Installation and setup
The Helsinki 1.5's installation guide, available as a .pdf document from the Gradient website, suggests starting with the Helsinkis toed-in about 45°, and with the woofer magnets facing each other. SimpliFi Audio's own installation guide, provided to me by Tim Ryan, agrees with the 45° angle and goes further, saying each speaker should be no more than a foot away from either its respective…
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While examining the Helsinki 1.5's drivers and their baffles, and while poking around behind its connector plate, I never found a crossover. But I assume there is one.
I'd never before heard anything like it. Over the years, the spatial performance of my favorite speakers has been such that a very good sense of scale is implied, but that has always required either a physically large speaker or some assistance from room boundaries—either of which produces the sorts of reflections and delays that help one believe one is hearing something big. The Gradient Helsinkis approached scale in a different and remarkable way. Examples abounded, but my favorite was while listening to the Andante of Mozart's Symphony 38, K.504 ("Prague"), played by Colin Davis and the…
Sidebar 1: Specifications
Description: Three-way floorstanding loudspeaker. Drive-units: 0.75" aluminum-dome tweeter, 5" paper-cone midrange, 12" paper-cone woofer. Sensitivity: 85dB/W/m. Impedance: 6 ohms nominal, >4 ohms minimum. Recommended amplification: 25–250W.
Dimensions: 36" (920mm) H by 14" (360mm) W by 19.75" (505mm) D (sort of). Weight: 50.6 lbs (23kg).
Finishes: Birch, Walnut (oiled), Oak (oiled), Black, White; metallic paint on driver enclosures, add $750/pair.
Serial Numbers Of Units Reviewed: 00376, 00377.
Price: $6500/pair. Approximate number of dealers: 5…
Sidebar 2: Associated Equipment
Analog Sources: Thorens TD-124 Mk.II turntable; EMT 997, Schick tonearms; Shindo SPU, EMT OFD 25 & OFD 65 cartridges.
Digital Source: Ayre Acoustics QB-9 USB DAC (with Apple iTunes).Preamplification: Auditorium 23 Hommage T1, various ">Bob's Devices step-up transformers; Shindo Masseto, Fi 2b preamplifiers.
Power Amplifiers: Shindo Corton-Charlemagne, PrimaLuna DiaLogue Seven monoblocks, Electrocompaniet AW400.
Integrated Amplifier: Ayre Acoustics AX-7e.
Loudspeakers: Audio Note AN-E/SPe HE, Wilson Audio Specialties Sophia 2.
Cables:…
Sidebar 3: Measurements
I performed the quasi-anechoic measurements on the Gradient Helsinki 1.5 with DRA Labs' MLSSA system and a calibrated DPA 4006 microphone. The nearfield measurements were done with an Earthworks QTC-40 microphone, which has a ¼" capsule. Gradient specifies the Helsinki 1.5's voltage sensitivity as 85dB/2.83V/m; my estimate was 84.4dB(B)/2.83V/m, which is within experimental error of the specification. However, this is lower than average; as Art Dudley noted, the Helsinki 1.5 was a little more power-hungry than the speakers he's accustomed to. The impedance…
Everyone wants something different from a loudspeaker. Some people value midrange neutrality above all, while others will sacrifice some of that accuracy to get extended lows or a speaker that will play immensely loud with only a few watts of power. Some want stereo imaging that is sufficiently delicate, stable, and accurate that the speakers open a transparent window on the recording's original performing space. Some will sacrifice all of the above to get a speaker whose "jump factor" can jerk zombies out of their stupor. And there are those who are prepared to lose just a little bit of…
Rather than reaching for Mahler symphonies, I found myself listening to recordings of small numbers of instruments and with a fairly restricted dynamic range—such as our December 2009 "Recording of the Month," Anouar Brahem's The Astounding Eyes of Rita (CD, ECM 2075). Even so, the grumbly bottom-octave notes of the double bass in the middle of the slow movement of Brahms' Symphony 4, in the recording by Carlos Kleiber and the Vienna Philharmonic (SACD, Deutsche Grammophon/Esoteric ESSG90018) were satisfyingly audible, if somewhat miniature in scale. Similarly, while the softly struck bass…
Sidebar 1: Specifications
Description: Two-way, sealed-cabinet, stand-mounted loudspeaker. Drive-units: 0.75" (19mm) magnetically shielded, aluminum-dome tweeter; 5" (110mm) magnetically shielded, Radial2-cone woofer. Frequency response: 75Hz–20kHz, ±3dB. Nominal impedance: 6 ohms ("easy to drive"). Sensitivity: 83.5dB/2.83V/m. Recommended amplification: >15W. Power handling: 50W program.
Dimensions: 12" (306mm) H by 7.5" (189mm) W by 8" (202mm) D, including grille and terminals. Weight: 14 lbs (6.3kg).
Finishes: All real-wood veneers: Cherry, Black Ash; add $200/pair for…
Sidebar 2: Associated Equipment
Digital Sources: Ayre C-5xeMP universal player; Simaudio Moon Evolution 750D CD player; dCS Puccini SACD player & USB-input D/A converter with Apple Mac mini for media storage; Apple iPod Classic 160GB.
Preamplifier: Simaudio Moon Evolution P-8.
Power Amplifiers: Classé CTM-600 monoblocks, Simaudio Moon Evolution W-7, Balanced Audio Technology VK-55SE.
Integrated Amplifier: Peachtree iDecco.
Loudspeakers: BBC LS3/5A.
Cables: Digital: Kimber Illuminations Orchid AES/EBU, Stereovox CV2 electrical S/PDIF, Belkin USB. Interconnect (balanced…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Harbeth's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses. Harbeth specifies the P3ESR as having a sensitivity of 83.5dB/W/m. My estimate was slightly less than this, at 83dB(B)/2.83V/m, but this is within experimental error of the specification. This is a significantly lower sensitivity than the norm, meaning that the little Harbeth will need a fairly powerful amplifier to play at acceptable levels in all but…