Sony SS-NA5ES loudspeaker Measurements

Sidebar 3: Measurements

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Sony SS-NA5ES's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield. My estimate of the Sony's voltage sensitivity was 86.7dB(B)/2.83V/m, which is very slightly higher than the specified 86dB. The SS-NA5ES's electrical impedance is specified as 4 ohms, but, as can be seen in fig.1 (solid trace), the impedance remains above 4 ohms at all audio frequencies other than the lower midrange, where it reaches a minimum value of 3.4 ohms at 220Hz. However, the electrical phase angle (dotted trace) is extreme at some frequencies—there is a combination of 5 ohms and –40° at 130Hz—and the speaker will thus sound best when used with amplifiers that are comfortable driving 4 ohms.

Fig.1 Sony SS-NA5ES, electrical impedance (solid) and phase (dashed) (5 ohms/vertical div.).

The impedance traces are free from the small wrinkles that would imply the presence of enclosure resonances of various kinds. When I investigated the cabinet walls' vibrational behavior with an accelerometer, I did find a relatively strong resonant mode at close to 600Hz on both sidewalls (fig.2). However, this resonance is of sufficiently high frequency and Quality factor (Q) that it shouldn't affect the speaker's midrange character.

Fig.2 Sony SS-NA5ES, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of side panel (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

The saddle centered on 55Hz in the impedance-magnitude plot (fig.1, solid trace) suggests that this is the tuning frequency of the twin 1.5"-diameter reflex ports on the Sony's rear panel. The blue trace in fig.3 shows the woofer's output, measured in the nearfield, and it does indeed have a sharply defined notch at 55Hz, where the back pressure from the port resonance holds the cone still. The port's output (red trace) peaks sharply between 40 and 70Hz, suggesting that the woofer alignment is of fairly high Q; and the black trace, which shows the complex sum of the woofer and port outputs, scaled in the ratio of the square roots of their radiating areas and taking into account the time delay caused by the ports being mounted on the cabinet's rear, does have a slight residual peak. Though there are a couple of peaks in the ports' midrange output, these are well down in level.

The underdamped woofer alignment presumably gives the impression that the SS-NA5ES has more bass than its 55Hz tuning frequency would suggest; I suspect that the excess of energy above 8kHz in fig.3 is intended to balance the low frequencies. But other than that, the Sony's farfield response on the central tweeter axis is superbly flat from 300Hz to 8kHz. This graph was taken without the grille, which introduced a 4dB peak between 4 and 5kHz, and a 6dB suckout centered at 6.5kHz; for serious listening, the grilles are best discarded.

Fig.3 Sony SS-NA5ES, anechoic response on central tweeter axis at 50", averaged across 30° horizontal window and corrected for microphone response, with nearfield responses of woofer (blue), port (red), and their complex sum (black), respectively plotted below 300Hz, 625Hz, and 300Hz.

The SS-NA5ES's lateral dispersion (fig.4) is superbly evenly balanced—something that correlates with precise, stable stereo imaging—with no off-axis flares or suckouts evident. The speaker does become more directional above 7kHz, which, in rooms that are not too small or dry, will tend to work against the top-octave boost on-axis becoming too audible, as AD found. In the vertical plane (fig.5), suckouts develop in the crossover region more than 10° above and below the central tweeter axis, and the use of multiple tweeters does give rise to a complex radiation pattern above 4kHz.

Fig.4 Sony SS-NA5ES, lateral response family at 50", normalized to response on central tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

Fig.5 Sony SS-NA5ES, vertical response family at 50", normalized to response on central tweeter axis, from back to front: differences in response 45–5° above axis, reference response, differences in response 5–45° below axis.

In the time domain, the Sony's step response (fig.6) indicates that all four drive-units are connected in positive acoustic polarity. While the combined outputs of the three tweeters—the sharp up/down spike at the 3.7ms mark—leads that of the woofer, the delay of the tweeters' step smoothly blends into the start of the woofer's step, indicating optimal crossover design. The SS-NA5ES's cumulative spectral-decay plot (fig.7) reveals a superbly clean decay throughout the midrange and treble. While the cursor indicates a small ridge of delayed energy at 1200Hz, this is well down in level.

Fig.6 Sony SS-NA5ES, step response on central tweeter axis at 50" (5ms time window, 30kHz bandwidth).

Fig.7 Sony SS-NA5ES, cumulative spectral-decay plot on central tweeter axis at 50" (0.15ms risetime).

Like Sony's more expensive, floorstanding SS-NA2ES, which I reviewed in September 2013, the SS-NA5ES is a well-engineered loudspeaker.—John Atkinson

Sony Electronics, Inc
16530 Via Esprillo
San Diego, CA 92127-1708
(858) 942-2400

BradleyP's picture

The dealer network for these primo Sonys seems a bit, um, unconventional. $6k standmounts are the purview of high end brick-and-mortar shops, but these are not available in such shops. Perhaps the distributors are custom installers, but I can't quite tell from the Sony ES website. That's quite a hindrance.

koshy1972's picture

I guess you can find your nearest dealer from this website.

Seems like not so many inventories left, so probably took some time to receive. Hope this helps.

Anon2's picture

I am sure that these speakers sound fine. But we are to pay $6,000 for some Scanspeak drivers in a laminated wood enclosure?

I hope we can see a test of these--reportedly outstanding--speakers for $2,500 less:

Or for roughly the same price, we can afford ourselves of a tried and true design, with some elements of advanced materials science:

And for less than 1/2 the price, it might be time for a very long overdue test of these speakers that boast plausible technology, perhaps better than this product under review, and the same billed weight:

If I were so endowed financially, I might save my pennies for another year or so and get these highly decorated stalwarts:

And, based on my actual experience of listening at a show, we might, again, save a few more dollars and get this speaker which has some proprietary technology to bring to the table:

It might be time for Stereophile to emulate our friends from the UK and do some head-to-head group testing of products. $3,500 for this product? Maybe. $4,000 is a stretch. But $6,000? I don't know.

Allen Fant's picture

Nice job! AD
it is good to see Sony ES back in the speaker facet of our wonderful hobby. Most will snub Sony for making speakers, this is just one reason why there is not better representation in the B&M world. Sony knows their customer base and has corresponding dealer/retailers strategically placed across the USA.
Further, back in the early 1990's Sony has a set of "ES" marqued speakers that were for home Audio and car Audio too.
A very fine return to form, IMO. Happy Listening!

Anton's picture

First, great post, low2midfi! I am with you!

Regarding these new Sony speakers.

I hope they are great and wish Sony the best. The main problem I would say "I have" with makers like Sony or Technics is that they disappear from the hobby for X number of years, then 'mount an assault on the state of the art' with products like this, then disappear again shortly thereafter.

I have not seen a tradition of models evolving or being improved over time, no evolution of a model (think Vandersteen, Thiel,) etc... These models are hit and run, which I think diminishes their value.

If you look at the history of many (most?) of the most esteemed speakers in this category, they have a history of incremental improvement and of ongoing product support, even trade ups!

So, I don't give this new Sony as much credibility as its price wants me to, because this speaker will be out of production in a cycle or two. I know this because I know Sony's history in this regard.

So, enjoy the speaker now, but it's a bit of a 'one night stand mount' product when compared to models that have traditionally 'stand mounted by their man' over time.


funambulistic's picture

I bought a pair of Sony ES SS-M5 speakers in '97 from my local brick-and-mortar store at a VERY large discount. The discount was primarily because of the Sony badge (though they were hardly a Sony speaker). I was shopping around with the various brands this retailer carried in my price range (Definitive, Paradigm, B&W, etc.) and, for the price, the Sony's were a clear winner; in fact, they were some of the best speakers I have ever owned (how I parted with them is rather tragic). They were shortly discontinued and only the SS-M9 (with the new "super tweeter") continued on for a year or two. I am glad Sony, Technics and Pioneer (or TAD) have new "SOTA" speakers, but, for what they do, their prices are too dear. I would rather stick with a manufacturer that constantly improves their product (as you mentioned, Vandersteen, for example) than what most certainly will be product on a limited run.

avanti1960's picture

I have heard these speakers on a few occasions and immediately noticed that they have a distinctive, somewhat unique character when compared against other stand mounts of similar size. A few listens with familiar program material and you know what they are all about. It is very obvious.
Yet a terse (or any) description of their sound was nowhere to be found in the text. A few words about it would have been most helpful because these speakers are not neutral and their sound flavor might be construed as polarizing.
Being familiar with their sound and then reading the review has given a unique perspective- one that makes me wholly disappointed in what I have read because it failed to communicate their essence.

Anton's picture

Would you be willing to elaborate on your impressions?

This is interesting!

Echolane's picture

I wish I knew more about what you meant when you said the reviewer failed to communicate their essence. Do tell.

I’ve been quite taken with these speakers since I read about them a year ago and, sadly, too late to acquire them. I think they would have been perfect in my TV room system. Their size would have been perfect. Their bass capability was remarkable for the size of the speakers and that and their excellent mid range would have perfectly suited the music I like to listen to, opera and classical. Trying to find thrm used is nigh onto impossible because so few were sold apparently. One ES dealer I spoke with who carried them said he would be surprised to learn Sony sold more than 100-200 total in the US. I think they got overlooked by the audiophiles community because they weren’t properly distributed to non-ES dealers. And then there’s the problem what audiophiles are t axxosrumed to thinking of Sony as capable of audiophile capability. What a shame.k

Echolane's picture

Yes, please elaborate on what you hear that is unique. The many reviews are all very interesting, but actually very little is actually said about how they sound,
I am looking for them in the used market as they have been discontinued just as several reviewers forecast. What a shame because I am convinced they were quite special.