Mantra Live – Wellington Mill

We have just completed our second project with Mantra at Wellington Mill, Ancoats, as they convert a warehouse space into a new 1,000 capacity venue.

Working in conjunction with the Mantra team, dBx Acoustics’ role is to ensure that noise from events in the Warehouse does not cause any disturbance to residents in the surrounding area.

Firstly, we carried out testing within the Warehouse itself, pushing the PA system to its maximum across the frequency spectrum. Think bass so loud that your eyeballs are vibrating and you wouldn’t be far off! This is louder than we’d expect the venue to operate. However, it allows us to set any noise limits based on the worst case scenario.

With the PA system doing its thing, we measured both inside and outside the venue at various points. Especially near acoustic weak spots such as doors and shutters. In this case the venue is almost buried within the building. However, there is an open shutter at the rear which will be used as the main entry point, and fire escape doors along the street, which need to be considered.

Comparing the noise levels internally to externally – correcting for traffic and industrial noise based on further measurements with the PA turned off. We were able to assess just how much noise escapes through the building fabric at all frequencies.

The Mantra noise survey and computer model

With the fun part out of the way, we set to work on the less exciting parts of the scheme; the noise survey and the computer model. The noise survey needed to be carried out during the quietest period of the night. This will be the time when potential impact from amplified music will be at its greatest. We were also able to use survey data from our 2015 project at Mantra to support the assessment.

We set up a computer model of the site and surrounding area, and input noise sources for the front and rear of the Wellington Mill building. By also modelling industrial and residential buildings, site terrain and relative heights, we were quickly able to predict how much music noise would reach each sensitive receptor.

Mantra Live - computer modelMantra Live - computer model 2

Manchester City Council requires that entertainment noise received at residential receptors should be 10 dB below the background noise level (LA90). The model quickly allowed comparison between the predicted entertainment noise, and the background noise measured during the noise survey. This demonstrated that even with the PA system working at its maximum, MCC’s requirements regarding noise could be met.

Mantra also elected to carry out a further assessment to consider low frequency noise (63 Hz and 125 Hz). Although this isn’t a Council requirement, it’s often bass frequencies residents can hear within their homes and find particularly disturbing. Again, the assessment demonstrated that noise in these frequency bands would be more than 10 dB below existing background levels.

All in all, the conclusion of the assessment is that with the Warehouse venue in operation, there will be no adverse noise impact on nearby residents. Good news for Mantra, but also good news for the community.

We’re looking forward to the opening of the new space. It will be great to see yet another of Manchester’s historic buildings brought back to life!