Why sound comes from behind the speakers

June 15, 2021
 by Paul McGowan

18 comments on “Why sound comes from behind the speakers”

  1. My impression is that the microphone analogy here is absolutely wrong. Or are there stereo microphones with a 3m distance between the two capsules? Puristic stereo requires crosstalk cancellation in order to avoid most strange and unrealistic sound effects. Even my two (!) channel tv creates strange sound effects when a sound seems to come from from behind the listening/viewing seat in my living room having no acoustic room treatment – generally high frequency sounds.

    1. paulsquirrel,
      There has been a theory postulated about erecting a wall right down the middle (between the 2 loudspeakers) to prevent crosstalk & comb filtering, however I’ve never been able to listen to
      that sort of home-audio set-up & it has never become mainstream; so I doubt that it works
      as well in practice as it is supposed to work in theory.

      1. Theories should be validated by experimental setups. The proof is in eating the pudding! Thus I installed a mattress reaching from my nose to the speaker plane for checking the theory’s predictions. Bingo, it worked. Then I installed a freeware for getting the same results from my computer. It worked too! And not only for me but also for all my audiophile buddies. And I am pretty sure that it will also work down under. Why hasn’t it become mainstream? Because it enhances the poor sound quality of poor recordings and mixes. I also assume that only a minority of music lovers focuses on holographic imaging, details and resolution. And home theater aficionados rather like deepest bass and spectacular artificial sound effects (!). I recommend to attend a demo of BACCH 2 SP from Prof Edgar Choueiri in order to get an idea what is possible today with 2-channel audio.

      2. Interesting, no one seems to care much about cross talk and filter combing when engineers hang 50 microphones over a symphony orchestra!

        Engineers seem to love having the more is better approach while sitting in front of their analog or ditigal mixing consoles, then, dicking around with effects to enhance the fine NATURAL accoustics of some concert halls.

        I see this all the time, especially with the worlds two top symphony orchestras. What ever happened to recording music in TRUE STEREO ???

        Always a continuing and ongoing pet peave of mine (O: You’ve seen my posts from time to time here.

        1. I’ve not tried to record a symphony orchestra, so that’s a bit beyond my experience. However, I have many times provided live sound for choirs with about 20 singers. I can’t provide every singer with an individual microphone. We definitely do have to consider crosstalk and comb filtering in a set up with (say) 20 singers and six microphones.

  2. Attention: John Price
    Until PS Audio reinstates ‘reply notifications’ this is really the only way to get a message or reply through to other contributors.
    Just wondering if you watched the review of the S.M.S.L. – ‘DA-9’ D class integrated amplifier that I posted for you a couple of days ago?
    It does not make any sense to me why you would even think of comparing a $699 ‘Made in China’, entry-level, PS Audio – ‘Sprout’ integrated amplifier with a $3,385 ‘Made in the UK’ LINN Majik DSM network music player; it is an unrealistic, & frankly pointless, comparison John.
    Who compares a VW V6 Golf with an Audi R8??
    The S.M.S.L. – ‘DA-9’ at $250 beats the pants off the $699 PS Audio – ‘Sprout’ as far as price goes, & it is just as easy to hook up to a source & a pair of loudspeakers as said ‘Sprout’.
    AND, by all accounts, it sounds fantastic according to all of the reviews about it.
    Then you go on to mention the ‘first ever made D class amplifier’ at $6,999…again wa-a-a-ay above the Sprout’s purchase price.
    ‘Puzzling Post’s’ by John Price 😉

    1. Hey Fat Rat!
      If you read my post carefully, you’ll see what I said about needing to setup an online account on the manufacturer’s website, and then login to it.
      And the fact that you need a professional installer to install the unit for you, is a put off to me.
      The 6K USD is what you’re gonna pay for all of that.
      So, ya, spending $699.00 for one of Paul’s Sprouts, makes perfick sense when you think about the financial aspect of the whole thing.
      With the pandemic still going on, money anymore these days, is still tite.
      And here in America, there are still quite a lot of people out of work.
      Sure the government mite have relaxed some restrictions, but we still have a problem with it.
      So you see, you have to go for the best bargains, when you find them.
      And as for the Sprout being made in China, that’s not exactly true.
      I have spoken to Scott over the phone.
      He was the one that designed the Sprout.
      And it was done in house, of PS Audio.
      You don’t believe me, you can email Scott at PS Audio yourself and ask him.

      1. John Price,
        Paul McGowan, Scott’s father & the CEO of PS Audio,
        has confirmed that the ‘Sprout’ is manufactured in China.
        You have completely ignored my argument, that a reasonable
        mind does not compare a $699 entry level product with one of
        much higher quality, build & features worth nearly 5 times as much.

        Have you watched the S.M.S.L. – ‘DA-9’ review yet, as you said that you would do?

        I stand by my June 15, 5:05pm post to you.

        1. Are you an idiot?
          Or, are you just plane nuts?
          I did not ignore anything you said.
          And yes, I did watch the video you posted.
          But here are two things wrong with that amp.
          #1. Noone down here as far as dealers go, can get their hands on it, in Florida.
          #2. it falls 10watts short with speakers that are 4ohms.
          And another problem that I could add.
          #3. No USB connectivity for hooking it up to a computer.
          These are the feachors I’m looking for in a small integrated amp.
          And FYI, I emailed and asked Paul about the Sprout this morning.
          I’m just waiting to hear back from him.
          But I am willing to bet, he’ll tell me something way different then what you’re telling me.
          If he doesn’t but he tells you what you’ve already told me, then I’ll listen to you.
          But on the other hand, if he tells me that I’m right, then I will tell you to your face to shut up.
          I like to keep my facts strate.
          I don’t have time for smart mouth bullies’ like you!

          1. John Price,
            I’d say that only an idiot would compare a $700 unit with a $3,385 one.
            I sorry that you feel bullied, but the problem is definitely with you as Paul has confirmed with me that the ‘Sprout’ is Made in China.
            Many of your posts are incorrect in their information; this is not the first time that you have done this,
            You are definitely the one who is ‘plain nuts’

          2. Answer: “The Sprout100 was designed in the USA and every unit is hand inspected in our US factory. The units themselves are built in China.”

  3. Nothing wrong with simplistic Paul, it works well for most people.
    Quit while your listeners are ahead 😉
    (All good up to the 3 minute mark)

  4. There is a great CD from Stereophile that can also help with this, STPH-005-2 CONCERT WITH ROBERT SILVERMAN. It is a nice recording and much info in the booklet. Track 10 is Mapping The Soundstage and JA1 walks around the room and the stage to have you hear what that microphone set up can do and if you can locate him in the space as he walks and talks.

    I have found that if the venue has little ambient noise I like omni mics that have a great sense of space and capture the natural reverb tails of the room…like our ears. Uni-directional mics are less so in that they pick up almost nothing from the rear of the mic and a little from the sides as their pattern is cardioid. Using these you are more concerned about leakage from performer on the sides. Then is it up to the engineer to “position” the players in the recording where he wants them. He can pan them left and right, anywhere from 9 O’clock to 3 O’clock (L and R) and louder would seem closer to the front, and more faint would seem further back.

    If you are doing an ensemble of 10 or more and you have a large, quiet room, and your mics have less that 17 db of self noise, you can get a great recording with spaced omni’s. It is all a matter of what the artist and the engineer agree upon.

    There is another choice with a Decca-Tree arrangement using Omni mics. The ensemble would be in an arc like you would see a symphony, you would have a pair left and right spaced 6 feet apart, and a center mic in the middle 3 feet in front of the line of the side pair. You have to try and see what works given the situation.

    In this regard some even like a pair of mics on the outside of the ensemble, left and right. You many also have to consider if you have some instruments that do not play as loud and you may have to use cardioids on them to bring them into the mix. Tubular bells or a triangle would be an example. This is why we get there early and take a while to set up and find out what works, and hope that someone is there that can control the HVAC system and shut the blowers off when recording. You want to be able to savor the quiet passages of the performance.

    Just my 2 cents.

    1. Aaah, the Decca Tree………usually hung right over the top of the maestro and string sections. Basically, you are forced to hear what the music director hears, NOT the audience so much. Also, NOT true stereo.

      Omini’s also do not image well in a stereo array, but what they really do, is create a large enveloping sound without much directivity from the source. My pair are used for organ and choral music in large church spaces for example.

      However, I admit, I ‘cheat’ a bit when I use a Mid Side setup, BUT, it is single point and has proven to work well pulled some 25′ back from the front of the concert stage and 15′ up to catch the natural ‘layering’ of the musician/sections as the composer intended. I get the accoustics of the venue and a bit more ability to locate those musicians on stage.

      ORTF has really been very nice in my experience for live orchestral performances as well, and NO DARN OUTRIGGERS!, talking TRUE stereo here ((O:

      Just my thoughts.

  5. I don’t buy this behind the speakers sound as being accurate. If the sound stage is somewhere between the back and front of the speakers it’s still in front of me and my listening position. It doesn’t all have to be behind the speakers or equal to the front of the speakers to be accurate. Either way can be accurate and three dimensional. If some people get their jollies because the entire soundstage is behind the speakers that doesn’t mean that’s the only way the soundstage is accurate. What’s most important is tonal balance, transparency and detail within that soundstage, The recording places the soundstage where it should be, not the room or speakers. I have heard sounds coming from behind, equal to, and to the forward sides and even to the sides of my listening chair and behind me depending on the recording. The job of the speakers are not to alter the soundstage in anyway forward or behind, it’s only job is to accurately reproduce what’s on the recording. And if everything you listen to is well behind or equal to the front of the speakers that is not the way every recording is recorded.

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