acoustic treatment for walls – new guy getting started

Hello, I’m a professional jazz pianist of 25 years. I’m setting up my very first studio and I have only a beginning / novice level of studio design knowledge. This forum was highly recommended by a trusted friend and studio technician. This is my first post. I am pleased to be a new member of the forum. I read the “forum rules”. Please let me know if there is anything I have neglected in complying with these rules, and / or how I might better communicate according to the standards of the forum. I just downloaded sketchup, did some learning, and created layouts. Sketchup files are attached. I suspect many of you have a lot of knowledge and experience regarding the first thing I want to figure out which is what to do with the walls. Here are the criteria I am working with: 1/ I am fortunate to have a room in my home with an excellent piano that I have always used as a rehearsal space. The project is to convert this room to a recording studio. 2/ I do not intend to create an all purpose studio for hire. I only intend to record my jazz trio - acoustic piano, acoustic bass and drums. I would like to provide for the option of a vocal booth at some point, but it is not necessary for now. 3/ I am hoping to use the entire room as a single recording room. I require only great sounding live recordings. I do not require overdubbing or takeouts or track editing. Others have told me, therefore, I don’t need separate rooms for the three instruments and I would get the “live jazz” sound I’m looking for with the three instruments in the same room. I am not sure if that is the case. Others have told me if I go that way I would want to consider moveable acoustic isolation barriers between the three instruments. (An added benefit to all three instruments in one room is eye contact between us). 4/ I’m not particularly concerned with the quality of the control room because I plan to take the tracks, exactly as recorded, to a full-service studio with a qualified technician to do any additional work. I only require great tracks. 5/ I want to obtain a very high quality sound that would be very suitable for radio broadcast or any other demanding application. My objective, of course, is the best sound I can afford. 6/ Currently the room is just a room with carpet and the current acoustical properties are, in my opinion, quite bad. During rehearsals there are horrendous bass booms. We put the bassist in a particular spot to reduce this. The drummer is extremely dynamics-conscious and sounds great when we play anywhere but in this room. In this room the drums are extremely overbearing. I’m playing a 7’6” acoustic piano that produces a pretty big sound. When the piano is the only instrument being played in the room it sounds, well, huge. But when we rehearse I have to mic the piano to hear it properly over the drums. To a layman such as me, therefore, it seems the room in it’s current state has abysmal acoustic properties. 7/ The room is basically 24’ x 14’ with 10’ ceilings, sketches attached. Outgoing noise such as neighbors is not an issue. Incoming noise such as airplanes is not an issue. The two windows have rolladen on the outside - rolling metal panel shutters. There is a window type opening to the adjacent room, two other openings, and a door to the outside. 8/ My distant second priority, to the extent possible, is to accomplish this with the least possible modification of or damage to the existing construction. Depending on the extent of modification I might reach a point where aesthetics come into play because it is a nice room in the front of my house and will continue to be just a rehearsal room much of the time. This concern is a very distant second priority but would be a nice luxury if possible. I am in the planning and research stage. I am very interested to learn where I go from here. The simplest idea I have acquired so far is to enclose the room in acoustic foam. I could cover the walls and ceiling. I could, if necessary, design something to provide air space between the walls / surfaces and the acoustic foam. I could design a moveable panel with acoustic foam on one side that could cover the door and the 3 openings when recording, and be removed when not recording, and also do the same with the 2 windows. I could place bass traps in all the corners, upper and lower. I would be very grateful to learn if simply enclosing the room in acoustic foam will produce the sound I want. I did some research on acoustic foam. I have 1128 square feet to completely enclose the room as mentioned above (79 linear feet x 10’ high = 790 + 338 square feet for the ceiling). The pricing I found for Auralex sonofiber 1” is $359 / 96 square feet = $4218. Sonex classic 2” is $191 / 64 square feet = $3366. Primacoustic sells a package of hanging acoustic panels, about $1500 - $2000 for this size room. These panels only cover what appears to be a small percentage of the surface area. I wonder if this will do the job. I visited 30 or 40 websites. I’ve tried to figure out if Sonex and Auralex are worth the cost, or if a thicker piece of generic foam is as good, cheaper, etc. I went to a foam dealer here in Las Vegas. (He has a warehouse full of foam - huge chunks the size of my garage). He sells various open cell foams “style HR, S, R, or D”, ranging in density from 1.5 to 2.5 pounds / cubic foot, and firmness of 20 – 50. His “HR” , 2.5 pounds / cubic foot, 2” thick, in any firmness sells for $112 / 56 square feet = $2256. He also has closed cell foam 1/8” to ½” thick. The ½” thick sells for $13 / 15 square feet = $978, or I could double it to 1” thick for $1956. I haven’t determined how to translate this data regarding the alternative foam options to a meaningful value of acoustic dampening. I could not determine if Sonex or Auralex are open or closed cell but some other manufacturers of acoustic foam advertise open cell. I am pleased to be a member of the forum. I would greatly appreciate input regarding these ideas. Greg

for aesthetics and performance, cloth covered 703 (or similar) insulation will be hard be beat. name brand acoustic foams are designed to deal with certain acoustic treatments and also are (typically) fireproof - whereas a number of other types of foam may have less performance and might not be fireproof... one tactic would be to cover the corners of the room with 703 type absorbers, place a number of absorbers on the walls - staggered from each other on opposite walls - and some 703 absorbers on the ceiling as "clouds". a pair each over the bass and piano, three over the drums. for the drums, i'd also create a a pair of low "gobos" to try to isolate the kick and toms a bit. so in your room you're probably looking at around 16 panels for the corners and walls and another 7 for the ceiling. 2 gobos. this should keep the space fairly alive while trying to sort out the room modes. if the prices for this are high for you, there are numerous do-it-yourself plans for building the absorbers. i'd start there and then do some measurements to see what frequencies are still out of line and you may find you need some slat resonators and/or panel traps to get them under control. lastly if you have the option, you might be able to add a couple of ceiling diffusers to any open spaces on the ceiling rather than adding more absorption.

Hi Glenn, Thank you for the reply! I am doing some research to learn about the techniques you recommended and terminology you used - 703 insulation, 703 absorbers, gobos, clouds, etc. Then I can hopefully post an intelligent reply. If you know of any forum posts or links that explain those that you could share it would also be excellent. Thank you very much. Greg