Page 3 Stereo Speaker Systems
Polk RTi12
(2004) $700
In absolutely pristine cosmetic condition, this pair of Polk Audio RTi12 speakers present a total of 12 drivers (both enclosures), all performing perfectly. This was Polk's top of the line model in the RTi Series.
The 50" tall cherry veneer cabinets also have two bass ports (front and rear) pushing a lot of air.Polk used their latest generation of "Dynamic Balance" drivers in the RTi12; each enclosure features a redesigned 1" silk/polymer dome tweeter, dual 5.25" mid-drivers, and three 7" woofers.
As other owners have said about the RTi12, we also highly recommend a high power, high current amp to run these properly. "Accuracy" pretty much describes these speakers and, as such, they will show up any weak link in your audio chain. Another weak link is the source material simply because the RTi12 will reveal badly recorded material. This is not the Polk's fault. What may be ok on other speakers, are just not on the RTi12.
Basic specs:
Bass-reflex design
Frequency response 30-26,000 Hz (-3dB)
Impedance: 8 ohms
Sensitivity: 90 dB
Power handling: minimum 50 watts up to 500 watts
Connection: dual 5-way binding post terminals
Finish: real cherrywood veneer
Dimensions: 11"W x 50"H x 21.25"D
Weight: 88 lbs each
Polk Audio RTi Series tech info...
During the summer of 2003, Polk Audio announced the complete re-design of the RTi Series product line. The RTi series was, at the time, Polk's best-selling speaker line occupying the "Better" position in Polk's "Good" (R Series), "Better" (RTi Series) and "Best" (LSi Series) product positioning strategy.
The newest RTi products featured all-new drivers and tweeters and striking contemporary cosmetics. The two top towers (including the TOTL RTi12) featured "Power Port Plus," the latest enhancement of Polk's patented Power Port venting technology.
There were five models in the range, three floor-standing, and two bookshelf, all offered in either Cherry or Black Oak real wood veneer finishes. Fit and finish was the best in Polk Audio's history. All-MDF construction with extensive asymmetric cabinet bracing ensured resonance-free enclosures for clean and accurate sound.
All RTi models feature the latest generation Dynamic Balance drivers and tweeters. The bass/midrange drivers used throughout the RTi range use polymer/mineral composite cones. The redesigned 1" tweeter is a silk/polymer composite dome for smoother response and better detail than the tweeter used in the previous RTi Series. It features a neodymium magnet, low-viscosity ferro-fluid cooling and a heat sink on the back of the magnet for better power handling and reliability.
All models featured Polk's patented Power Port technology that reduces turbulence at the mouth of the port. Power Port vastly reduces "chuffing" or "port noise" and provides deeper, more powerful bass than could be achieved with conventional ported or sealed designs of comparable size. The two top floor-standing models, RTi10 and RTi12, featured "Power Port Plus" their latest enhancement in Power Port technology. Power Port Plus uses two ports (one front, one rear) and internal "plates" to further reduce AIR turbulence and increase bass efficiency.
A computer designed tweeter faceplate radius, stand-off grilles and baffle edge radii all contribute to minimizing diffraction for more open and spacious imaging.
The two larger floor-standing models, RTi10 and RTi12, use multiple long-throw 7" woofers to combine the wide dynamic range benefits of a single large woofer with the tight, punchy, accurate bass response of small woofers. The RTi10's dual 7" woofers have 50% more surface area than a single 8" woofer while the RTi12's three 7" woofers have the same surface area as a single 12 inch. Combined with Power Port Plus, these multiple woofers deliver deep high impact bass with speed and accuracy.
The RTi models are magnetically shielded to allow safe placement next to televisions or video monitors. All models feature gold plated 5-way binding posts with dual inputs for bi-amplification or bi-wiring.
Polk Audio Monitor 4.6 Series II
(1990) $200
In excellent cosmetic condition with all drivers and crossovers functioning perfectly, the Polk Audio Monitor 4.6 Series II is a front-ported 2-way system. Each rosewood veneer cabinet contains a single 6.5" coated woofer and 1" dome tweeter. Originally listed at $300/pair in 1990, these were the next-to-smallest model of the seven models in the series.
As usual when it comes to the various Polk Monitor models, the usual chatter seems to revolve around which tweeter is inside the box. The 4.6 Series II uses the Polk SL2500 tweeter; the same as used in all of the bigger models in this particular lineup.
Relatively heavy at about 34 lbs (each), they measure 17" high x 8.5" wide x 10" deep. Bottom line: most people would agree that ANY of the Polk Monitors are great speakers. Being relatively small, the 4.6 Series II will probably suit just about anybody seeking a finely satisfactory overall sound in a bookshelf sized speaker.
Basic specs:
Frequency response: 30Hz- 25kHz
Amp power: 20-100 watts
Efficiency: 90 dB
Impedance: 8 ohms
About Polk Audio (vintage years)...
Polk Audio was founded by Matthew Polk, George Klopfer and Sandy Gross in 1972. Matthew, George and Sandy met each other while attending classes at the John's Hopkins University in Baltimore. After graduating in 1971, the team collaborated on producing a sound system for a local bluegrass convention. Matthew designed the speaker system while George built the cabinets. After it was discovered the producers of the convention could not afford to pay for the system, George designed a logo for Polk Audio and attached it to the speakers. Sandy was behind the marketing of Polk Audio and also helped create Polk's worldwide dealer network.
After spending a short period of time dabbling in professional audio, Polk Audio turned its attention to high end home audio. With the release of the first successful model in 1974, the Monitor 7, Polk Audio started to become a recognized name in audiophile circles. Polk used a two way configuration on the vast majority of its speakers like the popular Monitor series (5, 7, 10 and Monitor 12) typically with high performance 6.5" mid/bass drivers with rubber surrounds and passive radiators. Later Polk speaker models used arrays of drivers, called SDA for Stereo Dimensional Array. Polk Audio is still in business today.
+++++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++++
Sonus Faber Concertino Home
(Italy, early 2000's) $600
From the renowned audio designers led by *Franco Serbin at the Italian company of Sonus Faber, this is a pair of the elegant, refined Concertino Home speakers. They are mirror-imaged with identical serial numbers.
They are in flawless, fully functioning condition and in virtually mint cosmetic condition. They have all original drivers and the cabinets are sumptuously finished with real leather baffles and lustrous piano black laminate side panels. All embellishments including the badges, fasteners and banana connections are gold plated. They originally sold globally for $1100/pair and were never discounted.
Back story:
First released in 1995, the original Concertino speakers were part of the Concerto collection. The Concertino bookshelf has been a huge success and is, so far, one of the most popular Sonus Faber products. The aim of this successful collection was to make Sonus Faber's design and sound quality available for all without having to drain their bank account.
The Sonus Faber Concertino Home is a replacement for the Concertino after the Concertino was discontinued. Similar to the Sonus Faber Concertino, the Concertino Home are a bit smaller and less box shaped, the front and the back panel being sloped towards the inner side of the speaker, while the first series was more traditional. The Concertino Home seems to be better suited to bookshelf positioning, as they are less deep. The binding posts of this second version are much better.
Seen and noted:
"The Sonus Faber Concertino Home version have a precise point of view on music reproduction and they aren't colored. Surprisingly when doing a comparison between the Concertino and the Concertino Home, though while being different in their interpretation of music, they give the same impression of no listening fatigue and refined and detailed reproduction. There is a slight edge in favor of the newer pair, due to the better quality of their drivers. The Concertino Home are more detailed, precise and dynamic. The high frequency extension is quite similar where due to the new tweeter, is a little bit more detailed.
Another review here:
https://www.audioasylum.com/messages/speakers/60801/b-review-sonus-faber-concertino-home-speakers-b
The Concertino Home series is more efficient, can be driven harder, is more informative, more palpable, has a forward but non-fatiguing midrange and is easier to interface. Vinyl (records), for its tonal balance, is a perfect partner for the Concertino Home speakers. They are very versatile, enjoyable, flawlessly built and a sure value."
Complete specs:
~System: 9 liters two-way system front reflex port
~Cabinet: Constructed with decoupled side panels for resonance control
~Tweeter: Sonus Faber design, neodymium ultradynamic linearity driver 1" silk dome ferrofluid, magnetically shielded
~Mid Woofer: Sonus Faber design, ultra-dynamic linearity driver 6" fiberglass multicoating cone, magnetically shielded
~Crossover: First order attenuated, cross-point 2.5kHz
~Impedance: 6 ohms nominal
~Power Handling: 30 to 150 watts (without clipping)
~Frequency Response: 50 to 20,000 Hz, tuning port included
~Sensitivity: 88dB/1 watts/1m
~Cabinet: Combination of leather and laminate side panels
~Dimensions: 8.2"W x 11.5"D x 13"H
~Weight: 18 lbs each
About Sonus Faber (pronounced "Fah-Bear")...
Sonus Faber is an Italian manufacturer of handcrafted speakers, headphones, and other high-end audio equipment based in Arcugnano, Veneto, Italy. The name Sonus Faber is derived from Latin and means "handcrafted sound".
The company was founded in 1983 by *Franco Serblin. Sonus Faber is one of several audio brands owned by Fine Sounds Group which also owns McIntosh, Wadia, Sumiko and Audio Research.
Sonus Faber's well respected products include Chameleon-T floor-standing tower speakers, Venere floor speakers, Electa & Electa Amator bookshelf / floor series, Aida tower speakers, and others. The Aida line of speakers sells for approximately $120,000.
In 2015, Sonus Faber introduced its portable headphone range Pryma. There is the Pryma 0/1, which comes with six variations of headbands and seven variations of earcups. In 2016, they released the Pryma Aria, a wireless version of the 0/1.
*About Franco Serblin...
Franco Serblin was born in 1939 and sadly passed away in 2013 but as a keen audiophile and entrepreneur was best known for forming Sonus Faber in 1983 and creating many stunning speaker designs which were always considered beautiful in design but also extremely musical and natural in presentation.
In 2006, after 33 years at Sonus Faber, he left to pursue starting a speaker company in his own name designing even more beautiful speakers which take you straight to the heart of the emotion of music. Franco Serblin’s speakers are still available today at boutique dealerships.
++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++
Koss CM-530
('78-'83) SOLD
In very good cosmetic condition and fully functional, this hard-to-find pair of Koss CM-530 speakers (like all of the Koss speaker models) have a cult following. While most of us "old timers" remember Koss as the leader in headphone technology during the 70's, Koss speakers are relatively unknown to most in the world of vintage HiFi. The Koss CM-530 had an incredibly long production run of five years. That fact alone says something because many famous speaker models never lasted that long in production.
Sonically, they remind us of ADS and Braun...yes, they are that good! Let your ears decide.
Each walnut veneer enclosure features an 8" passive radiator (to radiate the sound energy over the lower two octaves) plus a single 8" woofer (to reproduce the critical sounds in the midrange up to 3,000 Hz) and a single 1" dome tweeter placed in the center above the two 8" drivers.
Placing the enclosures horizontally enables them to yield true "mirror imaging" for a noticeably expansive soundstage. Using them vertically is not necessarily against the idea of mirror imaging but it does seem to slightly reduce the overall benefits of horizontal placement. Due to their size and weight, they are best described as floorstanding rather than bookshelf models.
The crossovers and tone pots have been completely rebuilt with new caps and connections. Because the original boring brown fabric grill cloth was ugly and faded, they were replaced with attractively unique and acoustically transparent black fiberglass screens. The new badges were custom made as per the original design.
Specs:Frequency Response: 36 - 17,00 Hz -3 dB
Impedance: 4 0hms
Sensitivity: 88 dB
Power Handling: 15 watts (min.) 75 watts (max.)
Dimensions: 24"H x 13.75"W x 11.75"D
Weight: 35 lbs each
High Fidelity Magazine Sept 1979 review:
"The Koss Model CM-530...seems eager to please, with an up-front, gutsy personality that will surely win many admirers. An important reason for that personality is a strong, well-defined, extended bass/midbass register. The design has bookshelf-style use in mind (Koss suggests, but doesn't demand, horizontal placement) and we prefer to keep it off the floor to avoid boominess. There certainly is no want of deep bass, if it's in the original signal with the speakers at listening level, yet internal musical details like tuba and trombone lines are unusually well differentiated from surrounding orchestral textures. Percussive sounds, too, reproduce unusually well, with plenty of punch and zing and (presumably thanks to Koss's care with time integrity) without significant blurring. The upper midrange is a little on the bright side, which also helps the zinginess of the transients and subtly emphasizes the plangency of woodwinds but can exaggerate any steeliness in string tone or the edge on overly close-miked vocals. Since this portion of the response is, subjectively, the least smooth, we judged it the speaker's least attractive characteristic; it is not, however, a marked fault, rather, a mild disappointment among the goodies. And the quality may actually be one of the contributing factors in the speaker's projection of detail and stereo imaging, both of which are very good and are part of what we called the "up-front" quality, the immediacy of the sound...All this adds up to an extremely attractive design. Those for whom tight- ness of sound control, associated with "accuracy," is a virtue may look (or listen) askance at the unfettered, vivid quality that the CM -530 projects; those who seek the sensation of nearby music -making should be delighted. Though theory and computer alignment evidently had much to do with its qualities, it is a model better calculated to please listeners than theoreticians. And, frankly, we're on the side of the listeners."
About Koss Corp...
In 1979, after a lifetime of innovation in the field of acoustics, John C. Koss was inducted into the Audio Hall of Fame.
It all began in 1958 when Mr Koss teamed up with engineer Martin Lange, Jr. to develop a portable stereo phonograph player with side-wing speakers. The pair demonstrated their new stereo record player at a Wisconsin audio show. One of the product's unique features was a privacy switch, which allowed listeners to hear music by plugging in the world's first SP/3 stereophone. The stereophones were intended to be an accessory to demonstrate the high-fidelity stereo sound that the portable phonograph player delivered.
The revolutionary sound of the Koss SP/3 stereophone became the hit of the show.
In 1968, Koss released the ESP/6, the world’s first self-energizing electrostatic headphone. To achieve its unprecedented sound profile, the ESP/6 employed the principle of a currentless, or electrostatic charge. The charge was applied to push-pull condenser plates, and caused movement of an ultra lightweight conductive diaphragm.
In 1969, passengers aboard Air Force One were treated to the Sound of Koss. The Presidential Plane’s state-of-the-art entertainment system featured Koss headphones at every seat - including the staff, press, and presidential quarters. About 50 Pro/4 units in total lined the aircraft.
In 1970, Koss set the standard for full-size professional headphones with the iconic Pro/4AA. At the time of their introduction, the Pro/4AA were regarded as the first dynamic headphones to deliver true full frequency and high fidelity performance with impressive noise-isolating capabilities.
For years before actually taking the plunge, Koss seemed on the verge of making loudspeakers as a natural complement to the headphones for which it is famous. When it bought Acoustech, the emphasis was on electrostatics based on the Acoustech design. But though some models eventually reached the market, it was the cone-driver models (like the CM-530) designed with computer assistance that have made Koss's mark in the loudspeaker field.
+++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++
Bose 301 Series IV
('70-'02) $250 (perfect)
This pair of Bose 301 Series IV with beautiful custom cabernet timberwood veneer are in excellent cosmetic condition and fully operational. Among all the many different Bose 301 models, the Series IV had the longest production run of an amazing 32 years! Say what you will about Bose, but LOTS of buyers definitely like them.
Because the mirror-image design featured new crossover designs and drivers, the Series IV is generally considered to be the "best" of the many different 301 models developed by Bose over the lifetime of the very successful Bose 301 series. They have a modern look with minimally rounded corners and added design touches to add an elegant look to the room.
Of course it's subjective about how the "sound" is...specifically, but, in regards to the Series IV, Bose claimed to have newly designed tweeters and a completely different bass port design that enhanced the bottom end. The "air turbulence-producing" flared slot port design on each cabinet were a departure from the earlier smaller round ports, resulting in deeper bass (to most ears)
The dual frequency crossover network was also upgraded (compared to earlier versions) with, as Bose stated in their sales sheets: "improved phase and amplitude power delivered to each of the drivers allowing them to better operate simultaneously over a full octave. The purpose of all this was to assure uniform power operation across all frequencies. The speaker lens provides a smooth spatial and high-frequency response with excellent spatial dispersion. Hence, it applies to any size room and ensures a broad distribution of sound. The 301 design allows hearing perfect tones equally distributed throughout most corners of the room."
With the right placement, they will suit most of those familiar with the much hyped "direct/reflect" purposeful design of the Bose 301s. The best suggested placement of these in the listening room is in the middle, between the L/R side walls to take advantage of the separate inward and outward firing tweeters. But, truthfully, since very few people have that "perfect room" with empty available rear and side walls, they sound pretty darn good wherever you put them.
The "somewhat-of-an-illusion" of the 301's spatial sound comes from the unique placement of the twin 3" high sensitivity tweeters in each enclosure (with one facing forward and one facing back) and the 8" woofers facing straight ahead. The Series IV are fairly efficient with a nominal impedance of 8 ohms and a rated 89 dB sensitivity.
++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++
BIC America DV52si
(1998) $125
In excellent cosmetic condition and sounding great, this bookshelf-size pair of BIC DV52si speakers feature their patented "Venturi" tube design. Each cabinet has a single 1/2″ poly dome tweeter and one 5.25″ woofer (with rubber surrounds) that deliver surprisingly low bass output for their size because of those tubes.
Back story:
In the mid 90's, B.I.C. America introduced a new line of loudspeakers featuring an unusual form of vented bass enclosure. Instead of a simple opening in the cabinet wall or a tubular duct with a constant cross section, the speakers use a tapered duct whose effective cross-sectional area varies over its length, from wide to narrow to wide again, before the duct opens to the outside of the enclosure.
The tapered duct is similar in principle to the Venturi tube used in flow-meters, which create changes in the pressure and velocity of the gas or liquid flowing through the tube. The tapered duct used in BIC Venturi speakers increases the sound pressure at the vent by as much as 140 times as well as providing improved loading of the rear of the speaker cone. The practical benefit is high-efficiency bass performance from a compact enclosure, a combination normally difficult to achieve in most affordable speaker systems.
Specs:
Frequency Response: 70 Hz-20 kHz (+/- 3dB)
Sensitivity: 90 db @ 1 watt, 1 meter
Drivers: 5.25″ polymer-coated woofer, 1/2″ poly dome tweeter
Gold-Plated Terminals: YES
Recommended Power: 10-125 watts
Impedance: 8 Ohm
About BIC...(NOT the "flick your Bic" lighters)Since 1973, BIC America (not to be confused with the company that said "flick your bic" lighters) is known to many for patenting their famous "Venturi Port") has offered a wide range of high quality components and speaker systems for the consumer electronics industry. Over the years, their audio components have consistently earned rave reviews from trusted publications and numerous “Best Buy” ratings from the leading consumer testing magazine. Still in business today, the BIC product line offers models ranging from in-wall speakers to tower speakers and these products have become recognized in the audio industry in the category of high performance speakers.
++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++
