How To Improve Room Acoustics

You will never get the best out of your audio equipment no matter how expensive it is until you get the room acoustics right.

Room acoustics can be a make or break for your studio. When it is done right, it can make an ordinary setup sound extremely professional. If not, you will get displeasing results even with the best audio equipment at your disposal. The point is, that the importance of room acoustics cannot be downplayed and you must invest time and resources to improve it to get the best results.

In this article, we will explain both professional and DIY techniques to improve room acoustics. Let’s get to them.

a) Basic Tips To Improve Poor Acoustics

Some general tips that do not require you to purchase any additional equipment or accessories but improve the acoustics significantly include the following:

1. Select The Correct Space

When it comes to home studios, many people do not have a dedicated space for it. They have to use a part of an already established space and touch it up to convert it into a studio. This is an instrumental step and many people get it wrong. There are certain criteria that a room must fulfill if it has to be used as a studio. 

For example, the room should not have reflective walls. Generally, the walls and floors that are lined with ceramics reflect the sound and make the acoustics bad. If you want to record loud instruments or even if the vocalists speak in a louder voice, the sound can bounce back and distort the recording.

Concrete is slightly less reflective and wood is the best material to stop the reflection. So, when you choose a room for the studio it should ideally have a wooden floor and walls, if not concrete can work but never establish your setup within ceramic structures. Furthermore, if you can find a non-symmetrical room, it would be even better. 

2. Use The Existing Furniture To Improve Acoustics

The key to perfect acoustics is to deaden the room but not completely. It can be achieved with absorbent materials such as the couch, curtains, and even books. You can place the couch in the exact opposite direction of the microphone. This way, when the speakers speak the sound waves will be absorbed by the couch. 

The position of the rest of the sound absorbers should also be the same. You can either plan the studio around the existing furniture or place the furniture later, either way, the placement of these materials should stay the same.

Some people use egg cartons for sound absorption, but they do not produce good results so we don’t recommend it. You can also use a thick carpet to cover the floor if it is not wooden.

3. Remove Hard Surfaces From The Room

Hard surfaces and those that vibrate such as table lamps, photo frames, and wall hangings should be removed from the room. These reflective surfaces not only degrade room acoustics but also take room which can be used to place your audio gear in the studio. 

4. Position The Mic Stand Correctly

The position of your microphone stand is also important if you want to prevent sound from bouncing off in the recording. Most experts suggest a 38 percent rule, which means the distance between the mic stand and the front wall should be 38% of the total length of the front wall. Furthermore, the stand should be slightly off-centered, such that the distance from the microphone to both side walls is not equal.

5. Use Cardioid or Hypercardioid Microphones

If you analyze all the acoustic problems of a recording room, you will realize that everything starts with sound waves bouncing off the reflective surfaces and then making it back to the microphone. The easiest way to mitigate it is to get a cardioid or hypercardioid microphone.

If the microphone has a true hypercardioid polar pattern, it will overcome most problems. This is because even if the sound waves are reflecting on different surfaces, they cannot be made back into the microphones. These microphones record only from one direction and block the sound waves from other directions, thereby ensuring clean and clear recording.

That said, it is not a complete solution but that helps tremendously. You will have to follow the other tips too to get professional results.

6. Identify The Problems

Once you have checked the basics run a test using applications like Room EQ Wizard or Rode FuzzMeasure 4. These applications will offer valuable insight into frequency response, which will let you know exactly how the sound is being recorded. To get the best sound quality, the frequency response should be flat and natural. Any peaks are potential problems and should be dealt with.

Furthermore, the applications will also measure standing-wave modes which identify the reinforcement points of certain wavelengths, flutter echoes, and the resonance produced by higher frequencies reflections. The diagnostics will help in identifying the corrective measures you have to take to improve the acoustics.

Fixing The Acoustic Problems With DIY and Professional Solutions

Once you run the diagnostics in the room you will identify problems which will likely include reverberation, sound absorption, or sound insulation. Here’s how to deal with them:

Fixing Reverberation By Improving Sound Absorption

Reverberation is essentially the overlapping of sound waves because of multiple reflections. The phenomenon distorts the sound even more when the gap between the reflected waves is too short and cannot be distinguished. Typically, a room that has fewer sound-absorbing panels will produce higher reverb and it will distort the audio recording.

Furthermore, the small rooms have more tendency to produce reverberation because the sound waves do not have to travel a long distance to strike with the reflective surface. So, fixing the reverbs in a small home studio may be a little more challenging compared to large studios. 

You can fix it by:

• DIY Technique: Heavy curtains, felted seats, and mats are excellent sound absorbers, place them strategically in the room.

• Professional FIx:  Use acoustic panels on all the walls, floor, and ceiling. Bare walls, once covered with these panels will not reflect the sound. It will not only control the reverb but also eliminate black noise and the echoes in the room. 

Managing Low Low-Frequency Sound Waves with Bass Traps

The acoustic panels mentioned above solve a very general problem. However, sometimes you are faced with a very specific problem that requires a specific solution. If you notice an unwanted boost on the lower frequencies, it indicates some surface in the room is reflecting those waves. 

Typically, sounds with low frequencies can only be reflected by large surfaces and corners of the room. So, you will have a fair idea of what exactly needs your attention. You can fix it by:

• DIY Technique: Cut a wooden frame out of 1 “ x 4” and cover its opening with a fabric and place two 2-inch OC 702 panels inside it. The length of the panel should be about 1” x 4” x 8’. Install the fiber class inside the frame and cover it with a breathable fabric. Place the panel in front of the large surfaces and the corners to fix the problem.

• Professional Fix: Use bass traps – the panels designed to dampen low-frequency sound waves to achieve flat frequency response. These panels specialize in absorbing specific frequencies and converting them into heat energy via friction. You can pick from two options including resonant and porous absorber. The only difference between them is resonant absorbers need manual tuning whereas their porous counterparts don’t.  

Dealing Standing Waves With Diffusers

Stationary waves, also known as “Standing Waves”  is a phenomenon produced by interference of sound waves traveling in the opposite direction. It can either reinforce certain frequencies or cancel each other out, either way, they produce an uneven frequency response. The points when two frequencies reinforce each other are called “frequency peaks”, whereas “Nulls” are the points where two frequencies cancel each other out.

You will identify standing waves by looking at audio waveforms and analyzing them for unusual anomalies. The audio waveform will show unidentified peaks and dips, indicating some sort of interference between reflecting sound waves. 

Here’s how to fix them:

• DIY Technique: Change the dimensions of the room by placing solid structures against the walls. Try to make the space asymmetrical because the symmetrical rooms are more prone to experiencing this phenomenon.

• Professional Fix: Employ bass traps or diffusers to increase sound absorption and improve the scattering of the sound waves to prevent standing waves. Bass traps are effective at mitigating low frequencies, whereas diffusers work well to bring down mid and high frequencies.

Conclusion

Dimensions of the room and the placement of equipment and furniture you already own play a key role in improving the acoustics of a room. Most of your problems will be fixed if you get the basics right, and those that still remain can be solved by professional accessories, but if you don’t have the resources, quick DIY solutions can also work.

Frequently Asked Questions