nOrh Synthetic Marble 6.9 Loudspeakers

Surprising Performance in a Moderately Priced Package

White nOrh SM 6.9

Product: nOrh SM 6.9 loudspeakers
Manufacturer & Distributor: nOrh Loudspeaker Co. - Taiwan
Retail price: $995 USD/Euro per pair, including shipping
Reviewer: Richard George
Reviewed: December, 2001

The nOrh Loudspeaker Co. of Thailand is proving to be a very prolific audio equipment manufacturer indeed. Not satisfied with producing excellent and highly acclaimed loudspeakers, ranging from the inexpensive, multimedia 3.0 speakers to the extraordinary, top-of-the-line 9.0 Marble speakers, nOrh has continued to refine its existing loudspeakers and to develop new speakers that capitalize on lessons learned from past projects. The latest in their line of unique loudspeakers is the nOrh SM 6.9, the subject of this review.

The high-end nOrh loudspeakers, the 7.0 and 9.0, are noted for their unusual shape and renowned for their exceptional sound quality, sound which is undiluted by acoustic anomalies created by, or passed through the speaker cabinets. Ideally, direct radiating sound from the drivers is all that can be heard from any speaker, but in reality most cabinets color the sound output due to cabinet design or material choice, or both. The drum shape of nOrh speakers prevents standing waves within the cabinet, standing waves that reinforce certain frequencies and could adversely affect sound output of the drivers. In addition, the dense marble from which the cabinets of the 7.0 and 9.0 are made simply does not resonate at any frequency that audibly alters or colors sound emanating from the speakers. Finally, the 7.0 and 9.0 speakers utilize very expensive components, including high-end ScanSpeak drivers. With the introduction of the SM 6.9, nOrh has attempted to achieve sound quality output as close to the performance of its high end speakers as possible, while keeping the price within reason. Since the SM 6.9 costs one-half the price of the 7.0, and one-third the price of the 9.0, the reasonable price is obvious. But, can the SM 6.9 even approach the sound quality of the 7.0 and 9.0 despite using less expensive components?

What is the SM 6.9 Loudspeaker?

The SM 6.9 loudspeaker is similar in design and dimensions to the most expensive nOrh loudspeakers, the 7.0 and 9.0: it is a drum-shaped, bass-reflex, inverted horn, two-way loudspeaker. The tuned port is located on the back of the cabinet at the apex of the horn. The sample measured 40.0cm high (including the stainless steel feet) x 36.2cm wide (drum diameter) x 48.6cm deep (15 3/4 x 14 1/4 x 19 1/8 inches). This is a very substantial speaker: despite its modest dimensions, it weighs approximately 22.7kg (50 pounds). The rated frequency response of the SM 6.9 is 40Hz to 22,000Hz with a sensitivity of 87dB/1watt/1meter. By comparison, the 7.0 (which is slightly smaller than the 6.9) is rated to 43Hz, while the 9.0 is rated to 33Hz.

nOrh SM 6.9, crossover exposed, showing three high quality capacitors and three coils

The SM speaker line currently includes the SM 5.1 (which utilizes a much smaller cabinet), the SM 6.1, and the SM 6.9. The cabinets in the SM line are made from synthetic marble, a material that is "77% marble powder mixed with resin and gel coat," according to nOrh. The synthetic marble was used to provide the acoustic benefits of marble while substantially reducing production cost and retail price. Additionally, since synthetic marble consists of marble powder 'glued' together by resin and covered with gel coat, it should be more resistant to damage than natural marble, which can fracture under some circumstances.

As with most nOrh loudspeakers, the SM 6.9 is a two-way unit. It uses a Vifa M18W0-09-08 woofer and a new Vifa XT25TG30-04 tweeter. Both drivers are flush-mounted on the felt-covered MDF baffle. They are coupled through a high quality crossover network. The woofer is the same driver that nOrh used in the now discontinued model 6.5. The Vifa XT tweeter is a 'dual concentric dome' tweeter. The twin, concentric domes are supposed to improve off-axis performance of high frequency sound. An easily removable, black cloth, speaker grill covers the baffle and both drivers. Two, gold-plated, three-way binding posts are located near the back on one side of the cabinet. The SM 6.9 speaker cannot be bi-wired.

Setting up the SM 6.9 speakers was very easy compared to some loudspeakers. Speaker stands were needed to elevate the 6.9s to a proper height. One set of speaker wires was plugged to the single pair of binding posts on each, and the speakers were positioned on the stands at least 25cm from the back wall. A little toe-in between the speakers seems to improve stereo imaging somewhat. Speaker positioning does not appear to be critical with these loudspeakers. With many loudspeakers, break-in is a painful process. However, with the SM 6.9 speakers, it was enjoyable: they sounded very good right out of the box and were pleasureable to listen to while they were breaking in. After about 80 to 100 hours of playing, they seemed smoother sounding with improved detail, and they continued to improve slowly throughout the evaluation testing.

How Do They Sound?

Simply put, the SM 6.9 loudspeaker has excellent quality sound with wide frequency response and superb dynamic range. Even nOrh claims that the SM 6.9 sounds almost as good as their own 9.0, at one-third the price. Having read details of SM 6.9 design and construction prior to listening to the new nOrhs, the quality of sound was no surprise. The real surprise of the SM 6.9 was its flexibility. This loudspeaker was designed to handle up to 300 watts. This type of high-power handling ability should satisfy almost anyone, including people who wish to fill large spaces with music. Not only does it sound excellent with such high powered, solid state equipment, but it also works exceedingly well with lower-powered, tube equipment. While I expected the SM 6.9 to work acceptably well with a 35wpc, push-pull, tube amp, suprisingly, it sounded superb with this amplifier, even at relatively high volume.

Even more surprising was that the SM 6.9 sounded very good with a 4 wpc monobloc single-ended triode amplifier - within certain limits. The clarity, detail, and richness of sound were not impaired by the low power. In fact, at very low volumes the SET amp sounded better than either the push-pull tube, or solid state amplifiers. However, high volume is not attainable and dynamic range and bass were problematic. While the bass would play deep and clean with only 4 watts, complex bass passages would lose focus and become smeared and jumbled due to inadequate power. As with many nOrh inverted horn speakers, the 6.9 works best with large amounts of available power to control bass and provide appropriate dynamic range to the music. While they are rated to handle 300 watts, volume could be turned quite high enough with the 35 watt tube amp and 100 watt solid state amps used in this evaluaion.

Positive Impressions

As with other nOrh drum speakers, the first impression of the SM 6.9 is visual. This speaker is as large as nOrh's largest drums and, in a small room, can be quite imposing. It has an appearance of great mass, which is verified when one tries to move these speakers. However, while sometimes awkwardly deep, the SM 6.9 has little width or height compared to many other offerings by other manufacturers, particularly many of the larger horn speakers. The SM 6.9 speakers are also quite beautiful, with a smooth finish and perfect shape. The surface of the white, synthetic marble was flawless, and the turned, stainless steel feet complemented the appearance of the drum. The speaker cover, which has a primary purpose of protecting the drivers from damage, is simple, black, acoustic cloth adorned by unobtrusive nOrh badges.

nOrh SM 6.9, Blue Finish

The SM 6.9 has very detailed output throughout its frequency range. While the XT tweeter seems to be slightly less detailed than some metal dome tweeters on similarly priced loudspeakers such as B&W and Polk, the output is smoother, more refined in sound, and slightly more forgiving of a harsh source or recording than many metal dome tweeters. The Vifa bass drivers are also very quick in reponse and detailed in sound reproduction. Transients, both high and low, are quickly, sharply, and accurately reproduced. The dynamic range is simply superb for a speaker in this price range. When played softly, the SM 6.9 relays the musical information distinctly, with proper timing, tone, and emphasis; the SM 6.9 is clear, clean, and detailed at low volumes. Even bass is detailed and complete. When played loudly, these speakers can shake the walls and bring neighbors running. Many people want to be able to feel the music, not just hear it. With an appropriately matched amplifier, the SM 6.9 will satisfy. And, when played loudly (within the limits of amplifiers on hand for this review), the dynamic range remains uncompressed and true to the recording.

Frequency response of the SM 6.9 is rated from 40Hz to 28,000Hz. But the rating only tells half the story. While some loudspeakers create the impression of strong bass through resonance and coloration of the sound, the nOrh SM 6.9 achieves good bass by excellent design and high quality components. In addition, while many speakers are rated down to 40Hz, few deliver bass this deep with such authority. On a Nautilus Audiophile recording of 'Magic Man' by Heart, the 40Hz synthesizer tone was clear and powerful. Despite the strength and depth of bass on the SM 6.9, the bass is always clean, sharp, and lacking unwanted resonance. The relatively small diameter bass driver, 16.5cm (6.5 inches), allows low frequencies sounds to be quick, while the thick, synthetic marble, inverted horn shape, and overall speaker weight seem to allow this speaker to produce strong bass with no unpleasant side effects. Kick drums are quick and sharp, as they should be; bass drums are deep and pounding rather than muted and booming. The SM 6.9 even has the ability to fairly convincingly reproduce the sound of kettle drums and most pipe organ music. Unless a potential buyer frequently listens to 30Hz pipe organ music, there is little need for a subwoofer.

The quality of high frequency sound produced by the SM 6.9 is very good. High frequency musical instruments are rendered cleanly, smoothly, and with no audible distortion. Of course, in the price range of the SM 6.9s, most speakers reproduce high frequencies reasonably well. As with the other nOrh inverted horn speakers that I have auditioned, mid-frequencies sound clear and open. Vocals sound compelling and natural, and this applies to both female and male vocals. Coloration of vocals, which is all too common with many, sub-$1,000 speakers, is completely lacking. They simply sound correct with no added nasal tonation or chestiness.

A pair of SM 6.9 loudspeakers produces a soundstage that is wide and very deep, often involving the entire end of the listening room to good effect. Given an appropriate recording, instrument placement within the soundstage is quite well defined in three-dimensional space. Not only does the SM 6.9 reproduce three-dimensional sound images, it is nearly invisible. When music is playing, sound simply seems to emanate from space between and around the speakers.

The Vifa XT tweeter that is used in the SM 6.9 has an unusual shape; a sort of protruberance extends from the center of the middle tweeter dome. Vifa claims that the dual concentric cone design, along with the 'wave guide center plug' (the protuberance) provides for greater dispersal of high frequency sound and results in better on- and off-axis sound quality. In fact, the SM 6.9s have a relatively large sweet spot that probably results from superior high frequency dispersal.

Vifa Drivers in SM 6.9

Negative Impressions

As with most, good quality speakers, the SM 6.9 is detailed and very revealing; it should not be used with low quality sources, cables, or amplifiers. Any weakness in the system will be audibly accentuated with the SM 6.9, which could lead to expensive revision of the offending sound system.

Placement of the SM 6.9 generally is not critical. However, as with many speakers, particularly bass-reflex speakers with rear-firing ports, it is important not to place the speakers to close to a wall. When placed too close to the back wall, the soundstage compresses in size and most three-dimensional imaging is lost. In addition, some musical detail seems to be lost or smeared. Finally, the speakers should be elevated at least 30cm above the floor; if the 6.9s are too close to the floor, high frequency detail and soundstage suffer.

Physically, the SM 6.9 may be difficult to place. At over 48cm in length, plus the need to be placed away from a wall, the speakers will occupy substantial space. More importantly, they are heavy and awkwardly shaped. Each speaker weighs over 20kg. Of course, the nOrh speakers are not the only large or awkwardly sized speakers on the market; there are many high end speakers that are much larger and weigh well over three times as much as the SM 6.9.

Unlike the more expensive marble speakers in nOrh's lineup, the 7.0 and 9.0, the SM 6.9 is equipped with ordinary, removeable speaker grills that are covered with acoustic cloth. Sound quality with the cover in place is acceptable for background music or home theater use. For serious listening, the grill cover must be removed, or it will dull the output and muffle detail.

Aesthetically, the SM 6.9 speakers seem to cause two reactions: some people think they are exotic, beautiful, and very impressive; others think they are chunky and awkward looking. Of course, since the nOrh drum speakers are quite unconventional in appearance, a wide variety of reactions are to be expected. The white finish, synthetic marble on the test units was smooth and flawless. However, slightly different pastel colors, including pink and green, have been mixed into the outer surface and seemed to have been swirled into place to give the speaker a more distinct appearance. With dim lighting, it appeared as though the speakers were coated with an uneven layer of dust; in bright light it was apparent that it was part of the finish. The marbling in natural marble is distinct and adds to its beauty. The marbling in the synthetic marble of the white SM 6.9 was too subtle in dim light resulting in an occasionally undesirable visual effect; if the marbling was more bold and striking, it would always appear deliberate and likely would enhance the appearance of the speakers. As can be seen in the photos, too subtle marbling is not a problem with some colors of the SM series speakers.

Conclusions

The SM 6.9 loudspeaker is yet another product from nOrh that exceeds expectations. Its sound quality is exemplary, with the right source. It is surprisingly flexible as to the amount of power it needs, provided that the amplifier is of good quality. As with any good quality loudspeaker, the SM 6.9 reproduces sound so faithfully that a low-quality amplifier or source becomes obvious and demands replacement.
While the SM 6.9 performs surprisingly well with low powered tube equipment, it really shines with higher powered equipment that better takes advantage of the power-handling capability and tremendous dynamic range of the design.

The SM 6.9 sound quality is dependent on the source material and the quality of upstream components. The 6.9 can be harsh, when the recording is harsh, or wonderfully smooth and clean sounding. When played softly, the SM 6.9 provides nearly all the detail expected from a familiar cut of music; even low bass is present. When played loudly, these speakers are capable of providing driving, pounding music that can move the listener without smearing musical detail. The quality of the sound does not diminish when the volume is turned up. In addition, dynamic range is excellent: at high volume (within the limits of the amplifiers being used for this evaluaion), there was no significant compression of dynamic range.

Has nOrh succeeded in its attempt to produce a speaker with nearly the sound quality of the 9.0, but at a fraction of the price? The answer clearly is, "yes." As far as the speaker cabinet is concerned, the dense, heavy, synthetic marble of the SM 6.9 should be acoustically equivalent to the natural marble of the 9.0. And, of course, the shape is the same. The sonic differences between the SM 6.9 and the 9.0 result from the use of 'merely' high quality drivers and matching crossovers in the 6.9, compared to top-of-the-line, spare-no-expense components in the 9.0.
For the nOrh purchaser who wants the absolute best in aesthetic appeal and sound quality, not to mention exclusivity, the nOrh 9.0 is, without question, the speaker to have. For the rest of us, to whom an extra $2,000 is a significant sum of money, it is hard to find fault with the SM 6.9s. They provide detailed, musical sound with dramatic presence and feel across almost the entire audible range, and they have a well-finished, unique, and exotic appearance.

Manufacturer's Comments

Thank you very much for the review. I believe that our synthetic marble line is a good alternative but not a substitute for real marble. Sonically, the material is identical. I agree that natural marble has a look that can be approached but not duplicated. The nOrh marble loudspeakers are the best we know how to build. Unfortuantely, working with real marble is difficult and expensive. Therefore, we wanted to provide a close approximation for a more reasonable price. High end audio is always about diminishing returns. There are some people who demand the ultimate. For these few, they want the best sound and the best looks and they are willing to pay in order to get exactly what they want.
nOrh Loudspeaker builds our marble products for these people. For the rest of the world, it can often be a frustrating search to find the product that gives them the level of performance that is at that point where any small improvement will cost significantly more. For some people, the nOrh 3.0s will be good enough. Other people will be satisfied with the 4.0s. We believe that the SM 6.9 are good enough that only those few who can afford to seek the ultimate need spend any more money.

The model just below the SM 6.9 is the SM 6.1. This speaker is more efficient and overall, less critical than the SM 6.9. I believe individuals with lower powered tube amplifiers might be happier with the SM 6.1. We also have a Prism version of the 6.9 for people who find either the style or placement of the SM 6.9 difficult. The Prism 6.9 is a large floor standing loudspeaker. The bass is deeper: -3dB at 33 Hz. The SM 6.9 benefits from the less resonate synthetic marble cabinet.

I would like to point out that the benefits you hear in bass reproduction are directly related to the cabinet. We believe that the synthetic marble and marble cabinets we make allow the drivers to generate more bass energy because the bass is not absorbed by the cabinet itself. This is no different than someone riding a bicycle. If the bicycle (frame) is stiff, then the energy is better transferred to the wheels. If the bicycle is springy, then some of the energy gets transferred to the frame. Once again, thank you very much for your thoughtful review.

Some photographs used in this review are courtesy of nOrh Loudspeaker Co., Ltd. Many thanks to Michael Barnes, president of nOrh,and everyone else involved for providing the units used for this review.