Megaphones: Part of the MONACOR DNA

We're celebrating one of our most successful product categories: the megafone.

There are well over 4,000 products stored in our almost 10,000 square meter warehouse. One of them has a very special place in our range: the megaphone. As at 2021, we've sold almost 400,000 of them. The principle is simple and equally popular with the police force, fire brigades, demonstration organisers and leaders of meetings: Inside is a small but powerful amplifier that creates sound pressure. Our product range extends from small handheld megaphones to professional devices that generate up to 124 decibels. You could use it to drown out a running chainsaw, as our marketing manager likes to emphasize. Our guideline for megaphones: Durable, handy, powerful.

Are you looking for megaphones or technical information about megaphones? You've come to the right place.

Are you a retailer, installer or specialist planner and have questions?

Sven Schindler has answers:

+49 421 4865 351

schindler@monacor.de

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MONACOR megaphone: Reliably drawing attention

Megaphones are used in various situations: Dirt, moisture, hectic handling in emergency situations. Our megaphones have become so legendary because they can handle such scenarios with ease. And still continue to perform. Often for much longer than most users assume.

With our range of reliable megaphones, we have the optimal solution for every application

A few basic decision-making criteria will help you to choose the right device. Range is no doubt the most important criterion. The following applies here: The greater the sound pressure (in dB), the greater the range of the megaphone. There is also the option of choosing between megaphones with an integrated microphone, with a handheld microphone or devices with an additional wireless microphone. By the way: All of our megaphones use standard batteries for power supply. No exotic energy storage devices that you would have to go hunting for in the international electronics jungle to replace. As an alternative, some devices also offer a 12 V connection. Other distinguishing features are the size, weight and power consumption. With the help of these comparison criteria, you are guaranteed to quickly find the ideal megaphone that is suitable to your individual needs in the MONACOR range.

Megaphone TM-45 with special power and handheld microphone

The TM-45 is the right megaphone when you need to reach a particularly large area or number of people with your voice. This megaphone is specifically for large areas – Make sure that you are not too close when volume levels are very high. A chainsaw, for example, is approx. 110 decibels – only for comparison.

Handheld microphone with removable helix cable
45 watts of power
Up to 124 dB
Lockable talk switch and volume control
AUX input with level control
Jack for external 12 V battery operation
Switchable siren
Connection cable for motor vehicles
8 mm threaded bushing for tripod mounting

to the megaphone TM-45

Handheld microphone with removable helix cable
45 watts of power
Up to 124 dB
Lockable talk switch and volume control
AUX input with level control
Jack for external 12 V battery operation
Switchable siren
Connection cable for motor vehicles
8 mm threaded bushing for tripod mounting

to the megaphone TM-45

Megaphone TM-25 with switchable siren

The advantage is obvious: A siren is like a judge's gavel that immediately draws attention, even summoning loud crowds.

Built-in microphone
25 watts of power
Up to 115 dB
Switchable siren
Jack for external 12 V battery operation
Volume control
Connection cable for motor vehicles

Our TM-25

Built-in microphone
25 watts of power
Up to 115 dB
Switchable siren
Jack for external 12 V battery operation
Volume control
Connection cable for motor vehicles

Our TM-25

Megaphone TM-17M with MP3 module and playback function

You can also use a playback function to play back previously saved statements or instructions.

Handheld microphone with helix cable
for price-conscious beginners
Lockable talk switch and volume control
Record/playback buttons on microphone
Recording function via microphone (up to 20 sec.)
Sound sources: USB stick or micro SD card
Volume of MP3 and microphone separately adjustable
Siren operation switch
Jack for external 12 V battery operation
Connection cable for motor vehicles

Megaphones with MP3 function

Handheld microphone with helix cable
for price-conscious beginners
Lockable talk switch and volume control
Record/playback buttons on microphone
Recording function via microphone (up to 20 sec.)
Sound sources: USB stick or micro SD card
Volume of MP3 and microphone separately adjustable
Siren operation switch
Jack for external 12 V battery operation
Connection cable for motor vehicles

Megaphones with MP3 function

Here you will find our entire range.

What does the term megaphone mean exactly?

Above all, megaphones are used to address large crowds, in emergency situations, at demonstrations, rallies or gatherings. Modern handheld megaphones can also play back pre-stored or built-in sound effects or tones. Finally, a megaphone amplifies sound. This can also be accomplished using a microphone, an ELA amplifier and an ELA loudspeaker. So let's be precise: A megaphone (also obsolete: speaking trumpet, colloquial: loudhaler) is typically a portable or handheld cone-shaped acoustic horn. It serves to amplify a person's voice or other sounds and direct them in a certain direction. Using normal speech, the sound goes directly from the mouth into the narrow end of the megaphone. The megaphone then emits the sound waves at the wide end. It basically works like as follows:

A (modern, electronically amplified) megaphone has a microphone at the mouth end that converts sound pressure waves into an electrical signal.
An electronic circuit then amplifies the electrical signal.
This powerful electrical signal is then fed into a speaker, which converts it back into sound pressure waves.
A horn on the loudspeaker of the megaphone matches the impedance to the impedance of the air in free space and provides directivity so that the sound is projected forward.

Technical challenges with megaphones

Megaphones distort the sound of the voice somewhat because the technology is concentrated in very little space and weight. In addition, the batteries must last as long as possible. Cost-conscious technical optimisation is therefore demanding:

The driver in the megaphone should have a frequency response that is as flat as possible up to 200 Hz, which is a big challenge in a very small space. Precisely because of the horn loudspeakers, megaphones have to make compromises in the high frequencies in favour of the range.
Even deeper basses have a hard time in a megaphone – more space in the device would be needed to reproduce richer bass in the case of deep voices.
Acoustic feedback is also an engineering challenge in a small and lightweight housing.
The sound is better with good directivity, for example if you stand a few metres in front of the megaphone and are addressed directly. However, the directivity of small funnels decreases greatly the lower the frequency. Here, too, the small size of the megaphones prevents a better sound. Anyone who is already slightly offset from the beam direction of the megaphone experiences a lower sound quality.
A horn introduces significant waveform distortion at higher volumes. The purpose of the horn is to convert a high pressure, low amplitude signal into a low pressure, high amplitude signal. Because air is increasingly non-linear at higher pressures, the higher the outlet pressure, the greater the asymmetry and hence distortion. This can actually turn a sine wave into a sawtooth wave when it reaches the mouth of the horn. Preventing this distortion of the signal is not easy.

Since the 1960s, the electronic megaphone has replaced the acoustic megaphone.

Electronic megaphones: An overview

An electric megaphone is a mobile PA system. Ultimately, it is an electronic device that uses electrical energy to amplify the human voice. It consists of:

a microphone that converts sound waves into an electrical audio signal,
a battery-powered amplifier that increases the power of the audio signal,
a speaker that converts the audio signal back into sound waves.

Electric megaphones, while slightly heavier than acoustic megaphones, amplify the voice to levels exceeding 120 dB. They have replaced the acoustic megaphones in most cases and are usually used wherever no stationary PA systems are available, for example at outdoor sporting events, at rallies and demonstrations or in places where an operation or mission needs to be coordinated.

The transistor was the breakthrough for mobile megaphones

Electronic PA systems have been around since the development of tube amplifiers in the early 1920s. However, the tube versions were too heavy to be portable. The development of microelectronics was needed for portable electric megaphones. This followed the invention of the transistor in 1947. The world's first transistorised megaphone was launched in 1954.

Megaphones: Handheld PA system

Electronic megaphones usually take the form of the old acoustic megaphone, with a microphone on one end and a horn speaker on the other, a pistol grip on the side, and a switch to turn it on. When in use, the trigger is pressed to turn it on when speaking. Other, larger versions hang from the shoulder by a strap and offer a separate handheld microphone on a cord that can be spoken into, allowing the user to speak to a crowd without the instrument covering their face. A wide variety of modern electric megaphones are available to purchase and features such as performance, weight, price and accessories such as alarms and shoulder straps all contribute to consumer choice.

The shape of the megaphone directly affects the projection area; narrower horns compensate for lower power by focusing the sound more than wide horns.

A Brief History of the Megaphone

The original inventor of the speaking trumpet is the subject of historical controversy. There are very early references to archetypes of the megaphone:

Orators in ancient Greece wore masks with cones protruding from their mouths to amplify their voices in theatres.
Hellenic architects may have deliberately used acoustic physics in the design of amphitheatres.
Drawings from 1675 and 1682 show an indigenous leader in North America using a birch bark megaphone to address his warriors.
A drawing by Athanasius Kircher from 1684 shows a man using a megaphone.

Both Samuel Morland and Athanasius Kircher are credited with having invented the megaphone around the same time in the 17th century:

Morland wrote about his experiments with various horns in a work published in 1655. His largest megaphone was a copper tube over 20 feet long, which reportedly projected a person's voice a mile away. Morland's megaphone, however, was straight and tubular.

Twenty years earlier, Kircher described a device that could be used both as a megaphone and to "listen in" on conversations from outside a building. His coiled horn was mounted on the side of a building, with a narrow end inside that could be spoken into or listened to, and the wide opening protruding through the outer wall. Kircher's horn was a "cochleate", meaning that the horn was twisted and wrapped to make it more compact.

A later, papier-mâché trumpet of a special design was the Sengerphone.

Are you a retailer, installer or specialist planner and have questions?

Michael Krebbing has answers:

+49 421 48 65 352

krebbing@monacor.de

The term “Megaphone” was not created until 200 years later, in connection with an instrument by Thomas Edison

In 1878, Edison developed a device resembling the speaking trumpet. Edison hoped to use it to help the deaf and hard of hearing. His variant consisted of three separate funnels, arranged in a row. The two outer funnels were about two metres long. They were made of paper and connected to a tube inserted into each ear. The central bell resembled Morland's speaking trumpet, but with a larger slot. This was for the mouth of the user (i.e. the speaker).

With Edison's megaphone, a low whisper could be heard up to 1,000 feet away, while a normal speaking voice could be heard over a distance of two miles. However, the instrument was much too large and not mobile. That limited its use. George Prescott wrote: “The biggest drawback right now is the size of the device.” Before the invention of the electric microphone, the first pop singers sang with a megaphone. Since the 1960s acoustic megaphones have generally been replaced by electric versions (see below), although the cheap, lightweight and robust acoustic megaphones are still used in some areas, for example, for cheering on at sporting events and cheerleading, as well as by lifeguards at swimming pools and beaches where moisture could damage the electronics of the electric megaphones.

Want more MONACOR? Go ahead and take a look at what we have to offer in the area of sound technologyIf you are a retailer in the field of audio technology and are looking for new partners or are planning PA projects, please contact us directly.

Or find out more about key topics in our magazine:

Planning a PA system

3 steps to a better sound experience

Planning PA applications with ceiling speakers

basic knowledge of coverage and selection