A track I have recently been using to judge a speaker's low-frequency behavior is "All Too Well (Taylor's Version)" from Taylor Swift's album Red (24/96 FLAC, Big Machine Records/Qobuz). At 2:25, when Swift sings "'Cause there we are again in the middle of the night," the bass line drops an octave. The effect sounds awesome even on the little KEF LS50s, but on the Monitor Audio with the ports open, it was all too much.
I blocked both ports on each speaker and listened again to the low-frequency warble tones. Now the tones were reproduced evenly down to 63Hz, but the 50Hz and 40Hz tones were slightly suppressed. The 32Hz room mode was still boosted a little, but now I couldn't hear the 25Hz and 20Hz tones.
I ended up removing the foam plug from the bottom ports, which kept the magnificence of the dropped bass on "All Too Well (Taylor's Version)" but didn't allow the excited room mode to get in the way of the music. With just one port blocked on each speaker, the low frequencies offered good extension and weight coupled with excellent leading-edge definition. The kickdrum on the Taylor Swift track was well-differentiated from the bass guitar, which was similarly pitched.
I have been a fan of Taj Mahal since he performed live at Stereophile's Hi-Fi '95 show in Los Angeles, accompanying himself on piano and guitar. After reading Tony Scherman's review of Taj Mahal's Savoy in the July issue, I added the album (24/96 FLAC, Stony Plain Records/Qobuz) to my Roon library. Mahal's croaky vocals were stably presented as a narrow central image, and the individual images of the women singing the refrain in "Mood Indigo" were clearly defined and spread across the stage.
What you hear in the way of imaging accuracy will depend, of course, on how a recording was made. While Sasha Matson justifiably praised the then–20-year-old Barbra Streisand's singing in his June 2023 Recording of the Month review of Live at the Bon Soir (Legacy/Columbia), he noted that the piano sounded like it was "recorded in a coatroom." Listening to the 24/96 Qobuz stream of "Cry Me a River" on the Platinum 300 3Gs, the piano sounded more recessed than distant, but I was transfixed by how—forgive me for again using this word—palpably the speakers presented the image of Barbra's voice.
Looking back, I see I haven't commented yet on the Platinum 300 3G's degree of tonal neutrality. This speaker is commendably uncolored. Solo piano recordings are very revealing of problems in the upper midrange, but the piano on the Silverman concert recording sounded both natural and full range, with no notes emphasized. The only aspect of the Monitor Audio's sonic signature that did occasionally concern me was a slight emphasis to recorded sibilance, more noticeable with the solid state Naim and Parasound amplifiers than with the tubed Audio Research I/50 or, paradoxically perhaps, the class-D NAD. The I/50's top octave starts to roll off prematurely into low impedances (footnote 1), which could account somewhat for its mitigation of this slight sibilance, though the shape of the Platinum 300 3G's impedance magnitude trace (fig.1 in the Measurements sidebar) suggests that this rolloff will be minimal.
With its clean, uncolored midrange, its well-controlled, extended low frequencies, its well-defined stereo imaging, and its ability to play much louder than my usual minimonitors, Monitor Audio's elegant-looking Platinum 300 3G is a high-performance loudspeaker. Strongly recommended.
Footnote 1: See fig.1 here.
