Audio Database
Air Pulse 3.1
Commentary

An all-horn speaker system developed by Platinum Audio using an innovative design method.

The Air Pulse 3.1 is a three way electrical and four way acoustic system. It is large in size to achieve multi-high-quality, deep bass playback. For this reason, it is constructed as a modular system consisting of three subassemblies for ease of transportation and installation.
The top and bottom of the three modules are identical low-frequency horns and contain a low-medium / low-frequency unit. The middle module consists of two mid-low horns coupled to the low-medium / low-frequency unit and an intermediate / high-frequency horn assembly sandwiched between them.
You can rotate the low-range horns according to the listening room condition and preference.

Two 30-cm cone type woofers are installed in the low and mid low ranges. The front of the diaphragm is used for the mid and low range horn and the back is used for the low range horn.
The diaphragm is made of a laminated, specially made composite material that provides complete piston motion over the entire playback band and uses a magnet assembly weighing 11 kg and a voice coil of 100 mm diameter.
This unit does not use an electrical crossover network to separate the low and mid-low frequencies, but determines the playback band by accurately calculating the acoustic cut-off points of the low and mid-low frequency horns. In the case of a low-frequency driver, the combination of the inductance generated by the volume of air in contact with the diaphragm and the capacitance generated by the acoustic reactance of the horn throat forms an acoustic filter equivalent to a two pole network, which determines the upper frequency limit for playback. By matching this with the cut-off frequency of the mid-low frequency horn, the mid-low frequency crossover is achieved. By using this system, excess parts can be eliminated, distortion can be reduced, and transient characteristics and phase characteristics are improved.

The low-frequency horn uses a split composite horn that is designed to operate as a corner horn, extending the cut-off frequency to approximately 20 Hz. The shape of the horn is a 3.5m hyperbolic exponential horn with a spiral shape and a moderate aperture.
The horn is driven by air vibrations fed into a slotted cylinder at the back of the low-frequency unit, and by carefully matching the air load to the throat between the diaphragm and horn throat, a flat response within the regeneration band is achieved.
The throat to diaphragm pressure ratio is set at 3 : 1 as the optimum value to match the elastic modulus of the woofer diaphragm.

The mid-range and low-range horns use an omnidirectional radiation type horn that uses the front surface of a woofer cone for output. The horn is a 812 mm diameter horn cut from a block of laminated wood and reproduces the 125 Hz to 900 Hz band.

The mid-range is equipped with a 10-cm dome mid-range with an aluminum-alloy diaphragm. Similar to the mid-range horn, the horn emits sound from the laminated wood in all horizontal directions.

A 9.5 cm ring type tweeter with an aluminum alloy diaphragm is mounted in the high range. By using a unique frame structure and upper and lower horn parts, sound is radiated in all horizontal directions.
Copper clad aluminum flat ribbon wire is used for the 75 mm diameter voice coil.

The 3-band crossover network is housed in a pedestal.
All components of capacitors, coils and resistors used in this network are individually selected and of the highest quality available. All connections are made with pure silver wire and silver joints are used for soldering.
The network circuitry is isolated from the enclosure to eliminate the effects of acoustic energy within the enclosure.

The enclosure is made possible by the cooperation of a woodworking expert, Scott Schmidt, whose work is housed in the New York City Galleria d'arte moderna di Firenze.
All wood components of Air Pulse 3.1 are made of the best available materials. The mid-range and high-range horns are made of special laminated wood. The horns are carved out of blocks of these laminated wood and cause little resonance. All baffles are precisely machined by a woodworking machine (computer-controlled NC multi-head lauter CMS PF102R8).
The spiral-shaped wall of the low-frequency horn is made from a combination of high-density fiberboard, phenolic resin, high-mass elastomeric dump material, and wood, providing very high rigidity and non-resonance.

Model Rating
Method 4-way, 4-speaker, all-horn system, floor type
Units, etc. For low band : 30 cm cone x2
For Middle Area : 10 cm Dome Type
For High Frequency : 9.5 cm Ring Type
Frequency characteristic 20 Hz to 20 kHz
25 Hz to 17 kHz ± 2.5 dB (on-axis or off-axis)
Sensitivity 96dB/2.83V
Maximum Sound Pressure (1m) 127 dB (continuous)
147 dB peak
Nominal impedance 12 Ω (System)
Recommended amplifier output 25W ~ 10,000W
Crossover frequency 125 Hz, 900 Hz, 6.5 kHz
External dimensions Width 820x Height 1,830x Depth 1,220 mm
Weight Approx. 400 kg
<drive unit>
Woofer
Magnet Ferrite, 11 kg
Voice coil 100 mm Bore Edge Copper Wire, Kapton Former Bobbin
Impedance 8 Ω (each bobbin), 2 units connected in series
Corn Long Fiber Wood Pulp (Resin Impregnated) 300 mm Diameter
Edge Cross
QTS(Total Q) 0.12
Maximum allowable input 600W continuous
Mid-range
Magnet Ferrite, 11 kg
Diaphragm 100 mm Diameter Aluminum Alloy Dome
Voice coil 100 mm Diameter Edge Wound Copper Clad / Aluminum Wire, Magnetic Liquid Cooled
Impedance 8 Ω
Maximum allowable input 10,000Wpeak
Tweeter
Magnet Ferrite, 5 kg
Diaphragm 95 mm Diameter Aluminum Alloy (Ring Shape)
Voice coil 75 mm Diameter Edge Wound Copper Clad Aluminum Wire Magnetic Liquid Cooled
Impedance 8 Ω
Maximum allowable input 10,000Wpeak
<Crossover Network>
Woofer Amplifier directly connected (without filter, without electric circuit)
Mid-range 12dB/oct(900Hz)
12dB/oct(6.5kHz)
Tweeter 12dB/oct(6.5kHz)
* Equalization circuit is not included in crossover.
Horn Configuration
Whole The speaker (one side) consists of six horns : two for the low band, two for the middle and low band, and two for the middle and high band.
Low frequency horn 35m long spiral type hyperbolic exponential hybrid horn
Compression ratio (woofer / cone : horn throat) 3 : 1
Opening Area : 1.2m2
Horn opening can be rotated 360 degrees
Mid-range horn An exponential horn with a horizontal omnidirectional and vertical 45-degree radiation pattern
Mid-range horn An exponential horn with a horizontal omnidirectional and vertical 45-degree radiation pattern
High-frequency horn An exponential horn with a horizontal omnidirectional and vertical 40-degree radiation pattern