REGISTER NEW USERLOST PASSWORD? WELCOME, Logout

Large volumes of air

Paul's Posts — 25 June 2012

By

Large volumes of air

In yesterday’s post I talked about dynamics and how many smaller speakers simply cannot reproduce those dynamics accurately.  One of my readers pointed out something obvious – the amount of air a big speaker can move relative to a smaller one.

Big line sources have a lot of drivers and surface area and can move lots of air – just like the real deal.  The opposite can be true for smaller speakers and that’s part of the reason they don’t sound quite as effortless when reproducing a big orchestral passage.

Imagine the amount of air a full 100 piece symphony orchestra can move when they get loud.  Now imagine trying to reproduce that same air movement, scaled to fit your room, with a pair of bookshelf loudspeakers.  Ain’t gonna happen.

You’ll get closer with a lot of drivers capable of moving lots of air.

email Large volumes of air Forward to a friend and help us engage more readers

Get new and fresh stories like this each morning by joining the folks reading Paul's Posts. Click here

Related Articles

Rolling it off What’s all the fuss about? Young turks Get that mole!

Share

About Author

Paul McGowan

Paul McGowan is the CEO and co-founder of PS Audio Inc. a Boulder Colorado design and manufacturing company of high-end audio products and services. McGowan has been designing and building high-end products for nearly 40 years. Hobbies include skiing, music, hiking, artisan bread baking, kick boxing and cooking. He lives in Boulder Colorado with his wife Terri and his 4 sons.

(9) Readers Comments

  1. Gannon

    June 25, 2012 at 6:18 am

    I figure it is all about proportion.

    While I’ve enjoyed the line-source demonstrations at trade shows…those speakers always seem to integrate into nearly any room easier than those approximating a point-source…they always seem impractical for actual use.

    I’m a huge fan of the imaging created by mini-monitors, and tend to use seven identical ones with two or four subwoofers in systems I design/specify and install. Five, at minimum, since I insist on surround sound playback capability. It can be amazing how Jim Fosgate’s Pro Logic II algorithm can parse room ambience out of a good symphonic recording, putting the room feel exactly in the surround channels as experienced in real life.

    But I cannot ever use merely one subwoofer in a room…heck, Todd Welte at Harman (under the tutelage of Dr. Floyd Toole, using Harman’s excellent research facilities) proved multiples were necessary for proper pressurization of the volume of the space. Especially for those rooms where more than one seat will be used.

    The physics of the energy required for proportionate reproduction of the entire range of perceivable frequencies is pretty secure…lower wavelengths require much more energy, and it ony makes sense that many woofers…placed properly in the room…are needed to deliver ‘em well.

    Cheers!
    John
    Detroit

  2. Tom

    June 25, 2012 at 7:02 am

    “Imagine the amount of air a full 100 piece symphony orchestra can move when they get loud.”

    I wonder how much air does get moved? And how far does it get moved?

    That air motion is compression and rarefaction, back and forth motions of molecules at tremendously varying rates. How many of those molecules move very far at all? We sure don’t feel a breeze in a symphony hall (unless it’s from the air conditioning system).

    When it comes to volumes of air moving around, I have to wonder if my little desk fan might not push more over a greater distance than a large orchestra does.

    • June 25, 2012 at 7:56 am

      You certainly feel it and hear it – I do when I am in front of a symphony orchestra – certainly the frequency of the air movement isn’t as slow as your fan so you don’t feel it like that – but think of how loud that orchestra gets and that’s all air movement.

  3. Gannon

    June 25, 2012 at 7:09 am

    OK, but how much air does it WIGGLE?! LOL…

  4. hahax

    June 25, 2012 at 11:44 am

    In the words of a good friend – a GOOD big one will beat a good little one every time. And I agree.

  5. Bassman23

    June 25, 2012 at 1:37 pm

    Some may not understand the conceptual difference between SPL and air movement. A loudspeaker “loads” the surrounding air by varying the air pressure, not by moving the same molecule of air across the room. One might imagine the difference between voltage and amperage, if one wants to think of voltage as the “load” and amperage as the “flow”.
    It takes more piston area to “load” the much larger wavelength of a bass note into a room than is required for the shorter wavelengths of treble notes. Bill Dudleston had a great white paper on this years ago.

  6. MountainSufi

    June 25, 2012 at 11:10 pm

    Howdy from Jackson Hole!

    In a small orchestra hall, such as ours at Teton Village, I SWEAR I’ve felt the air move when the full orchestra hits an enormous beat from silence. Four sets of big drums and 100+ musicians blasting it out at once turns it up to 11 on the Spinal Tap meter.

    Paul, I’re know you’re not a fan of horn speakers, but they can move a lot of air. Instantly, compared to a big array of speakers. It’s one of those things that is obvious but easy to miss.

    Avantegarde speakers are notoriously hard to position. When done right, they are pinpoint sharp, 3D audio (your term). 100% clarity that will break your heart and “something” that the large multiple speakers you’re talking about can’t help but blur.

    I again invite you to visit my dealer: http://www.6moons.com/industryfeatures/jackson/jackson.html
    Getting here from CO, will necessitate going thru Yellowstone & Grand Teton Parks as a business expense; you have to suffer getting here. You’ll find no horn-ey, shoutey sound. Pin point, with the width and depth of a football field.

    You’re close by, give it a go.

    Happy Trails!

    • June 26, 2012 at 6:30 am

      Boy, I’d love to go! Looks like real torture getting there through all that pretty country. I am not a fan of horns and don’t think I’d ever own a pair – but there are certain qualities I admire in them and that’s for sure.

Leave a Reply