pair ALTEC LANSING 604D / 606C
You are bidding on an unique pair Altec Lansing 604D Duplex (1957) in 606C walnut enclosures.
Depending on your internet connection bandwith you have to wait long to see all pictures but these treasures are worth while waiting and you'll see every detail.
First of all let me say one thing in addition: I'm a wild vintage collector and you can expect a lot of experience and an excellent hearing for now almost 35 years. I heard so many High-End equipments that I easily could publish a magazine. But this project started completely uncommercial and what did come out is real world class performers.
Maybe it is uncommon to advertise these dream-loudspeakers on eBay but I think this is a good method to reach many individuals all over the world and to show what is available from me. This advertisement is also a test if this kind of speaker is interesting to you as I engaged a high graduated manufacturer and I have a low amount of true quality vintage speakers more to sell.
Both speakers and enclosures are in excellent condition. Of course you'll find little damages to the paintwork on the Altecs. On the other hand remember that this pair drivers is 51 years old - and it will play music to you godlike in these enclosures and with my crossover networks. Everything is handcrafted to the highest standards, phase corrected crossovers tuned exactly to these speakers, hard wiring with musical consistent cable from Leonische Drahtwerke and pure copper terminals which let you connect these treasures bi-wired all through to the drivers separately.
Drivers
Let me describe the drivers of this auction: ALTEC 604D DUPLEX® all original paper cone drivers from 1957 with Alnico V magnets for bass and high frequency sections. Everything is original in best working condition. Even the high frequency diaphragms are original ALTEC and have not been replaced with cheap replicas. Developement of the drivers started in the late thirties. Jim Lansing and Dr. John F. Blackburn designed a 15" field coil woofer with a small-format compression driver mounted to a multicell horn which utilized a 4 x 2 cell pattern. In the mid forties, Altec Lansing replaced the field coil with a permanent Alnico V magnet structure and this architecture remained in continuous production until 1977. In addition to the fabulous magnet construction the seamless all-paper bass cone construction was built to the end of the fifties. The Altec Duplex is arguably the most famous speaker driver ever made.
A True Point-Source Speaker. Actually two loudspeakers in one, the Model 604D is comprised of an extremely efficient low-frequency loudspeaker and a high-frequency compression driver/horn assembly that are coaxially mounted together. This method of magnet construction is what makes the Model 604D sound so good - since both it’s low and high frequency signals emanate from the same vertical and horizontal planes.
The offered pair ALTEC 604D DUPLEX® is in best condition. These speakers are ultra rare. Specially in this condition. Look at my detailed pictures. Even the outer rim is perfect and soft because these drivers have never been abused.
Crossover Networks
The original Altec dividing network N-1600-B is a genius passive electronic part regarding the year 1957 and I will enclose it at no additional cost.
But there is more to hear: the 604D's low-frequency section, the high-frequency diaphragm, the phasing system, the small multicell horn, and the powerful Alnico V magnetic assemblies form a loudspeaker capable of uniform, peak-free reproduction throughout the range of human hearing. An ultra precise dividing network is required which merges all musical ingredients perfect together again.
The belonging ultra high-quality crossover networks are not off-the-shelf types nor computer designed networks making use of resistive loads. Instead, it was created through extensive tests using the actual 604Ds in my 606C enclosures in real time. These crossovers enable the 604Ds to exhibit well balanced, phase-coherent performance with ultra-low distortion and with godlike accuracy. The networks are constructed using components of the highest quality, including air-core inductors, polypropylene and paper in oil (PCB free) capacitors, and non-inductive wire wound resistors, which are hard wired with musical consistent cable from Leonische Drahtwerke.
The outstanding audio characteristics of the used oxygen-free-copper coils are further enhanced by the electrical benefits of the coil design: in contrast to conventional coils, where the individual turns of the windings lie side by side, the windings of these units are directly on top of one another, bringing them significantly closer to the theoretically ideal coil. Among other things, this is reflected in the coils Q-factor, which remains constant up to more than 100KHz. And since the unwanted capacitance of these coils is particularly low they are also extremely effective at blocking out very high frequencies. Air cored coils are, for physical reasons, unbeatable as far as accurate pulse reproduction and freedom from distortion are concerned.
In addition I use oil impregnated metallised polyprophylene dielectric capacitors. Due to the winding technology these induction-free capacitors sound wonderfully spacious and detailed. The capacitor’s ability to bring out the finest nuances and the most subtle distinctions make the music sound more alive and juicy, yet without unnatural emphasis of any individual effects. Ideal for those music lovers who want natural, unadulterated sound.
Last but not least the used binding posts have been cared for particularly. To meet the most exacting demands in mechanical precision and electro-acoustic quality I decided for copper terminals twisted from massive pieces of OFC (oxygen-free-copper) copper. The advantage of copper in comparison to brass is tremendous: as of it's core magnetic resonance frequency brass already moves very much in the proximity of the audio range and is noticeable as an undesirable harshness in the sound impression.
The introduced oxygen-free-copper binding posts allow for efficient and nearly lossless transfer of the audio signal to the speakers.
These ALTEC 604D/606C match every excellent amp design with capability to drive 15 Ohms speakers. For use in home theatre and high-quality audiophile systems, recording studios, and professional sound system installations.
The 606C enclosure
Without question my 606C is the finest speaker enclosure obtainable anywhere, regardless of price. A very special bass reflex principle combined with the advantages of a corner enclosure add additional depth and richness to the sound without false bass or other misleading frequency accentuations. Positioning away from your walls is also possible.
In the last years many different types of enclosures have become available. Few of these represent progressive steps in the art of enclosure design. In effect, the result has tended only to confuse the home music enthusiast. Many of the various forms of folded horn type enclosurs have achieved considerable popularity because of their excellent bass response. However, this good bass response is usually accomplished at the expense of lifelike reproduction in the middle range frequencies.
For many years Altec itself has made detailed and exhaustive measurements in the famous acoustical laboratory on all types of enclosures. The inescapable conclusion reached by Altec's research engineers is that no type can equal a carefully designed enclosure using the bass reflex principle for smoothness in frequency response and overall listening fidelity.
My 606C enclosures have been meticulously engineered to achieve full advantage of the potentials of the offered Altec loudspeakers. Most boxes are roughly shoebox or rectangular in shape. Technically speaking, this is a square prism. Unfortunately, these box shapes have a built-in flaw: box shapes with two or more sets of parallel sides will be respondent to a phenomenon called standing waves. Standing waves are sound waves that reflect back and forth between two parallel sides inside the box. This reduces the fidelity of the speaker tremendously.
Embarking a totally different enclosure solution my 606C cabinets were built with woods like musical instruments in addition and were comprehensively braced to maximize rigidity and minimize unwanted resonances. Enjoy the complete freedom from phasing difficulties of other cabinet types.
pair ALTEC LANSING 604D / 606C
To sum up: the listening result of these 604D/606C dream-speakers in the seating position is a startling, hollographic 3-D stereo image that exhibits superior latitude. This loudspeaker system reproduces the entire spectrum of human hearing out-and-out natural.
Individuality
Maybe you are interested in a more technical design of the speakers? Another grille-cloth? Transparent? No problem...
just order.
