Why does pulling out main speakers from wall improve sound?

That question interests me as well.  I have always assumed that it would add depth to the sound stage. 

To round out room reflections. An alternative is wall absorption treatment. Or live with image confusion.

Obviously "your" dealer is more interested in sales than good sound.

Sound radiates out and around each speaker until it bounces off the nearest hard vertical surface. If you have treated walls, it can be mitigated in the upper octaves. Too close to the front wall, and side walls can cause too much lower octaves.

The room is small, about 13.5x13.9x8.

In my treated room, the speakers are less than a foot from the front wall, and 3 feet from one side, 4 feet from the other side wall.

Because of the treatment, I get a true 3D soundstage if the recording is done well.

About half of my collection is recorded well, or very well.

PS, my speakers are deep, about 18". So the drivers are all about 30" from the front wall.

Simple answer: Because they are designed to work that way. Mostly due to the increased use of subwoofers the speakers no longer need the bass reinforcement of a near wall or near corner set-up. 

The port in the back is for bass. The port should be away, no doubt, so that the bass does not become boomy. I also use a speaker that does not have a pass port in the back. But you have to realize that the speakers do have tweeters and mid-range sounds coming from the drivers. They first hit the side walls and the wall behind you and then reach the front wall - from where they are again reflected back to you. My belief is that the more time it takes for these reflections to bounce off the front wall (wall behind the speakers) and then come to you, gives you more perception of depth. By "treating" the front wall, you are killing off some of them. But you do not want to kill all of them and have a dead sound. Hence some folks have reflectors/diffusers instead of absorbers on the front wall.

This is in layman's terms. Someone more technical might be able to provide a better explanation.

Speaker placement is very critical, and can make a huge difference in your room. Get a roll of tape and start marking the floor. Get a base line for your room size and start. Do you have any room treatment in your room at all. That is a huge rabbit hole to go down. 

It’s all about reflections and cancelations. A pebble dropped in the center of the pool creates a uniform wave pattern. A pebble dropped close to the side creates cancelations and a confused wave pattern. Stand behind your speaker, can you still hear the music?

My issue is the bass sounds so much better when I stand up. I’m pretty sure it’s floor reflection but don’t know how to correct it. My subs are stacked so the top sub center of the driver is about 34" and both are pulled out from the wall about the same 34" to the front of the cabinet. It’s almost 30’ to the back wall so I don't think that's where the issue is.

The qualitied among us can give the technical/physics lesson.

It just does, so DO IT! Most speakers do best when given the breathing room.

There are more minute sounds in music (like reverb trails) that need some space to develop and if you’ve got the speakers too close to the wall they get squashed and you’ll lose that sense of space/depth that those signals help create unless your speakers are specifically designed to be near the wall.  Pulling speakers out can also greatly help with achieving optimal frequency balance.  My speakers are about 6’ out from the wall that for me results in optimal frequency balance along with 3D imaging/soundstage.  The good news about experimenting with speaker placement, unlike most things in audio, is that it’s free!

Almost all speakers emit sound in 360 degrees though the exact ratio of the signal behind the speaker to in front of the speaker varies a great deal from speaker to speaker.

When you move a speaker closer or further away from a boundary (i.e. wall) these things change:

• Ratio of bass to mid and treble
• Time from first arrival signals to reflections from back wall
• Ratio of output of first arrival to reflected signals

So, that’s why. :)

The brain can judge distance from sound specifically its reflections, speakers close to a wall create reflections very close in the time domain to the original sound this means your brain 'knows' this is a small space. Speakers further in the room have a longer delay thus the brain hears a bigger space.

Nearfield Listening. Mine are 9 ft off the back wall. For those who have never played with it, I highly urge you to step outside your box and give it a try.

interesting question. because, with very few exceptions, speakers are designed to be listened to a good ways (1/4-ish a ways) into the room.

very few speakers are meant to be against a wall. boston acoustics floorstanding speakers, like A150, A200, A400, etc are among those designed to be against a wall.

here are some basic rules (there are exceptions) for for speaker placement:

1. your speakers are made to be placed away from the wall and well into the room, about 1/4 into the room away frmo the wall. yep. youre welcome to move em a good distance away from the wall and move em back, u know. its ok. lots of people do this,
2. theyre made to facing the listener
3. with nothing between em. you know all those pics of our gear on furniture sandwiched between two speakers? thats wrong, flat wrong. its as incorrect as pointing the speakers away from the listener is flat wrong or pointing em towards a wall or down at the floor. it makes a great display, but its wrong.
4. some speakers sound and image best with proper toe-in.

because your speakers are designed to be away from the wall and well into the room, pointed towards you with nothing between em or immediately at their sides, they wont function properly if theyre improperly positioned.

here are the ways they wont function properly if improperly positioned:

1. imaging
2. sound stage
3. frequency response

4. dynamics

and plenty of other ways i imagine

Depends on the speaker design. My Apogee full range ribbon speakers are dipole. So sound comes out of the front and back equally. For this reason, they should be between 3-6 feet off the back wall. The entire range of sound sounds better, more air between speakers. Improves in every way including imaging. Bass response also improves.

the other thing you might want to try is angling the speakers at 45 deg instead of having them straight out from the rear wall. I have done that to reduce room reflections and standing waves. Works well in my small room. Moving them out from the rear wall, as others have stated, does improve imaging for sure, and rear wall reflections.

I suggest you find a new dealer.

#physics

It is all about the frequency produced by the driver and how it interacts with the front baffle (the front panel on the speaker).

When the wavelength is equal or less than the cone of the driver, it will beam straight ahead and radiate very little.

As the wavelength increases, it "sticks" to the baffle and disperses in a semi-circular pattern.

When the wavelength becomes equal to the width of the baffle, it begins to diffract around the edge. This diffraction pattern is mostly radiated away from the listener.

As the wavelength increases, it will begin to radiate from the sides producing an odd lobed radiation pattern as is interacts with the front panel radiation.

When the speaker is too close to the wall, the diffraction from the baffle edge is reflected back at the listener and sounds terrible. This can be mitigated to a degree by rounding the corners of the speaker, but it does not cure the problem. Turning the speaker a bit moves the reflection away from the listener and can sometimes greatly improve the sound, but can also increase fatigue if it puts you in a high frequency beam.

Also, when the speaker is too close to the wall, the frequencies being radiated by the side reflects and interacts with the sound radiated from the front and causes combing, which also sounds terrible.

A 6" (15cm) driver will beam at 2200 Hz and above.

If the same driver is positioned in the middle of a 12" (30cm) baffle, it will have edge diffraction at 1100Hz, and will probably start having significant combing at about 800Hz and below.

Rear placement is room dependent.

A room "node" will occur at 1/2 the wavelength between the walls. Picture a guitar string being bent up, it is fixed at both ends, and it will swing up and down when released.

A 12' (3.6m) deep room will experience a "node" at 46Hz, and the room will resonate between the front and back walls at this frequency. Speakers at this frequency radiate in a spherical pattern, and will comb badly when they interact with the room node and it's harmonics which occur at each integer multiple (92Hz, 138Hz, 194Hz, etc). The only cure for this is moving the speaker into the room so it no longer interacts with the node. Room treatment helps, DSP makes a mess of it.

There is no Wrong....you place them where they sound best to you. Watch Michael Fremers first video on you tube. He was asked why his speakers are so close to rear wall....he says because pulling them out into the room is bunk. He claims his mega million speakers sound just fine as is. My speakers front baffles are maybe two feet from the rear wall if you got a tape measure....they sound great. They are also positioned with lots of toe-in, as recommended by Tannoy.

I think to many people get hung up on what they see and do not listen.

My Sonner Legato Unum stand mounts are 3.5 feet off the back wall. And my subs are not stuffed in a corner they are 6 inches behind my speakers. Sound is great.

There is not right or wrong it is what sounds good to YOU!

Suggest you’re dealer purchase Paul McGowan of PS Audio, The Audiophile’s Guide, The Loudspeaker. After he reads it then he should let you borrow. At least he was honest with you I guess. If he’s not up for it then you might want to order for yourself. 

I would think that there are probably some speakers that are more forgiving of placement than other speakers. . . .

The brain can judge distance from sound specifically its reflections, speakers close to a wall create reflections very close in the time domain to the original sound this means your brain ’knows’ this is a small space. Speakers further in the room have a longer delay thus the brain hears a bigger space.

This. It’s all acoustics - treble/staging is very dependent on how pure the initial sound wave is when it hits your ears. Further from the wall, the back reflection is sufficiently delayed that your ears/brain can distinguish. Too close together (too close to wall), you can think it’s just "muddying" the wave.

I believe most know about the lower frequencies being less directional and therefore less depending on room placement (think sub anywhere in the room). For these less directional bass frequencies, room modes are more the driving factor (frequency response, or "boominess" vs "suck outs").

...and maybe look for another dealer (or at least confront the rep [who hopefully isn't the owner])... :-)

Even in a small room, getting those drivers out at least 32 inches from the front walls and side walls will be a dramatic, almost miraculous effect on the stage depth and width. Transients and micro details (trails) are only possible for that realism your ears crave. And yes, best free tween ever. This alone made the HUGEST difference for my system compared to anything else.

Speaker placement varies with every speaker system, there are no standards to really follow. You can check out the Cardas website, you will find their system for speaker placement in a room based on the room dimensions which is a good starting point. You can also try the rule of thirds for placing speakers, a third of the way into the room from the front wall and a third into the room from the side walls. Start their and move incrementally forward and back, side to side until a familiar recording locks in place. You will know when it happens. It might take many tries to find the right spot but you will be happy that you went through the trouble.

@k600r you are absolutely correct, I have 2 sets of speakers, one set has to be up against the wall or no more than 6" out from the wall, and the other set sounds better about 1/3 of the way into the room, both sound best pointed straight forward.

Moving around and forward is not only a good idea, your dealer was polite at best, but part of the experimentation and the experience. Not going into technical details as many have pointed correctly the reasons behind it but try to locate them in the room where they sound more coherent to your ears, with a wide range of musical material. Depending on your speakers and room you may find that it would be an easy job or one demanding a lot of effort. All you have to do is enjoy, listen and be patient.

@jumia  

While most posts answering your question suggest pulling your speakers several feet off the rear wall, Focal, who know something about speakers, do not ascribe to this theory.  Focal uses a flexible equation to find the best speaker placement.

“Optimisation For perfectionists, here is a formula for optimal positioning: If A is the distance from the centre of the woofer to the nearest floor or wall, B is the distance to the next closest floor or wall, and C is the greatest distance (A < B < C), the equation B2 = AC defines the ideal loudspeaker position. • Example: If the centre of the woofer is 20” (50cm) away from the rear wall (A) and 24” (60cm) above the floor (B), then the side wall will be ideally 28” (72cm) away [C = B2 ⁄ A = 28” 

I found this a little confusing at first, but it became clear in short order.  There are three distances involved.  Floor to center of woofer, Side Wall to center of woofer and rear wall to canter of woofer.  The shortest distance is always “A”.  This is usually floor to center which is the only constant.  The next shortest distance is always “B”, and the longest distance is always “C”.  The distance “C” is always (B x B) divided by A. 

By example, if your floor to woofer is 24 inches, and you are 6 feet off the back wall, you would need to be 42 inches off the sides wall.  If you wanted 8 feet center to center on your speakers, your room would need to be 15 feet wide. 

In a nutshell, Focal suggests there is no rule about distance from back wall as long as C = (B x B) / A

Great thread!  Great question. Here’s my simpleton take:

The sound from your speakers bounces all over the place, like light in a mirrored room.  When speakers are near back and/or side walls, the sound off the wall comes back to yours ears so fast that the reflected sound interferes with the sound coming from your speakers. Moving the speakers into the room lets you hear more sound from your speakers, less of the reflected sound from the walls. Moving the speakers into the room can also actually help the reflected sound improve the sound of your speakers. 

Even a couple inches change in speaker placement can have outsized changes in sound quality. Experimenting with placement is a lot of fun…

According to an expert speaker guy, whom I don’t recall his name said 5’-6 is the magic number for speaker setup, the ear can pick up on the timing difference below this distance, so if your ears are 10’ from the speakers and a reflection path distance from a sound wave is 16’ then all is good, however if it’s less, then it will muddy the sound stage, so the if the speakers are 2’ from the back wall, we’ll that’s 4’ timing offset to your ears… so you pull them away 3 or more feet from the back wall to be greater than 5’-6… I think this would apply to the front wall too…

whose right… who knows… always fun to experiment though….

Steve

As I reflect back on all the hours viewing system set ups as lovely as they are with all those expensive components, I dare say most of these pictures have the speakers pretty damn close to the wall.  Dealers Display the speakers pretty damn close to the wall.  Then I began noticing a few set ups where the speakers looked weird being pulled so far from the wall. 
 

My large basement on the habitable side has my speakers right in the middle of the room and they are older and they really fill the room extremely well. I thought it was just the speakers but it was more than that.  In my other rooms and systems it's tougher to get those speakers very far from the walls, but I am rethinking things with a goal of pulling the speakers way the hell away from the walls.  Rectangular rooms are difficult where the long wall is being used for the system.  Points of egress and windows and doors make it difficult to use the Wall on the short side of the room for the system, very sad.

@aewarren ,

“I suggest you find a new dealer”

agreed. 

It is generally suggested that the front of the loudspeaker be placed 3ft (approx 90cm) from the front wall as a starting point.

The midrange is approx between 3khz and 90-100hz

The wavelength of a 200hz frequency is approx 171.6 cm. The half wave would be 85.8cm (approx 34.2 inches).

The wave is spherical in nature, so half the wave wraps around behind the loudspeaker and the other half wave is in front of the loudspeaker.

The lower frequencies of the midrange lie between 400hz and 90-100hz. 

As the loudspeaker is moved nearer to the front wall (2ft) the lower end frequencies get reflected off the front wall - as a result these lower frequencies reinforce the lower frequencies of the front half of the soundwave and we begin to hear muddiness in the midrange.

a simple test would be to - with your back to the front wall start speaking with a consistent loudness - now slowly walk away from the front wall until your voice sounds more natural  (ie: without the reinforcement of the lower midrange frequencies). This too would be a good starting point for the placement of the loudspeaker.

I hope this helps.

Reduces early reflections which are death for soundstage, imaging and detail.  Also proximity to walls boosts bass levels above that intended in many cases. 

SBIR - Speaker boundary interference response.

As noted, perhaps not fully correct, but as the frequency drops for a dynamic speaker, the radiation become omni-directional. The wave reflecting off the front wall is reflected, with not a lot of attenuation, and then cancels the front wave of the speaker. The critical distance is 1/2 wavelength as that will be completely out of phase.

Ideally you want to be far enough from the front wall that the round trip distance is > 1/2 the wavelength of a fairly low frequency. Put another way, the distance is > 1/4 the longest wavelength. 3.5ft, and you just created a suck-out at 80Hz. Even at 5 feet, you are still hurting important bass frequencies, and this is not stuff easily corrected if at all with DSP.

Counter-intuitive, but the solution is to put the speakers closer to the front wall, and then treat the walls with absorption. Not those those trinkets I see in audiophile pictures that cover a small portion of the wall. You need to cover a good portion of the space behind the speaker, and the absorption need to work at a low enough frequency to prevent the SBIR cancellation. You will get boundary reinforcement by being close to the front wall, but this can be corrected with DSP.

Great discussion. Much good info. Varies much between speakers but the answers that addressed “baffle step” ring with me (see what I wrote there). As a Wharfedale Linton Heritage speaker owner, I’m a fan of the current wave of throwback big boxes…with the right distance from the back wall and a little toe-in they seem like best of both worlds between crisp imaging and rich tone.

It also lowers the noise floor. Like each and every time your audiophile friends come over to listen to music and say: "Hey, you really ought to move those speakers out away from the wall".

🤣🤣🤣

@danager :  My issue is the bass sounds so much better when I stand up. 

I had that experience before too.  What I found is that my speakers were too far from the front wall.  It took me a couple of days of effort positioning the speakers in 1/2" increments to finally get them dialed in.  That includes the distance from the side walls too.  The crazy thing is, once I got them dialed in, the bass was nearly uniform all around the room- not just in the listening chair.  A good CD for evaluating the bass is Stanley Clarke's East River Drive.  The first track has a double tap of the bass drum.  When I got everything right that drum sounded good, not muddied to almost inaudible- except when standing up.

+1 @tonywinga 

You are balancing boundary reinforcement (getting close to the walls), with SBIR (cancellation from front wall reflection), and room modes. @bigtwin , Focal appears to be attempting to at least balance some of that in their formula, but as you noted, it may result in unrealistic values for many listeners.

@sc2, it is a little more complicated than what you have indicated. The distance they gave you appears to be to be outside the 10msec critical early reflection time. That may add a low frequency bass suck out (~50Hz). For many, even with a dedicated listening room, that may be too far into the room.  That gets us back to the speakers being closer to the front wall, the front wall heavily treated for reflections, and using equalization to address boundary reinforcement. 

Thespeakerdude

Very interesting comments dude, I like the idea about putting a absorption panel immediately behind the main speaker even if you pull it out a bit.  Maybe this will reduce the muddiness because all those waves bouncing off the wall may be a bad thing.

I have a down firing speaker so the absorption panel would need to rest on the floor

Audiospyder,

I like the idea about walking from the wall and listening to your voice. A very effective tool to learn from. 

So have you ever had trouble coming up with something to say while sitting across from your date.

Great news! read up on the posts herein and you're all set.

@jumia the floor is only a concern for boundary reinforcement. That can be fixed if needed by equalization (DSP). The front wall reflection comes back towards the listener (not the ceiling). It is critical.  The muddiness is usually a large suckout and some reinforcement around the wavelength = 4x distance to wall. Early reflections is there two but that's imaging not muddy. Muddy could be too much boundary reinforcement emphasizing bass too much.

In my opinion HENRY53 is offering the best and simplest answer and I am hesitant to try to expound.  God gave us TWO ears on the side of our head and a brain that can detect minute differences in the timing of sound.  A voice arrives a millisecond earlier to one ear and our brain can instantly locate the voice in the dark.  Some sounds reflect or bounce of surfaces and others are more likely to get absorbed and diminish. Moving the speakers off the reflective surface of the back wall and side walls allows for better timing of the sound arriving to our ears.  There are a ton of other considerations such as low frequencies attenuating in corners or even canceling out.  That's why i agree when people advise to experiment with location and angles.  

Any sound hits the human ears from reflective surfaces, front or side wall, that is not delayed by 5 millisecond will be perceived as the direct sound. That reflected sound will be convoluted with the direct sound coming out from the speaker and compromises the sound image (and possibly other traits of sound), again, if not delayed by 5 millisecond. The speed of sound is about 343 m/s at nominal temperature of 20°C in dry air. So the sound travel distance in 5 millisecond is 343x0.005/0.3048 = 5.63 ft. Half of this distance, from tweeter to the front/side wall, is 2.8 ft just under 3 ft. So, maintaining a minimum distance of 3 ft is the rationale. I won’t say to give improved sound by pulling your speakers out for that minimum distance, rather to maintain the clean, unpolluted sound. I hope this traditional wisdom from many other experts help answer your question.

Speaker Placement: How far from the wall should I place my speakers? - (gikacoustics.com)

Good video @yyzsantabarbara , it's my post from above but in easier to understand video form. They don't address how boundary reinforcement though and how to deal with it.

Some Great Explanations Here…

or your Dealer is either “pulling-your-leg”

…perhaps didn’t understand your question…

failed at a bad joke…or is on “the” CracK.