Infinity Modulus loudspeaker & Modulus subwoofer Page 2
The Modulus pedestals were supplied ready-assembled; all that I needed to do was to fill the 22", diecast aluminum center pillars first with 12 lbs of No.8 hard lead shot, then with dry sand to within 1" of the top plate. A foam plastic insert then ensures that the top plate is adequately damped. The base of the Modulus pedestal is fitted with four carpet-piercing spikes. These can be adjusted from above to ensure the stand is free from rocking; knurled screwtops then lock them in place. For those who are leery of spikes, Infinity supplies spike covers. The Modulus speaker is supplied with three conical "Iso-tip" feet, which mate with rubber-lined sockets on the top of the pedestal. Contrary to British audiophile practice, there is therefore some compliance introduced between the speaker and stand. Two knurled screws secure the speaker to the pedestal top-plate; these are not intended to be fastened tight, only to prevent the speaker from being carelessly knocked to the floor. Following Infinity's instructions, I tightened the mounting screws all the way, then backed off a full turn.
As mentioned above, Infinity apparently spent a lot of design attention on the Modulus's grille. Auditioning the speakers with and without grilles, however, left me in no doubt that the smoothest treble and the best imaging was obtained with the Modulus used au naturel. This was how I continued with the auditioning, therefore.
Although it is not mentioned in the Owner's Manual, I understand the Modulus does need fairly rigorous break-in before reaching its optimum performance. Accordingly, I drove the review pair with pink noise at quite a high level overnight for two nights before attempting any serious listening (footnote 2). I started off with the speakers toed-in to the listening seat, but found that pointing them straight ahead minimized a slight degree of liveliness in the low treble. I also started off with the speakers 6' away from the side walls and some 4' out into the listening room, but reduced this latter distance to 30" to usefully add a bit of midbass reinforcement.
The Moduluses are quite definitely minimonitors when it comes to the bass registers, 63Hz being about the subjective limit. Bass instrumental fundamentals were absent and the well-damped nature of the speaker's upper bass meant that the sounds of wide-ranging instruments like the piano sounded too small for ultimate satisfaction. The double bass also suffered to a greater extent than, for example, with the similarly sized LS3/5as. At the start of the Adagietto of Mahler's Symphony 5 (VPO/Bernstein, DG 423 608-2), the double basses punctuate the accompanying harp arpeggios with soft pizzicato fundamentals to reinforce the harmonic movement, only switching to their bows for a dominant pedal when the strings plunge down before the theme's first cadential resolution—a goosebump moment on speakers that have any significant output in the middle bass. Via the Moduluses without the subwoofer, the relative absence of the harmonic underpinnings left the music sounding rather thin. It wasn't that the double basses weren't there, but that they were just too lightweight to be effective. Via the Rogers (which is certainly more colored overall than the Infinity speaker), the upper bass was just sufficiently exaggerated to fool the ear in this respect.
The Moduluses did many other things well, however. They are impressively neutral in overall balance, being ostensibly flat-sounding from the upper bass to the high treble. The top octave can sound a little over-emphasized, exaggerating the audibility of tape hiss and LP surface noise, but the tweeter-level control offers sufficient range to compensate for this. Instrumental tone colors were therefore reproduced with an excellent degree of faithfulness, something I had not experienced to anything like the same degree with prior Infinity models.
Coloration levels were also very low; the only traces of character noticeable, and then not with every kind of music, were a slight "cupped-hands" color to male spoken voice, which also gave recorded flute too warm a sound in its lower registers, and some liveliness in the lower treble which was most noticeable on piano.
As with other very small-baffled loudspeakers, lateral image precision was stunningly precise. Images were locked into position, giving an excellent sense of solidity to the sound. Something I found surprising, however, was that image depth was more restricted than I'm used to with other good loudspeakers. The depth of image test on the Chesky Test CD, for example, has Bob Angus speaking and David Chesky playing a tambourine recorded increasingly farther from the microphone. On many speakers, the direct sounds become swamped with reverberation as the sources get quieter due to being farther back. Via the Moduluses, that reverberation seemed somewhat suppressed, so that the sounds tended to remain dry even as they got quieter. The same thing was noticeable on both my piano recording and Robert Harley's acoustic guitar and double bass recording on the Stereophile Test CD, both of which should produce instrumental images set back a little behind the plane of the speakers with a good sense of the surrounding acoustic apparent. The Infinities noticeably reduced the depth of image, even though the instrumental sounds were both well-located laterally and very natural-sounding.
Though the lack of mid- and low bass will be a factor here, my experience of other loudspeakers suggests that this subjective effect could also be due to a lack of energy in the presence region, which can have the effect of suppressing reverberant information. That this might be a problem with the Modulus was reinforced by the speaker's dynamics, which were on the polite side. Despite their diminutive dimensions, the Infinities would play quite loud, capable of giving spls around 96dB in my room before too much of a sense of strain cut in in the low treble. However, there was a certain lack of excitement about the sound even at highish levels, as though the speakers were unwilling to "give," in musical terms. Partly this was associated with a slight degree of congestion in the lower midrange which cut in with increasing level—this congestion was more severe before the speakers were broken-in—but it was also due to a reticence in the speaker's presence region. Even such well-recorded rock music as John Hiatt's Bring the Family (A&M SP-5158) lacked impact, even from LP, which was generally served better than CD in this respect by the Moduluses. Hiatt's acoustic guitar sounded as though it had been strung with a heavier gauge of string, reducing the transient attack of the instrument.
The only kind of music to satisfactorily avoid this over-polite rendition was rock, and then only when it was over the top, excitement-wise, in the first place. The opening track on Luka Bloom's excellent Riverside CD (Reprise 9 26092-2), "Delirious," features frantic Ovation acoustic guitar strumming—an unmistakably "rubber-bandy" tone color—behind his voice. No problems via the Moduli—goosebumps at last!
Following the auditioning of the Moduli on their own , I hooked up the Modulus subwoofer and its control unit. At first, the output of the Mark Levinson No.26 fed the Infinity control unit, with then the high-pass outputs feeding the Mark Levinson No.20.5s via 15' lengths of Audio Research cable. The DIP switches on the controller's rear were adjusted to suit the Levinson's 50k input impedance, which gave a measured response 6dB down at 100Hz. The subwoofer was positioned midway between the satellites, at first adjacent to the rear wall, then some 2' away from it. Unfortunately, no matter what combination of signal and component grounding I tried, I couldn't rid the system of hum through the satellites, presumably due to a ground loop of some kind. (The hum never came from the subwoofer.) Floating the CD player with cheater plugs, or the preamp, or one or two power amplifiers, or the Infinity subwoofer, or any combination of the above resulted in no change in the hum level, though floating all the components gave a large increase in the hum level. I also tried reversing the polarity of the floating components with no effect.
Finally, I fed the variable output of the Meridian 208 straight into the Infinity controller; this gave a slightly lower level of hum, as did making the only system ground that of the subwoofer. The only way to eliminate the hum was to take the satellite feeds from the crossover's parallel set of inputs. These are unfiltered, however, so much of the dynamic advantage offered by subwoofing was lost.
Footnote 2: Sometimes the obvious never does strike you. It was Tom Norton who pointed out to me that the least aurally fatiguing way in which to break-in speakers is to wire the pair in inverse polarity and place them face-to-face. This way, most of the midrange and bass energy cancels, minimizing the overall level of sound but still allowing you to work the speakers hard.