Full review and laboratory test of the Yamaha NS-5000 Loudspeakers by Australian Hi-Fi Magazine. Free download.

Yamaha has a longer history in the musical instrument business than it does in the hi-fi business, having been established in 1887 in Japan to manufacture pianos and reed organs. (Which is not to say that it doesn’t have a long history in the hi-fi business. Just for the record, that history started in 1922, when Yamaha built its first phonograph.)

The company's musical history is reflected by the company’s logo which, if you examine it closely, comprises three interlocking tuning forks.

Indeed Yamaha is still one of the largest piano manufacturers in the world, not least because in addition to manufacturing its own Yamaha pianos it now also manufactures pianos for Bösendorfer. So it’s safe to say that its skills in manufacturing musical instruments inform its skills in manufacturing hi-fi components, not least of which are the Yamaha NS-5000s, which have assumed the mantle of being the company’s flagship loudspeakers.

The Equipment

Yamaha’s musical instrument heritage is immediately evidenced in the absolutely superb piano black gloss painted finish of the NS-5000’s cabinetry and the precision with which the three drivers are built and fitted into each cabinet. If you examine most gloss-finished speakers carefully, you can see their surface looks ‘dented’ like the skin of an orange. Indeed this flaw is known by spay-painters as ‘orange peel’, but when I examined the surface of the Yamaha NS-5000s, I saw only a perfectly smooth, rich, deep gloss-black finish… just as if I were examining the surface of a Yamaha grand piano… or a Bösendorfer grand piano.

Obviously this is partly because of the quality of the paint that’s used, the number of coats applied, the rubbing between coats and the skill of the painters applying it, but it’s also because the paint is not applied over industry-standard MDF. Yamaha instead uses white birch plywood sourced from the Japanese island of Hokkaido for all the panels. Because of the cold climate, this type of birch is harder and has a tighter grain than most others, which not only creates a far better surface for the paint, but apparently is also sonically superior to MDF.

The front baffle of the NS-5000s is 29.5mm thick and all other panels are 20mm thick. A combination of steel bracing and wood strut bracing is used internally to control panel resonances, plus there’s a ‘J’-shaped acoustic absorber inside that Yamaha says eliminates standing waves within the cabinet. Each cabinet is 690mm high, 395mm wide and 381mm deep but in your room they’ll be substantially higher, because they’ll be elevated on stands which, I am very pleased to be able to report, are included in the price of the speakers.

As should be obvious from the photographs accompanying this review, the Yamaha NS-5000 is a three-way, three driver design. All three drivers looked distinctly different from any other drivers I have ever seen, and it turned out that this was because they’re all made using a material—Zylon—I had never previously heard of being employed in the manufacture of loudspeakers. This discovery, of course, led to an internet search whose first result informed me that Zylon was the tradename for a particular type of thermoset liquid-crystalline polyoxazole known as ‘p-phenylene-2,6-benzobisoxazole. Not being a chemist—and suspecting that few people reading this review would be either—I looked for a more user-friendly description and discovered that Zylon is the world’s strongest man-made fibre, one whose cross-sectional strength outperforms both steel and carbon-fibre. Zylon cord is apparently widely used for shrouds and stays on modern racing yachts, where it replaces stainless steel rigging.

My internet searching also revealed that Zylon is not only the strongest man-made fibre in the world, it’s also stronger than beryllium, with a tensile strength of 5.8 gigapascals (compared with only 0.24 gigapascals for beryllium). It’s also lighter than beryllium, with a density of 1.55g/cm³ compared with beryllium’s density of only 1.8g/cm³.

On the NS-5000, the Zylon cones and domes are coated with Monel, an aerospace alloy containing nickel, copper and iron. This presumably stiffen the cones and domes, but the coating is also necessary because if left uncoated, Zylon can be degraded by both ultraviolet and visible light, so the Monel also provides a light-proof coating to prevent this. It’s worth noting at this juncture that Yamaha provides a 10-year warranty on the NS-5000 speakers, which I believe to be not only the longest in the loudspeaker industry, but also twice that offered by all but a few manufacturers. In addition, the NS-5000 also comes under Yamaha’s one-year ‘new-for-old’ umbrella warranty so that in the unlikely event of the speakers needing servicing within 12 months of purchase, Yamaha will give you a brand new pair of NS-5000s.

The bass driver in the NS-5000 is very large. The company says 300mm, but overall it’s actually larger than this: I measured 328mm. Even the mounting hole diameter (the dimension usually quoted by manufacturers as ‘diameter’) was 305mm. But the important dimension is the Thiele/Small diameter, which I measured at 260mm, which puts the effective cone diameter (Sd) at 530cm². The frame of the bass driver is cast, enabling thin supporting legs that in turn enable maximum air movement behind the cone to energise the rear-firing bass reflex port. The driving magnet is huge—around half the width of the driver itself—and the 75mm-diameter voice coil is wound using square wire, a technique that puts the maximum amount of copper in the gap to improve both efficiency (which Yamaha quotes at 88dBSPL at one metre for a 2.83V input) and power-handling ability.

The midrange driver is extremely unusual, being a 75mm dome driven (obviously!) by a 75mm diameter voice-coil. Only a handful of companies in the world make 75mm dome midrange drivers, most of them based in the UK and Europe. US manufacturer Electro-Voice once made a beauty. The benefits using a 75mm soft-dome driver as a midrange driver are the power bandwidth extension at the low-frequency end and that you can get the resonant frequency down low enough that you can cross it at a low enough frequency to get a good transition to a large-diameter bass driver, as is done at 750Hz here in the NS-5000, plus the dome is small enough to enable a perfect transition to the tweeter at the upper end of its range—4.5kHz in this case.

Other advantages of using a dome midrange include very low harmonic distortion—typically –45dB HDL² and –63dB HDL³. I once asked Australian loudspeaker design engineer Billy Woodman—whose midrange dome design for ATC is probably the world’s most-copied—to tell me why, if 75mm dome midrange drivers were so good, so few companies manufactured them. His answer? ‘Because they’re so difficult to make and they’re so bloody expensive!’ The primary problem is apparently the composition of the material used to form the dome, because if it’s too soft it will deform, while if it’s too hard it will have a poor frequency response… and there’s apparently very little leeway between ‘too hard’ and ‘too soft’. Yamaha has obviously solved this problem thanks to its use of its Zylon/Monel combo.

The tweeter is a 25mm dome driver that, apart from the material used to form the dome, looks fairly conventional from the outside. However, the rear of the dome is anything but, because it has what Yamaha calls a ‘resonance suppression chamber’ behind it that uses multiple tubes of different lengths to control the back-waves from the dome to improve its performance. The same type of tubing system is also used behind the midrange driver. Any readers who have noticed that Yamaha’s RSC system is designed to accomplish the same end as B&W’s famous ‘Nautilus’ system can go straight to the top of the class.

As you can see from the photographs, the NS-5000 doesn’t have a grille as such. Instead a separate metal protective grille is provided for each driver. These grilles attach magnetically. I personally liked the look of these but I think Yamaha may have been wise to also offer a conventional full-sized black cloth grille as an option.

The NS-5000’s bass reflex port is located high on the rear baffle and has a curious ‘twisted’ appearance. Yamaha calls this a ‘twisted flare’ and claims that it eliminates chuffing. Other manufacturers use similar perturbations in their ports to achieve the same end. In common with many other manufacturers, Yamaha also provides multiple foam bungs that can be used to plug the ports to alter the low-frequency response of the speakers to best-suit the room in which they’re being used, their position in that room and, of course, listeners’ personal tastes.

In Use and Listening Sessions

The NS-5000 has only a single set of speaker terminals—a very high-quality set, to be sure, but a single set nonetheless—which means no bi-wiring or bi-amping. The terminals are seemingly located in an odd place… down very low on the rear baffle, but this is actually an ideal location because it means the speaker wire is mostly hidden from sight by the rear leg of the speaker stand.

I can describe the sound of Yamaha’s NS-5000 speakers in a single word: Effortless. Indeed the sound from the Yamahas was so effortless that for almost all my listening sessions, I had the uncanny sense that the speakers weren’t ‘there’ at all, and that I was listening to live music. I have experienced this with only a handful of loudspeakers in my lifetime, all of which cost far more than the NS-5000s. The sense of effortless is difficult to express in writing, but perhaps the most obvious characteristic is that the sound doesn’t seem to be issuing from the speakers at all, but is instead just created in the air around you. And by this I don’t mean the sense of focus you get when you move into the ‘sweet spot’ of a pair of speakers, it’s instead a sense of space.

Effortless also describes the bass delivery from the NS-5000s. Sure it was tight, and sure it was punchy, but whereas many speakers seem to have to work hard to deliver tightness and ‘punchiness’, the Yamahas just delivered bass with a total sense of effortless and ease, as if they weren’t even trying. I suspect a good deal of this is the size and design of the driver itself. Most manufacturers are trying to use multiple small drivers to deliver bass to avoid the cost and crossover problems that are part and parcel of using a large-diameter bass driver. Yamaha’s uniquely profiled 328mm driver, with its Zylon/Monel cone and powerful motor system, simply provides superior bass… bass where you can really feel the low frequencies, rather than just hear them… and bass that’s totally free of unwanted overtones, so you hear only the notes that are played, at the exact time they’re played, and for the precise duration. If you’re wondering how this could be, consider that every time the NS-5000’s bass drivers move, they’re displacing 1,060 square centimetres of air (left and right bass drivers combined). Some other manufacturers use as many as four 170mm-diameter drivers in each channel to deliver bass. Visually, this may look impressive, but in reality, such a system would displace only 984 square centimetres of air, so you can see that Yamaha’s two large bass drivers move more air than eight smaller bass drivers.

Bass quantity and quality will, of course, be affected by where you place the speakers in your room and the ‘bung status’ of the rear-firing bass reflex ports, remembering that bung status doesn’t have to be the same for the left and right speakers. If, for example, your left speaker is closer to a wall than your right speaker, which would tend to lift the level of bass a tad, you might have to ‘bung’ the left speaker to more closely-match its low-frequency output to that of the right speaker, so spend considerable time working out which combination is best for your setup. In my listening room, the left and right speakers were identical distances from both rear and side walls, and I found I liked the bass from the NS-5000s the best when I didn’t use any bungs at all. When playing favourite tracks from Jean Guillou’s album for Dorian, The Great Organ of Saint Eustache, which has some lovely versions of music from Bach, Mozart, Liszt, Charles-Marie Widor, and Nicolas De Grigny, the NS-5000s were very impressive, delivering the deep organ notes with heft and authority.

The midrange sound from the Yamaha NS-5000s combined studio-monitor level accuracy with true-to-life sonic quality. The result was astonishingly good sound. It’s an unfortunate fact that many studio monitors have flat frequency responses across the midrange, but are tonally incorrect (usually too crisp), while other speakers that have a neutrally balanced sound don’t have a flat response across the midrange so you hear unevenness in the sound. Yamaha’s NS-5000s are both flat and tonally correct. The clarity of Alicia Keys’ voice, as replayed by the NS-5000s, was uncanny for its precision and tone, and they were able to reveal, for example, on her album ‘Here’, how well she can change the tone of her voice to best-suit the song, sometimes roughing it up, and at other times making it sound beautifully sweet. The accuracy of the Yamaha’s sound was also beautifully evidenced by the sound of Simone Dinnerstein’s Steinway D as she plays Bach’s Goldberg Variations (on Telarc CD-80692). You can clearly hear her weighting the keys and when she holds a note, the sound dies away perfectly for the entire time she sustains. The attack of the hammer on the string was also perfectly delivered, no matter how hard (or softly) the key was struck.

High frequency performance just followed on organically from that of the midrange, and I certainly could not hear when sound transitioned from the midrange to the tweeter: the transfer of sonic duties was seamless. Yamaha’s soft dome tweeter delivered that elusive ‘air’ around the high harmonics, and also delivered the high frequencies at the correct level to well beyond the capability of the human ear to hear them… and it did all this without any unwanted harshness or ‘zing’, even when I elevated the volume levels to beyond what I’d usually consider prudent: both for the safety of the tweeters themselves and the comfort of my neighbours.

While I was playing at high levels, I was impressed by the extraordinary dynamism of the NS-5000s, revealed beautifully when, for example, Martha Argerich was in full flight playing the many climaxes in the first movement of Rachmaninov’s Piano Concerto No. 3. The Yamahas were also able to illuminate the exceptional degree of interplay between piano and orchestra, one that’s rarely achieved because most pianists focus too much on the keyboard and not enough on the music as a whole… though Riccardo Chailly also deserves much credit here for this.

Conclusion

I could not conclude this review without referencing one of the most innovative and successful loudspeaker designs of the modern era, the Yamaha NS-1000 and NS-1000Ms, which were also the first-ever speakers to use beryllium tweeters. These speakers were wildly successful for Yamaha and ended up in a good many recording studios around the world, as well as in thousands of high-end audio systems. They’re revered for their sound quality and performance to this day, but these days are also collectors’ items… as you’ll discover if you try to buy a pair second-hand!

I need to reference that famous design because these new NS-5000s are superior in every way, so I feel completely confident in predicting that they will become even more famous than those speakers, and even more sought-after.

But of course you should not be buying loudspeakers based on their fame or their ‘collectability’… you should be buying loudspeakers because of their performance, and the manner in which they deliver music into your listening space, and here you should be in absolutely no doubt that Yamaha’s NS-5000s will deliver music to your room with absolute sonic realism. They sound superb. # greg borrowman

POSTCRIPT: In order to use any main speakers in conjunction with the Yamaha NS-5000 Loudspeakers you will need to ensure correct integration of the subwoofer's output with that of the main speakers by setting the subwoofer's volume, phase and crossover frequency controls correctly. You can read an article on a simple, effective method of how to do that HERE

Readers interested in a full technical appraisal of the performance of the Yamaha NS-5000 Loudspeakers should continue on and read the LABORATORY REPORT published on the following pages. Readers should note that the results mentioned in the report, tabulated in performance charts and/or displayed using graphs and/or photographs should be construed as applying only to the specific sample tested.

Laboratory Test Results

Newport Test Labs measured the in-room frequency response of the Yamaha NS-5000 speakers using a pink noise test stimulus and you can see the result in Graph 1. This graph is unsmoothed, though the fact that nine traces have been averaged to obtain this one trace does introduce a slight smoothing effect as a result.

As you can see, the trace is superbly flat and is superbly extended both down into the deep bass and also out to the extreme treble, where the NS-5000’s tweeter is still going strong right out to the upper calibrated measurement limit of 40kHz. At the bass end, the trace is 3dB down at 38Hz, so overall, the response of the NS-5000 was measured by Newport Test Labs as being 38Hz to 40kHz ±3dB.

Graph 2 shows the high-frequency response in greater detail, showing the response that would be obtained in an anechoic chamber, and without some of the inherent smoothing of a pink noise trace. You can see that despite the increased detail and resolution enabled by the gating technique, the NS-5000’s response is still exceptionally linear out to 17kHz. Above 17kHz there’s a peak centred at around 21kHz that rises to +6dB before returning to +3dB at 30kHz, then to around –2dB at 40kHz. This is a superb result: not least because few adults will be able to hear frequencies above 17kHz anyway, and those few that can would be unable to perceive such a minor increase in level at such high frequencies. The very slight dip at 4.5kHz (the crossover frequency) is caused by cancellation at the microphone due to the measurement technique used, and should be ignored.

Low-frequency response, measured using a near-field technique that simulates the response that would be obtained in an anechoic chamber, is shown in Graph 3. You can see that with no bungs in the bass reflex port, the bass driver shows the classic ‘bass reflex’ tuning, where the woofer’s response rolls off down to the port resonance frequency, then rises below it, before falling away (black trace). The port’s output, meanwhile (black dashed trace) peaks at 25Hz (slightly below the minima at 28Hz) to ensure output at low frequencies. When the port is completely blocked off, the alignment becomes that of a sealed cabinet, with the response rolling off smoothly, and increased output from the driver itself at low frequencies (red trace). Using a half-bung (green traces) takes a path midway between. I am surprised at how effectively you are able to tune the NS-5000’s bass response with the bungs—Yamaha has obviously put some very serious design effort into ensuring these alignments are truly effective in adjusting the low-frequency response.

The impedance of the Yamaha NS-5000 is shown in Graph 4, and the first thing you should notice is that the traces for the left and right speakers are almost identical right across the frequency band, which indicates superb quality control and driver matching at Yamaha’s factory. The ‘saddle’ between the two low-frequency resonant peaks (one at 14Hz; the other at 50Hz) is at 26Hz, showing that you won’t get much low-frequency output below this frequency if you use the bass reflex tuning (no bung), whereas the green trace, where the cabinet has effectively been sealed, shows that with this alignment you’ll be able to get low frequency response to below 26Hz.

The impedance remains above 5Ω out to 7kHz, where it dips to 3.6Ω at 20kHz before rising, which means the NS-5000 will be a very easy load for any amplifier. The high-frequency dip effectively means the NS-5000 should be listed with a nominal impedance of 4Ω, according to IEC standard 268-5, but the fact that the dip is so high in frequency means a 6Ω nominal rating would be closer to the ‘real-world’ impedance, exactly as specified by Yamaha.

Newport Test Labs measured the sensitivity of the NS-5000 at 86.5dBSPL at one metre, for a 2.83Veq input, which is very slightly below the average 87dBSPL efficiency for large, floor-standing speakers and 1.5dB lower than Yamaha’s rating of 88dBSPL. However, since Newport Test Labs’ measuring protocol is very strict, the 86.5dBSPL result is excellent. It means you won’t need a hugely powerful amplifier to drive the NS-5000 to its maximum SPLs.

Graph 5 is a composite graph that splices the in-room pink noise low-frequency response (from Graph 1) to the gated high-frequency response from Graph 2, while Graph 6 shows all the responses measured so far on the same graph, and adds a (pink) trace of the midrange driver.

Yamaha’s NS-5000s returned exceptionally good measured performance in all the tests conducted by Newport Test Labs. I wholeheartedly recommend them as a truly superior speaker design. # Steve Holding