Contact Us / Log in or Sign up / Call us today! 520–392–9486, 8am – 6pm

QDA Series

Showing all 5 results

  • image of a QDA 11 Sound Diffuser Absorber
    image of a QDA 11 Sound Diffuser Absorber

    The QDA – 11 is two units within one. First, a quadratic diffuser based upon prime number 11 with a diffusion frequency response from 385 Hz. – 3,450 Hz. Behind the prime 11 quadratic diffuser is our activated carbon broadband low frequency broadband absorber from 30 Hz. – 400 Hz. Broadband lower frequency absorption is required in all small rooms. The absorption performance is the same as our ACDA-10 unit. At the base of the QDA-11 is our more frequency specific carbon absorber from 30 Hz. – 50 Hz. This base absorber is designed after our ACDA-12 unit and offers large amounts of absorption from 30 – 50 Hz. which is the frequency range of unwanted pressure issues in the majority of today’s smaller rooms. The QDA measures 24″ w x 60″ h x 9″ deep and weighs 225 lbs.

    – ACDA-10 Riverbank Test Result

    – ACDA-12 Riverbank Test Result

    Diffusion and lower frequency absorption goes hand in hand with the front and rear wall locations. The front wall is an area of high unwanted low frequency pressure and the rear wall follows the same pattern. Low frequency energy builds up at the boundary surfaces of  front and rear wall locations. You need both a frequency specific and a broadband absorption approach to deal with the magnitude of these low frequency pressure issues.

    The QDA-11 was designed for those who do not have the physical space requirements to accommodate deeper units but still want the advantages of broadband and frequency specific absorption along with the diffusion benefits offered by quadratic diffusion.

    If you order the QDA today you will also get

    • A free one 30 minute phone or video consultation on your room mode issues with me, the products inventor, Dennis Foley
    • A 100% risk free 30 day money back guarantee
  • image of a QDA 13 Quadratic Diffuser Absorber from Acoustic Fields
    image of a QDA 13 Quadratic Diffuser Absorber from Acoustic Fields

    The QDA – 13 are two units within one. First, a quadratic diffuser based upon prime number 13 with a diffusion frequency response starting at 285 Hz. and going through 3,450 Hz. Behind the prime 13 quadratic diffuser is our activated carbon broadband low frequency absorber from 30 Hz. – 400 Hz. At the base of the QDA-13 is our more frequency specific carbon absorber from 30 Hz. – 50 Hz. The QDA measures 27″ w x 60″ h x 16″ deep and weighs 275 lbs.

    ACDA-10 Riverbank Test Result

    ACDA-12 Riverbank Test Result

    The Quadratic Diffusion in the QDA takes your sound and spreads it out across your room in the way nature intended you to hear it without your room getting in the way. Your room prevents this naturally occurring sound-field from happening because it has 4 walls, a floor, and a ceiling. Diffusion minimizes the reflections that want to destroy your precious direct sound from your speakers. Whilst reflections from room surfaces help you localize and define sound and distance, these reflections must be managed through diffusion so that the reflections do not get in the way of the sound coming from your speakers. This is why your ears are longer than they are wide.

    With the QDA you will finally get to experience the involvement that your expensive speakers are producing but which your room is stopping you from hearing. Through no fault of your own you have become so used to, and accepting, of poor diffusion in your room that your ears and eyes will open wide when you hear Quadratic Diffusion for the first time…Seriously, words fail to describe just what an impact diffusion has until you try it for yourself!

    If you order the QDA today you will also get

    • A free one 30 minute phone or video consultation on your room mode issues with me, the products inventor, Dennis Foley
    • A 100% risk free 30 day money back guarantee
    • And castors so you can move the units in and out of your room if your listening room serves multiple purposes.
  • Image of a QDA 17 Quadratic Diffuser Absorber
    Image of a QDA 17 Quadratic Diffuser Absorber

    The QDA – 17 are two units within one. First, a quadratic diffuser based upon prime number 13 with a diffusion frequency response starting at 225 Hz. and going through 3,450 Hz. Behind the prime 17 quadratic diffuser is our activated carbon broadband low frequency absorber from 30 Hz. – 400 Hz. At the base of the QDA-17 is our more frequency specific carbon absorber from 30 Hz. – 50Hz. The QDA measures 37″ w x 60″ h x 17″ deep and weighs 325 lbs.

    ACDA-10 Riverbank Test Result

    ACDA-12 Riverbank Test Result

    Want the ultimate in musical involvement? Looking for an emotional connection and experience each and every time you play your music? Then our flagship Quadratic Diffuser Absorber is for you.

    • An acoustical industry first; Middle range diffusion and low frequency absorption all in one beautifully crafted unit.
    • The quadratic diffuser 17 gives you diffusion from 225 Hz. all the way up to 3,400 Hz. This provides you with incredible separation, definition, and additional timbre quality to your precious mid range and vocals.
    • The low frequency absorber starts absorbing energy at 30 Hz. and moves through 200 Hz. so your bass instruments are both powerful and clear.
    • The combined effect is a larger and deeper sound stage than you will have ever experienced before so you can hear your mid range and vocals as clear and clean as if you were in the studio with the musician.
    • A beautifully crafted solid wood cabinet designed to match your room decor.
    • A unit that measures 35″W x 60″H x 18″D and weighs 250 Lbs.
  • Image of a QDA-23 Sound Diffuser Absorber
    Image of a QDA-23 Sound Diffuser Absorber

    The QDA – 23 are two units within one .First, a quadratic diffuser based upon prime number 23 with a diffusion frequency response starting at 185 Hz. and going through 3,450 Hz. Behind the prime 23 quadratic diffuser is our activated carbon broadband low frequency absorber from 30 Hz. – 400 Hz. At the base of the QDA-23 is our more frequency specific carbon absorber from 30 Hz. – 50 Hz. The QDA – 23 comes in three units. Each of the two diffuser sections measures 27″ w x 60″ h x 17″ deep and weighs 275 lbs. Together they are 55″ wide. The ACDA-12 base measures 55″ w x 12″ h x 17″ d and weighs 175 lbs. Total weight for the units is 725 lbs.

    ACDA-10 Riverbank Test Result

    ACDA-12 Riverbank Test Result

    Want the ultimate in musical involvement? Looking for an emotional connection and experience each and every time you play your music? Then our flagship Quadratic Diffuser Absorber is for you.

    • An acoustical industry first; Middle range diffusion and low frequency absorption all in one beautifully crafted unit.
    • The quadratic diffuser gives you diffusion from 200 Hz. all the way up to 3,400 Hz. This provides you with incredible separation, definition, and additional timbre quality to your precious mid range and vocals.
    • The low frequency absorber starts absorbing energy at 30 Hz. and moves through 200 Hz. so your bass instruments are both powerful and clear.
    • The combined effect is a larger and deeper sound stage than you will have ever experienced before so you can hear your mid range and vocals as clear and clean as if you were in the studio with the musician.
    • A beautifully crafted solid wood cabinet designed to match your room decor.
    • A unit that measures 36″W x 60″H x 20″D and weighs 275 Lbs.
  • The QDA series of products incorporates the ultimate of everything in one product. We have quadratic diffusion, broadband and frequency specific absorption all wrapped in a furniture grade wood finish. It is our highest performing product and our most expensive.

    The QDA S series of product keeps the diffusion and part of the absorption and wraps it all in a MDF cabinet that is clear coated to prevent dirt and moisture impact. You get a prime number 11, 13 or 17 for the diffusion sequence and our ACDA -10 or ACDA-12 technology in the base. You can choose what type works best for your room and usage. You can choose broadband ACDA -10 absorption from 30 – 200 Hz. or more frequency specific absorption from 30 – 50 Hz. All units are on casters for easy positioning.

    With the QDA S series, you get your choice of diffusion and absorption type all in one unit in a cabinet that looks good but without the high cost of wood and paint finishes. The alder wood has a smooth and mellow tone quality that is equal to the more higher priced cherry woods.

Showing all 5 results

We Ship Worldwide

+1 520–392–9486


We stand 100% behind our product performance levels so we are happy to offer a 100% Money Back Guarantee* if you are unhappy with the performance results, for any reason.


*Read More About Our Guarantee
FREE ROOM ANALYSIS
Call Us 520–392–9486
100% Money Back Guarantee