Transcript
IG Series White Paper
Description The NEAR® IG Series is a line of three full-‐range speakers and two subwoofers; purpose designed for use outdoors or in high humidity, extreme temperature indoors locations. Goals When considering the design of NEAR outdoor loudspeakers, we started by defining the goals. The first of our goals was: they must sound great to everyone on the patio or deck, at every volume level, without fatigue…outdoors. Outdoors is an incredibly noisy environment where there are few walls, an infinite floor and no ceiling⎯all of which have enormous implications on how sound is produced and perceived. Second on our list was: they must endure…for years, even decades of full exposure to often nasty weather. They must do more than just work, they must sound fantastic and look great doing it over their entire lifespan, without yellowing, rusting or fading. And yet many outdoor speakers are really indoor speakers adapted for outdoor use. Look at our competitors’ literature – they actually brag about bringing their brand’s indoor sound outdoors. No, no, no. For truly great, awesome, your-‐guests-‐will-‐talk-‐about-‐it-‐ after-‐they-‐leave-‐the-‐pool-‐party outdoor sound you need a completely different approach, one with the realities of outdoor sound foremost in mind. You need NEAR.
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NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
The NEAR® Outdoor Heritage New England Audio Resource was founded by Bill Kieltyka, a former engineer with the legendary high-‐end speaker company Bozak, a company known for its innovative curvilinear aluminum speaker cones and the world’s first high quality, full range, residential outdoor loudspeaker⎯the Bard. After leaving Bozak, Bill founded New England Audio Resource (N.E.A.R.) in 1988 and designed the company’s first product – the outdoor AEL-‐2.0 (All Environment Loudspeaker), featuring, of course, aluminum cone woofers. The AEL series was a big success in residential and commercial applications including Universal Studio’s Jurassic Park® and Islands of Adventure® theme parks, as well as atop New Hampshire’s Mt. Washington, a place reputed to “enjoy” the worst weather in North America. NEAR AEL on Mt. Washington In 1997, the audio quality and weather resistance of N.E.A.R speakers caught the attention of Bogen Communications, Inc. Bogen recognized the advantages of the N.E.A.R technology for their commercial applications, and acquired the company with Bill continuing as the lead designer for NEAR®-‐branded products. Today, the NEAR designs take advantage of 25+ years of single-‐minded dedicated development of outdoor loudspeakers. From frigid mountain-‐tops, to high-‐humidity habitats in Central America, NEAR has seen it all. NEAR speakers have been exposed to (and survived) indoor pools with high chlorine content, fertilizer spray, bug and animal infestations. All were learning experiences that advanced the state of outdoor sound art. Bill and the team analyzed every part failure over the decades and said, “we can do better,” and we did! Today’s NEAR products are the beneficiaries of decades of past successes and failures. And we’re just getting started! The Case for In-‐Ground Design The NEAR IG series look and sound great when used as freestanding on-‐ground speakers that can be camouflaged among planters and pots. But we primarily designed them to be partially buried in the ground, affording homeowners and commercial venues superior sound performance, lower visibility and ultimate security. Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
When installed in-‐ground the earth itself now becomes a half-‐space domain for low frequency reinforcement and an infinite baffle extension for the midrange frequencies. Many conscientious loudspeaker designers measure loudspeakers by placing the baffle (front face) flush with the ground to minimize reflections. By eliminating the effects of the enclosure and adjacent surfaces, in-‐ground measurement provides the most revealing view of the true performance of the speaker. Well, now we have a full range outdoor system installed in the ground that mimics this very ideal. The IG series enclosures are designed with ribbing and arcs to offer a solid and durable cabinet, but there’s nothing like infinitely increasing the enclosure wall thickness by burying it! Packing soil around an already rigid enclosure further dampens enclosure wall resonances to zero. By completely eliminating enclosure resonance the performance of the NEAR™ drivers comes to the forefront. Details in the music that you can hear on high-‐ end indoor speakers, but not on typical outdoor speakers, can be clearly heard and not veiled by enclosure or driver resonances. The bass impact of in-‐ground installed NEAR® speakers is clear, precise and detailed. Midrange, particularly the lower-‐mid region that carries the “body” of vocals, is rich, smooth and highly articulate. Imagine being able to understand the lyrics even at low volume levels. Well now you can with NEAR. The Case for Omni-‐directional Sound Very little outdoor listening is done on axis. Most listening locations are typically several feet away from the loudspeaker, well off-‐axis. Typical outdoor speakers radiate sound mainly in one direction. With such designs listeners positioned near one speaker cannot clearly hear the other channel in a stereo installation. Guests on one side of the patio may only hear the backup singers or string section while people on the other side only hear the lead vocalist or brass. Left Ch.
Right Ch.
3'
12'
Left ch. = 100dB Right ch. = 88dB
Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
Worse yet, the “hot spots” around directional speakers make conversation in those zones difficult. For listeners positioned close to any one speaker the sound is overly loud, fatiguing and unpleasant. Listener fatigue is a very real thing, especially when a speaker is shouting at you to pay attention. Instruments need to flow from the speaker, not be launched into the space like a flashlight beam. Listeners positioned well off-‐axis of typical directional speakers may find the volume to be too soft and/or lacking in clarity and articulation. Only the lucky few people positioned equidistant from the speakers will hear a full-‐ fidelity performance at an appropriate volume. That’s no way to treat guests!
High Q monopole loudspeaker polar plot. Note that listeners 20-‐degrees or more off-‐axis hear severely reduced output above 4kHz, resulting in dull, unexciting sound.
The NEAR® IG models are “omnidirectional” designs that radiate sound evenly in a 360-‐ degree pattern for more uniform coverage and better sound quality for every listener. In stereo installations everyone can hear a true stereo image and all the music on a recording, not just half of it. In the monophonic installations typically employed to cover large spaces, NEAR’s omni design helps achieve a uniform blanket of sound across the entire area. As listeners move through and around the space they’ll be rewarded with uniform volume levels, perfect octave-‐to-‐octave tonal balance, and clear, natural vocals. Low frequencies are deep and powerful but not overblown or lumpy, while high frequencies are extended and airy without the “shouty” quality of so many outdoor speakers. Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
Polar plot of omnidirectional NEAR IG6. Note that all listeners, regardless of their position hear well-‐balanced sound
Woofer Design The woofer drivers in the NEAR® IG series were designed and refined by Bill Kieltyka over decades of R&D effort. They are unique and exclusive – you will never find any other driver as sophisticated or so ideally suited for outdoor use as the NEAR woofer. UDIO Motor and Basket – Cast aluminum is the ideal basket material; it is rigid and strong, doesn’t rust, and is non-‐magnetic. Compare those qualities to rust-‐ prone steel that is magnetic which draws magnetic energy away from the voice coil gap. We’ve seen some brands use plastic baskets. While rustproof, plastic softens in high heat, turns brittle in cold, fractures and warps easily. NEAR UDIO driver: Blue = magnet, Green = voice coil Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
NEAR’s Upside Down, Inside Out (UDIO) motor structure is unique and superior. It starts with the use of powerful magnets* positioned inside the voice coil former. This places the magnetic energy closest to the voice coil providing a symmetrical magnetic field exactly where it does the most good, instead of behind the VC as in conventional driver motors. This drives the dome shaped woofer diaphragm, which is designed to shed water and provides very flat, even response. That’s the “upside down” part. The “inside out” refers to voice coils wound both inside and outside the aluminum former. Double windings center the coil more precisely in the gap while increasing power handling and acoustic efficiency. The IG series sport 89dB 1M/1W sensitivity (average across all models). It doesn’t take tons of amp power for IGs to pump out the high SPL it takes to fill outdoor spaces. At the same time IGs will handle all the power a commercial amplifier can crank out. With UDIO, frequency linearity actually increases as the volume level level goes up. With the combination of these audiophile grade technologies, the IG Series achieves a new pinnacle of performance. *In the IG6 and IG8 all magnets are Neodymium; in the IG5 and IGS12, LF magnets are ceramic
Patented Magnetic Liquid Suspension – Years ago Bill tried an experiment that proved critical to understanding how to design better sounding speakers. He removed the cone from a midrange speaker and played it. To his surprise the speaker made sound! The spider suspension moved the air in front of it as a normal cone would but the sound was highly distorted and nasty. Later tests concluded that the distortion of the spider bleeds through the cone (albeit at a much reduced level) and adding a subtle veil to the music. All speakers with spiders (almost every non-‐NEAR speaker in existence today) have distortion caused by spider non-‐linearity. To see and hear a demonstration of this phenomenon, click here. That experience convinced Bill that a spider-‐less driver would have less distortion than the conventional approach. After years of research and trials, N.E.A.R. was awarded a patent in 1993 for Bill’s innovative MLS technology.
Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
Magnetic Liquid Suspension (MLS) is a superior method for guiding a speaker's voice coil assembly through the magnetic field. MLS eliminates the traditional mechanical "spider" and replaces it with an advanced high magnetic density, low viscosity Ferro-‐magnetic fluid specially formulated for NEAR speakers. This exclusive fluid stays permanently suspended in the gap, allowing the voice coil to remain centered and to operate with superior linearity. In fact, the louder it plays, the more accurate the centering forces become. The results are lower distortion, greater linearity, more consistent long-‐term performance and longer cone excursions. Thanks to their long-‐throw capability NEAR woofers produce Mechanical more bass for a given size Spider than competitive outdoor speakers. The NEAR® 6-‐1/2 inch woofer matches or exceeds the output of many typical 8-‐inch speakers. Without the burden of overcoming the resistance of mechanical spiders, MLS woofers respond more quickly to musical impulses for the kind of clarity and minute detail retrieval usually found only in ultra high-‐end indoor speakers. What’s more, the clarity and detail are there Former even at low volume levels and at every ambient temperature. Where traditional speakers don’t start sounding good until cranked to a moderately loud level, NEAR® speakers sound Outside Inside clear and intelligible from late-‐night whisper to coil coil rock concert loud. Where traditional speakers perform poorly in extreme heat and cold, NEAR speakers sound great from below freezing to desert hot (-‐20 to +160 degrees F; -‐29 -‐ +71 C). There’s nothing like ice fishing to the sound of Reggae pumping from your NEAR speakers. MLS also contributes to NEAR® speakers’ legendary reliability. The fluid prevents debris from entering the gap, preventing rubs and buzzes that drive homeowners Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
and integrators crazy. In addition, the fluid draws heat from the aluminum voice coil, increasing power handling and reliability as well as minimizing impedance shifts that roughen frequency response and lead to compressed sound. Lastly, MLS eliminates other failure opportunities – that of the spider material breaking down due to temperature and humidity stress, and failure of the glue used to secure the spider to the basket and voice coil. Unlike fabric spiders NEAR’s magnetic solution does not break down or change in any way, even when subjected to years of environmental stress. NEAR speakers perform consistently over time. Metal Diaphragm Technology Cone – The ideal speaker cone would be infinitely rigid to promote the piston movement necessary for great sound. At the same time an ideal cone would be light so that it can start and stop instantaneously in response to music for perfect clarity. And it should be well damped to avoid “ringing” and midrange distortion. There is no single material that has all of these ideal properties, so NEAR cones combine low-‐mass stiff and soft material layers. NEAR’s Metal Diaphragm Technology (MDT) alloy cone is ceramic-‐hardened aluminum formed to a catenary dome shape to increase rigidity. Specially designed geometric ribs further stiffen the cone and break up resonance modes. Thin sheets of soft rubber applied to the rear of the MDT cone act to dampen higher frequency resonance. The end result is a driver that excels at both low frequency and midrange reproduction without the harsh “metallic” distortion often heard in metal diaphragm drivers. And of course hardened aluminum alloy makes a great outdoor speaker material from a durability point of view, as it is impervious to moisture, oxidation and contaminants. For instance, as the ambient temperature increases, metal alloys remain virtually unchanged. Compare that to a polypropylene cone that softens as it warms up, creating a less-‐than-‐ideal joint connection between the voice coil and cone. The result is loss of detail and clarity as well as bass transient impact. To see a demonstration of the effects of heat on metal and plastic cones click here. SupraPolymer Surround – A woofer’s surround is a vital component of its performance and a common failure point for outdoor speakers. In the NEAR® “spiderless” design it plays an even more critical role. NEAR’s surround design is the product of decades of intense research. Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
It starts with a polymer material that is impervious to salt, fertilizers, chlorine, UV, temperature extremes and the other environmental elements that destroy typical rubber surrounds. There is no speaker better for indoor or outdoor pools, marine, lawn or garden applications than NEAR. The NEAR SupraPolymer surround is specially tuned to absorb residual cone resonance modes, preventing them from radiating back through the cone. The sound is always pure and free from the resonances that can make speakers sound harsh and fatiguing. Over years of use and exposure to the elements, there is little change to these characteristics. NEAR speakers sound the same many years later as they did on day one. Tweeter Design Like the woofers, the NEAR® tweeter is an exclusive design, refined over decades of research. It uses a titanium alloy dome diaphragm suspended by the same stable and robust SupraPolymer surround material as the NEAR woofer. Ferro-‐magnetic fluid in the gap keeps the voice coil centered and cool while keeping debris and other contaminants out. The tweeter is mounted on a polymer bridge over the woofer at a height carefully chosen to minimize diffraction effects. As the tweeter and woofer are coincident, the distance between each component and the listener is always the same making tonal balance consistent regardless of where the Ferrofluid reacting to a magnetic field listener is located. Durability and Enclosures No matter where you live the outdoors is a tough environment for a loudspeaker. Sitting in the ground in a sunny environment, a speaker’s interior chamber temperature can easily reach beyond 150 degrees F (66C), even BEFORE any power has been applied to the woofer. We have already introduced many of the materials and techniques that make NEAR® speakers the most durable and longest lasting outdoor music speakers you can buy. But there’s even more to the story. NEAR’s association with professional audio company Apogee Sound proved helpful in making our speakers even more robust. The adhesives used in NEAR drivers are the same Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
high-‐temperature, stress-‐resistant type found in arena and musical instrument professional loudspeakers. The IG Series enclosures are fabricated from LLDP (Linear Low-‐Density Polyethylene) a miracle polymer that sheds moisture, dirt, chemicals and paint. UV inhibitor pigments are embedded uniformly throughout the material so the sun won’t fade the color and garden tools won’t harm their looks. In order to disperse sound in an omni pattern, the woofer and tweeter face upward. There is a small 5-‐ degree tilt to the driver array that allows water to roll off the cones. Strategically placed drainage channels shunt water off of the speaker to prevent accumulation. The “ribs” you see around the enclosures are more than mere decoration, they serve to stiffen the enclosure and break up panel resonance. Even when they are used free standing (instead of buried) NEAR IG series speakers sound pure and undistorted. But for ultimate performance we recommend burying IG speakers up to the NEAR logo, whenever possible. The grille is .8mm thick powder-‐coated stainless steel. A hydrophobic fabric covers the drivers to shed water and prevent debris build-‐up. For a video demonstration of the hydrophobic fabric, click here. Look closely and you’ll notice that the grille holes are rectangular. That was not a random choice. When water (or any fluid) gets onto a round perforated screen, the holes become plugged with the fluid and tend to stay that way due to the liquid’s surface tension. It takes a fair amount of external force to clear liquid from round holes. In the case of a speaker, the liquid blocks high frequencies, creating dull sound. NEAR’s rectangular perforations create unequal surface tension making the liquid easier to clear. Usually just the soundwaves themselves or a little breeze is enough to clear water from the NEAR® grille. Terminations and System Configuration
Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
Every IG Series model comes out of the box equipped to operate either as an 8 Ohm or 70 Volt speaker. In 70V operation there is no need to use external transformers; an 8-‐ conductor cable exits the bottom of the speaker that allows an installer to choose 2W, 4W, 8W, 16 Watt or 32W power input from a 70V amplifier. See the IG-‐Series set-‐up manual for more information.
IGS12 Subwoofer When added to two or more full-‐range IG series speakers the IGS-‐12 subwoofer adds the last half-‐octave of bass foundation that makes music really come alive. Just about everything that can be said about the IG-‐series full range speakers holds true for the IGS-‐12 subwoofer. It too uses a woofer with spider-‐less MLS suspension, a composite MDT cone, UDIO motor structure and pro-‐grade adhesives. Its enclosure is the same durable LLDP material. The differences lie in its larger (12-‐inch) driver and acoustical alignment; it is a sealed bandpass enclosure – the perfect solution to the challenges of delivering bass reliably outdoors. In a bandpass design the woofer sits in a sealed enclosure – perfect for protecting the business end (motor, voice coil, suspension) from outside contaminants such as moisture, debris and wildlife. The better protected front (cone) side of the woofer fires into a ported enclosure to take advantage of the high acoustic efficiency of a vented alignment. In this way the IGS-‐12 is the best of both worlds – sealed and vented.
Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
Perforated aluminum screens prevent critters from entering the vented chamber. And of course the MDT cone and SupraPolymer surround are impervious to whatever humidity, chemicals and contaminants could enter the vented chamber. The IGS-‐12’s bandpass alignment is by nature bandwidth limited and Blue = sealed chamber, Grey = vented chamber requires only a gentle slope external low pass filter. We recommend the LPF built-‐into the NEAR 6XL power amplifier. The Sound You want your speakers to deliver great sound, every time you turn them on, regardless of ambient temperature and volume level. Whether you are listening for five minutes or five hours, well-‐engineered speakers will continue to draw you in, pleading to be played again and again. Traditional outdoor speakers can’t deliver this kind of listening experience. Their reliance on mechanical suspensions (spiders) causes them to sound different in cold weather than hot, at soft volume than loud. Their increased distortion makes them fatiguing to listen to for extended periods of time, and their directional dispersion is an impediment to full stereo enjoyment and relaxed conversation throughout the listening area. NEAR’s spider-‐less MLS woofer design, superior materials, 360-‐degree dispersion and other advanced technologies overcome these obstacles. Whenever you turn on NEAR® speakers the sound is perfectly balanced from octave to octave, regardless of the volume level, environment and listener’s position. Although the midrange dominates the number of octaves, and dictates the accuracy of many of the instruments (especially vocals), the bottom and top of the spectrum along with the harmonics are all important. The octave-‐ to-‐octave balance will predict whether the sound is as close as possible to the original Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
instrument, or whether the instrument becomes thin and “bright” (too much treble or upper midrange), or lumpy and thumpy bass. With NEAR® speakers, bass is strong, impactful yet tight and musical. Vocals and midrange are clear and articulate; highs are present but never harsh. In short they sound like real music. Judge them by absolute standards of accurate reproduction of reality as you would judge an expensive audiophile-‐grade indoor speaker. They sound great, not just “pretty good for an outdoor speaker.” As the NEAR motto says, “Nothing comes closer.”
Copyright 2015
NEAR is a division of Bogen Communications, Inc.
http://www.nearspeakers.com
