The Cardas Room Setup Guide: FAQ: Room Design

A collection of questions we've received over the years about room design

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Acoustic Wall Paper

Q.) On your Listening Room Design page you mention 'acoustic wall paper: "I make a very special, hi-density, "acoustic wall paper". It is only 3/8" of an inch thick. It starts absorbing at about 300 cycles and eliminates all slap and reflection between the walls it is applied to."

Is that something you sell? If not, how is it made? Can regular wallpaper be applied to it? I'm trying to dampen a room in a way that my wife, who is concerned about the decor, would not object to. Regards, Max

A.) Hi Max. The product I was referring to is a very hi density urethane foam, but it would have a low "wife acceptance" factor (dark gray and cannot be painted). I am developing another product that is similar, but is a semi rigid, paintable foam, with a very high wife acceptance factor. - George

Golden Trapagon Room

Q.) Hi George. Just had a small question regarding the Golden trapagon room. What are the distances (from rear wall, side wall, etc. ) for speaker placement in such a room - Ashish

A.) It would depend on the size of the room, but in general they would be placed on the narrow end of the room at the room width divided by 18 x 2 and room width divided by 8 from the rear wall and each other. (rw/18) x 5 = speaker to side wall. (rw/18) x 8 = speaker to rear wall and speaker to speaker. All measurements are to center of woofer- George

Golden Ratio

Q.) I looked at your room set up diagrams and did not understand what value the 1 and the 1.618 represent. Could you please explain.

A.) The ratio of 1 to 1.618 is called Golden Ratio. It represents the least divisible of ratios. It is sort of halfway between all the multiples. It can also be derived from something called a Fibonacci sequence: 1 1 2 3 5 8 13 21 34 55 89 144... each successive number being the sum of the previous 2 and closer to Golden Proportion.

The reason we use this ratio is it does not produce beats. In the case of wall reflections, the speaker's frequency of interaction is proportionate to its distance to the walls, so in doing this we graduate the bass resonant frequencies so they cancel rather than beat or double. A good audible way to hear this is in tuning a guitar to a major chord. As the last string is pulled in to tune, the beats between the note will disappear. Beats are particularly noxious in audio because they are an additive quality that is easily heard by the ear. It is thought one reason the Greeks used Golden Ratio in there temples is the sound of these structures. Dig around on our web site, there are many examples of the use of this proportion. - George

Speaker Placement

Q.) You recommend to place speakers RW x 0.447 from the rear wall and it means the speakers are almost in the middle of the room. I have a reservation from the stand point of appearance. My speakers are 52 inches from the rear wall now and I am willing to pull it more. Does this gives me any benefit? Conventional wisdom says the closer to the wall, the more bass sound and vise versa. My speaker is B&W S800 which does not reproduce low end too easily, so it is my concern that pulling the speakers farther away from the wall may make the sound thinner. - Massi

A.)This would be ideal setup in a dedicated room but obviously there are other considerations. The quantity of the base is normally of far less concern than the quality of the bass. This setup will yield excellent musical bass without accentuated notes common in most setups (such as the rule of thirds). Alternate setups that are quite effective can be found on our site under "Insights/Room Set Up". - George

Golden Trapagon Size

Q.) George - Your website "insights" says, "For example, if the wall behind the speakers is 10 feet x 16 feet, the room would then be 26 feet long and the wall behind the listener would be 13 feet x 21 feet. Ideally, the rear portion of this room would vent into an attic space filled with fiberglass insulation." Could the wall behind the speakers be 8 H x 13 W and behind the listener 10 H x 16 W? - Patrick

A.) Yes, a 10 x 16, 13 x 21 room would be a scaled up version of a room 8 x 13 at one end and 10 x 16 at the other. You can make golden trapagons in any size you want. The idea is, the wall behind the speakers is a golden rectangle and the rear wall is a larger golden rectangle, 1.618 x the front wall's area. So, the rear wall's heigth and width dimensions will be 1.272 (square root of phi) x those of the front wall.

The length could, in fact, progress from either end using a fibonacci sequence. So, if the room was 8 x13 on one end and 10 x 16 at the other, the length could be either 21 or 26 feet (8+13=21 10+16=26) - George

Q.) As to the "rear portion venting into the attic", does that mean leaving a part of the ceiling open to the rafters, or do you mean some other way of venting? Thanks. - Patrick

A.) Exactly, you put fiberglass insulation in the attic to absorb the sound wave. This also equalizes the pressure on the opposite side of the ceiling so it does not "drum". The opening is usually covered with cloth so that it does not show. The idea is to have some absorption at all frequencies in the room. The vent is basicaly a hole that absorbs all frequencies. Typically you can cut the bottom bump in a room by 6db using this technique. - George

Dipole Speaker Placement

Q.) I tried to place the speakers in my living room according to your idea of using Golden Ratio. The measurements were made on the basis of your article in one of the online, high-end zines. I do not remember exactly in which one, but can find out if necessary. The distance from the front side of the speakers' woofers to the rear wall was calculated from the room height, divided by a certain ratio (which gave me a result of approx. 190 cm, - by memory, I'm writing to you not from home) and the distance from the woofer centers to the side walls was calculated from the rear wall lenght divided by another ratio, resulted in 175 cm). After I moved the speakers accordingly, I was simply amazed by the results! I never heard anything comparable from my sound system before. Honestly, the placement of my rather big loudspeakers (ribbon Apogees which weight and height are comparable to my beloved wife's) in our multifunctional guest room according to your idea was not very practical. My wife and I agreed to rearrange some settings and disturb some convenience, only to keep the placement under the golden ratio.

Recently I revisited your website, and after checking the article on loudspeaker placement, I found the actual placement, referring to the side walls, must be the same, but the distance to the rear wall should be much larger. In my case 281 against 190! In this case it was calculated not from the room height, but from the rear wall lenght. Well, it brought me into the some confusion. Further moving ahead of the loudspeakers will kill other use of the room besides purely listening purposes. I just do not know, whether initial placement according to your advise is good enough. I will be grateful if you will find a free minute to instruct humble music lover from Odessa, Ukraine. My room measurements are RW lenght - 630, SW lenght - 590, room height 320.

A.) The original formula uses .618 x the ceiling height for the rear wall placement and is ideal for dipole speakers such as Apogees and Magnepans because they cancel their side wave. However, the common box speaker radiates low frequencies in all directions, thus the formula that places the speaker to rear wall at 1.618 the side wall distance. Stick with the original formula, it suites your speaker well. - George

Square Room Venting

Q.) Hello, First of all I'd like to say thanks for all of the great information provided at your site regarding speaker placement and listening room dimensions, I've found it very interesting and useful.

I'm one of the unfortunates that has a room measuring 8' H x 14' 7" x 15'. My speakers are set up on the long wall.  Should I consider this room "square"?  If so, the statement at the bottom of Diagram G, Speaker Placement in Square Listening Rooms: "Golden Rectangles, 1.618 (side wall) x 1 (rear wall) on one side and 1 (side wall) x 1.618 (rear wall) create diagonal lines for speaker placement in a square room."  leads me to think that the Golden Rectangle may be rotated ninety degrees and used similarly to the way shown in Diagram "F"- Horizontal and Square Listening Rooms. Am I interpreting this correctly?

1.) Not being certain if the dimensions in my room are close enough to being square, which diagram should I use?

2.) Am I correct in thinking that I can place my speakers anywhere along the line created by bisecting the corners of the golden rectangle?

3.) Would the Nearfield Listening Position in Diagram B be an improvement over the the other diagram(s) that would be applicable to my room?

Thanks in advance for your time, I really appreciate it! - Best regards, Dave

A.) Hi Dave - Yeah, that is square room! You seem to understand the suggestions, except that "Near Field" refers to a listening position that has the listeners head the same distance from the speakers as the speakers are from each other. This is probably going to be the best place to listen in this room, no mater how the speakers are arraigned. I believe that you will find that softening the walls and the room in general will make the biggest improvement.  Carpet with thick foam padding or batting on the walls covered by cloth, or anything else you can come up with along those lines, will make the room much more pleasant. Let me know what works best for you. I am always interested in the solutions that people find for Square rooms. - Cheers, George

Q.) Thanks George!  I'm going to try your ideas with the room treatments and set up for the near field position, this room is driving me nuts! - The best, Dave

A.) Do you own the house?  If so I have an idea that might work. - George

Q.) Hi, yes, I'm the owner.  I do have plans to knock out a wall and extend the room another 5 feet, making it 15' x 19', but who knows when this will happen!  I'd love to hear your idea. - Dave

A.) Ok here is a semi radical idea, but cheap and easy. If there is an attic, you can vent the room into it through a couple feet of fiberglass insulation. Use the pink stuff with no backing. A square room peaks all its nodes in the center of the room. An opening 4’ x 8’ (one sheet of dry wall) in the center of the ceiling will do fine. You can cover the hole with linen cloth. This will dramatically reduce the 50~/100~ cycle bump.

Felt works good for wall covering or linen over foam or cotton batting. If you have a source for pretty cloth, it works great and gives you tremendous latitude for tuning the room while still maintaining a pleasing aesthetic. - George

Q.) I just love radical ideas!  Ok, let me be sure and understand your idea. I will cut out a section 4' x 8' out of the sheetrock in the ceiling, leaving joists intact, stuff  a couple feet of fiberglass up in to the space, then make it pretty at the ceiling by covering with  (probably in a frame) some linen cloth, or maybe burlap. I understand that burlap has good a good way of not reflecting sound. Do I have it right?

Thanks so much!  My wife has pretty much figured me to be crazy already, so this won't surprise her at all. - Dave

A.) Yup that’s it. Maybe a little chicken wire or something to keep the fiberglass under control and yes, burlap is fine, if you can find big enough rolls. My current room has cotton batting on walls double or triple at corners, edges and reflection points.  The surface of the room is a blue linen I purchased at a yardage store. It is sewn together and stapled at the edges to hold it on the walls. It's rather extreme, but it looks great and it is the best sounding room ever.  The unachievable goal of a perfect listening room has a little  absorption at every frequency, evenly distributed (a little more at reflection points).  This is easily achieved at mid and high frequencies, but the low frequencies require more industrial strength tricks. In  the case of your square room, the hole in the middle seems ideal. If not, you get a little extra insulation and it only cost a little more than a sheet of dry wall to put it back.  Let me know how it works out. - Cheers, George

Long Wall Speaker Placement

Q.) I enjoyed reading the article on room setup posted on your site. I have recently moved my system from a 18x30 room into a room that is 12'9"x20'. I am not getting all the soundstage and detail I previously had (I have moved, not just my gear, so there's no going back.) I would like to try putting the speakers on the long wall. Are there any guidelines or recommendations for doing that? Any info is greatly appreciated. (Gear is Madrigal Mark Levinson and the speakers are about $8-9K and not sold in this country. Cables are Neutral Reference.)

A.) I have added a couple pages dealing with long wall and square rooms. Have a look at Diagrams F and G, under "Insights/Room Set Up".

Basically form a golden ratio between the side wall and the rear wall, (behind speaker). This will give a placement that nulls the two major interaction nodes. Either diagram will apply in a long wall setup. Because of the variables and the wall behind the listener - in a long wall setup it is difficult to make a formula that covers all the combinations. - George

Long Wall Placement Formula

Q.) I wish to try my Maggie 1.6QRs along the "long" wall in my listening room. The long wall is 250" in length (20'10"). The short (side) wall is 170" in length (14'2"). If I follow your placement protocol, the center of the 1.6 woofer panel would be 69" from the side walls (250" x .276) = 5'9", which means the woofer centers would be 112" (9'4") apart.

However, if I follow the protocol vis-à-vis the back wall, the center of the woofers would be 250" x .447 = 111.75" = 112" (9'4") from the back/long wall. But the room is only 170" (14'2") deep along the side/short wall. Thus the Maggies would be in my lap. This cannot be, can it?

A.) The room setup formula is optimized for lengthwise setup in a rectangular cuboid and often cannot be applied with the speakers firing across a room or in a cube shaped room. However, most aspects of the formula can be realized if the two major periodic interfaces of the speakers are graduated in a ratio of 1.618 to 1. In other words, pick a speaker to side wall or speaker to rear wall position and multiply by either 1.618 or .618 to determine the other measurement. - George

Where To Sit

Q.) I have my bookshelf speakers set up with the Golden Ratio. I was wondering if there's a particular place I should sit. I currently sit pretty close to the wall that the speakers face.

A.) You can sit any where you want as far as the formula concerned. If you are concerned about stereo balance you must be more or less equidistant from both speakers. If you want the exact, three dimensional mix (most mixing is done from what is called the Nearfield Position) to hear the exact perspective that things are recorded in, you must be one corner of an equilateral triangle with the speakers being the other two. - George

Placing Maggies

Q.) Hello George, I want to experiment a bit with your  Golden Rule method of getting rid of dips and resonances in my current setup, but I am a bit confused about the results I get following those rules. So could you please help me calculate the position for my Magnepan dipoles MG 1.6 QR?

My room is 5.07 meters wide, 4.85 m deep and has a 2.56 m ceiling height. According to  your  method, for a horizontal room, where the speakers are set up across the wide wall, it says: multiply the distance from the back wall by 1.618, then you get the optimum distance of the speakers from the side wall. - Joerg

A.) This is not a multiple!   Figure f indicates placing the speaker center on a diagonal line that extends from the corner. Any point on this line is  in a ratio of 1 to 1.618 in distance from, respectively, the back wall and the side wall. - George

Q.) So far, so good. For dipole speakers, there seems to be another rule: ceiling height multiplied by 0.618 results in the optimum distance of the speaker to the back wall. This calculation seems to be important for optimum bass response and clarity. - Joerg

A.) This  is an alternative placement  for dipoles . Because the dipole cancels a portion of its side wave, the side wall is, at times, less significant than the ceiling reflection (in a low aspect ratio room, for instance).   You would not  necessarily use this method  and if you did, it would preclude any other method. - George

Q.) In my case, the above would mean the following: Multiply ceiling height 2.56 m by 0.618 = 1.58 m distance of the Magnepans to the rear wall. According to the other, the "Horizontal" rule, you multiply those 1.58 m by 1.618 (which results in 2.55 m) to get the distance of the speaker to the side wall. But 2.55 m distance means, for a 5.07m wide room, the speakers meet in the center!

Even if I take this measure only as a reference point and draw a line to the back corners and move the speakers along this line, even if I only allow a distance between the speakers of 2 meters, then the distance to the back wall would be only 0.8 meters. This is not a good setting for the Maggies, I guess, it's too close to the back wall. So, basically I am stuck, unless I got something major wrong here.

Let me add one final remark. I dug into this matter, since with my current setup, that I found acoustically by moving the speakers around until I found the best imaging possible. The center of the Maggies is 1.58m from the back wall and 1.45 from the side wall, slightly toed in. Funny, huh, a  Cardas  value by coincidence. - Joerg

A.) This is exactly how I got there in the first place!. It is more that a coincidence! Leave them there. The dip around 120 is the round trip time to the back wall. The wall reflection is a given of sorts . You can move it around, but not eliminate it by moving the speakers.  You can trap the wave with a set of padded book shelves or other devices. - George

Q.) I do get a big dip in the important range between 100 and 140 Hz; up to 20 dB, measured! I hoped, that with the Cardas  Method, I could avoid dips and resonances, as best as possible, and get a better bass response. At the moment, as I said, I am stuck, because calculations seem to guide me to some strange results. Your help in this is greatly appreciated. Kind regards from Germany - Joerg

A.) I am surprised that it is that deep!! 20 db is a lot.  Amazing!  I believe that  you are  in a 1/3 - 2/3 relationship front to rear. This doubles the dip. Sigh! Again, this is an artifact of a squarish room or a short front to rear aspect ratio. - George


Q.) Dear George, I'm very impressed with your Fibonacci /Golden Ratio approach in room design and speaker placement. I would appreciate it if you would inform me more on "Far-Field" speaker placement in relation to the Fibonacci/Golden Ratio. Thanks and regards, Frederick

A.) The results are very impressive. You can tell when you have them in the right spot by listening from the next room.  The progression simply scales the interaction of wall reflections so that they cancel. This is audible from any position. The "Nearfield" Listing Position is just the standard location for stereo mixing/listening. Cheers, George

Dipoles and Subwoofers

Q.) George, I used the dipole set up for my Bohlender-Graebener 520dx ribbon speakers and it worked out great. Now I'm trying to install a single, 12" downfiring subwoofer into the equation. Do you have any tips for subwoofer placement? Kind regards, Alan

A.) Hi Alan, With dipoles, I like in the center, positioned equally between the speakers. This avoids modulation of the dipoles. George

Nearfield Listening Position

Q.) Good morning, I'm Italian, sorry for mine bad English. In the "Room Set Up" section on your website, where is the point of where I listen? Thank you. Best regards. Roberto

A.) The traditional listening position is called the Nearfield Listening Position. It is where your head is at one point of an equilateral triangle and the speakers are the other two points. It can be heard quit distinctly if you play pink or white noise through your system and move your head in the general area of the nearfield point. Thanks, George

Q.) Good morning. Thanks for your help. I tried this configuration in my listening room yesterday and it has increased the quality of sound and the bass is more correct. In this configuration, however, the triangle seems too small. My room is 3.4m wide and 5.3m long and I have a triangle with a side of 1.52m. Can I increase the size of the triangle without changing the quality?

Another question. The tringle is equilateral. Should the speakers be angled toward me at thirty degrees? Best regards, Roberto

A.) Hi Roberto, the position of the speakers in the room determines everything.  You will hear the best sound where you are at. The Nearfield triangle is determined, in turn, by the position of the speakers. The speakers usually work best ninety degrees to the side wall. Some speakers like to be toed in about 5 degrees, rarely more. You can experiment by ear .

If  you draw a line from the current position of the speaker (center of the woofer), to the corner behind the speaker,  you can place the speakers on this line, closer to the corner and thus widen the base of the triangle. Depending on the speaker, you might go a foot or so before you get any noticeable degradation. George

Maggie Placement Solved

Q.) Dear Mr. Cardas, I wanted to pass on my experience using your Golden Ratio system for listening room set-up. I had been struggling for quite some time, to find a good set-up for my MG 2.5 R's. I'm unfortunate to have a sonically bright, square room (5.6 x 5.7 x 3m). While I was searching for room treatment suggestions, I followed a link to your web site and read your solutions for dipole speaker placement and dealing with a square room.

I did the necessary calculations to find the initial rear wall speaker distance, (for a dipole), then used simple algebra to calulate the ratio distances for "5" and "13". I then measured and marked the lower left and right hand corners of the inner and outer Golden Rectangles for each corner and penciled a diagonal line on the floor connecting these points.

From my previous 2.5R placement expereince, I knew a speaker separation of around 2.5m gave a nice wide sound stage. I then moved the speakers along the marked diagonals until I had the desired seperation distance, and did the equilateral triangle for listening position.

At this point, the speakers were still in a parallel position to the rear wall. I sat down for a listen, and was truely amazed at what I was hearing. No longer were the maggies "barking" at me, I had a mid-range I forgot existed, and I had a wonderful sound stage. After a few tracks, I toed them in 1.25cm and I had bass response, and very detailed, well focused imaging.

I want to thank you for providing such simple and elegant solution! Best regards, Brian

A.) Brian, the Maggies are great speakers and I know you will enjoy them. Cheers, George

No Room For Screen

Q.) Hi, I am trying to find a good location for my front, Magenpan 1.6 speakers. I utilized your Speaker Placement Calculator and the results were to place them 3 feet from the side walls and 6 feet from the rear wall. The problem is, I have a screen in-between the speakers requiring them to be placed closer to the walls and further back. What would be a reasonable compromise for locating the speaker placement. The room is 11 ft. 2 in. x 17 ft., with a 10 ft. ceiling. Thanks, Darin

A.) Darin, With dipoles the sidewave is canceled, so simply use the Dipole Speaker Calculator and spread them equally to towards the walls from the calculated point. Thanks, George

The Room Is A Component

Q.) Dear Mr Cardas, I am an audio enthusiast and I am currently using Cardas interconnects and speaker cable in my system. I experienced a marked improvement in sound quality when I switched from Monster to Cardas cables.

I however realized that most people overlook the physical room as one of the most important components of an audio system. I cannot see the point of investing in expensive high-end equipment without having a decent listening room. I am finally in a position to build a listening room from scratch and I require advice about the ideal dimensions for such a room. The architect has drawn plans and the current size of the room is 7m long by 5m wide by 3m High. How can I accurately calculate the relationships between these dimensions for optimal sound quality? Regards, André

A.) André, The ideal for a rectangular cuboid is to progress the dimensions by a ratio ot 1.618 to 1. Take the largest dimension and multiply by .618, which in your case would result in 7m x 4.3m x 2.7m. A great room can be created by adding a slight taper to the walls, see "The Golden Trapagon" in our "Insights/Room Setup" section.

Volume or Position

Q.) Hi, I have been using the rules on your site to set up my speakers. Unfortunately my room does not have parallel walls and one speaker always sounds louder than the other. Is it OK to use the volume controls on the power amp to center the image or should I move the speakers asymmetrically. Thanks Chris

A.) Hi Chris, Keep them symmetrical adjust the volume. Many systems can benefit from a bit of balance adjustment. Cheers, George

Squarish Room

Q.) Hello George, I just want to say that your cables are fabulous. They helped "neutralize" my strident-sounding system. I run Krells with Tannoys. My listening room has modest proportions. It's 12' x 11'. Kinda squarish I know. I positioned the speakers according to your mathematical equation and unsurprisingly, the speakers are in-my face now. I must admit though, the transparency and soundstage deepened like I've never heard before.

That said, my question is, have I compromised bass-depth and soundstage for transparency by having them positioned like this? Thank you for your time, Felix

 A.) Thanks Felix, glad you are enjoying the cables.

As to speaker position, I believe the deep base should not be compromised in quality and there should be less of a bass bump. Squarish rooms will have some compromises though. Usually softening the walls at the reflection points and behind your head will help transparency. Killing any slap or echo is the next step. Cheers, George