How would you treat this room?

A concrete room 5 times 6 times 4 m. Going to be used strictly for band rehearsals. What would you find most important to treat? The floor will probably have to be left concrete. Any input would be great to read! Best regards /Toby

No problem you leave the floor as concrete but then the ceiling must have absorption and diffusion (this is a rehearsal room, not a Control Room) placed homogeneously. The walls you can go just with absorption (and may use bass traps) or just do like the ceiling, depending if you want your RT60 around 0.4 s or higher, for a liver room, such has 0.7-0.8 s. Then you use diffusion to spread the sound in the room and obtain a live sound without the typical acoustical problems.

There is an announcement at the top of the forum about what to do to assure getting as many responses as possible. The announcement leads to this post. Actually, several people, who are experts on this forum, will not reply if you do not do what is written in the post. Many others who are very helpful, will not reply out of respect for the moderators' wishes. Having written that, a quick reply with what you have given, is use 30 m^2 of 100 mm minimum thickness mineral wool evenly distributed with 40% on the ceiling and the rest on the walls and fill the corners with superchunk type bass absorbers. Then listen to the room and if the highs are too dead cover the superchunks with plastic, slated wood etc to bring back liveliness. Andre

Thanks for all replies so far and sorry if i did not contribute as much info as i could have done, so ´ll do my best in this post. The location is an industrial area in Kungsbacka, South of Gothenburg Sweden. We are currently making an offer a plot in this area and if this falls through, we will look for other suitable plots elsewhere. The current plot is 2505m2 nearly square and situated 1 km from the nearest highway and railway, at the end of the industrial area next to a river. So it´s still in the planning and no final draws have been made. The reason for concrete build is for getting enough isolation to the outside (There are offices in the area.) and in between rooms. Non resonating, speed of built and so on. Of course this containment shell brings severe problems of it´s own. One plan is to have glass block windows on the entrance wall to let some light in and low frequencies out. So far corner traps and live floor, dead ceiling seems like a start. We are aiming for even rooms, definition as low as possible, still lively enough to be fun to play in. Economical as possible, like using second hand material and any tips for saving floorspace and still get good trapping in the lows would be great. We have looked at similar places and to be frank, we are not impressed. The usual way seem to be to put carpet on the floor, normal office ceilings (Resonates like crazy) and 5 cm rock wool and cover it with one plane of 7 mm gypsum.(Resonates as well..) Would it be wise to have the whole room deadish below waist level and more live on top? /Thanks /Toby

mattssons wrote:

Would it be wise to have the whole room deadish below waist level and more live on top?

What are you trying to achieve? My initial recommendation was based on room acoustic calculations. Andre

Not so easy to say unfortunately! I´m looking for a room that would be fun to play in and with as much defintion down low as possible with a room with this "tiny" size acoustically. So i´m looking for a big smile on the musician that walks into the room, thinking " i really want to play in here" Any other tricks anyone can think of colors natural light etc. Thanks /Toby