Towers of Power: A Look at the Best Super Speakers

“There is no replacement for displacement” is an adage among automobile enthusiasts that holds up just as well in the audio world. In the world of automobiles, it most commonly means that the best way to produce power is to have a large engine that holds more swept volume by the cylinders rather than using gimmicks to increase power from a small engine. This principle is true for audio as well. Producing high amplitudes or low frequencies or especially high amplitudes at low frequencies means displacing a lot of air, since sound is simply compression waves of air. While there are tricks that small speakers can sometimes use to seem big, when they are placed next to a speaker that has true displacement capability, the difference in sound as well as sight is obvious. In this article, we take a survey of some of the more powerful home audio speakers available at the moment.   

The speakers we will look at mostly hang around the ten thousand to twenty thousand dollar range per pair. Expensive, yes, but new car expensive not new house expensive. They are usually, but not always, full-range speakers with very healthy bass capability so a subwoofer definitely isn’t needed for most of these. The design decisions and component choices have a lot of variation at this price point, as opposed to budget speakers and their ubiquitous five or six inch woofers and one inch dome tweeters. However, one trait these goliaths all share is they are not small. Big air displacement necessitates a considerable amount of cone area, and a large cabinet is needed to hold large woofers. These speakers are not lightweight either. The cabinets are built to remain inert under strong internal pressures, and lots of bracing and mass is needed for that task. The heavy-duty motors of the powerful drivers employed by these behemoths add considerably to their weight as well. Let’s take a look at some of the specs for these speakers in the table below: 

Volti Alura

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At Volti Audio, big is beautiful, and this is evident in the Volti Aluras. Large and exquisitely built and finished, there is no hiding the Aluras, nor is there any reason to want to. And while they look nice, they sound even nicer.  This is due to the high dynamic range and low distortion of the Alura’s design. The Volti Alura is a 3-way design consisting of a horn-loaded 1” compression driver as tweeter, a 2” horn-loaded midrange compression driver, and a 15” bass driver driver in bass reflex enclosure. As can be seen in the pictures, the tweeter and midrange horn are built in a separate enclosure that rests on the bass bin. The design suggests very high sensitivity, which indeed the Alura has, and is specified at an extraordinary 99 dB. That makes it easy to drive with any amplifier and a nice fit for low-wattage tube amps; consider that it only takes 4 watts to drive an Alura to 105 dB. Keep in mind 105 dB is THX Reference level ‘peak’ sound in a THX soundtrack, and is the loudest a THX soundtrack will get in a THX certified system outside of the subwoofers.

It is often said that music lives in the midrange, and, if so, Volti Audio has furnished an exceptional home for that frequency band in the Alura. A massive 2” compression driver loads a large, vertically-oriented horn and covers the frequency range from 400 Hz to 6,000 Hz in what has to be considered the ‘centerpiece’ of the Alura. Rectangular loudspeaker horns are typically oriented with the long axis aligned horizontally, since the dispersion is usually wider along the long axis, but the Alura places the midrange horn in a vertical arrangement without compromising the horizontal dispersion because its dispersion along the short axis is surprisingly wide. Above the midrange horn lies the tweeter, which in the Alura, is composed of a 1” compression driver in an elliptical horn. In its band above 6 kHz, such a powerful driver would simply loaf along even at monster loudness levels, and this contributes to the Alura’s extremely clean sound; output levels that might be mechanically taxing to other speakers are not even a minor nuisance in such an overbuilt system. A consequence of employing such powerful drivers for home audio is that not only can they stay clean at enormous loudness levels, they also remain extremely linear at moderate levels. The bass driver is no exception to this engineering philosophy, and here the Alura uses a high-sensitivity 15” in a specially designed bass reflex cabinet that is carefully designed to compliment the sound of the horn-loaded top section for the greatest cohesion. Altogether, these components add up to a system that has as much power as it has finesse, and, while not inexpensive, it is very reasonably priced at $15,900 per pair.

JTR Noesis 215RT 

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So, you want dynamic range, eh? How about this as a solution: a three-way tower speaker using two 15” high-excursion woofers, a powerful concentric compression midrange driver and tweeter set in the back of a large 60 x 60 degree horn. Now let’s have it handle up to 2,000 watts RMS with a 95 dB sensitivity and give it a lower -3 dB point of a remarkable 18 Hz. What we have described is the JTR Noesis 215RT, and, as can be seen in the pictures, it is all business. It may look like a sonic cannon, but it produces a high fidelity sound, and this is partly due to the sheer excess of the design for home audio applications. As with the Volti Alura, when speaker drivers are only used within a small fraction of their mechanical capacity, they are more easily able to reproduce the signal with accuracy, since the drivers are kept far away from conditions that threaten linear playback. The crossover points between the drivers restrict their playback to frequency bands for which they are most adept, with the midrange driver and tweeter separated at 6.3 kHz and the bass drivers taking over at 350 Hz and below. Of course, the Noesis 215s do have the ability to stay clean well beyond typical listening levels, and can comfortably handle volumes that far exceed conventional speaker designs, so if you are after insane loudness levels, you needn’t worry; your ears will give out long before the Noesis 215RTs will.

There is a lot more going on with the 215RTs than just driver overkill. The Noesis 215RTs act as a true single point source for sound, because care is taken to physically and acoustically time align all the drivers. In many speakers the varying distances of the different drivers can cause different time arrivals of the frequency bands of those drivers, which can cause a smearing of the sound and loss of intelligibility. While measures can be taken to correct for driver distance disparity, there can be no perfect solution that completely overcomes the physics of that design. The 215 addresses this problem by using a concentric driver for midrange and tweeter, where the sound from both emerge simultaneously from the throat of the horn. The makes for excellent phase coherence and perfect time alignment between the midrange driver and tweeter. The woofers use a crossover point where the sound waves are long enough for the two woofers to act as one. Unlike many other larger tower speakers, the Noesis 215RT has no minimum listening distance. The base cost of the Noesis 215RTs is $3,499/ea, with upgraded finishes available for an additional cost, so it is one of the less expensive speakers in our roundup, but at a hefty 215 lbs., it is also one of the heaviest and most opposing.  

JBL M2 Master Reference Monitor

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Image courtesy of Harman International

In the short time since they have been released, the JBL M2 Master Reference Monitors have quickly become the go-to choice for the highest linearity combined with serious dynamic range. In fact, this speaker made our list as one of the best loudspeakers in the world.  The ruler-flat on-axis frequency response combined with the extraordinarily linear off-axis frequency response have given the M2s a reputation for being one of the highest fidelity speakers in production, and a crowning achievement among the JBL LSR designs. The M2’s reputation for accuracy has persuaded many to use it as a home audio speaker even though it is designed primarily as a studio monitor. JBL’s world-class driver engineering has provided the M2’s with not only superb linearity, but also tremendous dynamic range with exceptionally low distortion and compression. A powerful and sophisticated 15” bass driver uses an array of JBL’s cutting-edge driver technology, including the ‘Differential Drive’ dual magnetic gap/dual voice coil design, which helps the woofer track the audio signal with ruthless accuracy below its 800 Hz crossover point. The same ‘Differential Drive’ technology is deployed by the horn-loaded compression driver, which, in the M2, covers an incredibly wide band for a compression driver of 800 Hz to 40 kHz.

Image courtesy of Harman International

Another aspect that is critical to the M2’s extreme fidelity is the geometry of the horn. JBL’s Image Control Waveguide is specially shaped to produce a very neutral response well off of the main axis of the speaker, both horizontally and vertically. This is in line with the philosophy of JBL’s LSR monitors, from which the M2s descend, and the idea behind this performance goal is speakers that have acoustic reflections (sound bouncing off of nearby surfaces) which resemble their direct sound will make the room and the speaker placement less of a restrictive factor in achieving good sound. In other words, the M2s should be able to sound good in any normal room and will not need assistance from a bunch of awkward acoustic treatments to do so. There is no doubt that the M2s are state-of-the-art, and they carry a price tag to match at roughly $20,000 per pair. They do come with their own amplifiers and room correction equalization system, so the cost of the M2s is alleviated by not having to purchase equipment needed by other speaker systems.

Towers of Power: A Look at the Best Super Speakers Cont.

Legacy Aeris

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For those seeking state-of-the-art speaker design, a very attractive alternative to the JBL M2s are the Legacy Aeris speakers. Released at roughly the same time and sharing nearly the same price ($20k), they also both come with their room correction equalization processors to better remove the room’s acoustics from the end sound. Like the M2s, the Aeris have met with intense acclaim since its introduction. However, unlike the M2s, the Aeris are drop-dead gorgeous speakers, and come in a variety of exquisite finishes. Their ravishing good looks do not come at expense of performance either. The Aeris is a feat of audio engineering mastery; a 4 ½ way full-range speaker with a passive open-air top section for dipole dispersion which turns into a cardioid dispersion from 200 Hz to 80 Hz. Below 80 Hz, the Aeris uses a hybrid bass-reflex/ passive radiator subwoofer system with two high-excursion 12” woofers and a 12” passive radiator hidden at the bottom of the speaker. Each of the subwoofer drivers have their own 500 watt amplifier which adds up to a kilowatt of amplification for the deep bass of each speaker alone. The open-air top section uses a 4” AMT folded ribbon tweeter with a 1” AMT super-tweeter, and these tweeters carry the frequency range above 8 kHz. A titanium-encrusted 8” midrange woofer takes over from 8 kHz to 2.8 kHz (an astonishing range for a 8” woofer), and a 10” midwoofer takes the range from 2.8 kHz to 80 Hz.

As can be seen, there is a lot going on with this speaker. The fact that Legacy can combine so many different design elements in the Aeris and have it be not only listenable, but have an award-winning high-fidelity sound is a testament of Legacy’s world-class engineering. Along with its extraordinary linearity, it has a very wide dynamic range, as you would expect from the array of drivers on display. The sensitivity of the passive section of the Aeris is an above-average 95.4 dB (in-room) and is rated to handle up to 500 watts. That is a lot of firepower at the listener’s disposal, and THX Reference levels should be an easy reach of the Aeris on movie night. With such a powerful subwoofer section onboard, the bass extension digs very deep with a +/- 2 dB response of 18 Hz to 30 kHz. Most dedicated subwoofers cannot match the low frequency capability. All of this comes in a reasonably small footprint too, at 19” x 17.5”, so the Aeris is not a floor hog, however, there is its formidable 170 lbs. weight per speaker to contend with. But, as was previously mentioned, one cannot have a massive sound without sheer mass.

Funk Audio 8.6P 

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In our roundup, the winner for highest spouse-approval-factor is undoubtedly the Funk Audio 8.6P speakers for having the smallest footprint, thinnest enclosure, and top-notch veneers and cabinetry. This does not mean it is all style and no substance; far from it in the case of these speakers. The 8.6Ps are a fully active system with three 500 watt amplifiers on board each speaker: one amp for the tweeter, one for the mid range drivers, and one for the bass drivers. Needless to say, drivers that can handle that level of power have to be extremely capable, and the drivers used in the 8.6P are very capable indeed. To begin with, the large 6” x 2.5” planar tweeter can move a lot of air for the high frequencies, and its size gives produces tall vertical coverage while its planar design keeps a narrow vertical dispersion with a wide but tightly-controlled horizontal pattern. This minimizes acoustic reflections from the floor and ceiling, which can be very uneven in an MTM design, so a planar tweeter is ideal for this design. The 5” midrange drivers boast a 1” peak-to-peak excursion, which is an enormous amount of stroke for that driver size. They operate within 280 Hz to 1,650 Hz, and four of those bad boys driven by 500 watts for a range of only two and a half octaves will guarantee you ultra clean mids, which is a great design choice, since, as was mentioned earlier, music lives in the mids, especially vocals to which human hearing is most sensitive to anything ‘off’. The two 8” midbass drivers, which also sport a 1” peak-to-peak excursion, have powerful low-end yet retains high-sensitivity thanks in part to the powerful Neodymium magnet motor. Shorting rings help keep inductance and distortion at bay. 

Beefy drivers are great and all, but a good speaker needs more than just a stack of powerful drivers; a good design is needed to tie them all together to produce a cohesive sound. The baffle shape, which has been designed to optimize the planar tweeter’s performance, would normally cause time alignment and phase problems if the 8.6P’s were using a passive crossover, but an active DSP crossover system is able to set precise delays for the drivers to relieve these issues. What is typically done in passive systems to keep the drivers time-aligned is to move the larger drivers forward, as their ‘acoustic center’ is further back in distance compared to smaller drivers, however this causes diffraction problems of the shorter sound wavelengths of the smaller drivers when they reflect off of the front baffle of the larger drivers. With Funk’s active crossover system, the 8.2 can make the drivers behave as though they are at any distance position relative to each other, while physically being in the best positions for diffraction, thereby allowing the speakers to have the best of both worlds. The 8.6Ps are not inexpensive speakers at $15,675 shipped, but considering that includes a high-quality veneer, 3,000 watts of total amplification, and DSP settings that can tailor the sound to fit the user’s taste among many other features, they are a bargain.

RBH SV-831 / SV-1212

Unveiled at the 2015 CES, RBH’s New SV speaker line holds a speaker setup well worth inclusion in our roundup. While not technically a single speaker, the modular design of the RBH SV-831 LCR speaker and SV-1212 subwoofer is intended to be used as a full-range tower as much as they can be used separately. For the purposes of this article, we will consider the SV-831 and SV-1212 as a single full-range speaker. The SV-831 and SV-1212 can be thought of as the successor to the RBH T2 (Audioholics review of T2 can be read here), with some very substantial improvements using the same basic design. For starters, the SV-1212 subwoofer section is using high excursion 12” drivers instead of the 10” drivers in the T2, as the SV-1212 is very similar to the RBH SX-1212P/R since it is using the same drivers and same 6” port. The SV-1212 will be available in Standard and also Reference versions, much like the SX-1212, and also in passive and amplified versions. For those who wish to use the SV-831/ SV-1212 combo as a single tower, there will be a passive crossover network available on request that allows a single channel of amplification to power both, although it is intended to be bi-amplified which is the standard configuration for it. While the Standard version of the SV-1212 looks to be a very capable subwoofer system, the Reference version may prove to be a monster - with enough amplification, as its predecessor measured to have outstanding performance in this Audioholics review.

The midrange drivers from the T2 have changed from four 6.5” woofers to three 8” drivers in the SV-831. While that is a substantial 30% improvement in cone surface area, it becomes a huge upgrade when considering that the new drivers have almost double the excursion capability of the 6.5”s. The AMT tweeter also has a much larger surface area than the three dome tweeters in the T2, effectively doubling the T2’s surface area, which allows a lower crossover point of 1.5 kHz. The results are a speaker with 2 dB greater sensitivity (which puts the SV-831 at 93 dB sensitive) and 6 dB greater peak dynamic SPL. That should put THX Reference levels within reach of a normal sized home theater with even a moderate amplifier. The SV-831 and SV-1212 are expected to begin shipping around March. Initial pricing at the 2015 CES was said to be $2,515 for the SV-831 and $2,585 for the SV-1212, which would place the cost for a tower pair a little over $10k, which is quite a bargain for what you get. An option for powered SV-1212s with a 2,400-watt amplifier will be available for an additional cost. As with other upper-end RBH products, we expect the SV-831 and SV-1212 to be available in a variety of fine custom finishes.

Soundfield Audio Dipole1

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The Soundfield Audio Dipole1 speakers received high praises at their debut at the 2015 Axpona show. As the name implies, the Dipole1’s use a dipole dispersion pattern that is achieved in a couple different ways. In the lower section of the Dipole1, the bass drivers have an open rear baffle, while the upper midrange driver and tweeter on the front baffle are sealed. The dipole pattern of the front upper midrange and treble drivers are maintained by a horn-loaded planar mid-tweeter mounted on the opposite side of the front horn-loaded planar driver. The driver arrangement of the of the Dipole1’s from top to bottom with their cross-over range: a horn-loaded super-tweeter (14 kHz-28 kHz), a front-firing horn-loaded 11”x9” planar mid-tweeter (650 Hz-14 kHz), a rear-firing horn-loaded 10”x7” planar mid-tweeter (650 Hz-18 kHz), a 12” mid-woofer (60 Hz-650 Hz), a 12” subwoofer (60 Hz-14 Hz). The system is fully active with a dual 400 watt Hypex amplifiers for the mid-tweeters and mid-woofer. The subwoofer section is a 375 watt Rythmik system with adjustable volume, crossover frequency, and phase, so it can be tuned to listener’s preference. Altogether, the layout of the Dipole1 suggests an enormous amount of headroom and should be able to fill almost any size room with clear, powerful sound.  

The Dipole1’s are a top-to-bottom dipole system. A dipole dispersion pattern is chosen because, according to the Dipole1’s designer, “they enhance the spatial reproduction of stereo sound fields in a way that is more realistic, given the severe limitations of the format.” With some stand-off distance from the wall behind the speaker and a bit of diffusion, the rear reflections add a sense of spaciousness, size, and depth to the sound. Perceptual science has found that part of the way that speakers ‘image’ depends on the ratio of direct sound to room-modified indirect sound, and the Dipole1s use this phenomena to its advantage by having tightly controlled dispersion in front of the speakers as well as behind them. An advantage of a properly-executed dipole speaker is that much of the indirect sound produced by them can have a relatively flat frequency response. The benefit of this approach is that the loudspeaker becomes far less affected by room acoustics in rendering the recording, hence the quote in Soundfield Audio’s slogan, “room-friendly loudspeakers by design.” The base price of the Dipole1s is $12k, and can be ordered with a host of customized options such as different finishes, internalized amplifiers, a sealed compartment for the subwoofer driver, and, our favorite option, a choice of doubling up on the Rythmik subwoofer drivers for two 12”s per speaker.

Concluding Remarks

As was said previously, a big sound usually requires a big source. A set of mini Bluetooth speakers are not going to convincingly recreate an eighty-piece symphony orchestra in a major auditorium. A desktop sound system cannot fool you into thinking an earthquake is happening, nor will it be able to induce that involuntary flinch that seems to occur with a live snare drum or gunshot. Headphones can sound good, but they do not have the ability to realistically convey the presence of the low notes on a piano or pipe organ, let alone the power of a passing freight train. The speakers in this article cannot be discreetly tucked away where they will not be noticed (unless you hide them behind a false wall). They demand space. Hoffman’s Iron Law certainly plays a role here, which states that you can have two of the following but never all three: efficiency, bass extension, and small size. Clearly the speakers in our roundup have opted for efficiency and bass extension over small size. And for a wide dynamic range and bass extension, small size isn’t an option, period. That is part of the price that must be paid for a speaker system of such high fidelity that it could truly be mistaken for the sound of a full symphony orchestra or a passing  freight train.