The Monitor Audio Studio speaker is the brand’s high-end compact model. Similar to the Monitor Audio Gold 50 compact speaker in that both feature a ribbon tweeter, the Studio speaker sets itself apart with a pair of 4” (10 cm) drivers installed above and below the tweeter, whereas the Gold 50 is fitted with one 5” (13 cm) driver.
Monitor Audio Studio: the drivers
The cones of the Studio’s two 4” drivers benefit from RDT II Rigid Diaphragm Technology. Each is composed of a honeycomb Nomex core sandwiched between a layer of ceramic (C-CAM technology) and a layer of carbon fiber. Each driver is held in place by an axial rod attached to the back of the speaker.
This approach makes it possible to decouple the drivers from the front of the speaker and thereby reduce unintended vibrations. Also used for the large Monitor Audio Platinum 500 floorstanding speaker, these drivers ensure reduced distortion in the upper bass register (a direct benefit of RDT II technology). In the Studio speaker, the drivers are installed in a bass-reflex configuration along with two laminar ports. The pair of 4” drivers covers a frequency range of 48 Hz – 2.8 kHz, at which point the MPD (Micro Pleated Diaphragm) ribbon tweeter takes over up to 60 kHz.
60 kHz, for real?
There’s no doubt that a ribbon tweeter is exceptionally efficient. To understand its operating principle, it’s helpful to compare it to the classic dome tweeters which equip the large majority of acoustic speakers. Whether soft (fabric) or rigid (aluminum), domes have a structure which resembles the cone and surround of large drivers. The voice coil is directly attached to the dome of the tweeter. The electric current transmitted by the amplifier runs through it, causing both the voice coil and the dome to move. This creates the vibrations which produce high frequencies.
If domes are so often used for tweeters, it’s because their semi-spherical form allows for a wide dispersion of high frequencies. Since they don’t emit sound in just one direction, dome tweeters offer balanced sound even when the listener isn’t standing directly in front of the speaker. Moreover, dome tweeters have a low production cost. On the other hand, the principal of using a copper voice coil to drive a cone is not optimal from a mechanical viewpoint: the tweeter’s frequency response will be restricted by the coil.
For this reason, certain high-end speakers are fitted with a ribbon tweeter. The name comes from the fact that the tweeter is composed of a ribbon placed within a magnetic field created by magnets. The electric current sent by the amplifier runs through the ribbon and causes it to oscillate within the magnetic field. The extreme subtlety of the ribbon allows it to boast an exceptionally extended transient response, far superior to that of a dome tweeter. The high frequencies produced by a ribbon tweeter are especially discerning.
While ribbon tweeters offer certain advantages compared to dome tweeters, they are not without disadvantages. For example, a ribbon tweeter delivers less energy in the mids than a dome. Its impedance is also inherently very low, and it thus presents more of a challenge for the speaker’s crossover filter and amplifier.
The Monitor Audio Studio has a nominal impedance of 4 Ohms and a minimal impedance of 2.9 Ohms into 3.5 kHz. An amplifier capable of handling such a low impedance speaker is necessary, even though not all that much power is required from the amplifier at 3.5 kHz. The same cannot be said of a floorstanding speaker equipped with a bass-reflex port whose impedance plummets in the upper bass register. Such amplifiers have become relatively widespread: digital amplifiers, also know as class-D amplifiers with switch mode power supplies, can drive low impedance speakers without difficulty. This is not always the case for class-AB amplifiers, and you’ll need to keep an eye on the power ratings indicated for 8 and 4 Ohms. If the power rating doubles from 8 to 4 Ohms, the amplifier will have no trouble driving a pair of Monitor Audio Studio speakers. If the power rating isn’t 20% higher at 4 Ohms, this should be taken as a sign that the amplifier isn’t suited for low impedance speakers, and deafening sound levels should thus not be expected.
The Monitor Audio Studio speaker has inherited the mid drivers and tweeter of the Monitor Audio Platinum PL500 high-end speaker. In practice, this represents the speaker’s mid-high section, since lows are entrusted to several 8” (20 cm) drivers installed within a closed enclosure for the Platinum PL500. For the Studio, the pair of 4” drivers benefit from bass-reflex technology. However, comparing the Studio with the Platinum 500 floorstanding speaker is not very practical, since the two 4” drivers have completely different operating principles. Fitted within a closed enclosure, these drivers are limited in terms of extension in the bass register, and their transient response is naturally optimized. As part of the Monitor Audio Studio’s bass-reflex system, the same drivers have to exert themselves more, and their cones move more in order to restitute frequencies down to 48 Hz. Consequently, they are less efficient it the upper midrange, and Monitor Audio has chosen a lower cutoff frequency for the Studio than for the Platinum 500 with this in mind. This means that the ribbon tweeter has to make up the difference. In a nutshell: the Monitor Audio Studio is no match for the Platinum 500.
Monitor Audio Studio: test conditions and listening impressions
The Monitor Audio speakers need to be placed in an ideal spot–not too close to the wall–in order to open up and share the full depth of their soundstage. They should be placed sufficiently high and not too low. The ideal placement would be on stands at ear height.
Coming back to the ribbon tweeter, it is by nature very discreet. Fans of extravagance may be disappointed, while fans of subtlety will be delighted by the smooth and clear highs. The mids are natural and detailed yet leave something to be desired in terms of breadth, and as such we can’t say that we were completely satisfied. Our choice of the Hegel H190 amplifier–known for its neutrality–didn’t seem to be the best in the end, and an amplifier with less energy in the mids (the Denon DRA-100 or NAD C368 digital amplifier, for example) would certainly be a better match for the Monitor Audio Studio. The lows are tight and even, yet the impact and conviction ensured by larger drivers is lacking.
Monitor Audio Studio: compared to…
KEF LS50: the KEF LS50 offers less subtle highs, but its overall coherence, generous energy and wide soundstage make it a superior choice in the end. The amplified version (KEF LS50 Wireless) ensures a gratifyingly balanced sound.
Jean-Marie Reynaud Folia Jubilé: the small JMR is more natural, open and rigorous in its organization of the soundstage. The upper bass register is more powerful, and the JMR’s dynamic capacity makes it a more appealing choice.
B&W 705 S2: the decoupling of the dome tweeter allows this speaker to offer incredible spatialization, notably in terms of depth. Thanks to its bigger bass driver (6.5”), the 705 S2 is more powerful than the Monitor Audio Studio.
Monitor Audio Gold 50: also equipped with a ribbon tweeter–but only one 5” bass driver–the Monitor Audio Gold 50 offers a warmer sound and a wider soundstage. The lacquered finish and the curved cabinet make it an attractive alternative to the Studio.
Monitor Audio Studio: conclusion
The technologies implemented, while impressive, didn’t take our breath away while listening to the Monitor Audio Studio. By comparison, speakers in the Monitor Audio Gold series offer a more rewarding listening experience. The Monitor Audio Studio speakers do boast excellent neutrality and are a good match for fans of realistic audio restitution.
What we liked:
- The smooth and clear highs
- The accuracy of the sound message
- The speaker terminals
What we would have liked:
- A wider soundstage
- More expressive lows