Whilst isolation between rooms is important, the specification also called for absolute sound pressure levels not to be exceeded. This could be from structure borne sound, traffic rumble, lift motors etc. or airborne sound. The absolute levels not to be exceeded were:

To isolate the studios from external sources the whole area had to be fully floating.

The outer studio wall is constructed from slab to soffit to form the office boundary continuing between the individual studios to create the central wall. Once all of the studios were defined in this way. Floating floors were laid. These are based on neoprene blocks and have very dense flooring fitted to them (approx 150kG / Sq metre).

Different grades of neoprene acoustic blocks are used depending upon location. The inner studio wall was constructed on the perimeter of the floating floor and therefore the blocks around the perimeter needed to have a smaller deflection for a given loading that the blocks supporting the floor only.

The ‘dead’ load (The mass of this floor, inner studio walls, windows, doors etc.) crushes the neoprene blocks to close to their load limit and knowledge of the live loading is needed to avoid the maximum load ‘overloading the neoprene blocks. The blocks are much more efficient at their maximum load and the objective is to achieve a natural resonant frequency of the studio box below 10Hz. This is below the capability of most recording / broadcast apparatus and interfering vibration (noise) above the natural resonant frequency is effectively damped by the floating nature of the structure.

They are constructed from 92mm I stud with multiple layers of varying weight boardsThese layers are laminated together and each having a different resonant frequency forms an effective high performance wall.

The inner studio walls cannot be fixed to the soffit, as this would allow structure borne sound and vibration to enter the studio. Therefore a dense acoustic slab is gently crushed between the head of the wall and the soffit.

The structural stability of the wall is ensured by the bracing across corners (many studios are relatively small rooms) and the installation of a Casoline MF ceiling with multiple layers of Soundbloc plaster board ‘tying’ the box into a solid structure.

For larger rooms, acoustic wall ties are fitted between the inner studio walls and the structure. These need to be carefully specified to avoid ‘bridging the structure’.

Behind the fabric coverings of the walls and before the multiple isolation layers are varying acoustic absorbing areas specifically designed to produce the reverberation times required.

The sound passes thru the outer fabric and is controlled to give back a reverberation that is totally accurate and flat across the full frequency range.

This is designed to give the studios a natural sound with no colouration nor wayward reverberation.Acoustic control is in itself a bit of a “black art” at which Studio Schemes is a recognised expert. The calculations involved to work out the required absorbency across each section of wall includes:

The amount of glass and hard surfaces, doors, the composition of the ceiling, taking into account the effect of air conditioning grills and lights, the absorption of the floor as well as the expected sound sources

All these make marked differences to acoustic performance when designing to the acoustic level of these studios.