DESIGNING GUIDELINES - Competition FMU

Acoustic requirements for the preparation of the conceptual design for the building of the Faculty of Music

All the spaces intended for stage performance or for the preparation of performers should be designed so that they have adequate sound and technical conditions for a high level of acoustic comfort for music performances. The auditorium of the large stage, as well as the space of the stage, should be designed and equipped in accordance with the principles and requirements of spatial acoustics.

Considering that the location is on a busy road, the organization and orientation of the space for performances, as well as the modern construction protective measures against noise should be applied.

The conceptual design of the building of the Faculty of Music should envisage all the elements that are recognizable at that level of design documentation and necessary for the provision of adequate sound comfort in the faculty premises during the following design phases. This implies the creation of prerequisites for the following:

sufficiently low ambient noise level,
the expected level of sound image aesthetics in the spaces for music performances,
sufficiently good speech intelligibility in classrooms, amphitheatres and other spaces where speech is to be heard, directly or through a sound system.

General notes

In the conceptual design of the building of the Faculty of Music, special attention should be paid to designing all spaces in which the most complex acoustic requirements are set. These are:

Hall for concerts of the symphony orchestra,
Hall for chamber and solo performances
Hall for jazz music and big band
Hall for opera and ballet performances
Large sound studio.

For these spaces, it is necessary to meet certain conditions already at the level of the conceptual design in order to enable the implementation of quality acoustic designs in the field of sound protection and spatial acoustics in further design.

In order to ensure adequate sound protection of these areas, the conceptual design should meet the following conditions:

dilatation of the part of the building in which the said spaces are located from the rest of the building,
moving back these spaces away from the facade and roof towards the interior of the building,
the existence of a technical floor or similar acoustically neutral space towards the roof of the building.
surrounding each concert hall individually with some neutral spaces in which there are no loud sources of sound (corridors, storages, dressing rooms, pantries, rooms with quiet

electric equipment and alike),

buffer zone with double doors at all entrances from public spaces.

Adequate space for accommodation of the machine system should be provided in the facility so that the ventilation and air conditioning of the hall and the studio can be designed in an appropriate way according to the strict requirements of noise protection. This implies the following:

Sufficiently large spaces to accommodate air conditioning chambers and other mechanical equipment in a position away from the halls and studios (preferably outside the dilatation line through which

these spaces are separated from the rest of the building),

spaces for manholes and technical floors in the building in order to be able to route the ventilation ducts of large cross-section through the building, as necessary for the work with low-speed air circulation in them,
the manner of air distribution in the halls which is suitable for spaces for music performances (plenums above and below the halls).

While organizing the space and calculating the dimensions and the area of halls and studios, one should take into account the fact that their partition walls must be up to 50 cm thick (massive wall + interior cladding on both sides).

Hall for concerts of the symphony orchestra

The form of the symphony orchestra's concert hall should be parallelepiped ("Shoe box") with the required area and volume, with permitted minor deviations that do not jeopardize its acoustic quality. The recommended size of the hall (area and height) is a net and one is calculated up to the interior wall and ceiling coverings. The volume of the hall should be adjusted according to the determined area and form of the auditorium so that the ratio of these two sizes (volume and area of the auditorium) enables the achievement of the reverberation time value of T30 = 1.5-2.0 s. The proportions of the hall are adjusted to the acoustics requirements for a given number of audience members, so that the adequate values of other acoustic parameters can be achieved therein. The interior coverings should have an intensive relief, which is necessary for achieving an adequate sound image aesthetics, in all the aspects according to the requirements for symphony music concert halls.

The auditorium of the hall should be divided into a ground floor, a small balcony and low galleries along the perimeter. It is contraindicated to create the slope of the auditorium to the extent that is applied in theatres as thus the allocated volume of space is reduced. In that sense, the geometry of the auditorium should enable the view of the stage to the extent appropriate for concert events (the hall is not intended for theatrical purposes, and full visibility of the stage floor from the listener's position is not necessary in music halls). The galleries should, if possible, provide standing room. The auditorium should also provide for potential places to accommodate TV cameras without compromising the view from the seats. These places should be determined in accordance with the requirements for recording such events.

The required criteria of ambient noise in the concert hall is NR15, which requires for the organization of the space around the hall to enable the distribution of air in the manner that is common in concert halls. This means that the following should be planned:

- below the hall, there should be a plenum for adding air through diffusors in the floor under the seats,

- above the interior hall ceiling there should be a space for plenum for extracting air.

Next to the hall, at a suitable location, a technical control room should be envisaged for control of stage lighting and sound (when being used), as well as a space for video projector. These premises must have a good view of the stage. While sizing all the control rooms, it is necessary to take into account the loss of space for adequate acoustic interior processing on the walls and ceiling.

Hall for chamber and solo performances

The form of the hall should be parallelepiped ("Shoe box") with the given size and height, with permitted minor modifications that would contribute to the acoustic quality. The recommended size of the hall (area and height) is net and is calculated up to the interior coverings.

The required criteria of ambient noise in the hall for chamber and solo concerts is NR20. This requires for the organization of the space around the hall to enable the distribution of air in the manner that is common in concert halls. In this sense, the following should be planned:

- below the hall, there should be a plenum for adding air through diffusors in the floor under the seats,

- above the interior hall ceiling there should be a space for plenum for extracting air.

The auditorium of the hall should have a geometry that enables the view of the stage to the extent appropriate for concert events. It is contraindicated to create the slope of the auditorium used in theatre halls as thus reduces the effective space volume is reduced (full view of the stage floor from the position of the listeners is not necessary in such halls).

Next to the hall, at a suitable location, a technical control room should be envisaged for control of stage lighting and sound (when used), and so should a video projector room. The stage ought to be clearly visible from these premises. While sizing the control room, it is necessary to take into account the loss of space for adequate acoustic interior processing on the walls and ceiling.

Hall for jazz music and the big band

The conceptual design of this hall needs to provide space for interior coverings on the walls and the ceiling. The acoustic properties of this hall will be adjusted through the materialization of these coverings in the following design phases. In this hall, the auditorium can have a slope that allows better visibility of the stage.

The required criteria of ambient noise in the hall for jazz music and the big band is NR25. With such a criteria, it is desirable, but not necessary, to organize the distribution of air as in other halls with the plenum below the auditorium and the plenum above the interior ceiling of the hall.

Hall for opera/ballet shows

This hall should be organized according to the principles of theatre halls, which refers to the organization of the auditorium and its slope. A smaller gallery is desirable primarily because of its contribution to the diffusion of the sound field rather than for housing a portion of the auditorium. It can house technical facilities and possibly a small number of audience members.

The volume of the hall should be adjusted according to the determined area and form of the auditorium so that the ratio of these two sizes (volume and area of the auditorium) enables the achievement of the reverberation time value of T30  1.2 s. Interior coverings should have a relief that is necessary for achieving an adequate sound image aesthetics, in all the aspects according to the requirements for opera halls.

The orchestra pit should have adequate depth to allow some diffusion of the sound field therein. When determining the dimensions of the orchestra pit, it should be taken into consideration that all the interior surfaces are to have an interior covering that is approximately 10 cm thick.

Next to the hall, at a suitable location, a technical control room should be envisaged for the control of stage lighting and sound (when used), and so should a video projector room. The stage ought to be clearly visible from these premises. While sizing the control room, it is necessary to take into account the loss of space for adequate acoustic interior processing on the walls and ceiling.

Teaching classrooms and halls

In all the teaching premises, it is necessary for the acoustic response to satisfy the sound image aesthetic requirements. In this sense, it is necessary to take into consideration the existence of suspended ceilings at the distance of 15-20 cm from the concrete slab while determining the floor height in the building. Their materialization shall be defined during the following design phases.

Practice rooms for instrumental teaching

While organizing the space in the building and determining the area of practice rooms for instrumental teaching, it should be taken into account that the requirements for sound insulation between such rooms imply wall thicknesses of 30 cm. In the rooms that are classified as noisy (instrumental practice rooms, jazz halls), it is necessary to provide a lobby at the entrance with two doors, whereas some practice rooms by group should have a common access corridor separated with doors leading to other spaces. The lobbies can be used for storing various items.

It is desirable, in the smallest practice rooms, that at least one wall deviates from the parallelism (sloping surface) in order to minimize its own resonances characteristic of small spaces.

Dancing halls

While defining the height of these rooms, it is necessary to take into account that the suspended ceiling therein will be at a distance of approximately 50 cm from the concrete slab (acoustic treatment and placement of ventilation ducts).

The required acoustic treatment of the dance halls will be resolved through the materialization of the suspended ceiling and the surfaces of some of the walls. Some walls in the halls should remain untreated to allow for the achievement of the necessary requirements, such as the installation of mirrors.

Large sound studio

The acoustic requirements for the space of a large sound studio are the following

ensuring the adequate size (area and height) and
ensuring sufficiently low ambient noise level.

While determining the size of the studio, one should take into account that on all its internal surfaces there will be an acoustic treatment of approximately 15-20 cm, and on the ceiling up to 1 m in some places.

The required criteria of ambient noise in a large sound studio is NR15. In order to ensure this, it is necessary for the conceptual design to include a studio space that is:

in the part of the building that is dilated from the rest of the building,
positioned on the ground floor or in the basement,
surrounded by neutral premises or land,

A large sound studio should have artificial ventilation that would meet the criteria for ambient noise. In order to achieve that, it is necessary to provide space outside the dilated part of the building for a suitable air-conditioning chamber and a space for channels with a larger cross-section leading to the studios, which will enable low-speed air circulation in them. In the space surrounding the studio, spaces should be provided for such a channel distribution.

Other conditions

In the communications around the building, one should provide an access road and parking space for television coverage vehicles. The parking space ought to be in a position which will provide good communication with all the concert halls for the purpose of bringing in the equipment.