Switching to Dave Brubeck and the iconic Take Five, well let’s just say I had to pick up my jaw from the floor. Especially after doing A/B comparisons with my own speakers. On a side note, the fidelity of late 50s and early 60s recordings never cease to amaze me. My own speakers simply presented the sound of a saxophone, a very faithful sound. The Iguascus raised the bar by placing a saxophone in front of me. I could hear the flapping noise of the valves, the shimmer of the cymbals and the air/space they were recorded in. Simply stunning. Again, this level of resolution and musical presentation is seldom achieved.


There are many great sounding speakers these days. A smaller number of which are actually beautiful in design. Most of those using traditional materials like MDF veneered with exotic wood finishes. Some using aluminum. Even fewer of those could be called truly modern in aesthetics. The Waterfall Iguascu I suspect lead the pack in that small group. They are beautiful speakers than fit right at home in a loft or modern home. They compromise nothing in performance for those good looks. While they’re not cheap, if you have the means I recommend you listen to these speakers. They possess one of the best, if not the best soft dome tweeters I’ve ever heard. Detail and resolution, timing, etc are all superb at the price. They embody all the qualities in terms of imaging that a top flight monitor (bookshelf) speaker, and bass extension of a smaller tower. Plus strikingly clean and modern design. A rare combination of looks and substance.