Symmetry Audiophile Systems

Symmetry Electronic Crossover

The Symmetry ACS-1



Crossovers are one of the weakest links in the audio chain and probably the most neglected and least understood.



Because of the complex nature of the speakers, passive crossovers (internal to the speakers) are extremely difficult and costly to design properly. The benefits of Bi-Amplification are well known and the improvements to your system can be truly startling.

Some of the advantages of Bi-Amplification include the following:

1). Since the signals in the electronic crossover are line level, high quality low distortion devices can be used, which relieve the system of that "strained" quality often experienced in passive crossovers.

2). Instead of a single high powered super ampli- fier (usually high priced) one can use two lower powered amplifiers and experience greater dynamic range at no increased costs.

3). There is less demand on the amplifiers since they are not called upon to handle the entire range.

4). Pick amplifiers of your sonic choice for the lows and highs allowing increased flexibility

5). Features of electronic crossovers such as variable frequency and gain are extremely important in maximizing the capabilities of your speaker system.



Crossovers in their attempt to divide the audio spectrum among the various drivers in a speaker system alter the signal in two ways: frequency response and phase. The frequency response of most crossovers is acceptable, but phase response has been unfortunately neglected.

Since a square wave contains all frequencies, an electronic device that can pass a square wave is coherent in both frequency response and phase. Any deviation will show up as alterations of the square wave input signal. In the case of electronic crossovers, this deviation is almost entirely the result of poor phase response.



Simply put, proper phase response is the ability, of coherent signals (such as those complex tones encountered in music) to arrive at the listener's ears at the same time. A delay in the signal will smear the tone, resulting in poor transient response (the transient actually becomes blurred), and loss of definition and clarity. This creates a diffused image within the crossover region.



Symmetry ACS-1 Electronic Crossover, designed by John Curl takes a fresh new approach to crossover design. Near perfect impulse response and the ability of the ACS-1 to pass square waves introduces a new dimension into electronic crossover design. Properly set up, one immediately notices the seamless transition between drivers, the excellent clarity, and superb imaging throughout the crossover region.

Built around ultra fast, low distortion FET modules, the ACS-1 introduces no sound of its own and will not compromise the sonic performance of associated state of the art components.



We will be the first manufacturer to admit that life is full of compromises and a properly de- signed audio product is no different. A 12 dB per octave slope is the most difficult to design properly (which is why most manufacturers avoid it), but gives one the smoothest transition between drivers in the crossover region. The Bessel/ Butterworth filter network combines the sharp "shelf" of the Butterworth filter with the excellent impulse and transient response of a standard Bessel filter. Although our specifications are impressive our electronics are built for function, reliability durability and most important of all; sonic excellence. The only compromise we have not made is in our dedication to you in producing the finest electronic crossover that we know how to make. Give it your most critical evaluation, and I think you will agree with us that the ACS-1 is indeed an indispensible part of your system.


Specifications available on request.

Last modified: 12-Nov-2009