Secrets of Home Theater and High Fidelity - Best of Awards 2017
Reaching a new entry-level price point for Sonus faber, Principia leverages much of the technology developed for the Chameleon line but skips out on the interchangeable side panels to further reduce costs.

Utilizing Chinese manufacturing, the Principia 3 manages to deliver much of what makes the Sonus faber “house sound” so special at a greatly reduced cost.

Sonus faber Principia 3 Bookshelf Speaker


Sonus faber Principia 3 Bookshelf Speakers

  • Modern, attractive design
  • Excellent build quality for the price
  • Very revealing of source material quality
  • Unique reflex port design allows for close-to-wall placement options
  • Dual-binding posts allow setup flexibility

Sonus faber Principia 3 Bookshelf Speaker

I have been a fan of Sonus faber speakers for a long time now. Many years ago, I had my jaw dropped at a high-end audio shop while listening to a pair of circa-$30,000/pair Amati Anniversario speakers. The incredible sound and stunning good looks of those speakers set a new benchmark in my mind for what a speaker should be. The handmade Italian beauties just screamed class to me and I vowed that one day I would have a set of my own. Unfortunately, Sonus faber speakers were never designed for those with shallow pockets. High performance, Italian design, and hand-made build quality don’t exactly come cheap so it took me nearly 20 years before I was able to justify purchasing a set of my own.


two-way reflex ported bookshelf speaker


1 x 29mm (1.14”) soft dome tweeter, 1 x 180mm (7.1”) mid/woofer



Frequency Response (mfr):

45Hz – 25kHz, tuning port included


88dB SPL (2.83V/1m) nominal

Nominal Impedance:

4 ohms

Recommended Amplifier Power:

50-200W, without clipping

Dimensions (HxWxD):

13.2 x 7.75 x 11.5”


13.45lbs each


Black veneer


5 years parts and labor


$699/pair (optional stands $199/pair)


Sonus Faber


Sonus faber, Principia, Principia 3, bookshelf speaker, two-channel speaker review, Bookshelf Speaker Reviews 2017

Fortunately, for those of you without large investment portfolios or who don’t want to save for 10+ years, Sonus faber has started making less-expensive speakers using Chinese manufacturing lines to expand their brand and bring their sound and unique design to a much larger audience. Following on the heels of the Chameleon line of relatively inexpensive speakers we have the first true budget line they’ve ever offered – the Principia collection. Designed for two-channel as well as multi-channel setups, the five-speaker line starts at $549 per pair for the smallest Principia 1 bookshelf and tops out at $1,499 per pair for the three-way floor-standing Principia 7. There’s even a matching center channel at $349 to complete a home theater setup. The marketing slogan for the Principias is “perfect sound is a right for all music lovers.” While I wholeheartedly agree with that statement, “perfect sound” is a pretty tall order at the $699 per pair price of the Sonus faber Principia 3 speakers on hand here for review. Let’s see just how close to perfection they can come.


The Principia 3 is a standard two-way bookshelf speaker that has been given a Sonus faber “makeover.” The cabinet design is an interesting trapezoid shape (when viewed from the side) that is evocative of some of Sonus faber’s ground-breaking designs from the 1980s by the late Franco Serblin. The box is constructed of MDF with a black vinyl woodgrain veneer covering the majority of the cabinet. Black is currently the only finish option available but the speakers should blend in well in just about any environment. Around back are two pairs of five-way binding posts. The Principia 3 can be bi-wired by removing the metal jumpers between the two sets of posts. Their quality seemed a little flimsy to me, but they got the job done just fine.

Moving to the front baffle is where Sonus faber’s design esthetic really shines. Surrounding each of the drivers is a ring of brushed aluminum that really pops against the black front baffle. The single mid-woofer is a 180mm (7.1”) design with a free-compression basket and a thermo-molded polypropylene cone. Both the cone and phase-plug are an attractive silver color. The tweeter is a 29mm (1.1”) pre-coated fabric dome. Unlike Sonus fabers of the past, both drivers were designed in-house, though the manufacturing is completed by a third party. If you so choose, you can cover them up with magnetically-attached grilles. Since they use magnets there are no unsightly holes if you prefer to run the speakers au naturel, preserving the clean look of the Principia 3s.

Sonus faber Principia 3 Bookshelf Speaker Tweeter

Notice that there are no ports on the front or rear of the cabinet? That’s because Sonus faber uses a fairly unique bottom-mounted vent on the Principia 3. This reflex port consists of a ¾” U-shaped plastic base covered with a layer of thick rubber. A channel allows the air to escape. The key advantage to this design is that the speaker can be placed closer to a back wall without suffering as much bass blooming as a rear-ported design. With the exception of truly dedicated audiophiles, most users place their speakers very close to back and/or side walls for aesthetic or practical purposes, so designing a speaker to work better in these types of conditions is an excellent idea. The only real catch to the bottom port is that you must ensure that your mounting surface completely covers the bottom channel, or bass performance will be negatively impacted. If you are planning on using stands with the Principia 3s, I highly recommend you purchase the matching Principia stands ($199/pair). Not only does the stand complement the design beautifully, it covers the bottom port correctly. An added bonus is that the matching stands fasten to the speakers with screws, which makes for a very safe and solid connection.


The Principias 3s arrived well protected in thick foam inside a double cardboard box. That double-box was shipped within another box, so technically my speakers were triple-boxed. Considering that Sonus faber is selling these speakers through non-traditional markets as well as audio shops (you can get these on if you wish), the sturdy packaging was a wise decision. My units were shipped via UPS and came through undamaged so that says something in itself. Unboxing was a simple task but I was pleasantly surprised at how heavy each Principia 3 was.

Sonus faber Principia 3 Bookshelf Speaker Stand

Placing the Principia 3s in my media room was pretty easy. I was fortunate in that the Dynaudio Stand 4s I use had a large enough mounting plate to cover the whole bottom reflex port properly. The Principias would be temporarily replacing my beloved Sonus faber Olympica IIIs (see review here) so I lugged them out of the way and connected the 3s to my primary system consisting of a Wyred 4 Sound multi-channel amp, Marantz AV8801 Pre-processor and an Oppo BDP-83SE Nuforce Edition Blu-ray player. Since I typically use a bi-wired speaker setup, I removed the metal jumpers between the two sets of binding posts and connected my Kimber 4VS bi-wired speaker cables via banana plugs. The front channels of my amp are capable of putting out over a kilowatt (1000W) worth of power at the Principia 3s 4-ohm resistance rating so I made a mental note to watch the volume levels as I could probably melt the voice coils if I weren’t careful.

With everything connected, I hooked up my XTZ Room Analyzer II Pro kit and started tweaking the position of each speaker using the Real-Time-Analyzer function to visibly see the effects of each movement. I found the Principia 3s to be fairly forgiving of room placement. Midrange and treble response did not vary too much as I moved the speaker around. I found that placing them about two feet from my front wall gave the best bass response. This was about two feet closer than I usually place a speaker in my room. Typically, I would expect a lot of bass bloat with the speakers this close to the wall, but that didn’t seem to be the case with the Principias – their bottom reflex port really does work.

After a bit of trial and error, I settled on keeping the speakers each about five feet from the side walls which put them around seven feet apart. This seemed to give me the most even midrange and treble response. With the position set I then worked on toe. Using a combination of Room Analyzer II Pro software and some good vocal test tracks, I settled on aiming each speaker almost directly ahead with just a bit (five degrees) of toe-in. This seemed to give the smoothest overall midrange and treble without negatively impacting imaging or sound staging. The sloped front baffles aimed the tweeters almost directly at my ear level, so I didn’t need to change the rake at all. I left the speaker grilles off for my entire time with the Principias. Removing them increased detail and articulation slightly (and I mean very slightly), plus I thought the speakers just looked so much better uncovered.

Sonus faber Principia 3 Bookshelf Speaker In-Room Response

Sonus faber Principia 3 Bookshelf Speaker In-Room Response

You can see my final in-room frequency response curves above. These are measured at my primary listening position and as such are indicative of what my ears actually heard, room artifacts and all. You can see that the speaker is pretty flat with a few exceptions. The bass peaks around 50Hz and 125Hz are room-induced due to my seating position. There is also a bit of excess energy from 800Hz up to about 1250Hz as well as from 2kHz up through about 4kHz. This upper-midrange/presence region rise was even more pronounced with the speakers more toed-in towards the listening position. Bass response went deeper than I anticipated, with solid output down to about 35Hz. Bass tapered off quickly beneath that level, but this is very good for such a relatively small speaker. While I was not able to capture it here, I did experiment with tilting the speaker off the stand base. Each time I did that I saw the output below 45Hz taper off noticeably, reaffirming the need to keep the bottom port channel completely covered.

Prior to taking any measurements, I ran the Prinicipia 3s for about two weeks straight (300 hours) to break them in. While there was not a tremendous difference in the overall sound, bass speed and transients improved as the mid/woofer opened up and there was a subtle increase in the smoothness of both the midrange and treble.

In Use

With the break-in, setup, and measurements out of the way, it was finally time to sit down for some serious listening. Unless otherwise stated, all content was played via analog output from my Nuforce Edition Oppo universal player directly into the Marantz pre/pro set to Pure Direct mode which shuts down all Audyssey processing and subwoofer output.

Norah Jones

Norah Jones “Day Breaks”

The first disc up was Norah Jones’ latest Day Breaks (CD: Blue Note B01J81LH4E). While I’ve enjoyed Ms. Jones past few albums, Day Breaks is a return to the style of her stellar debut Come Away With Me. The intro track “Burn” is one of my favorites on this disc. Through the Principias, Norah’s vocals sounded very natural but just a touch forward.

Vocals were kept firmly centered in the soundstage with the backing instruments seemingly positioned to either side and slightly behind the singer. The Principias seemed to project a real sense of space, which is rare for a speaker of this price. Piano notes had a great sense of body and the reverb of each one just clung to the air before decaying away, much like you’d hear from a live piano. Higher notes displayed just a touch of extra energy on the initial strike, but it only contributed to a feeling of greater musical detail. The Principias really seemed to articulate Norah’s fabulous vocals. Bass and mid-bass response really impressed me as well. There is a great bass line in “Burn” and the Principias really did it justice. The natural bass was very tight and had enough depth to sound convincing. Considering that I was running the speakers without a sub, I was even more impressed.


Rachmaninoff “Symphonic Dances”

Since I enjoyed Day Breaks so much through the Principia 3s I dropped in my old standby, Rachmaninoff’s Symphonic Dances (CD: Reference Recordings RR-96CD). I wound up listening to the majority of the disc, as I was just so impressed with how well these $699 speakers were doing.

The musical midrange that Sonus faber is known for was very apparent, with string and woodwind instruments sounding great. Yes, there was a little bit of extra energy to some of the strings but again, it just added a greater sense of detail to the sound. The soundstage was nicely spread out and I could easily discern where certain instruments were placed on the stage. Image depth was good, with the sound presentation again being just a bit forward of the plane of the speakers. I kept turning the volume up as I listened and didn’t hear any distortion creeping through. This is a very dynamic disc and the Principias did a very good job transitioning between softer, more delicate sounds and more bombastic drum hits. Speaking of those drum hits, bass was tight, deep, and natural even at reference level volume.

Stevie Ray Vaughn

Stevie Ray Vaughn “The Sky is Crying”

Moving on to my SACD copy of Stevie Ray Vaughn’s The Sky is Crying (SACD: Mobile Fidelity Koch B0041IU1GA), I started with the title track. This disc is a bit brighter in tone than Day Breaks and I could definitely notice the difference through the Principias. SRV’s Stratocaster had a lot of bite to each note but I really liked how much detail I was hearing.

While I’m not typically a fan of speakers that are brighter through the upper midrange and lower treble, I was able to hear some subtle details in SRV’s picking technique that I didn’t recall noticing before. Again, the word articulate comes to mind to describe what I was hearing. Stevie’s vocals sounded very good though they seemed a touch shaded in the lower range of his voice, at least compared to more expensive speakers. As was the case with “Day Breaks,” bass and mid-bass continued to be a real shining point for the Principias. Having sampled a vocal track, I skipped forward to Stevie’s rendition of “Little Wing” and turned the volume up. At higher levels (above 90dB), the extra presence region output of the Principias was definitely more noticeable, but it still wasn’t harsh to my ears. I continued to enjoy the added detail the Principias were allowing me to hear but wondered how the speakers would fare with some less well-recorded music.


Metallica “Hardwired…to Self Destruct”

Conveniently, Metallica’s latest album, Hardwired…to Self Destruct (CD: Blackened B01KP8CSWE) was released before I had to send the Principias back. Personally, I think this is Metallica’s best work in a long time. Combining elements and styles from just about every one of their prior albums, Hardwired forges a set of songs that stand very well on their own.

Of the 12 total tracks, I foresee at least four becoming regular additions to Metallica’s live sets. While Hardwired was mastered infinitely better than the frankly atrocious Death Magnetic, it is not without issues. Someone at the mastering console was a little too generous with the EQ sliders and the result is a bright sounding album. While I appreciate the fact that you can actually distinguish amplifier breakup on the guitar tracks, there is enough sonic glare in the mix that it can sound really harsh at higher volumes. Of course with the songs being so good you WANT to crank these discs up. “Spit Out the Bone” is pure thrash-metal and possibly my favorite song on the album. Through the Principias, this track was a bit fatiguing. While the bass, mid-bass, and lower midrange sounded great, the bright recording combined with the extra presence-region energy offered by the Principias was not a good combination. The overdriven guitars and James Hetfield’s voice were just a bit too etched sounding for my taste. For the first time in my listening I found myself engaging the Audyssey mode on my pre/pro. This smoothed out the upper midrange nicely and took most of the edge off the sound. I could then crank up the volume to “appropriate” levels (95db+) without suffering too much ear fatigue. Unfortunately, engaging Audyssey also took away some of the life and detail from the midrange (as it does with any speaker) but you can’t get something for nothing.

Just for comparison’s sake, I switched back to my much more expensive Olympica III towers and replayed “Spit Out the Bone” in Pure Direct mode. Sure enough, the track still sounded harsh, but the Olympicas did a better job of keeping the brightness in check than the Principias. Considering the nearly $10,000 price difference between the two, this is not surprising. I would recommend pairing the Principias with sources and components that are on the darker side of neutral, particularly in the upper midrange and treble. This would help smooth out poorer quality recordings without doing too much harm to sources that are better mastered. Room EQ systems like Audyssey are another easy fix, though they have their own drawbacks.


Sonus faber Principia 3 Bookshelf Speakers

THE PRINCIPIA 3 BOOKSHELF SPEAKERS Are a Great Value and a Fitting Entry to the Sonus Faber World.

  • Articulate midrange
  • Detailed treble
  • Good bass extension given the driver and cabinet size
  • Good imaging and sound-staging
  • Can be played surprisingly loud before distorting
Would Like To See
  • A choice of finish options would be nice
  • Higher quality binding posts
  • Additional clarity in the mid-range
  • Reduced bite in upper midrange/lower treble

Considering their price point of $699 per pair, the Sonus faber Principia 3s do an awful lot of things right. Key attributes include excellent bass response and accuracy, musical midrange, clean treble, and very good dynamics. Top that off with the solid build quality and great aesthetics Sonus faber is known for and you have a very impressive overall package. Even the slightly-elevated presence region could be considered a benefit to listeners who value retrieval of detail over a more musical approach. As long as you don’t pair the Principia 3s with overly bright source gear they will serve you very well with just about any type of music. While I can’t say that the Principia 3s deliver “perfect sound,” they are some of the most engaging sub-$800 speakers I’ve yet heard and are a great stepping stone into the world of high-fidelity audio.