ECdesigns PowerDAC-S and Open Baffle Speakers
ECdesigns’s take on High Fidelity in a speaker system
This review should be read as a follow up to my previous review of ECdesigns’ powerDAC-R.
That first review introduced the reader to ECdesigns’ approach and “philosophy” and provided a lot of background technical information, but was brief when it comes to impressions of audio quality. Truth be told, the powerDAC-R left me a little frustrated. As ECdesigns explains, and most audiophiles well know, the quality of an audio system is a product of all its compenents. However well a DAC performs, the sound you hear depends as much on the quality of the amplifier and speaker it is paired with.
When ECdesigns suggested I test their new model, the powerDAC-S, I was excited to find out what improvements I could get listening to my speakers when directly connected to the powerDAC-S, that is, without the need for any “traditional” amplifier. As stated on their home page:
“Every component in an audio chain is imperfect and introduces extra degradation. Less components in an audio chain will give less degradation. Our PowerDAC-R makes it possible to remove the pre-amp from the audio chain and directly drive the amplifier. The PowerDAC-S now also removes the amplifier from the audio chain. The only thing left is a balanced power-supply and resistor attenuator that directly drive the speaker.”
One can refer to their documentation to understand how the powerDAC-S works and why it is so unique. It is designed along the same lines as the powerDAC-R but offers higher output power and the ability to drive speakers directly. The devil is in the details, and designing what seems like a minimal system is in fact quite complex. But to put it simply, one can view the powerDAC-S as a “straight wire with attenuation” (to paraphrase the “straight wire with gain” ideal system that audiophiles dream about). One will not find any other system with such a minimalistic design and so few components in the signal path.
When I first received the powerDAC-S (which I purchased at full retail price - it is worth mentioning that I am a regular customer), I used it with my modest (i.e. not “high-end”) Davis Courbet 4 speakers. The benefits of removing my amplifier (a Lavardin ITX) from the system were evident; directly connecting the powerDAC-S to the speakers offered a more natural sound. Yet, I felt things could be taken even further. Listening to the powerDAC-S with a variety of other (often more expensive) speakers did not convince me either that all the potential of the powerDAC-S was being realized.
It should be noted that the powerDAC-S can be used to drive headphones that require more power than the smaller “R” model can provide - my previous review adressed headphone listening with the powerDAC-R and I chose to focus my attention here on the powerDAC-S’ use with speakers, which is my preferred listening mode.
ECDesigns suggests pairing the powerDAC-S with speakers of their own design. These open baffle speakers use 4 Tang Band W8-2145 full range drivers in parallel, without any crossover filter (as crossover components involve their share of distortion). With a 102db/1W/1m rating, and 2 Ohm impedance, they are well suited to the powerDAC-S, which is limited to 4W per channel. The TangBand drivers have a relatively flat frequency response for full-range speakers and offer low distortion (manufacturer’s claims). I had heard the smaller Tang Band W5-1880 and enjoyed their very transparent and refined sound.
ECDesigns sent me a few more comments to explain why they chose these speakers:
“We selected this specific speaker as it has very low distortion and a flat SPL (very rare for an 8” full range speaker). We used an 8” speaker because it offers a large membrane surface area = higher resolution. This driver has a membrane made from bamboo fiber paper. This membrane and the whizzer cone are treated with a gel like (sticky) damping material applied to the rear of the membrane and whizzer cone. This may have fixed the peaks we see with drivers based on paper or paper kevlar membrane.
It has underhung motor, this means the entire voice coils always stays within the magnetic gap for very low distortion, higher efficiency (almost all power is converted to motion) and low moving mass (smaller voice coil).
Finally these full range speakers have very low inductance, this translates to a very fast response (larger voice coil inductance = higher impedance at higher frequencies or transients = slower response).”
ECDesigns does not sell these open baffle speakers. They provide the specifications to build them on your own.
I was hesitant to take on this project, as I am not an experienced DIYer: sourcing the wood, getting it cut, assembling it, seemed like quite a challenge.
Moreover, as ECDesigns explains in their documentation:
“In contrast to “boxed” speakers, open baffle speakers emit sound to both front and rear of the speaker into the room. This makes open baffle speakers less easy to setup than “boxed” speakers. Sound that is transmitted from front can interfere with (delayed) sound from rear and can sometimes cause unwanted resonances in audio frequency range. Most of these resonances are in the lower frequency range and often interact with the room … In reality this means that you will probable need to experiment with different speaker placements in your room, you might also need to use some kind of dampening on inner sides of the speaker or on some parts of your wall/room.”
My living room is long (11 meters) but fairly narrow (between 3.5 and 4 meters wide) and has a fairly low ceiling (2.5 meters) typical of modern constructions - I have no special acoustic treatment installed. How would these giant speakers perform in my home?
Once again, curiosity got the best of me. I ordered the wood online, took the panels to a DIY shop in Paris to get the speaker placements cut out, and set out to assemble it all.
ECDesigns was very helpful in answering all my questions and made a few valuable suggestions as well. I wired the speakers using copper foil, and added horizontal beams in the back to further improve the rigidity of the baffle.
The size of the front baffle and speaker positioning was determined based on the well-known IEC baffle model. The side panels serve a dual purpose: they add rigidity to the front baffle, minimizing vertical movement of the drivers, and improve the bass response.
The results far exceeded my expectations.
The combination of the powerDAC-S and open baffle speakers provide a level of transparency into the recording that I had simply never heard in the many audio systems that I have listened to, price notwithstanding. Instruments are heard with what can be described as full, natural tones and timbre. The sound is refined, dynamic and the “musical picture” presented is intricate yet cohesive. As a result, there is a sense of “intimacy” with the recording that leaves a lasting impression.
Audiophile recordings can sound impressive on many systems, but even lesser recordings shine through on this system. Here is a Qobuz playlist of some of my favorite jazz recordings: https://play.qobuz.com/playlist/8990336. They all sound terrific through the powerDAC-S/open baffles.
One of my “desert island” albums is Lester Young and Teddy Wilson’s 1956 Jazz Giants. Jan Evensmo, author of a masterful solography of Lester Young, describes this recording in the following words: “During two hectic days Prez has found his final, true Indian summer, never again to play like this!” The stage is set, and we cannot help but feel some nostalgia when listening to these fine players, together perhaps for the last time. Behind the delicate groove set by the rhythm section, Lester Young’s saxophone sounds incredibly vivid, and we can grasp all the subtelties of his craft and the emotions he conveys. We gain a better understanding of the music and even greater respect and admiration for these masters.
I must have run through my entire record collection. On Muddy Waters Live, the system really captures the “club” atmosphere of the recording, as we can hear the faint sounds of the public drinking and cheering, and “see” (locate) all the players performing on stage in front of us. The instruments sound natural, and Muddy Waters’ voice is heard with great realism.
As a side note, listening to such recordings on this system may lead one to reconsider the tradeoffs between digital and analogue. My turntable is now only used to listen to those recordings that are simply not available in a digital format. As with the powerDAC-R, the powerDAC-S offers all these wonderful sounds with even a basic source (CD player, PC…).
On a more modern note, on Billie Eilish’s “I Wish You Were Gay”, the powerDAC-S and open baffles accentuate the contrasts between the singer’s soft whispering voice and the multi-layered backdrop of sounds coming in and out of the song like crashing waves. As her brother Finneas explains: “…I really wanted it to get to this kind of bombastic, triumphant place, sonically. It was important to me that it got to an exciting climax with hefty beats and all these stomps and claps.” Mission accomplished.
That’s what it’s all about.
In an attempt to convey my enthusiasm for this system, and at the request of some, I made several video recordings of the system using my phone - they can be heard on my YouTube channel. In spite of the poor quality of the recording, one can perhaps get an idea of the type of sound to expect when listening to the system live.
Listening to the speakers using other amplifiers (a Lavardin ITX, a Purifi amplifier) gave good results but not as satisfying as when played through the powerDAC-S.
Is the system perfect? No system is. Some speakers may offer deeper bass. With complex crossovers or DSP, a ruler-flat frequency response can be obtained with some speakers but at the expense of some other forms of distortion. One can read about diffraction in open baffles, or the theoretical disadvantages of line arrays - all a source of much anxiety for audiophiles in search of perfection. Every system makes some compromises and one has to decide which aspects of sound reproduction are most important - something listeners must decide for themselves.
I did struggle with speaker placement, and am still not sure I have found an optimal solution (I am considering some acoustic treatments in my room). The speakers are very large and entail a certain commitment to the cause (and may also demand a certain level of tolerance from other members of the household). But unless your room has terrible acoustics, optimizing speaker placement should be seen as a bonus, not as a pre-requisite for musical enjoyment.
The output power of the powerDAC-S is limited to 4 Watts per channel. This may be problematic for those who listen to music at high volumes. If you need to listen to a symphony at a volume comparable to a front-row concert seat, then this system is not for you.
Listening recently to a “high-end” system - 45.000€ speakers (yes, there is such a thing) in a well-treated room - I was impressed by its “clean” and wide sound. But it lacked, to my ears, the exquisite transparency and accuracy of the ECD system that pulls me in completly to the music. That system could play well at very high volumes but something else was lacking, something I know I can enjoy with the powerDAC-S/open baffles. We all have different tastes and needs.
The ECdesigns powerDAC-S and open baffle speakers have shown me aspects of sound reproduction that a conventional audio system with separate components (DAC + preamp + amplifier + multi-way speakers) may never be able to offer, regardless of cost. In this case, less IS more. For me, there is simply no looking back.
Hopefully, this short review will have conveyed a sense of what can be expected from the powerDAC-S and its companion speakers.