Working together

May 15, 2021
 by Paul McGowan

I am pretty certain few rooms support perfect bass. It’s not that rooms are particularly biased against low frequencies, the problem is those pesky long wavelengths.

Consider that a 20Hz wave is 51 feet in length. A 30Hz note is 38 feet long and even a 60Hz note is just under 10 feet in length.

These long wavelengths mean they don’t fit into most rooms, so, with nowhere to go they bunch up like the bellows of an accordion. This squeezing of sound creates hot spots and dead spots within the room.

What to do?

The easiest is to find where in the room you can sit that has the smoothest response for the greatest number of frequencies. That, coupled with moving your speakers without mucking everything else up (like imaging and tonal balance), is the best way to make the most out of a tough situation.

Indeed, there are other means like adding digital correction and, if your bass is generated out of a subwoofer or separate woofer enclosure that can both be moved as well as digitally manipulated, then that’s a positive step forward.

What I don’t advise is to digitally manipulate anything other than bass frequencies—something requiring a separation of the woofer from the rest of the speaker.

As I cover in The Audiophile’s Guide, finding the best spot in the room for bass is a bit of a compromise, but it’s better to work together with the problems than wage war upon them.

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22 comments on “Working together”

  1. Ok, so, my room is 18′ x 13′ x 8.5′; ie. 54.5Hz x 75Hz x 120Hz; however there is a long 27′ hallway running off/from one corner of my listening room & a 4′ x 5′ x 8.5′ vestibule with 3 doors that open up into 3 separate bedrooms on the opposite wall, which increases said listening room’s ability to go lower without presenting any huge bass-loading problems…lucky me 🙂

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  2. My room is a little shorter than FR’s in the long length but a little longer in the short length. It is dedicated to being audio. So room treatments and decor are no concern (as long as there is a way to shut the door to the outside, the WAF remains very high)

    Having fought the room for a long time, I found that removing a corner closet door made a huge difference. If you’re a ‘closet’ bass only junkie not a bad place to listen. 😀

    That closet is now lined with hickory shelves (self milled) cd’s- records – equipment, cables & etc. added some paint first and some LED lighting. Enough blue or red glow to see when the main room is darkened. White when I need to find stuff. 🙂

    My speakers were never touted as full range from the initial reviews. So I added subwoofers, Isolation stands and spiked maple plinths. They all made a huge difference in the room bass coupling and overall tonal balance. Even the height of the subs off the floor made a difference. And finally using a 2 way electronic crossover to keep the low freqs out of the mains gave that extra ‘tonal and image cleaning’ for the final compromise.

    It took years of compromise to find acceptable, and then another few years of fine tuning treatments to reach the final acceptance of compromise. I’d almost hate to start the process over… but have the lessons of some experience now …

  3. My room is close to square ( 30′ x 28′ x 11′ ) but has some “interesting” features that mostly reduce reflections. My speakers ( Magico S7’s ) are full range speakers. The diagonals of the room are 40′ ( 30 Hz ) and since the house has a very open floor plan there are large openings on both sides of the rear wall that lead in and out of the room. I often notice as I walk in and out of the room there is a noticeable boast the bass when the right music is playing. The important thing is I have never tried to ( nor do I plan to ) do anything about the bass response. It is just the way the room plays. 🙂

  4. I used the Audiophile Guide Reference Disk and was happy that my room performed uniformly through the audible bass frequency range except for an isolated small mid-bass frequency bump (one note of the bass guitar) that I hear with the Reference Disk but have not noticed during routine play. I could not eliminate that one bump by adjusting speaker, listening position. It may just be some distortion that my ears are responding to. I don’t notice it when playing ordinary music. Reasons the bass is so uniform is that the room is large (similar to tonyplachy’s except less square and the ceilings are cathedral) and open to other areas of the house on two sides, allowing those long bass wavelengths to develop, and my loudspeakers are placed along the long wall so they are far away from the corners of the room. If I had a dedicated listening room in my house, it would not be nearly as large as my living room, so there are certain advantages of using the living room for my audio systems.

    1. I don’t mean to suggest that a large room is superior to a smaller room that is acoustically treated or just happens to work well by luck. The same speakers I now have in the big room have sounded superb in smaller rooms, so for those with smaller rooms, don’t be discouraged by us posters who brag about our big rooms. Big rooms have their challenges too; for example, you need more powerful bass drivers to achieve the same SPL, and uncontrolled reflections can add unwanted reverb as well as nodes. For those experiencing “big room envy,” get your minds out of the gutter and work with what you have 🙂

      1. Joseph,
        I can be ‘Gutter Rat’ when circumstances call for it.
        It’s not the size of the room; it’s the magic in the reflections.
        (It’s ok to have a big room, but more importantly you’ve gotta
        know how to use it…or so I’ve been told) 😉

    2. Beware the double bass- at least that what it sounds like. Have a sub set up & main speakers spec rated down to around 18hz – but prob with -3 db drop off – and no problem with lower notes but there are 2 notes on the disc “Bass” track that “boomed”. I fiddled with the crossover freq on the sub but no difference – then noticed on my old Pioneer SA508 meters that the boom wasn’t in my room – it’s on the recording! The levels jump when the notes are played – because of the natural resonances of the instrument I presume ? :
      No problem with Eminem massive saturated bass & Level 42 etc at all frequencies so maybe it would have been better to use an electric bass for the test disc?
      PS that’s not to say the other tracks aren’t really useful – especially the sample tracks like “Unsatisfied” etc – even my disinterested better half said “Beautiful” when I invited her to listen to the track & set up after re positioning the speakers!

      1. Just checking again – yep there they are – same two / three notes resonating via laptop / Beyer 990 pro headphones – so no room acoustics (my end) involved there…. nothing’s perfect….

  5. 23x26x8-9.5 with a bar in the middle(kitchen/living). As I’ve been learning all this stuff the last two years,I experiment a lot . I have hid some chucks of insulation. Walking around you can find hotspots of different frequencies. But if i play test tones and walk around, you can visualize a grid system of standing waves and for the upper frequencies too. (It may be better not to do the test tone experiment)Interesting. But probably what I’m stuck with. Most “listening” is near field. I have to move my speakers everyday. No biggy, i know where to put them. Ill still get Paul’s book/disc because I’m retired and like messing around with the free stuff.

  6. Paul, if it’s correct , that the IRSV has a (variable) crossover frequency around 70Hz, then this would be too high to move the towers where bass sounds best and also too high to move the towers far from the main panels at all without loosing coherence between both. How is an optimization with those speakers done if the crossover frequency is not low enough to be free in subwoofer positioning?

    For sure, optimizing position of a one box speaker with integrated sub in a room is as problematic, because as you mentioned, one has to sacrifice a bit of tonality and soundstaging wins to optimize the lowest frequencies then. Not optimal either. Wouldn’t the essence of your article be to offer a speaker with separate sub crossing over low enough for flexible positioning?

      1. Yes, so I guess integration is even better then, but for optimal sub bass you have to be lucky as you probably won’t move panels and pillars where sub bass is best 😉

  7. Paul are these long wave length low frequency problems made worse with the use of dual or stereo subs? I read somewhere that a second sub smooths out the response.

    Theres a subwoofer EQ by Velodyne on the market that has a microphone and spectrum analyzer to adjust the low end to the room.

    You can fix room problems by positioning the microphone at the sweet spot but the problem will still exist at other room positions.

    Velodyne solved that problem with an optional add on device that allows the use of 6 microphones placed around the room to average out the low end so its even tbroughout the room. They called it their room averaging accessory.

    You might lose some accuracy at the sweet spot while averaging the bass throughout the room so using their presets feature works out nicely.

    You can apply room averaging when there are many people in the room and easily switch back to single mic setting when there’s just one listener sitting at the sweet spot.

    Or keep it on 6 mic room averaging mode if you like to bounce around from the sweet spot to the couch.

    I do own this EQ but not with the optional additional 6 microphone component. They don’t make the model anymore, its only available on the used market.

  8. Well, well, well! Funny how sometimes Paul really tells it like it is!
    I did find that taming the room made some beneficial difference to the sound of bass. Still, dips and peaks are somewhat problematic. Not wide enough to be “heard” but REW worked wonders to help with the situation.

    None other than Floyd Toole states the same thing. If you have to play with frequencies, only do it with low ones.

    Modern designed speakers come with their own DSPs and microphones to help you tame these low frequencies. This is why it is so disappointing that Paul decided to go the old fashioned way. Very hard to get SOTA performance with passive designs.

    I think my wife is right. She tells me to sell all my “vintage” stereo equipment before the audiophiles die of old age. Younger ones tend not to subscribe to all this nonsense.

    1. CtA,
      I’m pretty sure that if Chris Brunhaver believed that going active with DSP is the better way to go in loudspeaker design that that would be the direction that PS Audio would be going.
      Why don’t you put your money where your mouth is & design & produce a loudspeaker that will trump the PS Audio FR30’s.
      I believe that you haven’t a clue what SOTA is in audio;
      you just regurgitate other people’s theories.
      I for one do not subscribe to your nonsense.

      1. Actually, going DSP and active would have always been a no-no for Paul. DSP and powered speakers requires digitizing the signal. There are nor DSPs or crossovers using DSD. They are only PCM based.

        It would have been an absolute contradiction fro Paul to record and support DSD but produce speakers that then digitize to PCM to reproduce.

        Paul has many contradictions, but it would have ben extremely hard for him to support this.

        Mr. Fat Rat, I don’t care about your opinions. They are never based on anything except “memories”. Memories are faulty. You only know brand names.

        1. CtA,
          And you don’t know home audio & therefore your regurgitated theories do not interest me.
          Anyone in audio knows brand names & I know a lot more, but due to your arrogant outlook you’ll never know…enjoy your ignorant bliss 🙂

  9. Surprised no one mentioned bass traps. Essential to getting those pesky modes under control. Room treatments also improve (reduce) the “overhang” or reverberation of these frequencies so the music isn’t as smeared due to overlap of one note that should finish and other starting. You will need a very understanding housemate/wife/etc. as most room treatments are not beautiful in the traditional sense.

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