Acoustics engineer needed -

[EnJeanEar]

Good people of GroupDiy,
greetings from central Greece, which is tried by unprecedented storms and rainfall.
Due to massive floods in our region, we are currently situated in a small space, because, well, life goes on.

We are looking for an acoustics engineer to provide us with an improvement study of acoustical properties, which will include construction, material and placement of treatment.
Our main goal is to correct and enhance the acoustics inside the rooms. Soundproofing and isolation are not required at the moment, thankfully inbound and outbound sounds don't pose any problem.

Due to situation, material shortage and logistics slowly picking up, budget is really tight, so please, if anyone would like to take on this project, be kind and pm me with a discounted quote for your provided services.

I am attaching a drawn layout of the space, all dimensions in meters. Feel free to ask any questions.

Thank you all very much,
Stay well, stay safe.

 

[Dylan W]

If your budget is truly tight, you can start reading about acoustics and learn yourself. It’s a deep field, so expect it to take some reading and experimentation to get oriented, but it’s doable. For a small control room, you could start by dealing with corner bass traps, first reflection points, and SBIR effect. Live rooms are trickier, not as much of an exact science as control rooms. You can play around with combinations of broadband absorption, slat walls, binary diffuser panels (which can be DIYed, I’ve done it), and polycylindrical diffusers.

You might also look into the “My Room” design, it seems like a really nice option for smaller rooms, both control room and live. It’s nice because it combines properties of absorption, slat walls, and diffusion. https://gearspace.com/board/studio-building-acoustics/581809-myroom-acoustic-design.html

A DIY tube trap wall is another nice choice for small control rooms.

 

[RoadrunnerOZ]

You have built yourself a problem with the control room having windows either side of the monitoring position. Standing waves between the windows are going to be a problem. For mixing when you don’t need the visual connection you may want to use heavy curtains, like acoustic curtaining or heavy velvet with a backing (you can also buy acoustic curtain backing).
You’ll also need to treat the rear wall and probably the front and sides as well - you can build Helmholtz absorbers for the problem frequencies in the room which can be calculated using a room modes calculator but these can be expensive timewise to build.
I have had success using compressed glass-fibre panels which have a cloth coating on one side and can be mounted in picture frame style housings and screwed/glued to the walls. The edge framing is either timber or alloy with an MDF 6mm backplate, the idea being to keep the raw edges and rear sealed from the breathable air. I use high mass compressed glass-fibre up to 160Kg/cuM, 50mm thick, the existing walls provide the restraining surface for absorption of sound to prevent reflection as long as the panels are hard fixed to the surface. The surface can be covered with decorative cloth but it must be acoustically transparent - if it’s easy to breathe through it will work.
You really need to get a proper analysis done of the spaces to do it professionally but there’s a lot you can do yourself with a bit of research. I’ve been involved with the design and construction of over 30 studios, some big, some small, some domestic. It largely depends on the acoustic materials available in your country and your budget vs cost of materials and design.

If your budget is truly tight, you can start reading about acoustics and learn yourself. It’s a deep field, so expect it to take some reading and experimentation to get oriented, but it’s doable. For a small control room, you could start by dealing with corner bass traps, first reflection points, and SBIR effect. Live rooms are trickier, not as much of an exact science as control rooms. You can play around with combinations of broadband absorption, slat walls, binary diffuser panels (which can be DIYed, I’ve done it), and polycylindrical diffusers.

You might also look into the “My Room” design, it seems like a really nice option for smaller rooms, both control room and live. It’s nice because it combines properties of absorption, slat walls, and diffusion. https://gearspace.com/board/studio-building-acoustics/581809-myroom-acoustic-design.html

A DIY tube trap wall is another nice choice for small control rooms.

Looks like the link at the beginning of the post is not working any more??

 

[ubxf]

It also depends if you're working in stereo or multichannel . Important as well is acoustic treatment of the ceiling and consideration of the air conditioning

 

[RoadrunnerOZ]

It also depends if you're working in stereo or multichannel . Important as well is acoustic treatment of the ceiling and consideration of the air conditioning

Good points - flat ceilings and parallel walls are always a problem.
Acoustic coupling room to room via the Aircon requires the building of acoustic baffles in the inlet and exhaust lines.

 

[Dylan W]

Looks like the link at the beginning of the post is not working any more??

Here’s the white paper for the latest iteration of the design:

https://www.aes.org/tmpFiles/elib/20231001/18225.pdf
And the thread:
https://gearspace.com/board/studio-building-acoustics/1078997-myroom-acoustic-design-mark-ii.html
Unfortunately I believe Bogic passed away a few years ago. IIRC all the construction details were in those threads. There was a simple way to generate a non-repeating diffuser slat wall of indefinite length by converting a randomly-generated binary sequence into the diffuser slat lengths using hexadecimal encoding. I think it’s mentioned in the white paper. Very cool stuff.

 

[RoadrunnerOZ]

Here’s the white paper for the latest iteration of the design:

https://www.aes.org/tmpFiles/elib/20231001/18225.pdf
And the thread:
https://gearspace.com/board/studio-building-acoustics/1078997-myroom-acoustic-design-mark-ii.html
Unfortunately I believe Bogic passed away a few years ago. IIRC all the construction details were in those threads. There was a simple way to generate a non-repeating diffuser slat wall of indefinite length by converting a randomly-generated binary sequence into the diffuser slat lengths using hexadecimal encoding. I think it’s mentioned in the white paper. Very cool stuff.

All very cool stuff - I’ve been down the diffuser path with difficult rooms and I’ve also been in some rooms with diffusers that have been disastrous. I got called into a studio one morning (2am) and the engineer was tearing his hair out trying to get a good mix. We eventually found some portable tall drum isolators and set them in front of the rear wall diffusers - problem solved - sometimes they get designed by someone with more of an eye on aesthetics than audio!
For this build though there is way too much costly work involved in designing and constructing diffusers for a low budget build. He really needs the long areas treated with absorbers for reasonably low frequencies for the lengths and low/mid for the widths and ceiling. Unfortunately the widths are 1/2 the lengths approximately in the L shaped room so there are going to be issues at 171 - 187Hz, 85 - 93Hz and around 375Hz - then you have the diagonal corner to corner issues. The large room is likely going to need tuned absorbers - handy site here for a calculator:
http://www.mh-audio.nl/Acoustics/HelmholzPanelResonator.htmlYou can also build slat absorbers. The main thing is to not intrude into the room and reduce floor space by too much - these diffusers can get thick, but fooling around with the panel timber thickness (hole depth) and number of holes or slat thickness (slot depth) and widths you can attack the problem frequencies quite easily and keep the depth down - these absorbers are not narrow band either.

 

[RoadrunnerOZ]

There are also diaphragm absorbers which will go to much lower frequencies but the problem areas for muddy recording seem to be in the 150Hz - 500Hz areas. There are room modes calculators for calculating the problem frequencies and their location within a room. An L shaped room poses even more problems calculating especially when it’s a symmetrical L. Sound tests are the best way to analyse a room properly that is not a regular shape. When measuring a room for problem frequency calculations the diagonals along the face of each wall, floor and ceiling and from corner to diagonally opposing corner also play a factor, contributing to resonances equally as much as length, width and height. Any reflection return path that can continue and repeat causes a standing wave.
The best rule of thumb for a live recording space is to have no two opposing surfaces able to reflect from each other causing a standing wave - ie surface treat at least one of the opposing faces with absorptive material - this can be staggered on alternate faces of two opposing walls - a ceiling should be fully treated.
The control room should be symmetrical left to right and care taken to eliminate all internal standing wave contributors to ensure the only thing you are hearing is the speakers and not tones generated by the room or cancellation of frequencies.