Acoustics

Electroacoustics

Many microphones in the collection come from the period 1920–1930. The collection contains precious types of the first carbon microphones, e.g. the microphone used in early stages of broadcasting of the Czechoslovak Radio (1923), several pieces of microphones of the system Reisz of the firm Marconi used in the Czechoslovak Radio in the 20s, and the chamber microphone Huth.

Several original electrodynamic microphones were made around 1930 (tape-type Siemens-Halske and coil-type Marconi, Philips and Standard Electric). The period after the World War II is represented mainly by electrostatic microphones Neumann and all other types (electrodynamic, electrostatic and piezoelectric of the firms Ronette, AKG and also Tesla).

The collection of amplifiers is incomplete.

The collection of loudspeakers provides a good outline of their development. It contains several important types, mainly electrodynamic loudspeakers including newer types.

Audio a video technique

The collection of phonographs containing also models of the first sets is relatively large. Peculiarity of the collection is a phonograph playing one cylinder after inserting a coin or a miniature phonograph Lioret for playing special short cylinders. The collection also contains cylinder dictating recorders.

The collection of gramophones contains the whole range of mechanical and electric devices. The most interesting of them are copies of one of the first Berliner manual gramophones, three fully functional Pathefones and a stereophonic mechanical gramophone from the 30s of ULTRAPHON. A masterpiece of the collection is the table gramophone of the firm His Master's Voice with so-called Lumiere membrane. Interesting is also the collection of miniature collapsible mechanical gramophones.

The collection of electric gramophones contains several table single-speed machines for playing standard records and several gramophone changers from the 30s and 40s. The Czechoslovak post-war production is well represented mainly by products of the factory TESLA Litovel (today ETA, Elektro-Praga Hlinsko).

The collection of tape recorders shows the development of magnetic recording of sound from the oldest wirephones to the most modern tape recorders of both Czechoslovak and foreign provenance. An interesting item in the collection is a blattnerfon for sound recording on a steel tape used in our Radio at the turn of 30s and 40s. The collection of tape recorders contains also studio sets. A peculiarity of the collection is an apparatus for recording and reproduction of sound of the system Philips-Miller.

Video technique is represented by cassette and reel video tape recorders of various system. The collection is completed with several cameras and other accessories.

Sound carrying media

The group of phonographs from the collection Audio and video technique is completed by a collection of about 500 black phonograph cylinders of factory production and about 200 yellow cylinders recorded by amateurs. The collection of standard gramophone records contains about 1100 pieces. Moreover, the collection contains records Pathe with vertical recording and large gramophone records used for sound background of films in the period before invention of an optical sound recording directly on the film tape. The collection contains also about 50 tapes for blattnerfon and about 20 tapes for the apparatus Philips-Miller. The collection includes also a device for reproduction of phonograph cylinders and standard gramophone records by electric method.

Phonographic recordings – samples>

Measurement of noise and vibrations

Measuring technique is represented by a complete series of instruments for measuring noise and vibrations from the firm Bruel & Kjaer and from the German firm RFT. The instruments are in a functional state. They include sound meter, analyzer, recorder, instruments for measuring equivalent noise level, measuring sound level in air and in water. A peculiarity is a synthesizer with acoustic output and visual representation of individual acoustic components. The collection closely relates to the exhibition of acoustics.