The basis of Monopulse loudspeakers lies in applying audio lessons that were learned working with phased-array radar systems, the prime purpose being to reproduce transient leading edges accurately.
The consequent need to time-align the outputs of the three drive units at the listening seat imposes some constraints on the driver layout.
These are solved by adopting a floorstanding configuration (which determines the height of the drivers above the floor), by placing the tweeter beneath the bass/mid drive unit, and by mounting a super-tweeter on the top, set back from the front panel under a metal protective hoop.
The complexity of this arrangement perhaps goes some way towards explaining the decision to go for a fabric covering over the front and sides of the enclosure. One worthwhile consequence is that the speakers are, therefore, available in a wide choice of different colours, perhaps chosen to match carpeting or curtains. Alongside the fabric, the top ‘hoop’ is polished steel (again with colour options), the back is covered in a thin foam sheet and more foam protects the super-tweeter.
Despite its very slim appearance from the front, the £1,195 per pair 62S still has room for a 160-millimetre bass/mid driver with a visible (through the fabric) cone diameter of 110mm. The main tweeter has a relatively large soft- dome diaphragm (which probably explains why a super-tweeter is fitted). Simple single element (6dB/octave) crossovers are used to maintain phase integrity.
The enclosure is reflex-loaded by a downward-firing port in the base, metal feet keeping the port clear of the floor with or without the use of thumbwheel-tightened spikes. However, there’s no extra plinth and the footprint is very modest, so physical stability is distinctly marginal.
Electrical connection is via twin terminal pairs set high off the ground, so trailing wires are unavoidable.
As the sighted operator sitting in the prime listening position, I was very impressed by the sound quality of the 62S during the listening test, despite a rather ‘heavy’ bottom end that made setting an appropriate listening level rather tricky.
The other listeners were rather less impressed, which with hindsight is of course entirely logical. The Monopulse is deliberately designed as a ‘sweet spot’ loudspeaker, and will, therefore, show expression and time coherence in a relatively small listening zone. As a result of this, maximum performance will never be evenly achieved across the wide seating area required to accommodate a listening panel.
In short, the bass end is rather too strong here, as is the top end, the combination giving a touch of ‘loudness contour’ effect which somewhat favours listening at modest levels. Imaging is impressively spacious, with potentially excellent focus and coherence, though the overall sound could be smoother and the top end, in particular, sweeter and less obvious.
Different in nearly every respect from the stereotypes, the Monopulse 62S has unusual styling and presentation and its sonic performance is strongly oriented towards the sweet spot listener. One can criticise the weak midband sensitivity and poor physical stability, but in other respects it certainly represents an interesting alternative.
LIKE: Fine ‘sweet spot’ focus and coherence with good definition
DISLIKE: Poor physical stability and weak midband sensitivity
WE SAY: Interesting alternative in styling and focus, but not without its flaws
DIMENSIONS: (WxHxD) 175x920x200mm
• Incorporates a super-tweeter
• Phase-accurate driver disposition
• Twin terminal pairs
• Port-loaded through the base
• Fabric covered with colour options
DISTRIBUTOR: Monopulse UK
TELEPHONE: 07785 558238
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