Room calculator

August 5, 2018
 by Paul McGowan

Our rooms are as important as our equipment yet only a scarce few of us have the luxury of choosing our room dimensions. Typically we take what we can get within our home and make the best out of it.

With our new building in process, we're heavy into the architectural tasks of designing three new music rooms from scratch, a rare treat afforded only a very few audiophiles.

Our years of experience and research have been boiled down to a few simple formulae for calculating the ideal room size and we thought it might be a valuable service to our community to make that knowledge freely available. Over time we will also publish the architectural drawings for our rooms so any curious or prospective builders can copy them.

One of our programmers, Kevin Briggs, built a really cool automated room calculator we just launched on our website. If you go here you can see it in action. In the future, it'll remain available under the web site's Resource Tab.

On that same page is a great explanation of how room dimensions are calculated and why they matter. Take a moment to visit this free tool and you'll get a quick education in the art of maximizing sound quality.


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26 comments on “Room calculator”

  1. There is a small bug in the calculator. When you change to metric units the value next to the ceiling height sliding scale remains in feet. It doesn't affect the calculated values, which are all correctly shown in meters.
    My listening room happens to be a layout 3, and by some miracle my actual room dimensions exactly match the calculated values!

    1. Thanks brodricj,
      I originally coded it this way intentionally for the sake of simplicity, but we have changed it based on your feedback. The height value now converts when the units change. There are still some caveats to the conversion, but hopefully you find this easier to use overall.

  2. This is a great tool. However, as stated, it’s useful to only “scarce few” who are building a listening room. I find the Cardas room setup website more useful, as it also helps with speaker setup. It’s a more comprehensive approach, without the room dimension calculator. The same ratios are there, but you have to do the math yourself.

    The speaker placement calculator helps you position your speakers, given the room dimensions that you have. The calculator also accounts for placement of monopole and dipole speakers.

  3. I wish room acoustics would be addressed for the common folk who are making a hi-end system work in double-duty living space. Which in today's modern floor plans, equates to a living space that bleeds into the kitchen short, you're dealing with 3 walls. Why isn't DSP more talked about in these challenging situations? I've heard some expensive systems use DSP corrections made before the preamp and the improvement is so obvious. Systems that were set up properly with a mic and multiple sound profiles. It seems to me that any alteration to the signal is considered taboo in the audiophile community but I argue that it's a practical solution to a sometimes unfixable problem. If our ears are telling us what we need to physically adjust in the room to correct the sound to our taste, why is a lesser solution to run it through a mic, compared to a target profile, and have the signal going forward adjusted before received by the preamp? Isn't that the beauty of digital?

    1. I have the same issue as do you with a big open room to the kitchen. On top of that, an angled set of walls with windows at the end where the stereo would be, and, a side wall that is mostly windows. Oops, I forgot to mention the coffered ceiling! I have come to the point where I would much rather listen to my music imperfectly set up and reproduced in a space like this where I can interface with friends and family than in a perfectly set up space buried in a basement or secluded area of the home! I have stopped worrying about the particulars and I just listen 🙂

  4. Thanks Reed for the link.
    Nice if you can apply these rules.
    But my room isn't rectangular, nor square.
    In fact it's 2 "squares" , glued together (with bricks and mortar, don't worry), but (as you understand) not in a rectangular shape.
    In other words, it's not SYMMETRICAL.
    Yes, I know it's stupid the builders didn't take my audio setup into consideration when the house was built in the 1930's.
    But I don't think I'm the only one with this "problem".
    And what's even a bigger problem, if I follow these rules I would end up with the speakers approx. 6 or 7 ft. from the rear wall (the wall behind the speakers).
    Not desirable in my room, unless I wanna use one of the speakers as a table as well.
    And so far I never met anyone (audiophile or not) who had placed the speakers 7 ft. from the rear wall.
    So these rules are all well and good if you have the luxury of a dedicated listening room, but in real life for most of us it's not so simple.
    But I do my best to come as close as possible.

    1. I'm close, mine are 6 feet...and that's from the front wall (by convention the front wall is the wall behind your main speakers). However they are sealed enclosures so they could go closer to the front wall if I wanted to.

      1. With 6 feet you are the proverbial exception.
        " convention the front wall is the wall behind your main speakers''.
        Maybe where you live (USA ?), but not in the rest of the world.
        No such "convention".
        For me, AS IN MANY REVIEWS (e.g. English !), the REAR wall is the wall BEHIND the speakers.

        1. The rear wall convention in the US is my front wall down has been mentioned many times before, things are universally backwards in northern hemispherical speak.

          1. You may like it or not, many reviewers and other people call it the rear wall, no matter what hemisphere they live (for God's sake, what has the hemisphere got to do with it...?!).
            Sounds logical, since it is the rear wall of the speakers.
            If you're not ok with that and think it's of the utmost importance to get back your peace of mind, then I advise you to write a letter to every magazine and urge them to stop with this.
            End of discussion.

            1. My front wall is the front wall whether speakers are in the room or not. Putting speakers in a room shouldn't turn a front wall into a rear wall. My rear surround speakers hang on the rear wall, and my front speakers are in proximity to the wall opposite that. I'm happy to concede we know which wall is which, whatever it's called, and whatever hemisphere you happen to live in.

        2. My speakers are also 6ft out into my room off my FRONT WALL, as recommended and placed by the designer. Not saying that works for everyone obviously, so do what works best in your situation.

  5. Do you want to listen to your music room - as concert goers listen to the concert hall - or do you want to listen to the music recorded and mixed? I guess Paul is going to voice his new beasts to normal listening rooms without sacrificing too much of the beast’s performance under anechoic conditions?

  6. I'm not sure how good this tool is for application to the science of acoustics. The ancient Greeks had nothing to measure with, knew only what they learned from trial and error. The modern science of acoustics was only invented in 1895. Fibonacci numbers have been found to be virtually useless in predicting the stock market but people still use them. It's kind of like alchemy. I don't think designers of concert halls use this golden ratio number method. So the whole problem strikes me as a lot more complex.

    In designing spaces for listening to recordings, all of the effort has been thrown at the room to adapt it to the electronics. No engineering effort seems to have been applied to adapting the electronics to the room. In rare instances where it has been tried, the results have been ineffective. Despite centuries of trying, alchemists found no way to turn lead or anything else into gold. I think that's where this problem is stuck.

  7. As a former corporate nomad, I got to experience a good number of rooms before I retired - none of which were designed as a listening room (sigh). My current setup is in a room that started out as borderline horrible, but was made tolerable by acoustic treatment. In the "real world" at least some acoustic treatment is essential IMHO.

    The very best purpose-built listening rooms I've had the privilege of experiencing were designed as a trapezoid, with slightly angled walls and sloping ceilings, and with judicious use of diffraction and absorption devices. If starting from scratch, why design something with parallel walls, even if using ideal overall dimensions?

    1. The geometric implantation of my dedicated sound room 1, consists of 2 trapezoids joined by its larger base plus a sloping roof of solid wood with an average height of 4.5 m. with a total of 280 cubic meters.

      The acoustic treatment follows the guidelines of Alton Everest in his book The Master Handbook of Acoustics, and I have not had to spend a fortune to get a sound environment that is not very dead but is not very alive either.

      To build a sound room from scratch with surfaces parallel to each other, seems to me very unreasonable.

      1. Amen! Congrats on that room. Everest's book has been on my buy list. I need to get off my butt and buy it.

        Although - I recall Paul mentioning somewhere that the objective for at least one of the rooms was to duplicate or mimic what the typical consumer would experience in their homes. In that regard a "normal" box room makes some sense, but it would still require some fine-tuning with acoustical treatment.

        But for the BIG room they are building for the AN1's , they should go all out. If they are going to manufacture SOTA speakers that only a few can afford, the room should be as good as it possibly can be.

        I had the opportunity to hear the setup Boulder Amplifier has in their current facility. They actually built the foundation for the listening room separately and then constructed the plant around it. The room is totally isolated (and trapezoidal in shape). Stuffed with probably $500k in gear and speakers. Needless to say, it sounded pretty darn good 🙂

        1. Well, the Vienna Musikverein has the shape of a shoebox and without contemporary acoustic treatment, and has one of the best acoustics among the concert halls, I think the ornamentations function as diffusers and the absorption is done by the public.

          The Boulder amplifiers are the subject of my unrealized dreams, because I being totally in favor of the balanced system from the source to the input of the speakers, I had to settle for balanced amplifiers of lower price, but that's life, you have to conform and enjoy what you have.

          I congratulate you for having been in the Boulder amps listening room since I believe that together with FM Acoustics they are among the best in the world. Both are TRUE balanced from the input to the output.

          1. Vienna Musikverein is rated by Beranek as the number one concert hall in the world. It is closely followed by Boston Symphony Hall. The opinions are far from unanimous however. Von Karajan preferred Boston because its slightly shorter RT 1.8 seconds at 1 khz as opposed to Muskiverein's 2.0 meant he could conduct slightly faster.

  8. The topic of room acoustics is GROSSLY underrepresented in the audiophile media and is equally as important as speakers! You can achieve equal levels of improvement by optimizing your listening room as optimizing your speakers (as Paul certainly knows).

    In the commercial sound engineering work we have done, this has proven to be so true. Recent experience working outdoor vs indoor music venues back-to-back has really demonstrated how much an effect on sound reproduction a room has. Perhaps audiophiles have the short stick re: room acoustics re: its focus in the main stream audiophile media - at least that's our opinion.

    Paul, perhaps a separate topic in the PS Audio forums may be of benefit to the fine friends of PS Audio?

  9. The text on the Room Calculator page, near the bottom, says "...rooms with curved walls or walls that meet at angles other than 90°."
    Lose the right angles and flat walls and you will avoid a lot of frustration, plus save yourself a lot of money trying to solve room problems by buying new equipment. This reminds me of one of my famous sayings: You can't pound nails with a table saw.

  10. There is always the problems of unrealized expectations. Last time there were high expectations that a Helmholtz resonator would cure an expected resonance at 27 hz. It didn't work very well at all.

  11. Paul and rest,

    Is it just me, or is that formula flawed? Shouldn't depth be same as length, thereby being the longest dimension? And your given formula doesn't seem to be what the calculator is using....please enlighten me!

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