About Us |
Rigging Safety is our #1 priority quae in MCMVCV
We have a Chicago office and a complete in-house Audio Lab for loudspeaker testing that's located in Minneapolis. We can also provide on-site acoustical analysis services.
Horn Design and Fabrication services. CAD software analysis for enclosure and crossover designs. Graph examples from: Liberty Audio, Praxis and Linear X test/measurement systems. Some measurement capabilities include:
Complex frequency response ( magnitude & phase) Impedance, Thiele-Small parameters, Harmonic & Intermodulation distortion, resonance analysis, rub & buzz, Time domain alignment, Waterfall (spectral decay) plot generation FFT,
Room Measurements (RT60, STI)
Sound System RTA and SPL measurements using the live music source. Loudspeaker polar plots
Below transportable 1/2 Space Baffle for accurate, repeatable testing of drivers without enclosure effects. Middle : Ease Focus acoustic modeling software predicts Sound Pressure Level and frequency response in a venue in 3D.
On the end: Finite element Analysis of a conventional woofers magnetic structure showing how the top plate bends the magnetic flux lines creating a small gap for the coil. Computer Aided Design available from concept to production.
We can draw and 3D print, a concept piece that can go into limited production runs imediately!
Check out some of our other sites
www.RibbonLoudspeakers.com this site highlights some standard models we can deliver quickly. There is also some good information about ribbons in general.
www.LEDloudspeakers.com On the home page there are many bullet points designed to explain the advantages of using LED's with loudspeakers
www.LEDspeakers.com B&W photos of LED's in action used in non traditional ways
www.NeoSpeakers.com Elemental diagrams on the first page. In the middle section are some of the best HiFi woofers and pro drivers available. There is also a collage of some of the big players in the concert arena
www.NeodymiumSpeakers.com Comparison between ferrite and neodymium drivers. Size Weight and Strength
2D cut away 18" Subwoofer
Progressive surround, dual spider, 4" voice coil, "radially magnetized" Neodymium magnet B-Hive Motor Technology (Specs. below)
The B-Hive motor is the future of high output woofers. It's an elegently simple design featuring "radially magged" high temperature Neodymium magnets surrounding an under hung voice coil that's encased in a low carbon steel return structure. This allows the cone to have high excursion with the lowest possible distortion. In addition because the entire length of the anodized aluminum edge wound voice coil is always in the magnetic flux or B field right up to the Xmax limit the Thiele-Small parameters don't change dynamically under various input levels. This also means that the amplifier can more easily control the coil. In addition the entire coil is intimate to steel so there are no temperature gradients along it's length and potentially damaging heat is wicked away through black body radiation. The shape of the motor was optimized using FEA (Finite Eliment Analysis) in order to dissipate heat, focus flux, and reduce weight. We looked at the thermodynamics of the B-Hive motor and choose the specific "crab trap" internal shape of the pot structure so that it forms an "air diode" which promotes convective cooling. The air flows one way when the cone moves back and forth pulling air through the motor. Heat is forced out of the pot structure and through the vents below the double spiders. . Externally the ribbed exterior dramatically increases the outside surface area without adding much mass and acts as a heatsink promoting the action of radiating heat out of the motor. This further reduces the effects of steady state power compression caused by extreme input levels over long periods of time. The result is a woofer with more linear excursion providing greater acoustic output with ultra low distortion, quick transient response, low power compression and very high linearity. Please note, No top plates were used in any of our testing and designs.
The CGN1808 subwoofer is 18" (460mm) in diameter with a 4" (100 mm) voice coil. It utilizes the B-Hive motor for it's magnetic circuit and it has Two inches (50.8 mm) of peak to peak fully linear excursion and can move more than Three inches (76.2 mm) before damage. It also produces no stray manetic flux, so it's inherently video shielded and can be easily shipped by air. It weighs 33 lbs. (15 kgs.) That's just a few pounds heavier than a conventional ceramic magnet pro 18" woofer but the CGN1808 typically has more than 4 times the acoustic output. It is extremely efficient and handles great amounts of power so use the biggest amplifier you can find. We curently make several versions of this subwoofer. One that's an excellent choice for a horn loaded design features a honeycomb fiberglass composite cone. (waterproof) Our most popular version utilizes a composite paper/Kevlar cone with the following Theile-Small parameters.
NomZ 8 Ohms, Sd. 137 sq. m., BL 22.65 TM, Revc 5.23 Ohms, Vas 435 l , Cms 163 uM/N, Mms 207 g, Fo 27.4 Hz, Qms 23.5, Qes .363, Qts .357 Xmax 12.5 mm fully linear, + 18 mm (>10% distortion 3rd. H) , 96.5 dB @ 1M 2.83 V
Here are some quick cabinet designs from Leap
Quasi 3 rd. /Butterworth , Vb = 7.25 cu. ft. Fb = 30.3 Hz, F(-3) = 33.81 Hz, Peak 0 dB
Extended Bass Shelf / BW, Vab = 9.94 cu. ft., Fb = 27.4 Hz , F(-3) = 28.84 Hz , Peak 0 dB
Damped Cheyshev / Bessel, Vab = 8.53 cu. ft. Fb = 25.1 Hz , F(-3) = 35.53 Hz , Peak 0dB
*Also in the design phase of your box please take into consideration that this 18" subwoofer is a few inches deeper (12") than most. The frame is a little larger in diameter. Techniccally it is really an 18.5". PLEASE NOTE this subwoofer moves a lot of air so we encourage the use of ports that are often twice the area of conventional norms.You should factor in the port velocity. Finally because the cone can move so far we reccomend at least 1.75" clearance from the front of the woofer to the back of the cabinet grille.
CGN audio labs Page 3