Recording Studio Acoustics

Our services include:-

• Recording studio acoustic design
• Recording studio acoustic reports
• Recording studio acoustic surveys
• 2D and 3D CAD recording studio acoustic designs

Below is a quick crash course in recording studio acoustics:

This is just to give a quick crash course in recording studio acoustics and I will be discussing basic recording studio acoustics on this page.

Sound can be calculated very precisely. As we know the speed of sound we can calculate which frequencies fit between two objects. This gives us sound nodes or standing waves.

We can then tell which frequencies will cause the biggest issue within a certain size room, which frequencies will stand out, and which frequencies will disappear.

If you have the luxury of starting from scratch, you can then apply these acoustic principles in your recording studio acoustic design so that there are either no obvious peaks and drops or that they can be controlled once the recording studio is built. But at least you will be prepared and know what you will have to overcome.

If you have an existing recording studio you will have to either remedy the acoustics you already have or drastically redesign your recording studio. This is all depending on the space you are working with and you may find that by just decreasing one wall by 1cm it will save your studio and bring peace to your life.

Example

We recently designed and built a studio for a client where the space was limited and soundproofing was a big concern. When the recording studio acoustic design was complete, the tolerances I gave to our construction team was only negative 5mm. What this means is the control room and live room dimensions could only be 5mm bigger than specified they could not be 5mm smaller.

(These tolerances are a tall order for the general builder, which is why we have our own construction team and all they only build our recording studios.)

When putting up the ‘last but one’ layer of plasterboard in the studio live room, it was evident that the acoustics were going to be impressive, but there was a nasty spring to the reverberation in the room. However, once the final layer of plaster board (12.5mm) had been applied, the reverberation in the live room not only made me smile, but made my client extremely happy, and the nasty spring had disappeared.

The long and short of it is, recording studio acoustics are an exact science, which can be mastered if you have a good understanding (and time) to calculate all possible variables. Basically, a whole heap of maths.

Our calculations are done on our own massive excel document which has over 15 interlinked worksheets and 2000 rows and 100 columns in each worksheet, just to calculate and reference recording studio acoustic responses and soundproofing effects within a single room.

Parallel Walls

You may have already come across the phrase “Avoid parallel walls when it comes to recording studio acoustics”, but this only really applies when the space has so many bad sound nodes/standing waves, that all you can do is try and cover them up by creating even more!

When building a studio the first thing you hear from associate studio owners is “make sure you don’t have parallel walls’. However, parallel walls are useful in a studio and can really benefit the acoustics if you can exactly calculate what they will do but most studio builders put non parallel walls in their designs as a “well, everyone else is doing it” type of approach.

When we do our designs we embrace parallel walls and non parallel walls. Parallel walls actually bring certainty and control; you know exactly what you will have when your recording studio is built. This is the reason; say your control room is 4m in length and 4m in width and 3m in height. If all those walls are parallel, the sound nodes/standing waves will be the same. If all the walls are non parallel/sloping in one way or the other, straight away the distance between each area is different at different points between each opposing surface. This basically means instead of you dealing with say 10 sound nodes/standing waves between each surface, you may end up tripling the number of sound nodes. The only thing you have done is decreased the level of each sound node. But you end up with a messy sounding room, which is a lot harder to treat.

Now, this is not to say that you should work in a box, because as you may well know, most top end studios have lots of apparent angled walls. The only difference is that these angled walls are either exactly calculated or the wall is actually fake and there is a parallel wall behind the visible wall, and the visible wall is fabric.

There are some magic angles that work extremely well when design the recording studio acoustics. However, these are only used if you have enough space.

Brightening or dulling the acoustics in your Recording Studio
Most control rooms normally have a reverberation time of around 0.9 seconds to 1.2 seconds max and have a live end at the back of the room and a dead end (or controlled end) at the front where mixing area is.

(The dead area is the controlled area were you can hear all aspects of the sound without much influence of additional reverberation. This area is not dead as this will cause ear strain, it is meant to be around 0.25 to 0.5 second)

(The live area is to imitate the living room environment, which saves time when you A/B music)

Live rooms normally have a reverberation time of 1.2 seconds to 1.5 seconds maximum, which additional means of controlling and reducing and increasing the reverberation time.

It doesn’t take rocket science to know that soft materials absorb sound and hard materials reflect sound. Also, that the weight of the absorbent material determines the frequencies it is able to absorb. The heavier and deeper the soft material the more low frequencies it is able to absorb. The same would be for reflective materials, the lighter the hard material, will result in only higher frequencies being reflected and lower frequencies passing straight through (just like it wasn’t there!).

So you can start to see that you can start to control the way sound behaves within a given space and you can drastically affect it with great results.

It is also worth mentioning that having curved reflected materials like half circles is always better for reflecting sound, as it disperses sound and doesn’t focus the sound.

It seems to be the latest craze to invest in bass traps in project studios; you just know you want them, without really knowing why! Corners of any room have the potential of acting like bass amplifiers, which basically means they will amplify any bass that hits them and send it out slightly louder in proportion to the overall size of the corner of the room. Kind of like using an old none powered megaphone, the sound is amplified as it exits, just like the corner of the room, so if it is able to find its way into the corner of the room, and there is a hard reflective surface to reflect back off, then it will head back the other way slightly louder!

Corners of rooms can be dealt with by either blocking in the corners, so the room starts to resemble a hexagon, or simply by adding absorption to the corner of the room, you will of course have heard of bass traps. Although, it has to be said that, most of these products that are sold are overpriced and are designed to take advantage of the project studio owner, but that is another rant of mine. Please note, I am not saying that the products these companies sell don’t work, but I want to point out that you could do the same, if not better, for a quarter of the price while still having a visually appealing studio.

Again, I am not saying you can fix all your problems by trying to absorb all the frequencies that cause you problems, as this will only cover up frequencies to a point, and your ears will be able to tell what is going on as you walk around you room, rather I am saying that you can fix issues with some slight structural modifications, or even better fix them before you build your recording studio.

You may have gathered that I am an acoustics consultant, and spend all of my time designing recording studios for clients and advising people just like you.

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