Back in March, in The Audio Voice, and now also available in a post on the audioXpress website I shared my “Test Tunes for Subjective Evaluation of Drivers and Loudspeakers," featuring some of the many audio tracks that I often use for the subjective evaluation of drivers and loudspeakers. Here are more selections from the audio tracks I often use for the subjective evaluation of drivers and loudspeakers. This time, the theme is Instrumental Music: Small-Scale Soundscapes.

All these tracks present unamplified music being played in a performance venue (or a studio that once was, or which could do double-duty as, a performance venue), rather than in a typical acoustically dead recording studio. Moreover, as far as I know, with no added reverberation.

These tracks are available as a playlist on two high-quality streaming platforms: 

Qobuz: https://play.qobuz.com/playlist/13835213

TIDAL: https://listen.tidal.com/playlist/bd580fba-b148-4ded-b373-dc487746e4e4

Please note: To its credit, Qobuz does not “normalize” the volume level of its tracks; therefore, you might have to adjust the volume levels as you go. If you listen on Tidal, you might wish to adjust your Account’s Settings to defeat "Loudness normalization."

As difficult as it might be to believe, there is only one guitarist playing the veritable torrents of notes that occur at times in this, one of the most dark, serious, and mysterious (and also, technically and musically demanding) pieces that classical guitarists play. Britten’s Nocturnal is not so much a set of variations on a theme, as an 18-minute reconstruction of a previously-deconstructed “Come, heavy sleepe,” by John Dowland (1563-1626). In other words, inverting the classical model, the theme is stated only at the very end.

Listen for the distinctive sounds of the variety of guitar techniques the composer Britten summoned, including harmonics and percussive pluckings and hammerings. Also, the “small sounds” of producing the music, and the incidental sounds such as breathing, and perhaps even of the guitar rubbing against the player’s clothes. Guitarist David Leisner has extraordinary technique, but even more importantly, he has a finely-honed sense of dramatic timing.

By the way; and I should have mentioned this last time: If you decide to use a track such as this one, where so much of the information is in the “small sounds,” for the subjective evaluation of drivers and loudspeakers, it is very helpful to listen to the track on high-quality headphones, as a reference.

Now that you have heard a modern (composed in 1963) instrumental version of “Come, heavy sleepe,” here’s a much more Elizabethan vocal version. Baritone-tenor a cappella harmony first, followed by an “original instruments” reprise. Joel Fredericksen’s voice should sound rich and weighty, but not boomy or slow.

The lute was a predecessor of the guitar; bass lutes were called Theorbos. Because it was designed to play a full octave lower than the other instruments for which it was providing the musical foundation, a theorbo often could be six feet long, or longer. This particular recording is wonderful; but there is a little more environmental noise present than we would wish. However, just as the case with old analog-tape hiss, there are times when environmental noise can be a useful diagnostic tool. Again, listen for all the small sounds of music making, such as clothes rubbing against the body of the instrument. And, revel in the truly luscious bass notes!

Jerry Bruck made this recording using the Schoeps KFM 6 “sphere” stereo microphone; I produced. The KFM 6 was a development of previous “dummy head” binaural microphone arrays, but which, importantly, was designed to make recordings for loudspeaker listening, and not just headphone listening. That said, the headphone sound is excellent.

After the start of the repeat, listen to violinist Nina Bodnar’s echoing of Arturo Delmoni’s melodic statements. Even though they play like “twins separated at birth,” there are tonal and, of course, spatial-cue differences.

The clavichord was an early keyboard predecessor of the harpsichord and the piano. The grand piano uses a complicated mechanism to propel a felt hammer upward to strike a string set from below. The harpsichord uses a simpler mechanism to move a plectrum vertically to pluck the one or two strings of a note. Whereas, the clavichord uses the least complicated mechanism possible, a simple lever, to put small triangular pieces of metal called tangents into contact with crosswise strings. The tangent does not rebound, but stays in contact with the string for as long as the key is held down. Unique among keyboard instruments, the clavichord’s mechanism both sets the string in motion, and determines the pitch of the note.

One might be tempted to think that the clavichord, in view of the above, is mostly a historical curiosity. However, András Schiff, one of today’s foremost exponents of the grand piano, last year released an entire album of Bach keyboard pieces played on a modern copy of a clavichord made in 1743.

Says Schiff, “My ears, my mind, soul and spirit are cleansed. The lower pitch (a'=404Hz) is relaxing, harmonious, and pleasing. There is nowhere to hide—unlike on the piano where the player can cover up his or her shortcomings with the aid of the sustaining pedal.”

The selected track is a three-voice fugue from Bach’s A Musical Offering, which is a suite of pieces all based on a single musical theme given to Bach by Frederick the Great of Prussia. (It is not clear who actually wrote the theme.) Apart from Schiff’s remarkable virtuosity, my purpose in including this track is to provide a frame of reference for the sounds of the later-developed harpsichord and piano.

Most clavichords were small enough to tuck under one’s arm. Because the strings run left to right, string length was limited; soundboard area was also limited. The result was that clavichords were suited for playing for one’s own amusement, or for family and friends in a domestic setting. But not for public performance in a larger setting. Harpsichords’ longer strings and larger soundboards allowed for performances in larger spaces.

That is a bit of a historical irony. That’s because one of the most famous pieces of harpsichord music was written at the behest of an insomniac who wanted “smooth and somewhat lively” music to cheer his sleepless nights. The insomniac was Count Keyserlingk, the former Russian ambassador to Saxony (this was circa 1741). The variations are named after Bach’s student Johann Gottlieb Goldberg, who lived in the Count’s house and, as needed, played outside the Count’s bedroom door. The Count rewarded Bach with a golden goblet filled with 100 gold coins. (Assuming that the coins totaled 22.5 troy ounces, today’s value for that amount of gold is circa $45,000.)

This recording was made in a church in Paris; the acoustic of the space supports the sustain and the overtones of the notes. By the way, Bach wrote the Goldberg Variations for a harpsichord with two keyboards, the upper one set back. This makes interweaving the musical lines easier, compared to the modern grand piano.

Whereas Jean Rondeau’s harpsichord was tuned to the Baroque pitch of A=415Hz, here we have a modern piano (maker not specified, but most likely a Hamburg Steinway, seeing as she recorded in Teldex Studio Berlin) tuned to the modern standard of A=440Hz. The venue is a late-19th-century concert and dance hall of approximately 4,900 square feet.

I think that Ms. Rana’s pacing, flow, voicings, dynamics, tone colors, and sense of musical architecture are all… perfect. Hers is my go-to version in modern sound.

William F. Buckley Jr. (himself an amateur harpsichordist) supposedly once remarked that the only piece of evidence for the existence of Space Aliens from Unidentified Flying Objects (UFOs) that could survive a moment’s critical examination was the catalog of works of Johann Sebastian Bach, in all its quantity (more than 1,100 works) and quality (supreme).

Bach wrote for the largest musical forces available in his time, but he also excelled in the smallest-scale works. Bach’s solo works for organ, for harpsichord, for violin, and for cello are well-known as masterworks. Less well known is Bach’s solo Partita for the transverse flute, which was an interim development between the recorder and the modern flute. Interestingly, this recording was made in the same church in Paris as was the harpsichord Goldbergs Aria. Listen for the sounds of articulation, and the sound of the space.

Johanna Martzy had a briefly successful career in the 1950s; but these days, with each passing year, her recordings get more and more respect. Back in her day, some naysayers thought that her Bach was too much “Just the facts, ma’am” mold as Sergeant Joe Friday (from the television show Dragnet). Today, her playing seems extraordinarily well-balanced between the desire to let the music speak for itself, and the necessity of having something worthwhile to say about it.

The violin is usually a “monophonic” instrument, meaning that it usually plays only one note at a time. Here, Bach adds harmonies and even counterpoint to the singing line. Listen for the range of tone colors, from darker on the lower strings to brighter on the higher strings, and to the very subtle dynamic shadings that serve to illuminate the architecture of the piece.

The recorded sound of a piano doesn’t get much better than this. The piano is a Hamburg Steinway 9-foot Model D, and the venue is Mechanics Hall, Worcester, MA. An historical product of the 19th-century’s “Worker Self-Improvement” movement, built in 1855, Mechanics Hall presented everyone from Mark Twain to Enrico Caruso, from Dvorak to Rachmaninoff. Today, it is reportedly Yo-Yo Ma’s favorite place to record.

Most of the notes (keys) of a modern piano correspond to “triplet” sets of three strings, all tuned to the same pitch. One result is the phenomenon known as “Double Decay,” where, after the hammer hits the triplet strings, for a brief time the sound decays rapidly; and then, for a longer time, the sound decays more slowly.

Add to that, the fact that as a pianist plays a piece, the sustain of any given note will interact with the notes that came before and which will come after. The bottom line is, the tonal quality of the piano is not constant—the frequency spectrum varies as a function of time. The matter is so complex that during the “die-out” of a note or a chord, some overtones even increase in intensity, before finally completely decaying.

Well, here’s another stunning piano recording. A Steinway D, but not identified as from New York or Hamburg. (The recording venue was a church in Bristol, England.) Regardless, this is an excellent example of the oft-repeated statement that great pianos each have their own character. What luscious overtones!

Now, here’s a New York Steinway, in a former Episcopal chapel in Virginia. Luscious overtones… but of a different character than the two above. What I have been trying to accomplish here is to suggest that while it is all fine and well to have a “favorite” piano track, it is better to have half a dozen favorites, of differing tonal characters.

The sum total of all the complex acoustical interactions within the sound of a great piano is what my friends at Steinway & Sons call the “Steinway Shimmer.” (The word “shimmer” makes me think of the desert mirages that used to show up in the “Wile E. Coyote and the Road Runner” cartoons.)

I just said that you should have half-a-dozen reference piano tracks; but now I am saying that if I had to pick just one track that best exemplifies the “Steinway Shimmer,” it would be this one.

Are you ready for a surprise? This is the same recoding studio and the same New York Steinway piano as the Rachmaninoff track immediately above! In much the same way as all great pianos (supposedly) have their own tonal “personality,” I think that most great pianists have their own distinctive touch.

But in this particular case, I think that a lot of the differences we hear in the overtones result from the stylistic divergences between Rachmaninoff, and a virtuoso re-interpretation of David Raksin’s film-score music. The “Meditation on ‘Laura’” has many very high notes, and many spaces between the notes or phrases; it also seems that the damper-lift pedal gets a real workout.

He keeps a blog called The Tannhauser Gate where he writes about worthwhile new music.

Headquartered in Santa Barbara, CA, Echo Test + Measurement is a little company with a big impact on audio test and measurement. As many large consumer electronics companies started using its AudioFire studio sound cards for production line testing, Echo designed a highly cost-effective, modular range of USB-based audio test interface solutions, which Stuart Yaniger had the opportunity to evaluate. He completed a series of tests and shares his experiences with the new Echo AIO modular audio test system. This article was originally published in audioXpress, March 2023. Read the Full Article Now Available Here

This Test Bench article analyzes the popular SW26DBAC76-4 10" low-profile subwoofer from SB Acoustics. Much of SB Acoustics' high-end audio developments are done by former Vifa/Scan-Speak engineers Ulrik Schmidt and Frank Neilsen at Danesian Audio, and the SW26DBAC76-4 was specifically designed (and patented) for applications that require a subwoofer that will fit into very shallow-depth enclosures.

The SW26DBAC76-4 has a unique and interesting feature set that starts with an extremely shallow 79.5mm (3.13") cast-aluminum frame. Other features include a flat 10" dual aluminum cone that is very stiff and reinforced by a large two-piece dust cap, plus an inverted cone attached at the front cone/dust cap joint. The outside rim of the inverted cone is attached to the outside perimeter of the spider, and moves with the cone assembly. The inside diameter of the spider that would normally be glued to the voice coil assembly is then connected to the motor structure. This is a clever design. This article was originally published in Voice Coil, January 2023.  Read the Full Article Now Available Here