Exceptional Acoustics
“It must be said that there are very few people with rooms as good as yours.”
This article expands on the studio’s acoustic design page, a brief introduction highlighting that Fulcrum Studio is not a standard room ‘treated’ with acoustic materials as an afterthought. Instead, it has been designed as a professional acoustic space from the ground up. Find out more about the initial inspiration for the construction of the studio in the ‘Small But Beautiful’ blog post.
The expanded details in this article will appeal to anyone interested in learning more about design features that create exceptional studio acoustics. These greatly aid the production of music and in turn, make the process much more enjoyable and rewarding.
Rather than waxing lyrical about principles that require a qualification in acoustics to understand, this article will explain the studio’s essential design features, their affect on sound and most importantly, how these features benefit working in the studio on a practical and musical level.
Small But Beautiful
Fulcrum Studio has been acoustically designed from the ground up
Sound Behaviour
Acoustic design has a direct impact on how sound behaves in a room. This affects the entire recording and music production chain, from how a sound source such as a vocal or instrument sounds in a room, its recording and the sound when played back.
Primarily designed with ‘control room’ acoustics, an accurate, transparent sound is captured and reproduced at the studio, which envelops the listener in a wide ‘sweet spot’. This means that because of the room, the choice of speakers, their geometry and setup, the speakers sound excellent away from the front desk and at the rear of the room, not just at a single focused point in the room.
The room design is based on the concept of a ‘non-environment room’. Philip Newell’s specifications build upon designs pursued by studio designer Tom Hidley in the 1990’s. The underlying psychoacoustic philosophy seeks to minimise room reverberation, while providing a degree of acoustic ‘life’ for those in the room. This makes it a comfortable space to work in, without the oppressive characteristics of an anechoic chamber, in which sound is heavily absorbed which can render it acoustically disorientating or uncomfortably ‘dead’.
Built to Sound Exceptional
Fulcrum Studio during construction
Four main design features work together to form the studio’s overall acoustic design:
Isolation box with suspended floor
Non-reflective walls and ceiling
Monitor wall with flush mounted loudspeakers / monitors
Rear wall absorbers
(1) Splendid Isolation
The isolation box is a ‘room within a room’ contained within the external structure of the building and standing alone. There is a physical air gap between the inner and outer walls, to prevent structural transmission of sound vibrations. The entire inner structure is supported on rubber ‘waffle pads’ that dampen vibrations between this and the concrete floor below.
For necessary openings in the isolation box, there are doors and windows on both the external and internal structures, with carpet-lined ‘tunnels’ between them. The tunnels are fixed to the inner isolation box and connect with the outer structure using foam seals, to maximise acoustic isolation between the inner and outer structures.
The fire doors used are heavy and minimise transmission of sound, with their generous thickness and density. The studio’s inner window is custom manufactured using laminated acoustic glass, to minimise sound transmission or amplification of internal resonances. Heavy timber stud walls with three layers of plasterboard and MLV (mass loaded vinyl) sheets sandwiched between the layers, attenuate sound transmission in either direction. A similar specification is used for the pitched ceiling, with its considerable weight supported on strong timber beams.
The walls and ceiling don’t totally trap all bass frequencies in the studio, but let the lowest frequencies pass through into the surrounding outside air, to be absorbed into the background noise of everyday life. This improves the sound of the studio without allowing escaping sound to impact on the neighbours. Mineral wool slabs fill the spaces between the vertical wall studs. Over this, a layer of ‘Acoustidan’ acoustic sheet made of bitumen and cotton felt provides further acoustic isolation and damping. Finally, the inner surface of the studio walls and ceiling are covered in 35 mm thick wood wool panels.
The total wall thickness of the isolation box is approximately 13 cm. Including an air gap between the external structural walls, the total is approximately 20 cm, which represents a considerable investment in materials and reduction of space available inside the studio. However, this is thoroughly worthwhile, in achieving the acoustic specifications of the studio.
(2) Wood Wool
Troldtekt wood wool panels, factory painted in white, cover the side walls and ceiling. These are the visible covering of the internal studio walls and provide a distinctive architectural finish, in addition to their acoustic credentials.
The mix of wood and cement create wood wool’s unique sound absorbing properties, which control internal sound reflections. They prevent sound emitted from the speakers at the front of the room from scattering and bouncing around the internal volume of the studio. This results in well-balanced acoustics with accurate stereo imaging.
Architecturally, the wood wool panels are beautiful to look at, with their fibrous, randomised aesthetic comprised of thin wood strands formed into 1200 mm x 600 mm panels. The wood is sustainably sourced Norway spruce from Danish forests and their open surface structure effectively absorbs sound. They are free of harmful substances and can both absorb and emit moisture, resulting in a healthy and comfortable indoor climate, which is beneficial for those spending many hours in the studio. The panels can be easily attached to stud walls with special screws that blend in with the panel’s fibrous surface without damaging them.
(3) Monitor Wall with Flush Mounted Monitors
“In the best control rooms, it is general practice to build speakers into the front walls. ”
The front monitor wall is a solidly constructed timber frame, with layers of plasterboard, bituminous membrane and OSB sheet attached, faced with decorative quartzite split-face stone. The heavy wall construction enables acoustic damping, preventing it from amplifying speaker vibrations and providing a diffuse surface to reflect speech and make the room sound less dead, giving it back some acoustic ‘life’ to benefit those working in the studio.
Acoustic Isolation
The internal laminated glass window and standard external double-glazed window. In-between, the acoustic ‘tunnel’, lined with carpet
Aside from the enduring qualities and impressive technical specifications of the studio’s Neumann KH 310A active monitors, they work well in the studio because of the careful way they are flush mounted (recessed) into the front monitor wall.
Mounting the studio’s main monitors this way improves the sound of playback in the room. This is because sound can only radiate from the front of the speakers, rather than behind and to the sides, which would occur if the speakers were mounted out in the room on speaker stands. An added benefit of flush mounting is that the speakers become more efficient, making them more accurate and energy efficient, as they don’t need to be ‘driven’ as hard as when mounted on stands out in the room.
Because the front monitor wall is heavy and well damped, the monitors are solidly supported, which keeps structural resonances and physical movement of the speakers to a minimum, further improving playback transparency and stereo imaging.
Speaker Geometry
Because the main monitors have a wide horizontal dispersion pattern, they have a wide sweet spot. Directed by Philip, Richard carefully calculated the angle and positioning of the front monitor wall, based around the geometry of an equilateral triangle.
Studio speaker setup
Prior to the construction of the monitor wall, speaker positioning and angles were calculated and carefully mapped out on the floor
The speakers are mounted fairly high (between the height of a small person sitting down and a tall person standing up), with the centre of the midrange driver set at 145 cm above the studio floor. This minimises interference caused by sound reflections from the studio desk and enables a consistent sound in the room, whether standing or sitting. The speakers have an excellent reputation for midrange clarity, an accurate sound and extended bass response down to 34 Hz.
(4) Rear Wall Absorbers
At the rear of the studio, there are two open wooden frames, faced with acoustic fabric to let sound pass through. These rear wall absorbers are designed to be 100% absorbent at all frequencies. In total, they contain an array of 5 hanging waveguide panels, set at 45° to the front of the room. The construction of the panels are relatively straight-forward, but calculated to ‘steer’ and absorb sound waves emitted by the loudspeakers at the front of the room, which hit them perpendicularly (straight-on). They are simple OSB wood panels covered on one side with thin MLV (mass loaded vinyl) sheets, with a further covering of Thermafleece UltraWool sheep’s wool insulation. This is perhaps the best example of readily available building materials being used in an inventive way to provide exceptional acoustics!
This design of acoustic treatment was developed for mobile control rooms for mixing live broadcasts and recording studios of any size. They serve as bass ‘traps’, which let low frequencies in, but don’t let them escape back into the room. Part of their job is to absorb unruly bass frequencies referred to as ‘standing waves’.
Solid panel absorbers of this type have been in use since the 1960’s. What was initially an empirically developed design by engineers, became backed up by scientific studies in the late 1990’s. The rear wall absorbers have a total width of 1.8 m, with a depth 60 cm. Although they take up a considerable amount of space in the room (which in this small room accounts for a large percentage of the total available space), they make a large contribution to the neutrality of the acoustics, taming audio frequencies that can quickly re-enforce each other and lead to a troublesome low end frequency response. The combination of acoustic design features result in a room that is a pleasure to make music and mix in.
If you feel inspired to start your music production project at Fulcrum Studio, contact Richard today, to book your free taster session and claim an introductory discount as a new client.
Many thanks to Philip Newell, international consultant on acoustic design. Philip has been involved in the design of many hundreds of studios for music. I consider myself extremely privileged, for Philip to have overseen the design of ‘small but beautiful’ Fulcrum Studio. After meeting Philip in person, we exchanged hundreds of emails (some during the challenging period of the Covid 19 pandemic), as he patiently and expertly guided me towards the completion of Fulcrum Studio.
Philip is an authority on acoustic design and the author of a large number of publications. His book ‘Recording Studio Design’ explains the key principles of successful studio design and construction, using straightforward language and practical examples. It contains far more detail than offered in this article and comes highly recommended for anyone undertaking a studio build of their own.
