Capita’s concert hall in Cardiff Bay is a unique hybrid of recording studio and concert hall
Hoddinott Hall is a unique hybrid of recording studio and concert hall that sets the model for a new breed of attractive ‘concert studios’. The hall is primarily the recording studio of the BBC National Orchestra of Wales, but it transcends the usual bleak black box into which professional musicians are consigned for most of their careers. Instead, it gives them a comfortable, friendly working environment.
It transcends the usual bleak black box into which professional musicians are consigned
As well as providing optimum acoustics for musical recordings, the hall is large enough to dissipate loud noise levels that could, over time, impair the musicians’ hearing. It also incorporates sound reflectors that allow them to appreciate the sounds they are creating, as well as clear glazed windows to supply natural daylight and seating for 350 people, to give genuine audience feedback. On top of that, the hall is a public venue, and has top-notch finishes in natural timber to match.
The hall opened last January as the second phase of the Welsh Millennium Centre, which was completed in Cardiff Bay in 2000. It is tucked at the back of the great beached whale of the first phase, where it hides behind its extraordinary windowless, curving wall of striated, rough-hewn, multi-coloured slate. It perches above the original internal car park at ground level, and only the top fourth floor is visible from the street as a mansard roof clad in wany-edge larch boarding.
The hall is named after the celebrated Welsh composer, Alun Hoddinott, who died last year, aged 79.
Box within a box
The main hall abounds in superlatives. Measuring 630m2 in area and rising to a height of 14m, it is nearly 6m higher than other BBC studios and one of the largest purpose-built recording studios in the world. The hall’s generous size gives it a reverberation time of 1.8 seconds with full orchestra, chorus and audience, which exceeds those of other orchestral studios and nearly matches that of a top-class concert hall.
The hall assumes a coffin shape for optimum acoustics, with the orchestra sandwiched between the audience seats, banked up on tiers at either end.
The hall attains the high level of Dw72, enough to muffle a car alarm in the car park directly below
Sound insulation all round the hall attains the high level of Dw72, enough to totally muffle a car alarm in the car park directly below. This was achieved by acoustically isolating the hall as a box within a box.
The two floor slabs were cast in situ in reinforced concrete, with the upper slab laid directly on top of the lower one, separated only by a polythene membrane. Some 130 steel jacks supplied by CDM-UK were cast within the upper slab, and these were very slowly raised on internal threads to form a 200m cavity between the slabs.
The outer and inner walls and lids are supported on complex steel frames and separated by a 575mm cavity. The inner walls and lid were constructed of high-density, precast concrete panels, 8m long and weighing 7.2 tonnes. The outer shell comprises three layers of 15mm insulated plasterboard.
Neoprene shock absorbers were incorporated into the steel jacks of the inner floor slab and the bases of the inner walls.
Acoustic linings within hall
The hall’s internal linings play vital roles as laid down by Arup Acoustics, as well as providing a finish suited to a public concert hall. Clear-lacquered timber, universally appreciated for its warm, natural appearance, was the material favoured by the orchestra’s director, David Murray.
The lowest wall surfaces are lined with projecting vertical battens that diffuse sound evenly around the hall. They are arranged in a mix of three cross-sections measuring 20mm², 40mm² and 60mm². Originally designed by Capita Architecture in MDF veneered in European white oak, they were eventually made at a lower price in solid American white oak by subcontractor Houston Cox.
Across the top of the vertical battens stretches a narrow oak-veneered duct for cabling. Directly above that runs what looks like a convex balcony front of beech-veneered plywood. This reflects and distributes sounds but, instead of fronting a balcony, it conceals the hall’s only air-conditioning supply duct.
In the absence of an audience, they extend to absorb the same amount of sound
Above the mock balcony front run a series of large, sliding ‘acoustic duvets’. Finished in grey natural wool and backed by glass-fibre insulation, these panels cater for the hall’s dual purpose as a concert hall and recording studio. In the absence of an audience, they extend to absorb the same amount of sound.
The ceiling also comes with adjustable acoustic panels. A grid of 25 beech-veneered, convex panels can be raised or lowered to reflect sounds to allow musicians to clearly hear themselves playing. Gaps between and in the centre of the panels allow some sound to rise to the full height of the hall and contribute to the desired reverberation time.
Bronze audience doors
Hoddinott is such a unique name, that you might well think it had been specially invented just to fit the audience entrance doors to the BBC’s new concert studio. Look how evenly the letters are spaced across two lines, with the second ‘o’ conveniently formed by central pair of door handles.
However, the project did not start off as clear cut as that. As David Walker, partner of interior design practice, Walker and Martin (WAM), recalls, ‘We were given a narrow opening in the wall, but as the hall was intended for live BBC broadcasts, all 350 audience members would have to be seated by a precise time. So we widened the opening to fit in double doors that would channel more people through.’
The second challenge was that this entrance was located on a first floor landing in the existing Welsh Millennium Centre. ‘The Welsh Millennium Centre didn’t want any more signage in their building, but the BBC wanted to establish a distinct identity for its new hall.’
Hence Walker’s brainwave of transforming the doors themselves into the entrance sign. His wheeze even manages to echo the Welsh Millennium Centre’s own brand of giant lettering cut out of its curved bronze entrance facade.
Another problem then presented itself. As this was a public building in Wales, the words ‘Hoddinott Hall’ would have to be presented in two languages, which was now becoming rather verbose. ‘So we suggested just the name,’ says Murray. Fortunately the name was unique and unmistakable.
The doors were made by Firman Glazing by cutting 4m bronze sheets by laser jet and then bonding these with epoxy adhesive either side of 12mm toughened glass panels.