Home studio : Introduction

Home studio : Position d'écoute

Home studio : Placement des enceintes

Home studio : Utilisation d'un traitement acoustique

Speaker Placement – Distance from the Wall

You can't hear enough bass from your speakers? The distance between the wall and the speaker has a huge impact on low frequencies!

At low frequencies, speakers are practically omnidirectional, meaning sound waves are also propagated backward, towards the wall in front of the listening position. When that sound wave hits the wall, it reflects and then interferes with the sound waves coming directly from the speaker.

This effect is called Speaker-Boundary Interference Response (SBIR). SBIR causes deep, problematic drops in bass responses below a certain frequency and can affect your low-frequency response even more than room modes. Because this effect cannot be corrected by software, you must use two reliable means: correct placement of the speakers and the use of acoustic treatment.

The Science: Wave Cancellation

The second major problem we observe is when placing the speaker at one-quarter of the wavelength for a certain frequency. In this scenario, the direct and reflected sound waves meet 180 degrees "out of phase," causing phase interference where the waves cancel each other out.

These cancellation points are called nodes. They occur at 1/4, 3/4, 5/4, etc., of the wavelength from the boundary.

• Example: For a 60 Hz sound wave, if you place the speaker on a node (1/4 wavelength from the wall), it will cause a zero or significant decrease in frequency response at 60 Hz.

• Conversely, placing the speaker at a point 1/2 wavelength from the wall (an antinode) will cause the two waves to meet and increase the frequency response at that frequency.

How Far From the Wall Should I Place the Speakers?

In general, we distinguish between three reliable placement options:

1. Flush Mounting (Absolute Win)

The only way to truly eliminate the SBIR effect by one hundred percent is to embed the speakers into a hard, solid wall. Since the speakers form the surface of the wall, sound waves do not have the ability to bounce off the front wall.

This placement is used in the world's most expensive and best studios. However, it's expensive and rarely done in home conditions. If you decide on this method, always consult the manufacturer first, as not all speakers are suitable for wall mounting.

2. Speakers as Close to the Front Wall as Possible (Second Best Choice)

Even without mounting them in the wall, placing the speakers as close to the front wall as possible is your second-best choice for nearfield speakers, which are common in home studios.

By placing them very close, the problem area (1/4 wavelength distance) is shifted to higher frequencies, which are easier to handle with acoustic treatment.

• In general, a gap of 0-20 cm between the speakers and the front wall is a good starting point for minimizing SBIR.

• Acoustic Treatment: At very close distances, acoustic absorbers with a thickness of 10 cm behind the speakers can do a great job. As the distance of the speaker from the wall increases, absorption is less effective.

• Always check the speaker specifications for the recommended minimum distance (e.g., for cooling).

3. Speakers Far Enough from the Front Wall

This option is demanding in terms of space, making it suitable mainly for large rooms. The speakers must be spaced far enough away from the front wall so that the lowest disturbed frequency is outside the frequency range reproduced by your speakers.

The easiest way to calculate this minimum required distance is using this formula:

Distance min (m) = (1,4 * 343) / (4 * f-3dB)

Où f-3dB est la fréquence de coupure basse de votre haut-parleur. Par exemple, si vos haut-parleurs ont une limite de -3dB à 55 Hz, la distance minimale par rapport au mur est de 2,18 mètres. Consultez le manuel de vos enceintes pour connaître cette valeur.

Simple Summary for Home Studios

In general, you want to avoid the critical SBIR effect for low frequencies between 40-200 Hz. For a typical home studio setup, this usually means the following speaker positions:

• Idéal : Encastré dans le mur ou le plus près possible du mur (voir les recommandations du fabricant)

• Bon : jusqu'à 1 m du mur

• Éviter : 1-2,2 m du mur

• Bon : à partir de 2,2 m du mur