In my review of Polk Audio's RT25i loudspeaker (September 2001, Vol.24 No.9), I was mightily impressed with Matthew Polk's execution of this $320/pair design. Although it has since been replaced by the RT27i, with slightly modified cosmetics and a different tweeter, the RT25i remains my favorite loudspeaker costing less than $500/pair.
Since that review, I've often wondered how Polk might fare with a speaker at a higher price. I'd been very impressed with Polk's demonstrations of their flagship LSi line at the Home Entertainment 2001 and 2002 shows, so when I learned that the…
Modern classical chamber music was also a good match for the LSi7. With the 1995 Santa Fe Chamber Music Festival performance of Kohjiba's Transmigration of the Soul (CD, Stereophile STPH007-2), the speakers "disappeared"—all of the subtle definition of harp, violins, and cello were palpable in the natural room sound. Similarly, the subtle percussion figures emerging from space on George Crumb's Quest (LP, Bridge 9069), combined with the delicate classical guitar technique, made me forget I was listening to a hi-fi system. With larger orchestral works, the Polk's superior high-frequency…
Sidebar 1: Specifications Description: Two-way, stand-mounted, reflex-loaded loudspeaker. Drive-units: 1" ring-radiator tweeter, 5?" polypropylene-cone woofer. Frequency response: 53Hz-26kHz, -3dB. Nominal impedance: 4 ohms.
Dimensions: 14?" H by 8 5/8" W by 10?" D. Weight: 21 lbs each.
Finishes: Ebony, cherrywood.
Serial numbers of samples reviewed: 00924.
Price: $820/pair. Approximate number of dealers: 150.
Manufacturer: Polk Audio, 5601 Metro Drive, Baltimore, MD 21215. Tel: (800) 377-7655. Fax: (410) 358-2870. Web: www.polkaudio.com.
Sidebar 2: Associated Equipment Analog sources: VPI TNT IV turntable, Immedia RPM tonearm, Koetsu Urushi cartridge; Rega Planar 3 turntable, Syrinx PU-3 tonearm, Clearaudio Aurum Beta S cartridge.
Digital sources: California Audio Labs Icon Mk.II Power Boss, Creek CD53 Mk.II CD players; Pioneer DV-333 DVD player.
Preamplification: Vendetta Research SCP-2D phono stage, Audible Illusions Modulus L1 line stage, Audio Valve Eklipse preamplifier.
Power amplifier: Audio Research VT100 Mk.II.
Integrated amplifiers: Creek 5350SE.
Loudspeakers: Alón Petite, NHT SB-3, Paradigm Atom…
Sidebar 3: Measurements The Polk LSi7 is of slightly above-average voltage sensitivity, at an estimated 88dB/2.83V/m. The impedance is specified as 4 ohms, but as the plot of impedance magnitude and phase against frequency shows (fig.1), the load remains above 6 ohms for much of the audioband, with a minimum value of 4.2 ohms at 212Hz. However, the electrical phase angle is quite severe in the upper bass, which will add to the drive difficulty. A good amplifier or receiver rated into 4 ohms will work best with the speaker.
Fig.1 Polk LSi7, electrical impedance (solid)…
It was a late Friday afternoon in May and I wasn't having much luck getting into Sony's multichannel SACD demo room at the Home Entertainment 2001 Show. Surely, as a member of the audio press and a freelance writer for Stereophile, I should have no trouble. Not this time. After several polite "Nos," a Sony consultant managed to snare for me the last ticket of the day.
I'm glad I persisted, because what I heard that day was totally new. It wasn't the huge room, or the $3000 SCD-XA777ES six-channel SACD player, or the pro-audio-level EMM Labs Switchman 2 six-channel analog…
The most worrisome note appeared in "The Winter of Our Discontent" (Sound & Vision, May 2001, p.43), in which Ken Pohlman commented that "A format war helped kill surround sound for music 30 years ago. This time it could destroy the whole music industry." He envisioned a Nuclear Winter befalling the music industry, resulting from "just the kind of brinksmanship we're seeing as the Super Audio CD (SACD) from Sony and Philips, and DVD-Audio, which is favored by a number of companies including Panasonic, Kenwood, and Toshiba, reach retailers' shelves." He went on to note that the music…
The SCD-C555ES took 15 seconds to change between different discs in its carousel, and about five to toggle between SACD and CD layers or from two-channel to multichannel areas of a hybrid disc. Track changes were almost instantaneous. I found the C555's Multichannel Management System (MCMS) essential for proper setup of the player. However, it works only when a multichannel SACD is selected for play. Once that's done and you set the C555 for Multichannel and SACD, pressing the Menu button and turning the AMS jog control dial will display eight options for loudspeaker setup (footnote 2).…
Getting Warm: "Red Book" Sound
To check out the SCD-C555ES's two-channel CD playback, I used "pure Red Book" 16-bit/44.1kHz, conventional CDs or selected the CD layer on the hybrid SACD discs. Compared to the much more expensive Krell KPS-28C CD transport playing conventional CDs, the C555 was more forceful and forward, with more presence and energy, but was less transparent, with a flatter soundstage. Fleetwood Mac's The Dance (Reprise 46702-2) excelled in punch and impact, but the band's voices had a bit more presence and hardness through the C555. David Bowie singing "Putting Out…
Sometimes the effect was startling. In "Anana," from James Taylor's Hourglass, just before the music starts, someone says "E-Rock-it" or "Erotic." In two-channel, the voice came from just behind the front speakers. In multichannel, however, the word jumped out from the right surround speaker in a flat, hollow voice startlingly different from Taylor's. The overall effect surprised me, and added lots of kick to the song's reproduction. For the rest of that track, the center channel conveyed almost all of the lead vocals, while the surrounds carried small amounts of backup vocals mixed with the…