('78-'83)  $750 (includes rare factory wall hangers)

In absolutely amazing operating condition, this pair of the elusive Rogers JR149 are cosmetically near perfect as well.  These diminutive round speakers were first designed in 1977 by *Jim Rogers.  Since that introduction, the JR149 has become mysteriously legendary for a number of reasons. 

After many tweaks and more testing, the JR149 was released for sale in 1978 as a ‘technical breakthrough’, the JR149 exhibied some strong ideas when it came to the cabinet structure. It's a 2.6 gallon volume design with the circular enclosure wall made from high grade aluminium and measuring 12" high by around 9" in diameter.

Designed as an infinite baffle sealed enclosure, it is very heavily damped with thick acoustic foam. Below the decorative solid oak caps at each end of the cylinder are two fiber discs held under tension via a steel rod, which run through the enclosure from top to bottom. Crossover and cable connections are in a separate metal housing underneath the loudspeaker – matched to the rest of the speaker, as Rogers had even made a specially designed round printed circuit board for the crossover section.

The obvious and primary reason would have to be the surprisingly satisfying soundstage that comes out of these smallish, round enclosures.  Hidden behind the articulated foam grills and then behind the second tier round metal housing are the high quality drivers: KEF T27 mylar tweeter & KEF B110 Bextrene cone midbass.  Those excellent drivers take their cue from the intricately designed crossover network that is cleverly tucked into the easily accessed bottom portion of each enclosure.

At their best, they should be hung on the wall with a slight toe-in.  Fortunately, this pair has the extremely rare, specially designed wall hangers.  These heavy iron hangers are perfectly designed to cradle the bottom portion of the enclosures for a snug fit while keeping them free from any loss of resonance.  

NOTE: The JR149 model is among the most attractive speakers ever made. When matched with the right amplifier few speakers of these dimensions out perform them and none are more acceptable in a modern living room.

Features and upgrades:
Rebuilt crossovers with many new inductors and/or capacitors. 
New articulated foam grill covers
Factory wall hangers
Solid oak top end caps

Specs:
Frequency Response: 70Hz to 20kHz
Impedance: 8 Ohms
Power Handling: 60W
Recommended Amplifier: 20 to 100W
Crossover Frequency: 3000 Hz
Sensitivity: 90dB
Dimensions: 9" diameter x 15" tall

*About Jim Rodgers...
Mr Rogers worked as an engineer for the BBC where he designed the famous BBC LS3/5A bookshelf speaker.
The '70s saw the rise of home entertainment from the record deck to hi-fi (high fidelity) and British designed amplifiers, speakers and turntables became the envy of the world.  In 1977 Jim Rodgers designed the JR149, based upon the renowned LA3/5A encased in a heavy gauge aluminium cylinder with wooden end caps.
He went on to design a super woofer to extend the base down to 30Hz and a larger model, the JR150.

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(hybrid) (1987) (rare, mint)  $400 (firm)

The Maxim III-H (hybrid) is best described as the last and best configuration (as designed by *Dan Siefert) of a two-way, compact system featuring 40-Hz resonance woofers, low IM distortion, low group delay and with high power handling capability.

The enclosures:
Essentially a 2-way system featuring front-ported, black-lacquered front baffles with grained red oak veneer enclosures, tuned-bass reflex (with radius edges) are based on the special relationship 4:5:6, which minimizes internal nodal reflections. Remarkably solid, 3/4" particle wood and high density fiberboard, plus rigid internal bracing. The narrow baffles provide excellent dispersion and enhanced imaging. They have sequential serial numbers for a matched pair.

The drivers:
Specially designed Dynaudio 6.5" woofers (18 oz ferrite magnets, 1.25" voice coils) feature ultra-compliant butyl surrounds combined with polypropylene cones containing proprietary inert damping compound that makes them twice as thick as most woofer cones.The SEAS tweeters (8.7 oz ferrite magnets) are 1" special aluminum domes with polyamide surrounds, this upgraded tweeter design makes them hybrid, or, the "H" model. (see Dan's technical explanation below)

The crossover network:
3.3 kHz, conjugate-compensated, first order, minimum phase

Specs:
Frequency response: 46 Hz ~ 22kHz
Impedance: 8 ohms
Power handling:  up to 250 watts
Sensitivity 86 dB @ 1 watt
Dimensions:  13"H x 9"W x 11"D
Weight: 18 lbs (ea)

Finally, the Maxim III-H (Hybrid) is true high quality system, 100% made in USA. They easily rival the quality of famous German/American speakers like Visonik, Braun, ADS, B&W, etc. 

The story:
Several years ago, we came across a pair of unknown (at the time) Siefert Research speakers. We were intrigued enough with the design and sound to jump online and (eventually) track down the designer, Dan Siefert. *(see bio below).
He was kind enough to reply with a wealth of inside information way beyond what was available online. He recommended looking for a pair of Maxim III. He also sent us a package with original spec sheets, sales sheets and technical design information about the Maxim lineup.  Back in December 2018, after finally finding a mint pair of Maxim III(H), we contacted him again in regards to what the "H" meant on these Maxim III(H) speakers.
Dan's reply: 12/27/18"
"With the Maxim III-H you have what I consider the best series of Maxims. The "H" stands for hybrid. Looking at the tweeter you will notice that the dome is aluminum but the surround (outer edge) is not.  99.9% of all dome tweeters are a single piece construction. So, if you have an aluminum dome (high stiffness), the surround would also be aluminum.  Aluminum makes a great diaphragm but a lousy surround (where you want high compliance, not high stiffness).  In the '80's there were almost no hybrid construction tweeters. Today they are somewhat more common. Bottom line: the hybrid tweeter combined the high stiffness of an aluminum dome with the high compliance of a polyamide surround making a very good speaker even better."

Stereophile magazine review 1985:
"There are very few loudspeaker systems of any price that don't make a critical listener accurately unhappy when he or she returns from a live concert to put on a recording. The Maxim is, amazingly, one that doesn't. In fact, of all the speakers in this price class that I have heard. I would say that Siefert's Maxim III is probably the most successful design of all. Mated with a suitable power amplifier, and not pushed too high a listening level, it is one of a small handful of moderately priced speaker systems that can make most audiophiles (and practically all music lovers) quite happy for an indefinite period of time. Recommended."~J. Gordon Holt (Stereophile magazine July 1985) Read more at https://www.stereophile.com/.../siefert-maxim-iii...

About Siefert Research...
Dan Siefert began his engineering career in 1975 at Great American Sound Company, designing high-end solid-state audio pre-amplifiers and power amplifiers.In 1983, Dan founded Siefert Research in Los Angeles, designing, manufacturing and marketing high performance loudspeakers...not through dealers but direct to customer.In 1986, he joined Harman International Industries, Inc . as a Senior Systems Design Engineer.While at Harman, Dan brought several speakers to market for professional, consumer and computer/multi-media applications. He was assigned to the Research and Development department, reporting to Dr. Floyd Toole. Dan then focused his attention on measurement technologies and contributed to the development of Harman's advanced subjective and objective measurement techniques.In 1996, he founded One on One Technical Products, Inc. and currently in 2018, as CEO, providing engineering services to the Consumer Electronics Industry. He is a member of the Audio Engineering Society (AES), the Acoustical Society of America (ASA) and the Custom Electronics Design and Installation Association (CEDIA). Dan is also a certified THX Home Theater Products developer.

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(France '15 -'18)  $650  (includes stands)

With perfect cosmetics and completely original internals, this pair of Focal Chorus 706 V2 is fully operational.  The cabinets have a custom finish featuring real dark mahogany veneer tops with satin ebony on the side panels.   They come with an excellent pair of 24" tall, heavy duty floor stands made of black baked enamel over tubular steel.  

Made in France from the company that's been making audiophile level speakers since the 80's, the Chorus 706 V2 bookshelf speakers are beautiful to behold and listen to. 
The Chorus 706 V2 speakers boast Focal’s latest 1″ aluminum-magnesium inverted dome tweeter. Inverting the dome optimizes the connection between the voice coil and the dome, maximizing efficiency and precision. Plus, the tweeter’s new lightweight polyurethane microcellular foam suspension allows the dome to move more freely for lower distortion, greater accuracy, and smoother sound.  With its impedance rated at an "easy-to-drive" 8 ohms, any high quality amp rated between 50-120 watts per channel should be just fine.

Drivers:
The 706 V2 mates a 6.5″ Polyglass mid/bass driver with a 1″ aluminum-magnesium inverted dome tweeter.
The mid/bass driver is a refinement of a Focal design (in production for 15 years) that uses a coating of tiny hollow glass spheres on the surface of the cellulose-fiber (paper) cone—increasing stiffness while only marginally increasing cone mass.
Similarly, the tweeter is a refined version of Focal’s inverted-dome unit, featuring a new suspension and magnet structure that reportedly reduces distortion at the crossover frequency by a factor of six.

Cabinet:
The 706 V2’s enclosure construction is truly impressive for a loudspeaker at this price level. Cabinet rigidity is usually given short-shrift in entry-level products, but not in the 706 V2. All six walls are made from 1″-thick MDF with internal bracing. The “V”-shaped enclosure (which gives the series its name) means that the sidewalls are not parallel, reducing standing waves inside the box. The cabinet is significantly larger than that of a traditional mini monitor, though still small enough for bookshelf mounting (if you must).

Crossover:
The crossover point is at 3kHz, with fourth-order (24dB/octave) slopes, realized with second-order electrical filters combined with second-order acoustic roll-offs. A single pair of binding posts is provided.
The 8 ohm impedance and high sensitivity of 90dB (high for a small speaker) suggest that the 706 V2 can be driven to loud levels with moderately powered amplifiers.

Specs:
Type: 2-way bass reflex bookshelf loudspeaker
Drivers 6.5’’ Polyglass midbass
             1’’ TNV AI/Mg inverted dome tweeter
Frequency response: 55Hz- 28kHz / Low frequency point (- 6dB) 47Hz
Sensitivity: 90dB
Nominal impedance: 8 Ohms
Minimum impedance: 3.6 Ohms
Crossover frequency: 3000Hz
Dimensions: 15.5"H x 8.75"W x 11.5"D 
Weight: 18 lbs each

About Focal...
Founded in 1979 in Saint-Étienne, France, by Jacques Mahul, Focal (originally Focal-JMlab) has grown from a small high-end driver workshop into a global audio leader. Known for in-house manufacturing, the brand revolutionized bookshelf speakers with the 1982 DB13 and set audiophile standards with the iconic Utopia Series.

'90s: The company gains international recognition and becomes a key player in the French acoustic market.
'95: The Grande Utopia loudspeaker is launched, establishing the brand's reputation for high-end, innovative design.
'02: The "Focal Professional" department is created for studio monitors. The company becomes known as Focal.
'11: Focal merges with British electronics company Naim Audio to form the Vervent Audio Group.
'16: Focal initiates its first OEM car partnership with Peugeot and launches high-end Utopia headphones.
2020-Present: The company continues expanding into yachting, high-end home audio, and integrates new materials like Flax and Beryllium.

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('10 -'15)   $650

Obtained from the original owner, this pair of Klipsch Reference RS-62-II are completely original in pristine cosmetic condition.  All drivers, crossovers are 100% functional.  The original boxes and documentation are included.  The original cost of just these two speakers alone was $1200.

Although these were designed by Klipsch as surround speakers, we use them as main speakers along with the addition of a small but complementary high quality powered subwoofer. 
The result?  In this type of setup they produce a fantastic soundstage while presenting themselves as a very attractive focus in practically any high-end stereo system that has a solid amp as the anchor.  In our opinion, there's really no need to have the entire Klipsch surround system (at a cost of $3100) in order to enjoy the latest Klipsch technology for your simple 2-channel stereo system (providing you add an unobtrusive powered subwoofer of high quality, that's discreetly tucked away out of sight.) 

Now in its fifth generation, these Reference II models yield even higher sound quality due to re-engineered drivers and a new crossover system. Complete with proprietary "Tractrix" Horn technology, each speaker offers the precision, clarity and effortless power for which Klipsch is known.
They exude elegance with several cosmetic upgrades, including new black metallic finished baffles, machined "Cerametallic" woofers, logos and feet.
The "wrap-around" curved grills attach magnetically.  On the rear are gold plated speaker connections and factory installed wall hangers.

Specs / Features:

~Type: 2-way dipole bass reflex 
~Chassis:
~Midrange: Two 6.5" Cerametallic cone woofers per enclosure
~Tweeter: Two 1" Titanium Compression driver paired with 90° x 60° square    Tractrix Horn per enclosure
~Power handling (nominal / music): 150 / 600 watts
~Efficiency: 97dB
~Frequency response: 50 - 24000 Hz
~Crossover: 1300 Hz
~Impedance: 8 Ohm
~Dimensions: 16"W x 15"S x 9.2"D 
~Weight: 23 lbs each

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('73-'77)   $500 (stands not included)

Obtained from the estate of the original owner and in pristine cosmetic condition with all original drivers (woofers professionally refoamed in June 2026), this pair of The Advent /1 is fully operational.  They were part of the 3rd distinct line of speakers which Advent produced ('73-'77).  The enclosures, vintage tan-linen weave grill cloth, drivers, badges and crossovers are all excellent.  Essentially when they are in such great condition as these are, they're very difficult to find.

They are a 2-way design (in sealed walnut vinyl veneer enclosures) with 10″ woofers & the proprietary, unique angled 1.5" "fried egg" tweeters (reddish orange in color).  The Advent /1 speakers have the same drivers are the Original Large Advent (OLA) except in a slightly smaller cabinet
Advent said that the Advent /1 was designed to closely resemble the sound of the Original Large Advent (OLA) but without the higher price and larger cabinet of the OLA.  All we can say is that the Advent 1/ is definitely worthy of having the Advent name;  For their size, they do produce some overall sound that's very satisfying indeed.  As far as comparing them to the OLA, we'll let your ears decide.

The dual/angled tweeter array was the first--and only--multi-tweeter design ever done by Advent's designer *Andy Kotsatos. The speaker is historically notable for that reason alone. He described in great detail how he manually positioned the tweeters with modeling clay in several different orientations, then took measurements and did exhaustive listening tests at normal listening positions. In this way, he was able to come up with a tweeter arrangement that had virtually no destructive interference/cancellation in actual use, from normal listener positions, even fairly close up. 

Specs:
Impedance: 8 ohms
Frequency response:  52 Hz to 18 kHz
Dimensions: 22"H x 13"W x 10"D
Weight: 25 lbs each

*Originally, Henry Kloss had a noncompete clause when he left KLH that prevented him from peddling loudspeakers for some specified period of time.  According to legend, he designed the Advent loudspeaker and filled a couple of trucks with the things. On the day that the non-compete clause expired, the trucks rolled out to the stores. It is entirely possible that these very first loudspeakers were entirely of Henry's design.
By the time Andy Kotsatos arrived at Advent R&D in the early 70's, there were discussions about a loudspeaker not sounding right. One of his tasks was learning how to run the General Radio stripchart equipment, and he wound up running lots of loudspeaker and crossover curves. Bruce Gregory, the lead electrical design engineer, wound up redesigning the crossover and Andy did the voicing by tweaking the parameters. There was a lot of back-and-forth (and lots of curves) getting the thing right. They also made a design change to the tweeter but the details are sketchy.  If anyone has an early Advent Utility, most likely it is one of these revised units, since they were the ones that sold in volume.
Personnel involved with auditioning the Advent loudspeaker product line most likely were Andy, Bruce, Henry, Stan Pressman (head of marketing), and Joe Hull.
After leaving Advent, veterans Andy Kotsatos and Frank Reed founded Boston Acoustics in 1979. Andy Kotsatos was also known as Andy Petite. (his grandfather immigrated to the United States and worked as a waiter in a French restaurant. Because of his small stature, the rest of the staff named him Le Petit: French for small. Eventually bending to the social pressure to Americanize, he changed his name from Kostatsos to Petite.) After founding Boston Acoustics and achieving success with the company, Petite changed his name back to Kotsatos.

About Advent...
The legendary Henry Kloss founded Advent Corporation in 1967. (Kloss was the "K" in KLH) The name came from the legal description the advent corporation ("advent" means "approaching" in Latin.  Around 1968, Kloss had quit KLH to develop a low-cost projection television, but had trouble financing the leading-edge research and development that was still required. To earn some money, he decided to build a high-performance, low-cost, dual-driver speaker system with a 10 inch woofer called simply The Advent Loudspeaker .
(This was later on given the retronym "The Larger Advent", after the introduction of "The Smaller Advent Loudspeaker"). It rivaled the sound of the then top-line AR Model 3a (which used three drivers and a 12" woofer, but only cost about half as much.

There was some confusion because Advent produced a number of different versions of these two way Advents: First was the Advent Loudspeaker, then the Smaller Advent Loudspeaker followed by the "New" Advent Loudspeaker then came the Advent/1, Advent/2, Advent/3, 4000 series and 5000 series to name a few. They were usually offered in both wood veneer and vinyl-covered "utility" cabinet versions, which other than appearance were acoustically identical.
Henry Kloss left Advent around 1977 and, eventually, long after Kloss’ departure, Advent ran into hard times and never emerged from a bankruptcy declared in March 1981.

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('68-'71)  $500 (stands not included)

Most knowledgeable vintage speaker addicts would probably agree that when it comes to the best of the KLH "Classic" models, there are three models in an illustrious group of 7 models that stand out: the Model 5, Model 6 and Model 23. 
NOTE:  Please read the section below about the tweeters & woofers.

Bear in mind, the others that are considered classics (17, 28, 31 & 32) are excellent in their own right but...the 5, 6 & 23 garner most of the praise over the last half century.
It's been said that the Model 23 came to market in mid-'68 and was offered for only about three years. Not all that many were sold, maybe 20,000 pairs. That's a fairly low production number because something like 100,000 pairs of each model were sold with the models 6, 17, 20, 22 & 24. 

Fortunately, this pair of KLH Model 23 have been well cared for over the last 50+ years.  They were opened up to check the crossovers and wiring.  The original woofers have been lightly re-doped and sealed where needed.  That was followed up by a careful light sanding and refinishing of the furniture-grade (and gorgeous) oiled real walnut veneer enclosures.  The original grills are near perfect; their unique double-layer fabric just oozes that much sought after vintage quality and styling.
NOTE: About these beautiful cabinet designs...besides some serious bracing and stuffing inside, the outstandingly gorgeous framed front baffles are like works of art; especially when seen in person.  The grill cloth itself is an acoustically transparent mix of brown and gold weave.  They are easily removed thanks to the gentle velcro attachments.

About the tweeters (and woofers):
These original woofers in the Model 23 are identical to the Model 5 (and a few other models of the era): when they were first released in the late 60's, each enclosure contained one 12" acoustic suspension woofer and one 1.75" tweeter (with the recognizable protective metal screen and square magnet structure of early KLH tweeters). 

Unfortunately, the original tweeters were long gone on this pair when we obtained them.  Instead, they contained a pair of crappy 8 ohm tweeters.  These tweeters were removed because this was unacceptable for a couple of reasons: the original tweeters were 4 ohm and of much higher quality.  Thus began the search for tweeters.
Unfortunately, today (some 50+ years later), it's nearly impossible to find any of the replacements for the original tweeters in the Model 23 (and other similar models of the era).  Even if you could find one, it would just be another 50+ year old tweeter that may or may not last very long. 
So, what's the point of gambling with another original tweeter with an obviously limited lifespan? 
Instead (after affirming their compatibility with the Model 23 specs) we tried several different models of both vintage and modern 4 ohm tweeters. 
Settling on a matched pair of brand new Dayton Audio 1" neo soft dome 4 ohm tweeters was a no-brainer.  These tweeters, with their "Waveguide" technology seemed a perfect match.
The result?  An excellent soundstage and smooth transition at about 1500 Hz.

Even though it shares the same woofer as the Model 5, the basket, cone & voice coil are the same as the Model 6 but the magnet is much heavier than the Model 6 for two reasons: the larger cabinet and cones which were selected to be heavy. Looking at a model 5 or 23 cone you will see the weight in grams written on the cone, usually around 23-25 grams while the Model 6 cones weigh in around 18-20 grams. The larger cabinet and heavier cone equals a lower resonant point than the Model 6. The larger magnet is needed to maintain efficiency and transient response. The woofer from a 6 weighs about 5.5 lbs and those from a 5 or 23 are about 8 lbs.  Perhaps that's why the bottom end (bass) is right up there with the famous Original Large Advent speaker (as it should be since *Henry Kloss had his fingers & brains tied up in all of them).  No doubt best described as "very very satisfying", the overall sound of the Model 23 is just great!

Essential specs:
~8 ohms (nominal)
~85dB sensitivity
~Amps between 25 and 100+ watts per channel
~Dimensions: 26" H x 13.75" W x 11.5" D
~Weight: 50 lbs each

*About Henry Kloss and Victor Campos on the model 23...this would have been late 1967 or early 1968 because Kloss left KLH sometime around that time in. Campos did some great work for KLH. Another character who worked at KLH in 1966 was Win Burhoe of EPI fame. KLH really knew how to make speaker drivers, especially woofers. They were among the very few companies that wound their own voice coils, fabricated their cones, etc., they were very vertically integrated.

*About Henry Kloss...
Henry Kloss, whose prolific hi-fi design and manufacturing career spanned a half century, died of a subdural hematoma on January 31, 2002, three weeks before his 73rd birthday.   Habitually clothed in khaki trousers and oxford cloth shirts, their button-down collars unbuttoned and sleeves rolled, Kloss (pronounced with a long o, to rhyme with "close") looked like someone familiar with tools. Indeed he was. As a boy, he was able to add rooms and bath fixtures to the Pennsylvania cabin he shared with his mother and two sisters.

After entering MIT in 1948, Kloss worked part-time for a contractor and bought woodworking tools to make furniture for his basement apartment. Instead, he used them to turn out enclosures for a speaker system an MIT professor and his student had designed. Henry dropped out of MIT after being drafted. Stationed in New Jersey, he took a New York University night course in high fidelity taught by Edgar Villchur, who had conceived a radically new type of loudspeaker.

In 1954, Villchur and Kloss founded Acoustic Research to develop and produce it. Henry provided the facility, a cabinet and speaker-assembly shop he was already operating in a Harvard Square loft. Two other partners, Malcolm Low and J. Anton Hofmann, son of the great pianist Josef Hofmann, supplied $5000 in capital. That led to the AR-1, the world's first acoustic-suspension loudspeaker system, with its relatively small enclosure and proportionally prodigious bass.  But Villchur remained home in Woodstock, New York, while Kloss ran the Massachusetts factory. That caused friction, leading Kloss, Low and Hofmann to break away and put their initials on a new firm. In 1957, they founded KLH.

In 1967, after producing more landmarks, including the KLH Model Six speaker, the fine-sounding Model Eight radio, and a hi-fi system in a suitcase designated Model Eleven, Henry started Advent to work on projection television. The speakers he built to fund that effort quickly became best-sellers.  Henry Kloss embraced innovation. He was quick to employ the transistor, which was crucial to the KLH Eleven's portability, and he ingeniously combined previously unrelated concepts with two Advent firsts: a cassette deck featuring Dolby noise reduction (which he had prodded Ray Dolby to adapt for consumers) and chromium dioxide cassettes. That synergy made the medium truly music worthy.  Yet Kloss was genuinely modest about such achievements. "Some of the particular things I have done...could have and should have been done before," he once told me.

After leaving Advent, Henry started Kloss Video and, in 1988, co-founded Cambridge SoundWorks, for which he designed some three dozen products. His newest radios, marketed by Tivoli Audio, have the simple, signature look of his KLH models, even down to their planetary dials.  Kloss, informed by his own muse and unimpressed by fashion, created boldly original, straightforward, utilitarian products that lowered the price of performance. Longevity was another criterion, in what he built and what he bought. When he retired his second Checker automobile after 14 years of use, Henry vowed to drive his new Mercedes diesel for 20.  He owned it to the end, 17 years in all. For the many people who so admired Henry Kloss, that wasn't long enough.

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(England '82-'84)   $500

In pristine cosmetic condition, fully serviced & tested, this pair of Bowers & Wilkins DM-17 Limited Edition bookshelf speakers are accurately defined as true mini-monitors. 
They have the desirable walnut enclosures; the unique and very rare factory stands are included.  

The hefty and hermetically sealed enclosures were designed as 2-layer structures consisting of 1/2" thick high density particle board, 1/4" Bitumen pads and a 3/4" thick front baffle assemblies.

At 85 dB, they are not considered very efficient; as such, they need some very good, solid amp power to make these monitors do what they were designed to do!  Any concerns about too much amp power is taken care of because B&W was clever to include a built-in "Audio Powered Overload Circuit (APOC) system".  
NOTE: The APOC system reads the voltage applied to the voice coil of each unit, and when the limit is exceeded, the relay operates to cut the input signal, thereby preventing thermal damage due to overload. The red LED next to the B&W logo lights up while the APOC system is operating and automatically recovers after an overload condition has passed.

It should also be noted that the DM-17 was one of the very first of the B&W designs to incorporate the tweeter housing isolated on the top of the cabinet.

The drivers:
~The 6" mid-bass driver is made of ferritic material that had been treated with the same dumping treatment as the woofer. The ferritic material is made of highly crystalline, highly rigid polymer that provides tight bottom end sound pressure levels.

~The 1" dome-shaped tweeter is installed in its own protective dome screen and located on the top of the cabinet. Constructed of woven polyester fiber due to its excellent characteristics and, thanks to the use of a strong magnet, the overall volume was kept to a minimum.

Crossover network:
The DM-17 uses a butterworth 24db/oct. crossover with matched components.  B&W was famous for measuring each capacitor and coil so they could match them exactly - if the marked value was only within 10% they would get them to within 1%.  (another reason that B&W is so widely admired for their premium speaker designs)

From the B&W dealer sheet: (original MSRP $900/pair)
"The DM17 Limited comes into the B&W range equipped to occupy the top position among compact two-unit monitors. Despite its miniature dimensions, its performance may be judged by standards as exacting as those applied to full size monitor systems. For those whose ear demands such standards, but who's listening room is of limited size, the DM17 Limited now clearly becomes the loudspeaker of choice.
Regarding the placement of the high frequency driver on the top of the enclosure; it avoids the situation with normal cabinet construction, where sound waves from the tweeter not only radiate towards the listener but also travel along the baffle surface towards the cabinet edges.
When sound waves meet sharp cabinet edges they re-radiate (a process known as diffraction) and, due to the time delay, interfere with and time-smear the sound coming directly from the drive unit.
Having the tweeter separate from the main cabinet also allows its time-alignment with the midrange driver to be finely adjusted so the two outputs add perfectly in phase through the crossover region."

Essential specs:
Minimum amp power required:  40 watts
Nominal Impedance: 8 Ohm
Frequency Response: 85 - 20000 Hz 
Sensitivity: 85 dB
Dimensions: 16"H x 10"D x 8.5"W
Weight: 20 lbs each

About Bowers & Wilkins...
The sleepy coastal town of Worthing in South England might not look like a hotbed of 1960s freewheeling experimentation, but for audio fans it’s a place that’s synonymous with innovation. Thanks to the first Bowers & Wilkins speakers built there in the early years of the company, music lovers could experience albums such as Sgt. Pepper and Pet Sounds in new, mind-expanding depth and clarity.
In 1966, John Bowers set up his company with his partner Roy Wilkins and  began assembling speaker systems in the workshop of their electronics shop and designed their first speaker, the P1.  The profits from this beginning allowed them to invest in new calibration equipment.  By 1968, the high quality "Domestic Monitors" (DM1, DM3) brought more recognition from the audiophile community.In the 70's, with John Bowers at the head of the company, things really took off...with the development of curved cabinet forms and the use of new cone materials such as Kevlar, they hit it big with the Model 801 which almost immediately became the reference speaker of choice for many of the world's leading recording studios. 
Also, the first model DM6 from acclaimed designer Sir Kenneth-Grange appeared in 1976.  The later DM7 and DM17 were the first that featured the iconic "tweeter-on-top" that's still used today.  
In the 90's the appearance of the (now very famous) B&W "Nautilus" which totally upended the preconceived notions of speaker design.Even though John Bowers passed away in 1987, today, in the so-called digital age, B&W just keeps moving along with its latest versions of the Diamond Series and so much more.

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('06-'11)  $500

In excellent cosmetic and operating condition, this pair of Energy C-Series 500b-1, were obtained from the original owner who bought them new in 2010 for $750 (pair).
This model was part of the larger Energy Connoisseur C series, and they are a 2-way bass reflex design featuring twin rear bass ports, dual 6.5" composite fiberglass woofers and 1" aluminum dome tweeter.

The C-Series C-500 is best known for its capabilty to produce great extension, slam and impact, with virtually no distortion for huge, clean audio.  Essentially, the bottom end coming out of these speakers is nothing short of astounding and extremely satisfying.

Specs:
System Type: Bass Reflex, Rear Vented
Frequency Response: 35Hz-20kHz +/- 3 dB
Recommended Amplifier Power up to 150 watts
Components: Chambered 1″ Aluminum Dome, Dual 6-1/2″ Composite Fiberglass cones
Impedance 8 ohms nominal; Minimum Impedance: 4 ohms,
Sensitivity (anechoic) 91dB, Sensitivity (2 speakers in a typical room) 94dB
Crossover Point 1.2kHz and 2.5kHz
Overall Dimensions: 8"W x 37.5″H x 14.5"D
Weight: 44 lbs each

About Energy...
Currently owned and operated by the Klipsch Group inc., Energy has been a leader in audio research and development as well as in the engineering and manufacturing of speakers since 1973.  They took what they learned from their involvement with some of the earliest Canadian studies on psychoacoustics, and proceeded to achieve pure, accurate sound reproduction in all their Energy speakers through three vital performance principles: flat on-axis frequency response with wide bandwidth; wide, constant dispersion; and low distortion and resonance.
Worldwide Distribution:
Klipsch Group, Inc. oversees business operations for the Energy®, Mirage®, Klipsch® and Jamo® speaker brands and distribution companies worldwide. This technology powerhouse is focused on leveraging its highly acclaimed product lines to offer a unique and powerful single supply source for its retailers, distributors and contractors globally.

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