Bose Acoustimass-15 Review





QUICK LINKS:

INTRO
THE CUBES
THE SUBWOOFER
THE COLD HARD NUMBERS (1)
THE COLD HARD NUMBERS (2)
BUT I HEARD...
FAIR LISTENING
MARKETING & BOSE
BOSE & THE PATENT SYSTEM
GOT THX?
THE ALTERNATIVES
THE BOTTOM LINE
FURTHER READING
FEEDBACK

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INTRO:

As a part of a small sect of audio enthusiests who loathe the company Bose Corp. for its marketing deception, shortcutting in manufacturing, and shameless consumer trickery, I was recently passed on a website written by a "Bose-o-phile", who was defending the company. After a brief email correspondence with this dimwitted individual, I vowed to represent our side: the TRUTH. The review on this page is directed towards the Acoustimass-15, one of Bose's most popular systems, and holds truths to the entire Acoustimass AND LifeStyle series systems as well. After all, the Lifestyle system is merely Acoustimass speakers packaged with a Bose integrated preamp. The AM-15 is priced at $1299.99 USD MSRP. When you are done reading, check out my Bose alternatives page here.

THE PACKAGE:


five "swivel satellites" and one "bass module"

THE CUBES:

The $1300 Bose Acoustimass system implements five dual-cubed, 2.5-inch, paper-cone satellite speakers. Incidentally, you can buy these exact same drivers for $35 a pair here. The material that is used to build these speakers may seem adequate to the unassuming novice; However, upon closer inspection, it is clear that they are built with little regard for performance. To start off, the cubed satellites are made of what Bose claims is a "revolutionary new space-aged paper", when in fact my own observations show that they are identical to Manila hemp paper. Quality is besides the point here, as any type of paper has perhaps the worst resonant properties for upper octave frequencies (2 KHz to over 20 KHz). Research has shown that the best materials to use as tweeter domes are alloy metals and fabric materials, depending on what tone you want your highs to have, as they are both strong and light weight materials. Typically metals such as titanium and aluminum have a much sharper, more detailed, and brighter distinction, whereas fabrics like Mylar and silk have a more mild, smooth signature (the crossover can magnify or nullify these properties). Because of its characteristically wide dispersion angle (180 degrees in conventional dome tweeters) and lower distortion (typically under 1% THD), dome tweeters sound much more open and airy with an expanded soundstage as opposed to cone tweeters; However, Bose disregards this fact, because making cone tweeters out of paper and thin, plastic dust caps is a much cheaper manufacturing process. You'll never see this design used by any other speaker company, but you'll find it abundant in $200 boom boxes and mini-systems. Furthermore, the 2.5-inch paper cones used are the perfect size where both tweeter and midrange drivers perform weakest. In home applications, high-pass tweeters should be between 0.5 to 1 inch in diameter, and never more than 2 inches. Larger tweeters are especially poor performers when powered by tiny piezoelectric magnets such as those used in the Bose cubes (results in added magnetic phase distortion on the voice coil). Midrange drivers should never be smaller than 3 inches in diameter, are commonly 3 to 6.5 inches (ideally over 4 inches). These very specific driver sizes correspond to acoustic properties that allow for greater ease in the magnet-coil structure driving the speaker at its targeted frequency as well as having sufficient cone surface area to push the required amounts of air. Remember that all sound is is the rapid movement of air. Bose's incongruous selection of dual 2.5-inch drivers provides some of the greatest sonic failures within this system.

One of Bose's largest mistakes may be the fact that they rely on one single driver to reproduce midrange and high frequencies together. I'm referring to the cubed satellites, which are forced to produce signal from 200 Hz to 20 KHz (which I might add it will never do). You may argue that there are two speakers in each satellite, but there is also no active crossover separating the signal, so both are driving the same frequency bands. No other speaker company that exists today even thinks about building these "crossover-less" satellites because the resulting performance is evident in the sound produced (or rather, not produced). However, this isn't some big mistake in Bose's research team... This system was designed to be small and aesthetically appealing (WAF), and this concoction was the only way to make it so. If high and midrange frequencies each had their own discrete drivers, Bose would have the same satellite speaker as every other competitor---only without remotely similar performance, and thus nothing to market.

Finally, the Bose satellites are enclosed in cheap, thin plastic cabinets. This decision is just as foolish as every other they have made. The purpose of speaker cabinets is to provide an inert barrier that absorbs backfire, prevent phase distortion, potential sound cancellation, and dampen resonance caused by the driver. Thin plastic is a very reflective and resonant material as you well know, and fails miserably at all of the aforementioned goals. It also fails at magnetically sealing the drivers so that it not only gives off EMI (electromagnetic interference), but also receives it with little resistance.

THE SUBWOOFER:

The Bose Acoustimass subwoofer, or "Bass Module" as they'd like to call it, consists of three 5.5-inch drivers in a seventh-order band pass configuration. The three-chamber band pass design is the worst of all major subwoofer enclosure types (i.e. Isobaric, Ported, Bass-Reflex, Acoustic Suspended, Infinite Baffle, and Transmission Line). Its only purpose is to boost decibel output at the expense of accuracy. It does this by burying all woofers within the cabinet in three separate chambers, and using them to drive air out of its port(s). First of all, 5.5-inch drivers are NEVER subwoofers; they are clearly midrange drivers. In fact, Bose doesn't even claim that its "Bass Module" is in fact a subwoofer. True subwoofers start at 8 inches and taper off at 15 inches. Chosen size largely depends on the application, be it music playback and type of music or movies. Smaller subwoofers move faster and thus have tighter bass response for improved clarity and accuracy, but larger subwoofers can reproduce lower frequencies and at louder volumes. Sometimes you will find 6-inch subwoofers in multimedia computer systems and novelty 18-inch subwoofers, but those are largely non-conventional designs that do not have any advantage over others. Just to clarify, when properly built, a 5-inch woofer can hit as low as 45 Hz within ±3db, as most good midranges are expected to. But the Bose paper-cone drivers are already very poorly crafted to begin with, coupled with cheap crossovers located in the amplifier section (distortion anyone?), and then told to act as a subwoofer. This contrived effort quickly reveals its weaknesses in a computer frequency sweep test.

Build Quality. None of the three so-called "subwoofers" have any substantial driver-baffle bracing (I fail to see Bose's reasoning behind this). Even tweeters have driver bracing, because without it your speaker will soon rattle itself to death and fall apart. What makes this situation even worse is the fact that the woofers are accommodated with very thin foam surrounds. A surround is a flexible membrane that is used to attach the speaker cone to the baffle. Organic foam surrounds are known for drying out, rotting, and falling apart within 5-10 years of its machining (whether or not it is being flexed and worked). Alternatives to foam are flexible rubber compounds such as Butyl and Santaprene.

I also noticed that the three Bose subwoofer drivers are made of the same Manila paper as the satellites, but of a slightly thicker species. Treated paper and multi-layered laminate is acceptable for subwoofer cones, in fact some companies such as Velodyne and REL implement them quite well; However, once again Bose uses non-durable paper that can warp and tear quite easily under heavy loads or even high humidity. Pricier subwoofers are often made of more exotic materials such as Kevlar, carbon fiber, carbon-Kevlar composites, Aero gel, aluminum, and polypropylene/polyurethane/hyperpolymer-urethane plastics.

While on the subject of its structural integrity, the AcoustiMass subwoofer is housed in the lowest-grade particle board negotiable. It is a cheap, thin LDF (Low Density Fiberboard), that is a fraction of the industry's standard MDF's (Medium Density) density and thickness. Every other speaker company employs nothing less than MDF in their subwoofer cabinets, and a general rule of thumb is that the MDF be at least 3/4 inches thick with more thickness emphasized on the front baffle. To give you an idea in differences, MDF is three times denser than LDF. The optimal cabinet material should be heavy, rigid, and solid such as Methacrylate Polymer or solid cast aluminum, which is used by companies such as Wilson Audio and Krell, but also costs over 15 times that of MDF!

THE COLD HARD NUMBERS (PART ONE):

Many Audiophiles, professionals, newsgroups, and the like have ripped up, rebuilt, clocked, and benchmarked the much debated Acoustimass system time and time again. The resulting numbers are always consistent to the very hertz. Here is a recent one from Sound and Vision magazine (which is slightly more generous than others I've seen)
  SATELLITES BASS MODULE
Frequency Response 280 Hz to 13.3k Hz at 10.5 dB 46Hz to 202Hz at 2.3 dB
Sensitivity (SPL at 1 meter)* 85.1 dB N/A
Impedance (minimum/nominal) 5.3/8 ohms N/A
Bass Limits (-3/-6 dB) 280/220 Hz 46/40 Hz
 
* measured with 2.8 volts of pink-noise input

To reiterate the above, the Acoustimass's bass module responds to 46 Hz to 202 Hz at 2.3 dB, while the satellites respond to 280 Hz to 13.3 KHz at 10.5 dB. I have never seen any other speaker tested with a 10.5 db allowance!! Still, this leaves a frequency gap between the satellites and bass module of about 80 Hz! That is 80 Hz of sound that is completely lost within the system's poorly constructed internal crossovers. That is a HUGE loss of midrange sound that is responsible for the majority of substance in contralto, baritone, and tenor vocals in music, and many sound effects in home theater. Not to mention that the Acoustimass also ignores audible signal from 20Hz to 45Hz on the low end, AND 13KHz to 20KHz on the high end. Do the math folks, this Bose system only produces 13,176 of the 19,980 Hertz in teh audible spectrum. That's only ~66% of the actual recording being played back! Is this the kind of performance you'd expect from a $1300 product?

Not only will you experience a huge loss of sound, but the fact that the subwoofer has to respond to frequencies as high as 280 Hz means that there will be extreme amounts of localized midbass in the Bose Bass Module. A well-mated subwoofer should never have to produce any frequencies above 80 Hz, and ideally should be crossed over around 60-70 Hz. The purpose of a subwoofer is to produce non-directional low frequency effects that are not supposed to be localized. Translation: essentially when you're watching movies with a Bose system, you will hear the gunshots and explosions coming from the subwoofer next to the CD rack in the corner of the room, and NOT from the television screen. In music, you will hear the singer's voice come from the subwoofer next to the CD rack in the corner of the room, and NOT the converging point of the two main speakers. This is known as poor 'sound imaging'. For you current Bose owners, try unplugging all your cubed satellite speakers and play a DVD on your AcoustiMass system. I used the DVD 'X-Men' for my review. You will be able to follow the entire movie off of dialogue picked up by your Bose bass module.

All this lacking of sonic fidelity and richness is doctored up by placing overemphasis and accentuation on 80 Hz and 200 Hz in the bass module to give the illusion of powerful bass, and by placing the same accentuation on 7 Hz in the satellites to give the impression of full high-frequency coverage. In the quest for high fidelity and accuracy in sound reproduction, this system is antithetical to the goal. As illustrated below, there is nothing linear about the frequency response...


NOTE: HERTZ ARE NOT EVENLY MARKED OFF

ABOVE: Data gathered from an anechoic frequency sweep test of the AcoustiMass-15 unit. Remember that the goal here is linear response. You want a frequency chart to show as flat a line as possible, which illustrates accurate sound reproduction without colorization. It is true that sound is perceived logarithmically by the human ear, but this should have no influence on a speaker's design because instruments don't produce sound logarithmically, nor do voices or action sequences. One should rely on the speaker to reproduce the recording faithfully. But notice the high end roll-off at sub-20kHz frequencies at the far right and the extreme colorization from 1 kHz to 20kHz with HUGE emphasis on 5 - 7kHz. Also shown is the frequency dip between 200 Hz - 300Hz within 3dB. The deep bass rolls off prematurely at around 50Hz and is spiked with colorization at about 200Hz. The bass module and satellites don't even begin to harmonize until beyond -10dB. Remember the representation of accurate sound reproduction on the above graph would be a flat line across the 0dB mark. Just look how miserably Bose stacks up in that regard...

BELOW: Another thing to consider is that the only relevant information on the frequency sweep graph are the measurements between -3dB to +3dB as I've isolated below. This is how the AcoustiMass looks from that standpoint....

THE COLD HARD NUMBERS (PART TWO):

Bose has a "product data sheet" as they like to call it, on their website in Adobe Acrobat PDF-format, which can be viewed by clicking here. If and when you look at this document, you will soon realize that absolutely no where are there any specifications for the system's actual performance; Merely product size, dimensions, and shipping weight. There is mention of the AM-15 being quote: "Compatible with all surround receivers 10 - 200 watts per channel/rated 4 to 8 ohms"-----Am I missing something here?! Isn't pretty much every satellite/subwoofer system sold on the consumer market today quote "Compatible with all surround receivers 10 - 200 watts per channel/rated 4 to 8 ohms"? So then what has Bose just told us? Absolutely nothing. This is how they get away with telling us nothing about the speaker system's performance. What they don't tell you is that because the satellite speakers and bass module are sooo incredibly small, that they are also incredibly inefficient due to lack of internal cabinet air space. This is why the AcoustiMass system runs at an unadvertised 6-ohm nominal load, which will put more load on your amplifier than the more common 8-ohm speakers of the competition. Yes your nice expensive receiver you just bought is going to run a few degrees hotter than you expected in order to push the Bose cubes just as loud as a regular satellite speaker. Especially if you bought the Acoustimass with the passive Bass Module.

BUT I HEAR BOSE IS GOOD!:

Popularity. Popularity of a name brand doesn't equate to quality. Bose mystique feeds off of its well-targeted audience: the ignorant, ill-informed, mass-market consumers who search for simplified hifi audio solutions in "all-in-one" chain stores such as Walmart, Best Buy, Sam's Club, Price Costco, Sears, Montgomery Wards, etc. A Bose speaker, when put up against the in-store competition of Technics, Cerwin Vega, Pioneer, Kenwood, and Sony speakers, may indeed sound like a better buy. Since these Japanese mega-icons are established corporate monsters, the buyer will feel confident knowing that he or she made a thorough comparison. If you are too lazy to do the few hours of research, stop by a local hifi specialty audio dealer, and you weigh YOUR $1300 on convenience/style over quality/performance, then drive down to Sears and hand over your money. You will be rewarded accordingly for your efforts.

Audio newbies often throw out the "But I heard that Bose is good!" defense, to which I respond "From who?" Was it a sound engineer, electrical engineer, materials scientist, studio engineer, producer, recording professional, musician, Mark Levinson? Ray Dolby? George Lucas? Anyone credible? Or was it your neighbor with the GoldStar walkman, Teac boom box, Funai mini-system, and Sylvania receiver? Perhaps the ubiquitous Bose Ads that you find in completely irrelevant magazines such as Popular Science, Times, Playboy, GQ, People, Astronomy, etc, had some sort of subliminal effect against the better of your judgment.

FAIR LISTENING:

In all stores that sell Bose, you will see one of two types of Bose displays. First, there is the more common 'end-cap display' with a small TV screen, neatly laid out Bose components with speakers and extended arms that reach around to create a surround environment. In this setup, the trick to making the Bose system sound good is in unfair comparison and unrealistic environment. In most of these low-end stores, no other 5.1 surround system is configured in such a way because the store does not have a dedicated listening room. Therefore the experience of listening to Bose is more fulfilling than hearing the other 5.1 speaker systems that are all lined up in a row on the shelf-top facing you. The Acoustimass displays are also only about six feet around, therefore when you're listening to the Bose demo in the pocket, the speakers will most likely sound powerful from three feet away. You put the same system in your average 15 by 20 foot living room and in order to fill that airspace with the same sound pressure level, the AM-15s will audibly distort in numerous frequency bands. Bose also carefully selects music and movie sequences that flatter their speakers and most effectively utilize its built-in accents. And as a former employee of one of the top three largest hifi audio specialty retailers in the United States, I personally know how stubborn Bose is about not allowing their speakers to participate in fair speaker comparisons in listening rooms. I know how Bose reps require that a store's floor plan has to place Acoustimass/LifeStyle systems in separate areas with their own displays far away from other speakers.

The second breed of Bose displays is the 'expo room'. These are placed in stores that are deeply in cahoots with Bose Corp. These are stores like Fry's Electronics that lease out 2000 square feet of showroom floor for Bose to erect their own specially designed theater room and an attached catalog room. The thing with these show rooms and theaters is that they are very heavily sound treated with acoustic sound padding and acoustically engineered and calibrated rooms. The control room behind the theater is operated by a $30,000 rack of professional-grade preamplifiers, equalizers, DSP processors, and amplifiers. The technical prowess and build quality of this rack system compared to the Bose Lifestyle media console is a night and day difference. The subwoofer used is positioned in the optimal location to maximize spatial loading. The expense of running a room like this is in the hundreds of thousands of dollars range. Again this is a gross overstatement of the Acoustimass' true capabilities, presented in an impractical, unrealistic environment. I can almost fully guarantee you that the Acoustimass system will NOT sound the same as they do in this room. If you don't believe me, then on your next visit to this Bose demo kindly ask the Bose spokesperson to show you their control room. They will be reluctant and steadfast to do so. Some will deny such a control room exists. I would also be interested in dissecting the speakers and subwoofer they use in this room to see if they matched that of the Acoustimass system that they sell to consumers. My guess is they are likely modified as well.

Finally, it is useful to know that in comparison tests, psychologically the listener is more attracted to the speaker systems that have more emphasized bass and treble, and less midrange-- a fault of pop/rock sound engineers. This is the wrong approach, as it is the goal of every audiophile to find the most balanced, most accurate sound. If you do decide to shop around for the AcoustiMass system, point your attention to the bass module. On it, there are tone controls (bass and treble dials), which control the tonal saturation of the speakers. It is standard practice by EVERY audiophile to neutralize tone settings. So neutralize the dials on the subwoofer and listen to how terribly dry and lifeless the entire system sounds with music. What's worse, turn the tone settings all the down to the base setting and the system sounds like utter GARBAGE. Only when the settings for bass and treble are completely saturated will the speakers sound "bearable" within the 3-foot Bose bubble.

MARKETING AND BOSE:

It is estimated that Bose has spent more dollars on advertising last year than ALL other high-end companies COMBINED. Does it have an effect? Sadly, yes. A few years back, the United States Air Force signed Bose onto a multi-million-dollar contract to design noise cancellation headsets for Air Force flight crews. Bose won the contract over two other companies simply because of their "more established name" (brand recognition). The concept of a noise cancellation headset is to actively monitor the noise frequencies emitted from a jet engine and the turbulent wind, and reproduce the exact signal 180 degrees out of phase, thus theoretically canceling it out completely. Many reputable manufacturers have successful done so as well. Bose produced a model that cost approximately $1000 per unit, which failed to cancel out a significant amount of noise. The company used the contract as an opportunity to unload obsolete parts from years back. Bose pawned off thousands of outdated interface connectors for which there were no longer commercially available mating jacks, and incorporated them into the headsets. The Air Force, proud as it was, didn't scrap the project, but instead spent countless millions more replacing the consoles in a number of aircraft to make them compatible with the said headsets. In the end though, the Air Force did terminate the contract when test crews found that the headsets were ineffective and non-durable. This whole mess was created over a brand name's alleged reputation and prestige. Bose is now selling a downgraded version of these headsets to commercial airlines and to the consumer public. They now work to a minor degree, but are not surprisingly still easily outperformed by their competitors. These consumer market headsets are also very, very poorly crafted. I belong to many audio forums and have heard stories about these very expensive headsets falling apart prematurely.

Few magazines are now willing to give honest reviews of Bose products due to a Consumer Reports review a few years back that gave the AM-15 embarrassingly bad ratings (score of 62 out of 100). Consumer Reports allegedly used a double-blind comparison test, which is in fact the ideal way to compare speakers. That particular review ended up in a lawsuit over "unscientific testing methods". Thankfully, Bose lost that lawsuit, but since then, Consumer Reports and various other magazines give neutral-to-rave reviews while more prestigious publications like Stereophile, Fi, and What HiFi? ignore Bose products completely.

BOSE AND THE PATENT SYSTEM:

To quote from Michael Wong, a visitor to this site: "...a casual perusal of their website reveals that they have used money and lawyers to repeatedly abuse the patent system. They have patents for the Acoutimass (Helmholtz resonator), the Direct/Reflecting technology (multipolar speakers), their Acoustic Waveguide (transmission line), and their JewelCube technology (amalgam of transmission line and other old ideas). In each and every case, their patent is a joke; an obvious example of the all-too-common trick of making one minor alteration upon a pre-existing idea and then using an army of lawyers to get it patented... And why all the bother? Because it looks good to write "patented technology" on the box...".

GOT THX?:

Considering the large emphasis on marketing that Bose places on its products as well as the ostentatious boasting of "innovation" and "performance", I am curious as to why NONE, count them: ZERO, of their speakers are THX-certified. George Lucas offers certification to any product from any company willing to undergo the scrutiny of his tests. I'm sure Dr. Amar Bose has brought in many Bose speakers to the Skywalker Ranch for certification only to have them rejected time and time again. I am no fan of THX-Certification myself; However, no one can deny that it is perhaps the singly most powerful marketing tool in the entire industry. One tool that Dr. Bose would not have overlooked, but again, one that he could not obtain for himself.

THE ALTERNATIVES:

I have made it quite simple to shop for an outstanding home theater system using the same $1300. I've been getting a lot of emails and guestbook entries requesting my opinion and advise on specific system designs. I am unable to answer all of them though I do read them all and try to answer as many as possible, but it would be much easier if you shopped and auditioned speakers based on the list I've compiled. Again, my opinion on the quote on quote "best speakers" cannot be relied on, nor can anyone else's. Since fidelity and sound quality is 100% subjective, no one can answer that question, but you.

> Surround Sound Speakers List <

THE BOTTOM LINE:

This six-speaker unit costs $1299.99 USD MSRP. From dissecting it, I can tell you it costs $100, no more than $150 tops, to assemble. It performs similarly to a $500 Optimus-Radio Shack surround sound system and is very easily outperformed by a $350 Cambridge Soundworks system. For $1300, there are at least three dozen other configurations from companies such as KEF, PSB, NHT, Mission, Tannoy, Diva, Polk, B&W, Energy, Paradigm, M&K, Infinity, Mirage, Monitor, Jamo, Axiom, nOrh, Dahlquist, Sound Dynamics, Acoustic Research, Phase Technology, Definitive Technology, Wharfdale, Boston Acoustics, and Klipsch that easily outperform all Bose speakers from the 151s to the 901s. If you are in the market for such a surround sound system, I have compiled an extensive list of speaker systems for you to peruse. Just click here. Bose equipment, particularly its flagship LifeStyle 50, resemble the sonic performance of my 11-year-old Aiwa 3-disc minisystem. And for $500, the Wave Radio is an overpriced hunk of junk! If you like the WaveRadio, have a listen to a Henry Kloss radio for a fraction of the price! So it is important to remember that Bose, like Bang & Olufsen and Nakamichi, sell lifestyle and designer products whose prices are very heavily saturated by image and appeal. They are by no means performance products. They have no cost-effectiveness, no bang-for-the-buck value, and draw no respect from any audio enthusiests. If your goal is to appeal to and impress housewives, then this system gets the job done, but if your goal is high fidelity, high performance, high endurance, upgradeability, and fair market value pricing then I would very highly suggest you look elsewhere.

I am by no means classified as an 'elitist audiophile' who touts his golden ears about in gross snobbery. I am an audiophile in its purest and most basic form: one who is enthusiastic about high fidelity sound reproduction, which I think we all are to some degree. I've worked in retail audio/video sales before (for a company that offered Bose) and have designed and personally installed home theaters for hundreds of clients of very diverse needs. I have no affiliation or financial ties to any competing speaker companies so I speak out of objectivity and out of a big-brotherly need to inform those that don't already share my knowledge and experience. Happy hunting!

FURTHER READING:

The internet is a great place. There are many growing online communities and discussion forums focused on home theater, home audio, and consumer electronics. These are great places for everyone, from the eager learning novice to the die-hard audiophile, to exchange ideas and experiences with eachother. If you would like to learn more on the subject of audio equipment or just need some guidance, here are some of the leading web forums out there (in no particular order)...

 
AudioAsylum.com Forums
Audioholics.com Forums
AudioReview.com Forums
Home Theater Spot Forums
AV Science Forum
AV Forums
The Outlaw Saloon
Klipsch Bulletin Board
Sound & Vison Online Forums
Club Polk Forums
The DVD Forums
Home Theater Forum
- A good Bose thread

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Reviewed and written by:
- Rich Wang, Webmaster Intellexual.net
  01/05/01


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