Reference

FRIED TECHNOLOGY

Loudspeaker design and performance has little to do with producing a flat frequency response. Music is wave fronts containing tremendous acoustic energy and is transient and dynamic in nature. Loudspeakers must be designed using technologies that maximize the potential to accomplish the reproduction of these transient wave fronts. FRIED combines transmission line enclosures with series crossover circuits. Both of these technologies maximize transient and dynamic performance and are best suited for reproducing music. FRIED, through technological advancements has further improved these technologies.

TRANSMISSION LINE
FRIED loudspeakers only use transmission line loading for all cone drivers because all other box designs introduce limits on transient behavior. The advantages of transmission line loading are highlighted below.

Reduces the reactive components of the impendence curve; thus, presents a purely resistive load to the amplifier, resulting in uniform power transfer for better transient response and dynamic presentation.

Guides the rear energy away from the driver to reduce the smearing of leading edge transients caused when internal reflections return to alter the cone movement of subsequent excursions.

Lower frequencies are not absorbed by the internal damping and are propagated in phase from the line termination, thus adding an extra octave to the bass response.

Air mass in the line is acoustically added to the mass of the driver diaphragm at the lowest frequencies making the driver perform as if the cone diameter was larger; therefore, a smaller driver with faster transient response can be used.

Plane source propagator, projecting bass data forward; therefore, reducing the interaction with room resonance problems.

FRIED has developed several technological advances to improve upon the performance of transmission line loading. Standing waves develop within the line and must be eliminated or they will cause abnormities in the frequency response. Damping is added inside the line to break up these standing waves. Traditional transmission line damping is comprised of either long hair wool or synthetic fiber fill and does an effective job controlling resonance. However, mechanical damping of the driver is introduced across the entire frequency range because a completely stuffed line restricts the air displacement at the rear of the driver. FRIED has developed a new damping technique that not only controls the line resonance but allows complete free flow ª of the air mass away from the driver eliminating mechanical damping that restricts transient response.

Typically, transmission lines are very long and must be folded several times within a cabinet. Common thought was that these turns caused abnormalities in the line performance. However, FRIED research found that changes in line volume through turns and folds caused more abnormalities in the frequency and impedance response than the fold itself. Therefore, FRIED developed new technologies to maintain constant taper to the cross sectional area as the transmission line folds or turns within the cabinet. Maintaining constant taper flattens the impedance making the system more resistive, which equates into more transient attack and increased dynamic range.

SERIES CROSSOVER
Common to the industry is the use of parallel crossover networks, a group of independent circuits for each driver in the system. FRIED, however, uses a series crossover circuit. Rather than each driver in the system working independently, a series network connects all of the drivers into the same circuit. This arrangement provides several advantages listed below.

Balanced reactively providing a purely resistive load to the amplifier, which allows greater power transfer at critical dynamic moments.

Impedance curve is flat rather than having large peaks at the crossover frequency that are reactive and destroy transient response.

Drivers stay in phase providing sharper leading edges to transient sound as they are connected to each other forcing them to work in unison.

Active impedance of the speaker drivers at the crossover frequency is stabilized so that power is shared more predicatively between speaker drivers.

Actual measurements registered a 6dB increase in dynamic range when comparing series to parallel networks in the same system.

Improved Doppler Effect provides a homogeneous response pattern since all of the drivers must share common frequencies over a broader range, which results in less separation of wave fronts into specific frequencies.

FRIED has continued research into series crossover networks and made technological advances to achieve even greater benefits. Typically, crossover circuits contain conjugate circuits such as impedance compensation (Zobel), notch filters and contour networks to hit target crossover points and flat frequency response. However, these circuits cause phase shifts and feedback loops that reduce transient attack by destroying time cues. FRIED has developed technology to eliminate all conjugate circuits from a series crossover circuit. FRIED has achieved a purely resistive impedance plot using a series circuit without conjugate circuits. This results in greater transient ability, dynamic impact and phase coherency over common parallel crossover networks.