Мюнхен HighEnd-2019. Кто лучший?

I am glad you liked the Menara. It was designed mainly to demonstrate the MD60N-6 dome midrange driver

– and then I also wanted to do the bass compensation (due to the baffle-step) a little bit differently, as in conventional 2½-way speakers (or in this case a 3½-way speaker) with two identical woofers, you often end up with a little too much bass, as you don’t really lose 6 dB below the baffle frequency in an ordinary listening room (that would only be the case in a full anechoic room). Ideally, you would use three identical mid-woofers, each with a nominal impedance of 12 ohm. Two of these would be used as mid-woofers that run all the way up to the tweeter (or in this case the filler driver) and only one woofer would fill in below the baffle frequency – then you would end up with a neutral balance (i.e. flat bass response). Now, we don’t have standard 12 ohm drivers in stock and I wanted to use only standard drivers. Therefore, I used two 4 ohm mid-woofers (MW19PNW-4) connected in series for the upper section – they share a common sealed enclosure (close to Butterworth alignment). The single lower woofer is an 8 ohm driver (MW19PNW-8) that has 3 dB lower sensitivity than the 4 ohm drivers and it sits in its own vented enclosure. Had I been able to use three identical 12 ohm drivers, I would have put them all in a vented enclosure an tuned them exactly the same way (I could have used a vented enclosure for the 4 ohm drivers, of course, but instead I chose to experiment a little with different bass tunings, hoping for more accurate “fast” bass from the upper drivers, though I realized that they wouldn’t go very deep – I took a chance).

The tweeter is our TW29BN-8 (I didn’t need the high sensitivity of the 4 ohm version and besides, the higher driver impedance allows for smaller value capacitors in the filter).

The midrange drivers were handmade prototypes using 3D printed parts (rear chamber and mounting ring/”butterfly”).

We have decided to keep the Menara as a concept design, which is why I am not sharing the cabinet drawings or the crossover schematic. This is a company decision. At some point however, we might decide to make a kit speaker based on parts of this concept (there are no specific plans at the moment, though).

I can describe some details of the crossover (keep in mind that it is a flat vertical baffle with no physical offset of the drivers):

1) The high-pass filter for the tweeter is 3^rd order with some attenuation (no L-pad, only series resistors). The tweeter is connected in reverse polarity (normally, in a system like this, you would expect this for the midrange/filler and not for the tweeter).

2) The band-pass filter for the midrange is asymmetrical (lower slope is 12 dB/oct, upper is 6 dB/oct). There is some attenuation and a little EQ/correction just above the upper crossover point. The impedance curve is equalized around the resonance frequency (this was not strictly necessary, but it did improve integration with the upper mid-woofers). Driver polarity is NOT reversed. This midrange driver covers the range from 1-6 kHz (see attached response curves – maybe you also saw this at the show). I have also attached the response curves for the final MD60N-6 prototype driver.

3) The low-pass filter for the upper mid-woofers is 2^nd order with impedance equalization at the system resonance frequency (this ensures a nice roll-off without any bump/boost – it makes quite a difference in listening).

4) The low-pass filter for the lower woofer is also 2^nd order with impedance equalization of the upper resonance peak of the vented system (as it would otherwise affect the electrical transfer function too much – as described above).

Notice that the two woofer filters are separate branches (as opposed to a cascaded filter, which is often seen in 2½-way speakers).

5) One more thing about the Menara crossover; there is an LCR-network across the input of the crossover (or the output of the amplifier, if you like) to equalize the impedance peak associated with the crossing between the upper mid-woofers and the dome midrange driver, as this would otherwise cause an electrical phase shift slightly above 60°. This is likely not a problem for a modern solid-state amp but still it can cause some colouration and this phase shift is a lot more than what you normally see in the crossover region of e.g. 2-way speakers.