Molle Music

Mutrox does not only deliver completely finished studio spaces. Sometimes we are asked to isolate the sound in a room. This was the case with Robert Mollee, who had a practice room built on the first floor of his house.

In the recently renovated high-rise apartment building Grubbehoeve, located in the Bijlmer and part of the "Bijlmermuseum," Robert Mollee has his practice space in a special apartment. Because crosstalk to neighbors in a flat is a common problem, Robert filled out the contact form on the Mutrox website. After a visit and some pleasant conversations, together we came up with a concept that was balanced in terms of objective and budget.

The construction method is a complete "box-in-box" or "mass-spring-mass construction" realized in the already existing space. We have not worked with conventional materials here. This would have meant that the space of 2.7 meters wide would have been very much reduced. The system used, which was designed by Mutrox, is a decoupling by means of a specially designed spring system between which absorbent mineral wool and an air cavity were placed. These springs were glued to the walls and rest on the decoupled floor.

This first decoupling of the floor is a new system we developed with a partner. A 2 cm thick Fermacell slab was glued to a 1 cm rock wool slab in order to achieve decoupling. Such a system has been in use with us for some time, but we made an improvement. The edges of the Fermacell board have a milled fastening frame so that these handy panels can be taken in and out as ´click laminate´. The big advantage is that these plates are thus not screwed but lie very stable, flat and firm.

To obtain mass, an acoustic mass plate glued between two layers of waterproof glued board was used. The 12 mm thick board with a mass of 12.5 kg/m2 has in itself an RW sound insulation value of 37 dB and was applied in the two decoupled layers. By testing the complete system internally, the total construction of air cavities, mass plates and Fermacell finishing board comes to a wall thickness of less than 15 cm but achieves an average insulation value of more than 50 dBA (building acoustics standard).

In order to achieve equivalent insulation even with the existing sliding door, without the disappearance of daylight, our Sonic Glass was used. These 13 mm thick panes consist of 2 layers of glass with acoustic foils in between, which provide a high insulation value. Of course, there are other suppliers of such sound insulating glass, but Mutrox has developed this Sonic Glass with a partner and achieves very high insulation values with this product that other suppliers do not achieve.

Despite the fact that, due to rain and municipal restrictions, the intended construction time of one week was extended by two days, Robert is happy with his new rehearsal space and can play music unhindered in the middle of the Bijlmer. Of course, we are again proud of the final result delivered by the Mutrox team of designers and executive builders.