Alta Audio Rhea Loudspeakers

At the Rocky Mountain Audio Fest (RMAF) 2015 I had the pleasure of listening to the newest Alta Audio loudspeaker, the Rhea. It greatly impressed me and many other attendees. Although only the second lowest in price in their line of five models which range from the Solo at $1,500 per pair weighing in at only 15 lbs each (a single driver model) to the Statement Towers at $250,000 per pair that weigh 485 lbs each and contain 11 drivers, the Rhea were clearly something very special at only $4,500/pr.

The Rheas are meant to be a much more affordable 2-driver model in the same spirit sonically as Alta Audio’s signature Celesta FRM-2 (Full-Range-Monitor) which cost $15,000 a pair with stands, weigh 55 lbs each, have a frequency response of 29Hz to 47kHz and are my own reference speakers. Like the Celesta, the Rhea are meant to be used in a relatively intimate space such as an apartment as opposed to a large house or concert hall, while at the same time offering impeccable, natural live sound even at relatively low volumes. (Alta Audio offers yet another model in between for larger spaces; the 3-driver floor standing Lelantos ($9000 per pair, 92 lbs each). I have heard them several times: if you want chest-thumping power and slam that can even go down to 26Hz and cause your house to shake while retaining Alta’s signature refined sound–this is your man.

Alta Audio CEO, founder and designer Michael Levy kindly loaned me a pair of the Rhea for this review. The Rhea utilizes, as do all of Alta Audio speakers, proprietary technology known as XTL and proprietary material known as 'DampHard' -- together they contribute to an exceptionally deep bass extension combined with a refined, detailed and fast, live-instrument sound. As explained on the Alta Audio website:

XTL stands for Extended Transmission Line, an Alta Audio proprietary technology used in all our speakers. We developed XTL using specialized sonic geometry to tune our cabinets like musical instruments, allowing all our speakers to deliver unprecedented clear, fast, and powerful bass....we tune the cabinet at multiple frequencies, not just one. DampHard: a multi-layered, multi-density material that makes up the walls of all our high-end speaker cabinets.

Although they are a 2-driver model, the Rheas come in a floor standing cabinet as opposed to a monitor-sized one. According to Levy, ‘The Rhea is a floor standing speaker because many people prefer them to stand-mounted speakers, and the format allows for a larger cabinet volume which relates to a higher maximum output.’ At 49 lbs each, the height is 35”, the width is 8” at top, 12” at bottom, and the depth is 11”. They also can be propped up 5” higher via optional separate black (light in weight) bases that come with spikes as footers ($250 per pair). This brings the height to 40”, the total weight to about 50 lbs, and brings the tweeter up to just below ear level when sitting on a couch. With only two drivers, the frequency response is mighty impressive from a high of 47kHz to a low of 32Hz and trust me, from my listening it is the real deal at that low end. The impedance is 4 Ohms and they can be run using 50 to 150 Watts per channel. The binding posts on the back allow for both spades and banana, and also allow for bi-wiring if desired.

Rear of the Alta Audio Rhea Loudspeaker

Rear of the Alta Audio Rhea Loudspeaker

The Rheas use DampHard behind the faceplates only. The Celesta by comparison has its entire case lined of DampHard and is of an extraordinary level of design/quality (The Celesta is less than half the size of but 6 lbs heavier than the Rhea!); this significantly helps keep the cost down for the Rhea, as does its use of less expensive, but still very fine, drivers. The tweeter is a 5 and 3/4” pure ribbon located near the top, and about 1” below it is a 7” midrange/woofer which if you were to chop off the cabinet right below it would yield a 14” monitor-sized cabinet. But there is another 21” to go in this beautiful sleek speaker, including a port at the bottom of the back. The pair I reviewed were in a gorgeous polished Rosewood, and I used them with the separate black bases; but they are available in a total of 7 different finishes including ‘Large Green’ and ‘Large Blue’. They are sold through several dealers in the USA.

How the Rhea sounded with three different amps

I used three different amplifier setups with the Rhea.

1. My reference Merrill Audio Veritas Mono blocks ($12,000 per pair, 700 Watts per channel at 4 Ohms, Class D). In this case, my PS Audio DirectStream DAC served as the volume control (e.g., direct to amps from DAC). They yielded from the Rhea a superb neutral/uncolored/transparent sound exposing minute details, a great 3-dimensionality and separation of instruments across the entire frequency spectrum. The most live sounding of the three. I would point to the 2015 live album ‘Trilogy’ by The Chick Corea Trio, Track 16, ‘Piano Sonata: The Moon’ to make my point. Another fine example: Matt Haimovitz (Cello), ‘J.S. Bach The Cello Suites According to Anna Magdalena’ (2015), CD (rip) in which Haimovitz speeds up the tempo and uses a Baroque cello.

2. VPI Limited Edition 299D Integrated (vacuum tube) Stereo Amplifier ($4000, about 40 Watts per channel). [Review forthcoming - Ed]. In this case I connected direct from DAC to this integrated amp which I used as the volume control.

It offered a wonderful match for the Rhea with an addictive warmth and sweetness particularly in the midrange and enough details exposed to please most anyone. It yielded a more laid back sound that was so easy to listen to for long periods of time, and a large soundstage. Voices in particular were such a pleasure to listen to on the Rhea with this amp. (Perfect example: Diana Krall ‘Love Scenes’. ) At $4k, a match made in heaven?

And if you are trying to bring in a new young generation of audiophiles? Play them (loud if so be it) the following 2008 CD (Indie Rock) which was introduced to me by my lovely teenage niece: ‘Vampire Weekend’, the last Track ‘The Kids Don’t Stand a Chance’. Well, actually they do.

3. PS Audio Sprout integrated amp ($500; 50 Watts per channel at 4 Ohms. Weighs only 2.9 lbs). In this case, after connecting the Rhea to the Sprout, I used Bluetooth to wirelessly stream CD resolution digital files from my MacBook Air to the Sprout with iTunes. This was by far the easiest to set up and whereas I originally intended this experiment to be just for fun, I was quite taken by surprise: although not yielding a sound quality in the same league as (1) and (2) above, it offered a very impressive mix for the money! Who would have thought?

Conclusion for overall sound

Use a decent amp (any kind) with the Rhea and you will get: Excellent total balance and dynamic range–live sound, no hardness or edginess at the high end, nice body and weight, large and clear soundstage (which, as with my Celesta allow it to float around the room as when I am sitting at the dinner table). Voices in particular are smooth and silky exposing venue reflections and reverb. Very nice bass dynamics; deep and extended, with some tightness and punch, and easily shaking my couch at times for some pieces such as Flight of the Cosmic Hippo by Béla Fleck and the Fleckstones. I also point out that the Rhea are far less sensitive to where you place them in your venue than are the Celesta; but I do suggest keeping them about 3–3.5 feet away from the back wall for the best bass response.


The Rhea is another Alta Audio winner that is live sounding with addictive overall musicality. It delivers about 85% of the sound quality of the Celesta at 1/3rd the price. Very versatile, the Rhea allows for a wide range of amplification as well as lots of flexibility for positioning within a room. A steal I’d say. Highly recommended without any reservations. 

Further information: Alta Audio