MartinLogan Sequel II loudspeaker Page 3
In the lower treble, I began to suspect a slight degree of character, noticeable as a slight hardness on female voice when driven to high levels, but again, this was exemplary performance. And the Sequel is one of the few speakers to accurately reproduce the "crackle" that rides above the body of the tone of trumpet and trombone in real life, or the rattle typical of the handstopped French Horn.
Moving down in frequency, the upper midrange, which I think of as the two octaves between 750Hz and 3kHz, ie, the region above the treble staff where high-pitched instruments still have fundamental energy (flute, violin, soprano, and piano, for example), was also relatively free from coloration, particularly when compared with a typical moving-coil loudspeaker. (This is the region handled most poorly, in my opinion, by a typical two-way box speaker.) Strictly speaking, there was a slight balance anomaly in this region, however, in that the lower octave seemed stronger than the upper. Listening to my own piano recordings revealed a slight break where the higher notes in this region moved back a little in space compared with the lower notes. This trend was continued in the upper octave of the lower midrange (200750Hz), where instruments having the bulk of their energy in this region were projected forward of the line joining the two loudspeakers. Male voices, for example, reproduced in a somewhat upfront manner. Aaron Neville, on "With God On Our Side," from the Neville Brothers' Yellow Moon (A&M CD 5240), was presented as being distinctly in front of the speaker plane. However, apart from the slight hardness at high levels noted above, I heard very little coloration.
This was not the case on lower-pitched voices, however. A slightly "woody" or "boxy" signature could be heardLA referred to it as "cardboardy"; at least he agrees that it is some kind of cellulosethat also accentuated the nasal character of viola and cello. It was almost as if the speaker emphasizes the wood of the instrument's body rather than the airspace within the wood. Violin, too, took on some of this character on its lower two strings, as did LP groove noise and recorded tape and microphone hiss. The rain gently falling on the recital-hall roof during Ivor Humphreys' performance of Gluck's Dance of the Blessed Spirits on the HFN/RR Test CD, while more noticeable than on any other loudspeaker I have tried, also took on the same sound quality. To put this into perspective, this trait"coloration" is too strong a wordwas made more obvious by the lack of departures from neutrality in the octaves above the lower midrange.
Jumping to the low frequencies, the bass was light in weight, having a shelved-down nature. Kick drums generally lacked visceral impact. That the Sequel had good extension, nevertheless, was apparent, however, organ pedals setting the floor into vibration. The Dorian recording of the Bach Goldberg Variations (DOR-90110), for example, appeared to lack for nothing in low-bass weight, the floor appropriately shaking.
It was in the upper-bass/lower-midrange transitional region, however, that the Sequel II was revealed as having problems. A confusion overlaid the tonalities of instruments having a high spectral content between 100 and 300Hz, coupled with a lack of body to their sound. At first, I though that I had inadvertently wired the speakers out of phase, but that proved not to be the case. But all the visitors to my roomLarry, Richard Lehnert, Guy Lemcoe, Stereophile's computer consultant and consulting audiophile Michael Mandellafter enthusing over the clarity of the Sequel's midrange and its superb soundstaging precision, remarked first that there was "something odd" about its upper bass, then decided that the sound was just undernourished in this region.
Overall, I suspect an overdamped low-frequency alignment, though in itself this doesn't explain the paradoxical nature of the bass. Listening to pink noise revealed a slight lower-midrange forwardness, as suspected, and extended, though reduced in level, low bass. The treble was impressively smooth, unbroken by major response peaks. Yet there was an audible "hole" between bass and midrange, a lack of energy in the transition region, that significantly worsened as the listening axis increased in height. This is the exact region where the Sequel II has its crossover, so I conjecture that this must be at least part of the problem. The problem did seem to lessen over time, suggesting that a long break-in period is mandatory. The effect was also less noticeable with the Levinsons than with the Krell, suggesting that those who fall in love with the midrange, treble, and imaging performance of the Sequel should shop very carefully for a matching power amplifier. Sam Tellig, who overall was disappointed with the Sequel II, suggests that it works much better with good tube amplifiers, for example, and even the B&K ST-140.
Incidentally, pink noise revealed that though the levels of spurious coloration from the enclosure were low, a single strong mode could be heard at 115Hz with the ear close to the side walls. The entire speaker could be felt to shake at this frequency.
I keep mentioning the Sequel's imaging without going into detail. The one area where the Sequel did excel was in its ability to throw superbly defined soundstage depth (with the caveat that this will be very dependent on room positioning). A track that featured heavily in the 1987 "Carver Challenge" listening tests was "Die Täanzerin" from the German woman singer Ulla Meinecke (German RCA PL 70932). Recommended by my UK friend Ricardo Franassovicia Statement owner, no lessthis has Fraulein Meinecke accompanied by a rich synthetic piano, by what sounds like the rhythm circuitry of a cheap Casiotone, and by finger pops. I agree that there is nothing real there, OK, but the appeal of the track for testing hi-fi components is that both electric piano and voice have been sweetened with a delightful-sounding reverberation chamber. I have been drawing a straight correlation with component quality and the length of time this reverberation tail stays audible. With lesser speakers, you hear that the producer has added artificial reverberation; via the Sequels there is a long, long, cavernous tunnel between and behind the speakers.
This ability to decode depth was apparent on every recording I tried. Returning to the Solti Die Walküure, after the nervous orchestral introduction (footnote 1), the Sequels enable you to hear Siegmund (for it is he) enter stage right at the rear and slowly walk forward to front center. His sister and eventual lover Sieglinde can be quite clearly heard to enter from the left rear of the stage (where the stage directions state that there is an inner chamber) and walk to the center front. Such verisimilitude adds considerably to the theatrical experience, to my way of thinking.
There were some peculiarities of the Sequel's imaging, which may have something to do with its quasiline-source design. Central images consistently seemed to have more height than images at the sides, for example, and as this applied also to perceived ambience, gave the impression of dome-shaped recording sites. The stage also seemed less wide than I was used to with the Celestions, and as mentioned earlier, images with a strong lower-midrange content were projected forward of the speaker plane. But, all things considered, I was much impressed by the Sequel's abilities in this region.
The Sequel II is a frustrating loudspeaker in that its superlative performance in many areas too clearly highlights problems that in a lesser design might go unnoticed. On the positive side, it has one of the smallest editorial effects on the sound in the upper midrange and highs of just about any loudspeaker I've heard. Soprano instruments and female voices are presented with their natural tonal qualities intact, and just hang in space in front of the listener. In this respect, the Sequel II is a non-speaker, acoustically disappearing from the listening room. Apart from a slight projection of the lower mids and that slightly wooden coloration noted above, this is an astonishingly neutral speaker in the midrange and above, especially when considering its relatively affordable price. Dynamics, too, provided that a beefy enough amplifier is used, were unmatched by any electrostatic that this gentle listener has heard, with the exception of the big Sound-Labs and, of course, MartinLogan's own Statement. And the quality of the bass was tight, extremely well-defined, and free from any boom or overhang.
Yet...even after all the fiddling with position and ancillary equipment, I was still dissatisfied with the speaker's performance in the crossover region, the transition between the upper bass and the lower midrange. That the sound ultimately failed to gel in this region was thrown into sharp contrast by the excellence above and below. In a sense, the evolution of the Sequel is an essay in the speaker builder's art, in that if you have an uncolored, dipolar electrostatic panel and a fast, well-tuned, reasonably omnidirectional woofer, just where do you arrange the crossover between them?
Intuitively, I feel that the original Sequel's 125Hz crossover frequency was a better choice than the II's 250Hz, in that the latter straddles a region where male voice and many instruments have their fundamental energies. But I am sure that the electrostatic panel just can't be pulled down that low in frequencyyou're starting to talk serious excursion for a 480in2 panel at 125Hz. In addition, the conflict between the panel's dipole dispersion pattern and the woofer's omni pattern will be more severe at this lower frequency. The result with the higher frequency join between the drivers, however, is a feeling of uncertainty about the sound of male voice and tenor instruments that is exacerbatedto an extent very dependent on choice of amplifier and cableby the lack of room energy in the crossover region and the slightly shelved-down low bass. It is almost as if, having solved the impossible task of making a relatively flat-response, neutral electrostatic panel with good dynamic range, designer Gayle Sanders had insufficient creative energy left to fully optimize the system design.
I must say, however, that once I had adjusted the room position to the optimum and changed to the Mark Levinson amplifiers, putting the low-frequency problems to one side, the transparency offered by the Sequel IIs was addictive. Changing back to my usual reference, the Celestion SL700, revealed that the British speaker is too forward in the lower treble and distinctly fuzzy-sounding by comparison, even though the integration between its upper bass and lower midrange is better handled than by the Sequel. Regarding long-term listening, I must say that the Sequel wins on pointsfor now.
To sum up, therefore, to give an overall value judgment, is difficult. If you value the integrity of low-frequency response and the ability of a speaker to kick, er, backside above all else, then the Sequel will definitely not be for you. But if you value the ability of a loudspeaker to decode recorded detail without that detail being thrown at the listener, coupled with a clean, clear midrange, relatively unfatiguing highs, and superb presentation of soundstaging, then MartinLogan's Sequel II must be on your short list, provided that you are prepared to experiment with the rest of your system (and perhaps spend a lot of money on a matching amplifier).John Atkinson
Footnote 1: I defy anyone to hear the horn theme in this introduction without thinking of the song "Over There." Which reminds me of the best definition of an intellectual I ever heard: "Someone who can hear the William Tell Overture without thinking of the Lone Ranger."John Atkinson