- Written by Dr. David A. Rich
- Published on 10 May 2012
The Phase Technology PC-3.5 Speakers In Use
I do not judge a speaker on a few CDs. Instead, I use at least 15 cuts ranging from string quartets to Mahler-sized orchestras. With the cuts on one CD-R, I can complete the initial evaluation in ten minutes. Marketing manager Tony Weber (a classically trained composer who studied under some of the most important American composers of the last century), formerly at Phase Tech, and now at Cary Audio pushes the limit farther with nine reference CD-Rs of eight different cuts each. This approaches what I call the random pull test: go to your collection and pull something out at random. I find 30% of classical CDs are well recorded so you have a 30% chance that your random selection will sound good on a well-designed speaker without intentional voicing. If it's cooked to sound good on specially selected discs chosen by the manufacturer (this is the standard CES trick for the $200,000 class) then the speaker will fail the random pull test.
The first reaction to the speaker is its wave launch. Unlike a three-way floor-standing speaker, all instruments emerge from a single point at the center of the speaker. In a floor stander with the woofer – midrange crossed over at 500Hz – 1kHz, the image shifts with the range of each instrument. Low brass and bass violin emerge from the bottom, oboes and clarinets in the middle, and the upper octaves of the violin or flute near the top. This is unnatural compared to the concert hall experience. Some floor standing speakers have a crossover below the frequency that the room dominates (250Hz and below). Floor standing speaker with a crossover that low will not exhibit the shift in vertical image.
The apparent size of lower-pitched instruments increases in the vertical direction as the PC-3.5s woofers become active, emulating the sonic characteristics of instruments that dwell in the music's bass line -- think of the size of a double bass or the bell of a trombone. The wave launch of the PC-3.5 increases the depth of the image, with the large brass sounding as if they are at the rear of the stage behind the strings.
On the Vladimir Ashkenazy recording of the Rachmaninov Etudes Tableaux Op 39 (reissue with other works Decca 455234), the hallmark clarity of Ashkenazy's finger work is apparent as is the pianist's joy in playing works of his countryman. The sound of the hammers striking the strings is well conveyed in this perhaps a little too close recording.
Despite its small form factor, the PC-3.5 provides full-range bass response without the port tuning that creates an artificial bump in the 100Hz range. Britten's Young Person's Guide to the Orchestra, which sequentially highlights each orchestra section, well illustrates the speaker's performance at the bottom end. I used the Pavo Jarvi performance with the Cincinnati Symphony (Telarc SACD 60660). The tympani solo has a strong initial whack, but also a clear tonal center thereafter. Differently pitched tympani match in tonality. One clearly hears the mallets striking the heads as the player moves among the drums. In the double bass section, the bowed strings are distant. If you want even more impressive low-end smoothness, add a good room EQ. This speaker loves being EQed at the bottom. Unlike most ported speakers, it is not significantly affected if the room EQ tries to extend the low end with a 6dB boost at 40Hz.
The unique style of Arvo Pärt's 3rd symphony is transitional, sandwiched between his twelve-tone serialism and his minimalist stage. The work ranges from chamber-like intimacy to the full breadth of the orchestra. On Neeme Järvi's first recording (BIS CD434) of the work, the PC-3.5 showed no signs of non-linearity at least to levels that I was willing to tolerate. The fortissimo trumpet solo near the end was clear without any signs of taxing the speaker's limits.
Bernard Herrmann's score for On Dangerous Ground requires a huge orchestra. Charles Gerhardt conducts the RCA Classic Film Score series recording of the work which was reissued last year on the 100th anniversary of the composers birth (RCA Red Seal 88697 81264). Engineer Kenneth Wilkinson preserves the orchestra's great sound and allows Herrmann's music to stand on its own merits without reference to pictures. The large horn and brass sections challenge the speaker to not only avoid compressing the dynamics, but also avoid obliterating the counterpoint of the string passages. The Phase Tech PC-3.5 handles the task nicely, with the strings remaining smooth and distinct. I listened to the CD on several two-way mini-monitor designs; the strings are either lost or turn strident because the woofer has too much to do.
I compared the Phase Technology speakers with a similarly priced Infinity C336 (now discontinued) speaker that also generates close to benchmark-like measurements (I reviewed it for AudioXpress) but uses a aluminum/ceramic driver material, a cone midrange, and a waveguide on the tweeter.
The Infinity speaker sounded dry, yet with a slight edgy coloration. The flute on the Windscape recording of Dvorak Arranged for Winds (MSR 1175) sounds more brittle, while the PC-3.5 floats the flute in space with more harmonic richness.
Without the waveguide, there is a less localization of the cabinet. A good illustration of this is Vaughan Williams Five Variants on Dives and Lazarus (Chandos 8502). The string sound is richer and the ensemble spreads across the stage. The narrow baffle may also help the speaker to achieve this.
There are similar differences with the Jerusalem Quartet's recording of Haydn's Lark quartet (Harmonia Mundi 2962030). As the first violin ascends the E string, the Phase Technology offers a more airy sound.
Without tweaking its placement, the Infinity C336 shines with the smooth octave to octave balance at and above the midrange. This can be attributed to the differences in the radiation patterns. The Infinity C336 off-axis energy is reduced in comparison to the PC-3.5. A 75 degree offset in the horizontal direction the Infinity C336 is down 7dB at 4 kHz in comparison to 3dB down for the PC-3.5. At 10kHz, the difference in respective output levels between the two speakers grows to 6dB. The result is less energy from wall reflections, making these speakers more room tolerant, but at a cost. The C336 tweeter had a resonance at 15kHz peak with an amplitude increase of 3dB from the 10kHz baseline. The audibility of this artifact is debatable.
PC-3.5 requires more attention to toe-in angles and its distance from the rear and side walls. Too much toe-in results in a sound that is too forward in the upper midrange. The distance between the PC-3.5s and the listener is more forgiving since the smaller length of the combined driver set allows the sound field to converge at a closer distance. Both speakers are friendly with respect to seating height.
The Phase Tech is perfect as a matched center. A floor stander in the center of the room looks a little strange. A typical center channel will sound out of kilter.
The typical placement of a center channel in a home theater will significantly degrade the sound of multichannel audio. A detailed discussion on center channel placement is found at the link below. In this Technical Article, We Don't Need No Stinking TV's, the Phase Technology PC 3.5 was often used for subjective evaluations of a system with optimally placed speakers
RCA and Mercury released numerous SACDs from master in the 1950s recorded in three-channel sound. One example is the famous Reiner Chicago Symphony Orchestra recording of Rimsky-Korsakov Scheherazade (RCA SACD 66377) under which the speakers virtually disappear. The sound of the woodwinds from a real center speaker emulates the concert hall effect. Unlike stereo, the mind need not create a virtual center.
The CSO brass require a speaker than can work well at high SPLs when the score requires it, but the sound never turns course in this three-channel recording played on the PC-3.5s. At the same time, the solo violin passages are smooth and well articulated. With the sound directed between the left and center speakers, the violin's wave launch is well portrayed.
It would have been interesting to run five Phase Tech PC-3.5s in multichannel, but it is rare to invest that much money in the rear channels. Phase Tech supplied the PC-1.5 matching two-way mini monitor for the rear installation of a five channel setup. This is more typical of how the PC series can be deployed. The combo of three PC-3.5s and two PC-1.5s in the rear produce truly exceptional multichannel sound on well-recorded SACDs using the Sherwood R-972 AVR with Trinnov EQ on. Unfortunately, most current multichannel classical discs have only ambience in the center channel since the recording engineers anticipate consumers will deploy a thin, on wall, center channel below the flat screen TV. The 1950s recordings, with a true center channel, are much closer to the real thing than these new SACDs, which are, in effect, stereo recordings with ambience from the rear speakers.