Mach 2 Estrema Loudspeaker

MACH 2 Estrema

- 2 woofers, unfiltered, unequalized
- 1 horn compression tweeter 
- 92 dB@1W/1m 2,83V
- 8 Ohm
- 130*34*44 cm
- 19Hz-20kHz
- S.R.T. (Semi Resonant Tube)

- Grandinote's warranty of 5 years
AVAILABLE IN MATT AND BLACK VERSIONS

From the smaller Mach with two drivers to the bigger one with many drivers in array (doesn't matter if horn or super tweeter, it's the same and we use both) the operating principle is always the same.

Fact is all Mach speaker do not have, neither crossovers, nor any other elements for equalisation/correction and all drivers are full wide-range. We have only a cut for the super tweeter that can't be called crossover cause a real crossover an audio signal into two or more frequency ranges.

Since we have no capacitive reactances, inductive reactances, or even resistors, we have removed any element that could lower the impedance of the system. Speakers with crossovers have minimal impedances, even as low as 1/3 or 1/4 from nominal impedance. There are cases of crossovers so extreme that they take the minimum impedance from 8 Ohms nominal to 1 Ohm. In our case, the impedance of Mach speakers is very close to the characteristic impedance of free-air drivers.

For Grandinote, the damping factor of the system is extremely important. Excellent impedance linearity is only one of the many advantages of a crossoverless speakers. I can describe more, such as the absence of time distortion, related to the phase shifts of the reactive components, again the greater damping factor, avoiding additional series resistances of the filter inductors, and several other advantages that result in detail, speed, coherence, spatiality… Grandinote also designed mechanical filtering on the drivers to eliminate any kind of break-up and linearise the response of their wide-ranges by avoiding reactive components (aka crossovers).

This is definitely the most important of the Mach's strengths. The minimum impedance, therefore, is around a value close to the "Re" of the transducer coil.

Grandinote Massimiliano Magri  explains the SRT technology

It's a lot of years that we tryed to get a great sound from crossover-less speakers.
We have understood that the only way to get this is to use drivers that don't exist...
We tested a lot of full-range and extended-range drivers:
always the sound was "nasal", annoying in the high frequencies.
These problems are caused by the high frequencies brack-up of the drivers.
By the crossover, these brack-up are killed, but the crossover also kills a lot of musicality.

Our solution is to use a "mechanical" crossover.
We optain this by a special treatment behind the drivers membranes.

This treatment kills brack-up, without steal musicality.
Finally we have our drivers to use without crossover:
the best voice that I listened from speakers.

This treatment also modify drivers paramters, expecially the Fs and the Qts.
We created drivers with low Fs and high Qts.
These parameters are perfect for transmission line and other perticular configurations.
We developed a solution is in the middle between bass reflex and transmission line.
Our cabinet is like a tube, with a larg downward port.
This tube is too short for a transmission line: it's another thing!
We call this solution "Semi Resonance Tube": S.R.T.

In this way, we have very deep, tight, fast basses, very different that all other speakers that I listened.