Acoustic horns - design based on Edison Phonographs Horns, this are made of papier-mache/applique for a greater sound 

The origins of the sound amplification by horn reaches back to the Paleolithic Era where the physical properties of a hollow animal horn has been used to amplify sound. The physics and mathematics of horns were developed for many years. The earliest appearance of the horn in connection to sound was published in the Times in 1786. In 1877 Thomas Alvea Edison used A horn speaker to amplify the sound produced from phonographs where the sapphire stylus moved on the cylinder record and created vibration in a small diaphragm that acted as a driver for the horn. The phonograph horn gave a voice to the cylinder recording even though the volume and fidelity were greatly reduced, but the success in recording sound and being able to play it back was quite primitive, as time and development moved the concept along. It was believed that the designs of the shape of the horn increases the efficiency of converting the mechanical vibrations from the driver into sound waves and effectively amplifying the sound output. This was achieved by matching the impedance of the driver to the impedance of the air, allowing more efficient sound radiation, sound pressure level (loudness) and this amplification was purely mechanical.

Until 1905 most of the cylinder playing phonographs were supplied with a small horn, customers often bought larger ones to make their phonographs sound better. These large horns which were usually cone shaped 10" or 14" ,either all brass or with a black body or brass bell called by collectors The 'witch's hat'. These little horns were supplied with a machine to contribute to a lower cost of shipping, therefore the aftermarket sprang up to supply larger horns which were often more decorative. After 1905, flower form horns, called morning glory horns nickel plated were in a variety of colours with added decorations like hand painted flowers. This particular horn was made by Hawthorne & Sheble company, a major supplier of phonograph accessories and Tea Tray Company.

The Edison was supplying large morning glory horns with its phonographs and by 1909 the cygnet horn had appeared with The Edison "Fireside" with a grain painted surface, conceived to resemble oak as a rare option to plain black .

Further development shows that the horns are not only to direct the sound but the main purpose is to match the characteristics of the sound wave from a narrow tonearm. The acoustics of the room and the diaphragm has a big impact on the sound and creates pressure vibrations.

Flat disc phonographs also used an external horn attached directly to the sound box housing and they moved along the record while playing. To improve audio volume the horn became bigger and bigger and the increasing weight became a problem to the life span of the records. However the external horns were evolving as more was learnt about acoustic energy to the acoustic nature of the room that the music was being played in. Music was changing too and people's demands for a better reproduction of their phonographs/gramophones was increasing.

Improvement on tonearms and soundboxes led to the fundamental design from the Victrola Company, where the Orthophonic horn was mounted inside the cabinet based on mathematical equations which was considered a great improvement in sound reproduction. These Exponentional horns allowed the sound waves to gradually transmit from the small tonearm to the listening room resulting in more acoustic energy being transmitted to the room rather than being reflected back to the tone arm as it was at earlier designs. A lot of companies adopted this development, but to get the greatest reproduction there were more factors than just the horn. When in 1925 electric reproduction came along the mechanical era was abandoned, even though there were still people who wanted to carry on with an early sound reproduction, we can discuss EMG and Expert who put a great of work into a research of the technology, materials, physics, mathematics and theories to give the best acoustic amplification from gramophones, where the sound that is heard in live conditions is vivid, colourful and easy to identify as being natural. 

Materials used to make  horns were nickel plated steel or brass, wood which will be matching the phonograph's case also papier-mache, cardboard even glass. Decorations were varied generally they were painted black, later with more vivid bright colours and flowers or faux grain to give a more expensive appearance. A few beautiful horns were painted with Japanese URUSHI laquer in Kobe, Japan in 1904 for Victor 6 by "Allen's paper lacquer horn" distributed by Byron Mauzy of San Francisco.

According to the acoustic experts, paper is hard enough and dense enough to reflect most sounds above 1000 Hz. The sound pressure must easily move within the design, the material has to be rigid and smooth so that it can give a  strong sound reflection.

Like a lot of people, we also got  fascinated by the old technology & we decided to make samples of horns based on a small research and took inspiration from the experts and have attempted with some success to bring this experience to light.

The conical shaped horns are the simplest acoustic amplifiers, they describe a perfect sphere of radiated sound, they have no phase or distortion of the wavefront. The small cone horns used in phonographs were not long enough to reproduce the low frequencies in early  recorded music, they had a high cut off frequency which reduced the bottom two octaves of the sound spectrum giving a characteristic "tinny" sound. Their acoustics shows insufficiency at low frequency, but they were still  a great for a voice reproduction. Our papier-mache conical horns are giving increased volume, but very sharp , they have shown great results  when used to amplify  voice recordings.

The Exponentional horn equations essentially predict the most efficient transfer of acoustic energy by determining the internal horn taper as a function of the horn's dimentions like throat, length, mouth, etc.  They efficiently transfer sound energy, maximizing the acoustic impendace from the driver to the open air  gradually transforming high and low frequencies and minimizing reflection of the sound. Exponentional horns greatly improve the tone but it must be remembered that they are only a component part of the sound reproduction & amplification system, the sound-box or reproducer also plays a key role in the overall sound quality of any acoustic phonograph reproduction & Amplification system.

Work in progress, 3d printed sections of the horn, After assembly  the Patterns are finished with a technical mirror finish composite material.

ABOVE; Finished Paper-mache copy of an E.M.G Mk. 4 internal horn