Linear Q Transition


Professional Loudspeakers



Dalbec Audio Laboratory

58 King Street

Troy, New York 12180

phone (518) 272-7098

fax (518) 272-2520



     I.         LQt Defined

     II.        Features

     III.       Benefits

     IV.       User list (Northeast U.S.)











     2003    All rights reserved




I. LQt Defined


The DALBEC AUDIO Linear Q Transition (LQtTM) Series of professional loudspeaker enclosures has been developed over 25 years of applications research.  The performance characteristics of the LQtTM line offer many advantages not found in this size and weight category.  Research associates at DALBEC AUDIO have been field testing a number of patent pending prototype systems in hundreds of venues throughout the Northeast for recently with great success. User endorsements of systems utilizing our  Linear Q Transition (LQt TM) components have been conclusive.


(LQttm )  or linear Q transition characteristic is defined as ; The directivity index “Q”  (inversely, the Beamwidth) of the system is directly proportional to the frequency of operation;  exhibiting a “linear” directivity signature ;  effective from  50 hz. to 20 khz.


FACT: The two most important characteristics an enclosure must exhibit for correct interaction within most venue environments are frequency/phase control and broadband directivity control. These characteristics are not exhibited by  conventional direct radiating enclosures.   Whether confronted with an acoustically sensitive auditorium, an outdoor or any other non-nearfield event, or feedback spill over on a tight performance stage, applying proper horizontal and vertical coverage management provides profoundly dramatic and often overlooked, successful results such as:

-          increased source articulation- greater critical distance (less room interaction)              

-          increased efficiency

-          greater gain before feedback

-          near/far field balance


All trained acousticians realize the value of the research of Harry Olsen (RCA ) ; and Western Electric scientists, 75 years ago ; defining these basic large format  pattern controlled concepts utilized today. This original large format concept has declined due to a number of disadvantages including:

-           size restraints (rigging, portability)

-           much higher costs for enclosures

-           lower fidelity in the nearfield listening area

-          excessive interference between shared components (large acoustic spacing)


Recent  research with line arrays as  described in AES 2SR.04 ;Sound Fields Radiated by Multiple Sound Source Arrays.(Christian Heil and Marcel Urban) defines the physical standard  improving the nearfield fidelity, and wavefront character  of the basic large format line array,   

This concept is currently state of the art ; although with a few disadvantages.


 Multiple components (8 minimum) per  L/R array  required;  Low Efficiency  Requiring

 two to three times  more power and or components over  waveguided systems.







DALBEC AUDIO's Linear Q Transition (LQt TM) concept bridges the gap between the old large format, rigged array, directive designs  commonly still accepted for larger venues (ie: arenas, stadiums, etc.) and the state of the art tightly coupled line arrays.  The result is point source fidelity ; Our dicentric line array performance approaches a cylindrical character from a single compact enclosure.


DALBEC AUDIO's LQtTM systems also feature:

-           coherent phase & frequency performance at critical distances

-           additional proprietary manufacturing techniques applied to reduce size and

            weight to improve maneuverability and installation requirements

-           computer modeled, coherent and directive LF enclosures

-           DSP or DALBEC ASP linear processor option for LQtTM Series

            incorporating a di-centricTM crossover, Bessel, CD & LF EQ ;  multiband limiting  


Our advanced dicentric models --  feature


-          patented enclosure architecture--  exceeding AES 2SR.04 line array criteria

            (improved efficiency;  and single component  cylindrical wavefront performance)

-           stress relieved, hand made "perfect polymer" large format CD HF wave guides

-           baffle mounted HF drivers






Immediate benefits of DALBEC AUDIO's LQtTM systems include:

-           increased clarity and fidelity for speech, music or combination of two at

            venue sizes with audiences at distances greater than 50 feet from stage

            ie:  auditoriums, houses of worship, theaters, arenas, stadiums, parks, etc.

-           increased control / greater gain in acoustically challenged rooms

            ie:  gymnasiums, venues with mobile microphones, large halls, etc.


Other benefits in choosing DALBEC AUDIO products include the following:

-           access to the Northeast's leading technical staff in engineered audio

            providing engineering assistance, licensed technicians & systems designers

-           room design / analysis 

-          custom fabrication of enclosures ; equipment racks ;  workstations

-           architectural integration with any installation atmosphere




IV. USER LIST partial

System Installations & Event Support



    Albany School District

    Brittonkill Central Schools

    Berlin Central Schools   

    Canajoharie Schools   

    Colonie Central High School

    Emma Willard School

    Fonda Fultonville Central   

    Gloversville Enlarged Schools

    Giffen Elementary School

    Hackett Middle School

    Hudson Valley Community College

    Junior College of Albany

    Lansingburg High School

    Niskayuna High School

    Union College

    Rensselaer Polytechnic Institute

    Sage Colleges

    Siena College

    Schenectady High School

    Skidmore College

    SUNY Albany

    SUNY Cobleskill

    Wildwood School


  Houses of Worship

    Our Lady Fatima

    Our Lady Grace

    Teresian House Chapel

    Union Old Chapel

    Christ The King

    Carmelite Sisters

    Grace Methodist

    West Stephentown Baptist Church

    Pineview Community Church

    St. Sophia G.O.                                                                              

    Victory Baptist


    The White House

    New York State Governor's Office

    New York State Attorney General's Office

    Senator Joseph Bruno

    City of Troy


  Not-For-Profit Organizations

    Adaptave Sports Foundation

    American Cancer Society

    American Diabetes Association

    Amnesty International

    Boys and Girls Clubs USA

    Mass. Museum of Contemporary Arts

    Rensselaer County Council on the Arts

    Rensselaer Historical Society

    United Cerebal Palsy Association

    YMCA  / YWCA


  Performing Arts / Entertainment                                        

   The EGG @ Empire State Plaza

   Troy Savings Bank Music Hall

    RCCA Blackbox Theatre

    Union Memorial Chapel

    Union  Nott Memorial

    Sage Bush Memorial

    SHS Black Box Theatre   

    Pepsi Arena

    Saratoga Performing Arts Center


    The Van Dyke

    Studio 54  NYC

    Troy Brew Pub/ REVOLUTION HALL

    Malt River Brewing Company

    Northern Lites Performance center