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The Gate
Presenting the Gate, one of the best loudspeakers in the world? :-)
Simply created on the theories and practical solutions of loudspeaker design, the four column open baffle loudspeaker system Gate saw the light in early 2010.
The goal was obtaining a no-compromise design capable of reproducing any genre of music and home theatre demands. Commercial designs just did not fulfill all requirements with the exception of the active amplified Beethoven Grand by Audio Artistry. An active amplified Magnepan MG 20.1 comes close.
The only solution is a multi-way full range dipole open baffle speaker system powered by active amplification. This system is made for the music lovers who aren't influenced by the latest fads in audio and want real performance from, or better said, "real" performers between their speakers.
The following section explains each important part of the design.
Design
37 years in the making! (I'm 37 years at the moment of building the first pair)
Okay, just kidding, the actual design took a couple of months of accumulating all (scientific) information available on speaker building and acoustics and especially noting what parameters mattered most in listening.
Enclosures, whether sealed or bass reflex, curved or thick walled, enclosures limit the driver potential and when not extremely well damped reflect sound back through the driver cone.
And transmission line as an option? Transmission lines are limited to the quarter length of the maximum wavelength they have to produce, aka the lowest frequency. In case of 20 Hz the line would have to be at least 430 cm.
Thus the age old open baffle option is used. No enclosure means nothing to reflect sound back through the cone and no "box" sound. Of course there is a requirement to having the rear of the cone radiate sound into the room; the speakers need to be placed at least 1 meter from the wall behind them to have the ear seperate direct from reflected sound.
The low frequency rolloff of open baffle systems is negated by operating more drivers for the lower frequencies. The 12 30 cm in the subwoofer and 8 20 cm woofers in the main loudspeaker provide enough power to reproduce the cannon blasts on Tchaikovsky's Overture 1812.
Dynamics, essentially the feeling of how easily a loudspeaker system can recreate sound, be it at low levels or from low to high levels.
To get a good sound the non-linearities of drivers need to be prevented and the amount of air displacement needs to done as quick as possible. The only option to achieve this is to couple the air to a large amount of driver surface. Planar loudspeakers like magnetostats and electrostats provide a large surface but are often limited to size and maximum excursion.
The Gate provides both surface and excursion with 12 30 cm and 8 20 cm woofers to cover the low frequency range up to the midrange drivers with ease.
Dipole dispersion, creating a realistic soundstage in a room means creating an equal power reponse on the whole frequency range. This means that both on-axis and off-axis the sound reproduced should be the same across the entire frequency spectrum. Omni directional speakers are best at this but are still plagued by the enclosures.
To achieve the best each driver isn't used higher than the frequency at which it starts to beam in a dipole configuration. All drivers are therefore crossed over as low as their design allows combined with reasonable excursions. The limit to the maximum sound level is then determined by the bandwidth fed to the tweeter.
The Gate uses a smaller diameter tweeter in front and back than used by most loudspeakers to raise the frequency at which beaming occurs, thus filling the room with more evenly matched high frequencies.
Active crossover and amplification, the biggest improvement to any loudspeaker.
No matter the quality of loudspeaker driver and amplifier, the loss in energy and control makes passive filters inherently inferior to active systems.
Loudspeaker drivers can only be used in their optimal frequency bands hence the need to divide the full bandwidth. By dividing it before amplification each amplifier is dedicated to the drivers connected to it, reducing intermodulation and energy loss and without filter components decreasing the control on the driver.
This also allows lower power (think tube amps) and sound quality matched amplifiers to be used.
The resulting design is guided by the KISS principle, what the easiest solution to any issue is, is what is being done. No complex solutions that cost a lot more (money and effort, not to mention sound quality) in the end.
The speakers
Main towers are a 3.5 way WWMT/TMWW design, providing a symmetrical vertical response and usually reproducing 70 to 20.000 Hz.
The midranges and tweeters are placed on a very shallow U-frame, woofers are placed in an H-frame to extend low frequency capability with the upper and lower woofer rolled off in higher frequency. Even without the subwoofers the mains are capable of recreating realistic bass and kickdrum.
Weight: 26 kgs.
Subwoofer towers are 12 30 cm woofers in total, set into 2 H-frames.
The subwoofers fill in the bottom octaves on music and movies with tight, clean bass.
When not in use for selected movies and music the mains are run full range to the bottom octaves.
Weight: 37 kgs.
Technical data
Frequency response: Tchaikovsky Overture 1812 proof
Measured music peaks of 101 dB at 3 meters during a demonstration.
Crossover: 2x Behringer DCX2496, all 6 outputs driven (alternatives need to cover 2x 6 channels of output)
Crossover frequencies: 70, 106/243, 3000 Hz (depends on crossover and SPL preferences)
Amplification required: subwoofer towers capable of driving down to at least 2 ohms (2 channels per side), main towers down to 4 ohms, total of 6 channels per side. Pro-audio power amplifiers are known to give great results for the money, at high-end level think Krell, Mark Levinson, Bryston.
Oh yeah, itĺl dryblow your hair when standing really close and playing bass heavy music (as witnessed and tested by people attending the DIY demonstration in Breda, the Netherlands).
The speakers in raw form in a normal sized livingroom (~3,60x6,20m, lined up against the long wall);
More info on aquiring the complete system or part of it, finishing and upgrades on drivers and electronics can be obtained by mailing me at the address in the bottom bar.
as the answer to the question