Optimizing Your Listening Position with the 38% Rule for Superior Acoustics

It’s not uncommon to invest thousands of dollars into the audio of your home studio, theater, or entertainment system and find that you still aren’t content. For many people, this can be attributed to the single most overlooked factor in home audio: speaker placement. Getting a feel for the sonic character of your room can be just as important as the quality of your speakers.

Reflections in your room can result in peaks and nulls in the frequency response that triple the linear region of your speakers. In other words, your speakers are important, but if your room is set up wrong, it can mean a whole lot of nothing. There are two main strategies to manage these reflections in your room: positioning and treatment.

When it comes to acoustics, optimizing the listening position in your room is by far the easiest, fastest, and cheapest way to make massive improvements to the balance, accuracy, and tonality of your speakers! It’s the easiest step you can take:to make sure you start on the right foot to make your room sound great - in just a few minutes and with no fancy equipment required, you can find your listening position. It sets you up for success with a solid foundation: If you put your listening position in an unbalanced spot in your room, you’ll never be able to accurately hear your music/sound source and the true capabilities of your speakers and equipment It doesn’t change as you move your speakers or acoustically treat your room:You can find your listening position regardless of whether or not you have any acoustic treatment, you’re changing speakers soon, or you’re adding a sub, etc.

Why it matters:By finding your ideal listening position, you can be confident that you are sitting in the low-end sweet spot of your room. This means you are sitting in the one spot in your room where low frequencies are the most balanced. In a critical listening environment, you want accuracy, balance, impact, and clarity in the low end.

Identifying room modes is key to avoiding mix overcorrections or low-mid buildup during tracking.

Quick Guide to Speaker Placement

For those who are looking for quick and simple steps to set up their room, we’ve included some general practices that can be helpful for your room sound. While every room will have its own challenges, here are some good places to start:

Place your speakers along the shortest wall
Form an equilateral triangle between either speaker and a point ~0.5 meters behind your head
Maintain a minimum distance of 1 meter between you and either speaker
Avoid placing objects between you and either speaker
Position tweeters at ear level and angled slightly towards your ears

The rest of this article will take a more in-depth look into the audio science of speaker positioning.

Finding the Right Listening Position

When setting up your home studio, the first step you should take is finding the right listening position for your space. We can’t tell you exactly what that is, but here are some best practices: Start by facing the shortest wall. Your listening space should be aligned with the length of the room. This will keep you further away from boomy low frequency peaks that gather along the rear wall and in corners.

Your distance from the wall will vary depending on your room size, but a good reference is the 38% rule by acclaimed studio designer Wes Lachot. The 38% rule says that in a rectangular room, on paper, the best listening position is 38% of the way into the room from the shortest wall. Avoid placing your listening position directly in the middle of the room. Odds are you’re working in a rectangular room, which means it has a bass null that collects directly in the middle.

This null occurs both horizontally and vertically, so you’ll also want to avoid having your headspace directly in the vertical center of your room. Wes also advises a minimum of 60cm (about 2 feet) from the back of the speakers to the back wall. Now that you have an idea of where you’ll be sitting, you can start placing your monitors.

Proper speaker placement for optimal acoustics.

A lot of people online say to form an equilateral triangle between the two mains and your headspace. This is a useful starting point, but many users find that angling the speakers slightly out so that the third vertex of the triangle is a foot or so behind the head of the listener will render a better stereo image. Vertically align the tweeters of your monitors approximately at ear level or tilt your monitors so that they are aiming at your ears.

You’ll also want to make sure there aren’t any items obscuring the path between you and either speaker. The spacing of your speakers is different from person to person. If space allows, you should shoot for anywhere between 1.5 and 2.2 meters of distance.

A good way to determine speaker spacing is by playing a reference track you’re familiar with and periodically moving the speakers inwards towards each other. Start the speakers around 2 meters without any toe-in (pan towards the listening position). Dry vocal tracks are good for this because the human voice is instantly recognizable and they tend to be fairly centered. As you inch the speakers inward, take note of the stereo field.

Does the track sound too wide or too narrow? At about 1.5 meters, start gently toeing in the speakers until you feel the track is properly centered. Be careful not to toe-in the speakers too much!

Another factor to consider when positioning your speakers is a phenomenon called the boundary effect. The boundary effect describes when sound signals reflecting off of the wall behind your speakers interfere with the signal coming from your speakers.

Speaker Placement for Home Studio

Boundary Effect Compensation

There are a number of ways to compensate for the boundary effect:

Place your speaker close to the wall, and use acoustic treatment to absorb any frequencies before they can be reflected. While this won’t neutralize low frequencies entirely, it will not hurt and can only help clear up your lower mid-range response.
Place your speakers sufficiently far away from the wall such that reflected frequencies are out of the audible region of your speakers. This method is only recommended for people with sufficiently large rooms. For the Kali Audio LP6, for example, the response goes down to 39Hz, so you could get away with 7ft (2.1 meters) of distance from the rear wall.
Embed your speakers directly into the wall. This is the most expensive option. It is generally only done in professional studios and often requires custom built speakers.
Use EQ to compensate for the boundary effect! If you bought Kali speakers, you’ll notice that we have these EQs built into the speakers and easily accessible from the back.

Horizontal vs Vertical Placement

The type of speaker you choose will determine if you should place your speakers vertically or horizontally. Most speakers are traditional 2-way bookshelf monitors, like the Kali Audio LP-6s and LP-8s. 2-way monitors have a woofer and tweeter that exhibit an interference pattern with each other.

Speaker makers will often include a waveguide that controls the radiation pattern of the tweeter, thus compensating for interference between the two drivers. Most 2-ways are designed to be placed upright. Horizontal placement of these units may result in some unwanted interference, resonance, and can negatively impact your stereo image.

Some speakers, like the Kali Audio IN-8 are designed to function in any position as a point source. These speakers can be placed on their side. Because high frequencies tend to be more directional and low frequencies tend to be more omni-directional, orienting your tweeters on the outside will widen the stereo image and keep the low end more centered.

If You Have a Sub

Some people recommend placing your subwoofer in a corner for increased output. While this will make the sub appear louder by exciting all possible resonant frequencies in the room (also known as room modes), it can result in an uneven frequency response and a “one-note bass”. In a 2.1 setup (2 mains and 1 subwoofer), we suggest starting with your sub centered between the two mains.

If your low end doesn’t sound right in a central channel placement, use the subwoofer crawl method. Place your subwoofer in your listening position, and slowly crawl around the room while the subwoofer plays a track that is familiar to you.

Step-by-Step Guide to Finding Your Listening Position

The 38% rule is more of a guideline - it’s a great starting point but not a hard and fast rule. So, let's jump right into finding your listening position!

Step 3: Post-it Notes or tape Place a Post-It Note or strip of painter’s tape on the floor along the line of your string every 6 inches (15cm). Yes, it is a lot of Post-It Notes, but moving 6” forward or backward can make a massive difference, especially if your room is not acoustically treated.
Step 4: Place a speaker or sub in the front corner of your room Now, you might be thinking, “isn’t that the worst place to put a speaker? Well, usually it is, but our goal here is to excite the room modes as much as possible and to make any imbalances in the room easy to identify. By placing the speaker directly in the corner on the floor, we can amplify the distortions caused by the room modes and ensure we are not hearing dips or peaks caused by speaker boundary interference (SBIR) from the floor, side or front wall.
Step 5: Cue up your three favorite reference tracks or pink noise I like to use a wireless mouse to control my computer or keep my laptop in my lap so I can easily listen to the same parts of the songs from different positions in the room.
Step 6: Take a seat - you’re ready to start listening! Be sure to keep your ears at the same height they’ll be when you are mixing, producing, or listening to music!
Step 7: Hit play and listen critically While playing either songs you’re familiar with or pink noise, sit in a chair (ideally with wheels) and slowly move from the front of the room to the back of the room along the center line you created earlier. As you are moving across your room, pay close attention to how balanced the low end is. Make mental notes of how things change and where you are in the room.
Step 8: Make your marks Mark the most balanced-sounding locations with a piece of tape or by writing an ‘X’ on the Post-It note. The Post-It note method is so powerful because it allows you to quickly compare two or three spots in a very controlled manner.
Step 9: Narrow it down With your options narrowed, go back and listen again, quickly comparing each location - speed is important here as we have terrible auditory memories. As you move through the room on your second, third, and fourth passes, start pulling up the Post-It Notes at the most imbalanced spots in your room. After a few passes, you’ll only have a couple of Post-It Notes left on the floor. Listen again to your last few spots taking your time to really pay attention to the subtleties between them.
Step 10: Finish up and enjoy your listening spot! Using all the marks you made, identify the sweet spot where your low end is the most balanced. Once you’ve identified the location with consistent and balanced bass, not too much or too little sub-energy, and no massive holes, you have found your listening position! Tear up all of the other Post-It Notes and make a note of your listening position unless you want to leave a Post-It Note on your floor forever.

Understanding Room Modes

Let’s take a quick second to discuss room modes. Room modes are resonances at specific frequencies in a room, excited by an acoustic source such as a loudspeaker. These resonant frequencies are usually in the 20 Hz to 200 Hz region. Room modes can cause certain frequencies to be amplified or attenuated in specific areas of the room. This can result in "boominess" at some frequencies and a lack of bass in others. You might have noticed room modes if you’ve ever tried mixing in a small untreated room, and a certain frequency in the low mids is particularly jumping out. You might overcorrect by turning that frequency down in your mix EQ, and go out to your car or listen in your friend’s acoustically treated studio to find your mix sounds thin and weak! Identifying room modes is key to avoiding mix overcorrections or low-mid buildup during tracking.

Room modes can cause certain frequencies to be amplified or attenuated in specific areas of the room.

Keep reading to find out how you can use room modes to help you find the best listening position in your room!

Above are four listening position locations we tested in our demo room, represented by the green, orange, red, and blue points. Here are the frequency response graphs for those same four listening positions, plotted in REW from 20Hz to 700Hz, covering the low to low-mid frequencies. Notice how the green position offers the most balanced response, particularly between 40Hz and 80Hz. For example, if you compare the red and green positions, you'll see an 8dB spike around 72Hz on the red curve. You can also spot a major null on the blue curve around 56Hz.

Do I need to take acoustic room measurements to find my listening position?

The short answer is no. When it comes to finding the low-end sweet spot in your room, your ears are an excellent tool. You’ll be surprised how accurate they are with a simple listening test! Of course, if you want to take room measurements to confirm you’ve found the perfect spot, you absolutely can.

What’s Next?

You’ve just completed the first major step in making your room sound great! Next up comes adding acoustic treatment to your room and placing your speakers so make sure to be on the lookout for our next article covering everything you need to know about speaker placement!