Description:
The ISP Technologies HDL4215 speakers are a 4-way line array box of the highest performance and fidelity. In order to achieve very uniform and extended high frequency response, precision HF horn geometries are required. This results in our offering of three different box types, depending on the vertical coverage required and their position in the line. The HDL4215N is a 12-degree vertical near-field box, the HDL4215M is an 8-degree vertical mid-field box, and the HDL4215F is a 4-degree vertical far-field box.
ISP Technologies is the only manufacturer to our knowledge that is making 4-way line array boxes (the Clair I-4 is a proprietary 4-way box, but the 4th ‘way‘ is a built-in subwoofer). All other line array boxes are 2 or 3-way (the Meyer Milo is 3 1/2-way, in that both 12-inch woofers operate below a certain frequency).
A 3-way line array box is compromised in terms of it’s off-axis midrange smoothness, since the cone midrange drivers must cross over to the HF drivers at 1.2 KHz, typically. At this high of a frequency, the off-axis path difference between the two midrange driver lines is easily in excess of 1/2 wavelength, leading to a 6 dB or more dip in response in the middle of the midrange. This is on top of the response dip in this range due to the line curvature and cone breakup. The result is that most line arrays suffer from midrange ’suckout’.
The ISP Technologies boxes cross over at 750 Hz from the lower midrange cones to four special midrange compression drivers. At this lower frequency the wavelengths are longer which reduces the path difference at 45 degrees to less than 1/2 wavelength, resulting in a less audible dip. The result is more consistent midrange over wider angles, with greater clarity on the voice.
Also, 3-way systems must compromise on the high frequency end since the 1.2 KHz crossover frequency requires use of a large-diaphragm (3 or 4”) driver. These large diaphragm drivers have either extreme high-frequency rolloff and loss of efficiency, or extreme dips and peaks in the 10 to 15 KHz region due to diaphragm breakup (very annoying to listen to). The 3 KHz upper crossover in our 4-way box allows use of a 1.75” diaphragm driver, which features response past 18KHz. The extremely powerful neodymium magnets in these drivers result in a sensitivity of 108 dB @1W/1M out to 18 KHz, which is simply the best performance of any driver by any manufacturer we are aware of! The use of four of these drivers per box minimizes distortion and maximizes output.
In addition, the boxes are carefully designed with the aid of our proprietary LINESIM simulation program to achieve smooth response at all frequencies and listening positions when used to our recommendations. The 12 degree vertical coverage of the ISP boxes means fewer boxes per side are needed. A 4 box line covers up to 48 degrees vertically. Competing boxes of this output capability are no more than 10 degrees, and as little as 3 degrees, requiring more boxes. Competing boxes that do have a 12 degree vertical coverage are typically only two-way, with smaller drivers and lower SPL capabilities.
Key Features:
? Hi-Fi meets Line Array for
High Definition Audio.
? True 4-way line array box,
5-way system with subs.
? Symmetric Driver Layout for very uniform coverage.
? Four HF drivers with neo magnets and 1.75 inch non-metallic diaphragms, to deliver a high-fidelity sound which is more pleasant than typical larger titanium diaphragms.
? Four upper midrange compression drivers. This driver does not suffer from the cone breakup of typical cone speakers used in this frequency band by our competitors, for stunning midrange clarity and dynamics.
? Lower midrange drivers are two 8-inch cone drivers per box, with extremely high magnet strength. These are only used up to 750 Hz, to avoid cone breakup. Further, these drivers are fully horn loaded down to the lower crossover point of 250 Hz, resulting in higher SPL and lower distortion. Competing boxes typically use four 5 inch to 8 inch cones which are only ‘waveguide loaded‘, essentially direct radiating, and they are used to a higher frequency, increasing the audibility of cone breakup and loss of definition.
? Upper bass drivers are dual 15-inch drivers with neodymium magnets. These are optimized for the frequency range of 100-250 Hz, and feature very high sensitivity, saving on power and reducing power compression.
? Supplied with 6 channels of high current DCAT amplification (2000 W RMS total power) per box.
HDL 4215 Data (Per Box, Preliminary)
Configuration: 4-way
LF Drivers: 2 x 15 inch, very high sensitivity, neo magnet, reflex loaded.
LMF Drivers: 2 x 8 inch, very high BL, horn loaded.
HMF Drivers: 4 x 2 inch compression, low moving mass, horn loaded.
HF Drivers: 4 x 1.75 inch compression, very low moving mass, horn
loaded, Polyester diaphragms(F), Mylar diaphragms (M, N).
Coverage: 4 V x 90 H (F)
8 V x 90 H (M)
12 V x 90 H (N)
Splay Angles: 0 to 4 degrees (F)
5 to 8 degrees (M)
8 to 12 degrees (N)
Frequency Resp: 80 Hz (4 boxes) to 18 KHz.
Construction: Baltic Birch Plywood.
Dimensions: 48” W x 18.25” H x 24” D
Amplifier: 2000 W rms, 6 channels (1 channel for each LF driver),
high current DCAT, fan cooled.
Power Required: 15 Amps x 120 VAC.
Crossover: Outboard digital processor required which is capable of
5-way crossover. DBX Driverack 260 recommended.
The system was modeled using our proprietary LINESIM program to predict the performance. This program performs extensive calculations based on the position and output of each driver to predict the sound level at multiple frequency bands from the first row to the last row. The system exhibits outstanding balance in all frequency bands. Below are the continuous output capabilities of 4 F-type boxes of the system in each frequency band, normalized to 1 meter distance:
LF: 142 dB @ 1m, 100 Hz to 250 Hz
LMF: 141 dB @ 1m, 250 Hz to 750 Hz
HMF: 142 dB @ 1m, 750 Hz to 3 KHz
HF: 140 dB @ 1m, 3 KHz to 17 KHz
ISP Technologies 5479 Perry Drive, Suite B Waterford, MI 48329Phone #(248)-673-7790 Fax #(248)-673-7696
