BY STEVE JOHNSON ()
Speakers appeared in the late 1800s. Most early versions were horn shaped and didn't require electricity or an electrical impulse to operate. With the invention of the wireless telegraph and radio in the 1900s, electrically powered headphones and speakers were developed for both commercial wireless communications and home use.
Edison cylinder player reproducer and horn.
Edison cylinder players and early Victrola and gramophone record players used mechanical speakers for reproducing the sound recorded on wax cylinders and early records. To reproduce sound from the grooves of the recorded surface, a needle was attached directly to a diaphragm. This needle and diaphragm unit was commonly called a reproducer. As the needle picked up the vibrations on the recorded surface, it transmitted those vibrations to the small diaphragm fixed to the small end of a long horn. The vibration of the diaphragm was then acoustically amplified by the horn. Many people who hear these early speakers for the first time are surprised at how loud the sound or music actually is without the use of electrical amplification.
Wired telegraph lines used a magnetic coil similar to a relay to create a metallic click triggered by voltage sent through miles of wire. This device was known as a sounder. The telegraph operator would listen to the clicks of the sounder which represented Morse code. Morse code was also used for early wireless radio communications. Early radio used spark gap transmitters. High voltage created a spark which could be heard over long distances when picked up by an antenna hooked to a wireless receiver and headphones. Early headphones needed very little electrical energy to produce a sound detectable by the human ear. A trained wireless operator listening to an early receiver with headphones could hear the spark transmissions sent in Morse code from many miles away. The wireless operator could either reply by keying Morse code using his spark gap transmitter or decode the message and hand it to its intended recipient. In 1912, the Titanic used a transmitter of this type to send out its distress call.
Early headphones and Telegraph “Sounder.”
The early headphones looked and operated similar to today's headphones, although the materials used were generally nickel-plated metal or hard rubber. The headphone cables were cloth-covered wire and connections were usually made using binding posts. By World War II, rubber-insulated wire-and-phone-plug-type connectors were commonly used.
Unfortunately, most early headphones do not have much value as there were many produced. Due to their high working impedance and low fidelity, they are not compatible with today's stereos or MP3 players. Typically you might find a set for just a few dollars. The exception is if the headphones were manufactured by one of the early radio manufacturers such as Crosley or Atwater-Kent. A collector of one of these lines might want to add a set to their collection and be willing to pay a premium for a working set in good cosmetic condition.
The invention of the vacuum tube brought with it the ability to amplify signals. These amplified signals could drive much larger diaphragms than the small ones used in early headphones. Many different types and sizes of speakers were manufactured, and due to the rapidly increasing popularity of radio, companies found a new market for larger horn- and cone-type speakers.
Early RCA horn speaker and an enclosed horn removed from its cabinet.
Vacuum tube amplification allowed the use of larger diaphragms. Mounted into the small end of a horn they produced vibrations that were then acoustically amplified in a similar fashion to the mechanical gramophone horns. The advantage of these new electrified horns was that by increasing or decreasing the voltage to the vacuum tube filaments it was possible to control the amount of amplification and sound level. Some horn speakers stood over two feet tall while others were built into wooden cabinets. To fit inside a cabinet the horn was curved back and forth to increase its length and at the same time reduce its overall outside dimensions.
Early horn speakers are popular with collectors. Almost any horn speaker will sell in the $100 to $200 range, but expect a horn speaker enclosed in a cabinet to usually sell for much less.
Peerless cathedral-style speaker and its cone, manufactured in Rochester, NY.
Speakers using a paper cone quickly became popular. Many were built into unique round enclosures with artful designs. Some like the Peerless shown above were enclosed in wooden cabinets. Still others with large diameter cones were designed to stand on the floor with some having elaborate designs on them.
A new replacement cone for a Stromberg-Carlson floor standing speaker.
Most of the original paper cones on these early speakers are either dried out, torn, or totally disintegrated when found. Fortunately, there are newly manufactured replacement cones for many of the more popular models as many collectors restore early cone speakers to like-new condition. Value is highly dependent on the style and condition, but typically ranges from as low as $25 in poor condition to hundreds of dollars in restored condition.
As radios and record players grew in size, speakers producing higher fidelity and sound levels required larger and more powerful magnets. “Electromagnetic speakers” using magnets powered by the radio or amplifier were popular in larger units. These speakers typically required a pair of wires to supply voltage to the voice coil of the speaker and unlike today's speakers, a second pair of wires to provide power to the magnet. Today most speakers have permanent magnets and only require a pair of wires for the voice coil.
Drawing of an RCA “Electro-Dynamic” four-wire speaker.
Over the years a few companies manufactured test speakers for use on the service bench. Since there were several types of speakers used in radios and amplifiers, a test speaker would have connecting jacks or switches to match speaker impedance and choose between the electromagnetic or permanent magnet types. Some test speakers also offered selectable capacitor substitution.
Service bench test speakers — 1930s Wright-DeCoster (left), 1950s “Ferret” Test Speaker (right).
The earliest test speaker I have found was the “Multi-Test” speaker made by Wright-DeCoster in the 1930s. It has just about everything needed to substitute a 1930s speaker on a repair bench including different output transformer taps, voice and field coil resistance, and voice coil transformers. The Wright-DeCoster test speaker is rare and I have only seen a couple over the years. I would expect to see one for $40 to $70, but would not be surprised to see one sell for $100 to $200 as it is a rare piece.
The most commonly found vintage bench test speaker is “The Ferret” test speaker made by Coastwise Electronics, starting around 1947. Besides having jacks and selector switches for selecting voice and field coils, the front has charts showing the switch settings for matching it with various audio output tubes. The Ferret also has a selectable bank of capacitors that can be used for substitutions on the service bench. Replacing the original capacitors is a requirement but an easy task in the roomy cabinet.
The Ferret is very popular among collectors, and when brought out at a swap meet, it seldom sits unsold after the first few hours. Typically it sells for $50 to $125, depending on cosmetic condition.
For more information and examples of early electronic technology view my collection at StevesAntiqueTechnology.com.
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