Tuesday, February 7, 2012

Improving the sound of your digital music - Part III: iFrogz Audio Spectra Ear Buds

(We continue with our series on Improving the sound of your digital music - earbuds are not your friends.
In Part II: Setting the reference baseline, we performed an A/B comparison test to measure the degradation from our reference system, with uncompressed digital copies played back through standard iPod earbuds. In Part III, we test the iFrogz Spectra Ear Buds.)

iFrogz Audio introduced their new line of Spectra Ear Buds at the 2012 International Consumer Electronics Show in January.  The new product has not yet been released for sale, but according to an iFrogz PR representative the target price is $34.99.  Spectra features a lithium alloy housing, a woven nylon anti-tangle cord, with an inline microphone that also provided remote control functions, and a 45-degree angled audio plug.  Users should be aware that the microphone/controller is in the left-channel lead, and not the right channel as is customary on standard iPhone earbuds.

Specifications for the Spectra are 16-ohm impedance, a 20Hz to 20KHz frequency response, and 93dB sensitivity +/- 3dB. At CES, iFrogz provided a set of silver Spectra Ear Buds for testing by the EE Daily News. This sample was used in an A/B/C comparison, according to the procedure described in Part II of this series, with the 'A' reference being a full-range loudspeaker system playing the test tracks from The Ultimate Demonstration Disc. After listening to the reference system, we immediately switched to the same track in WAV file format, listening to the test earbuds connected to an iPod Touch. The B/C test devices were alternated between the iForgz Spectra and Audeo PFE 132s (see part IV of this series).

From the very beginning of the test with the silver Spectras, we experienced a substantial degradation of the fidelity of the male voice that introduces the test disc. From the initial testing notes:  "The sound is very compressed, especially in the mid-range. The difference in reference material was immediately evident in male vocals, which collapsed into a very narrow image".  Since the difference in the sound was so great, we contacted iFrogz to see if the unit might have been defective, or if we overlooked something that we should be aware of during testing. The company also found this to be abnormal, and kindly provided a set of additional test samples, in black, blue, and purple colors.

While we were waiting for the additional samples to arrive, we burned in the silver Spectras, by playing music from the iPod continuously for more than 24 hours. We then redid the A/B/C test which we had terminated earlier.

Upon listening later to the male vocal on the Chesky disc with the black Spectra, we experienced an improvement that was significant enough to justify a 2nd test.   We briefly checked against a 3rd sample, the blue Spectra, and found them to be indistinguishable from the black sample. The results reported here include the initial test of the 1st sample, along with a subsequent A/B test that we performed with the black sample. Herein then are the complete results of our test on Spectra Silver and Spectra Black, with comparison to our reference.

Test of iFrogz Spectra Ear Buds
We gave the results of each test a subjective numeric grade.
  • 10 points: Indistinguishable from the reference.
  •   9 points: High-quality reproduction with all the essential elements of the recording, and only a slight loss of accuracy compared to reference.
  •   8 points: A quality playback, but loses some elements of the reference.
  •   7 points: Listenable, but alters the original or lacks significant characteristics of the reference.
  •   6: Fails to retain many elements of the original, or distorts the reference material.
Introduction - Male vocals
Reference system:  The narrator's voice has a deep chesty resonance in the reference, with a warm, very realistic sound. Each breath as he speaks is audible in great detail, lending a high sense of realism, as if he were there in the room with the listener.

Spectra Silver: 6 points. Male voices totally lack depth and resonance from lower register, sound more compressed and "hissy".

Spectra Black: 7 points. Retains more of the deep bass sound of the original male voice, compared to the Silver, but still more high-end emphasis. Breaths sound less natural than reference, more like hiss.

High Resolution
This is a female vocal of Spanish Harlem, performed by Rebecca Pidgeon. The reference has deep bass in the opening, with an airy, full-range and detailed quality to Rebecca's voice. The shakers in the distance are very detailed, conveying a realistic sense of space, while the violins are reproduced without any sense of excessive brightness. An acoustic guitar sounds very realistic and warm.

Spectra Silver: 7 points. Vocal is upfront in imaging, but more emphasis on high end, less nuanced. Imaging of shakers is off to the side, loses depth of soundstage. Good placement and imaging of instruments and excellent resolution of the shakers placed in background, but vocals somewhat "breathy" compared to reference.

Spectra Black:7.5 points. Opening bass much more subdued than reference. Rebecca's voice more sibilant, breathy. Piano bright compared to original. Good detail and placement of shakers in distance. Good sense of soundstage.

If I Could Sing Your Blues, with female vocalist Sara K. Track opens with a trumpet in the distance, to the right and conveying a sense of a larger space. Very natural and realistic, Sara K with a wide range vocal range. Drums in the rear of the studio on the left, with detailed cymbals.

Spectra Silver: 7.5 points. Trumpet more prominent and closer on the right, rather than toward rear. Very good reproduction of details in guitar and cymbals. Sound stage not as expansive, less depth . Good reproduction of range and clarity for Sara K vocals and very good high frequency response for cymbals.

Spectra Black8 points. Good imaging of trumpet on opening, but closer on right than in reference. Guitar loses some warmth, but detailed string plucks. Very good placement of drum set to the rear. Sara's voice loses some detail of the reference, less realistic. 

Maiden Voyage is another female vocal, with Brazilian singer Leny Andrade. The opening has deep bass, conveying the full body of the instrument, combined with detailed and airy cymbals to the right. Realistic piano contributes to a broad and deep soundstage, with excellent imaging of each instrument.

Spectra Silver: 7.5 points. Very good resolution of brushed cymbals, broad soundstage, good clarity and dynamic response on piano but brighter than reference. Bass plucks lack body resonance.

Spectra Black:7.5 points. Cymbals much more prominent in opening, bass more muted, less detailed. Good imaging and dynamics on piano, but bright compared to reference. Leny's voice also emphasizes upper register, losing naturalness.

Midrange Purity
Grandma's Hands is an acapella piece with male vocalist Livingston Taylor. Finger snaps are detailed, voice is full and realistic in the reference.

Spectra Silver: 7 points. Realistic reproduction of finger snapping, but lacked full-body depth of male vocal, consistent with other tracks.

Spectra Black8 points. Very good reproduction of opening finger snaps. Taylor's vocal slightly more breathy than reference, loses some of chest resonance.

Correnteza, by Brazilian singer and guitarist Ana Caram was recorded in a church, portraying the illusion of a rain forest filled with bird sounds. The reference immerses the listener in another space, with high frequency detail of bird sounds and realistic effects of water dripping. This is a very detailed, high-resolution vocal. The rhythm of of the drum has deep, full-body harmonics. There is a soft triangle detail at the end of the track.

Spectra Silver: 8.5 points.The iFrogz shine on this track. Very nice reproduction of immersive bird sounds, and Ana's vocal. Excellent imaging. Lack of depth in cello and subdued bass notes. High resolution of triangle at end of track.

Spectra Black8 points. Good presentation of breadth of soundstage. Drum beat is a prominent detail in the reference, subdued here.  The image and placement of Ana Caram is more blurred, less distinct and less resolution than reference. Very good reproduction of bird sounds. Triangle at end of track is less delicately detailed than in reference.

This track features the Fred Hirsch trio, piano, drum and bass, on Played Twice. Opens with soft drum hits to the right rear, followed by piano and deep bass plucks. A great amount of detail is reproduced in the cymbals, with full harmonics, air and transients. Realistic, full piano sound.

Spectra Silver: 7.5 points. Excellent piano reproduction, subdued acoustic bass. Some lack of air in cymbals. Pleasant, but lacks space, producing more closed sound than reference. Piano more prominent front and center, compared to left of center and distinctly defined amongst trio in reference.

Spectra Black8 points. The reference is an extremely realistic acoustic recording, with each instrument in the trio presented in great detail. The Black Spectra come up short on bass response, but do well on piano and cymbals. Soundstage is compressed, with less detailed imaging of the trio, but placement is good. 

Ask Me Now is a tenor saxophone solo, performed by Joe Henderson in a large recording studio. The reference blasts from the speakers to the right of center, with a full, realistic, three-dimensional body resonance. The echo in the recording studio comes through in playback, giving a sense of the size of the space. Each keystroke and breath is clearly detailed.

Spectra Silver: 8 points. In ear experience conveys details of keys. Reflections subside more quickly. Good low notes with extended highs, a bit brighter in ear.

Spectra Black: 8 points. Good detail and resolution of the saxophone, but less three-dimensional and lacking physical image from the reference. Good on low note blasts. Transients subside more quickly, losing sense of ambiance from studio echo. 

Visceral Impact
Sweet Georgia Brown by Monty Alexander, with two drum sets, and both an acoustic and electric bass. Opens with piano on left, audible mutterings of Monty Alexander, realistic full drum set to the right rear. Airy cymbals from second drum set to left rear. Clear sounds of both acoustic and electric bass. Dynamic soundstage filled with horn blasts.

Spectra Silver: 8.5 points. Good visceral impact but brighter than reference and piano. Electric bass more subdued, less deep acoustic bass. Excellent air on cymbals and full background of horns, but constrained to smaller space.

Spectra Black: 8.5 points. Good dynamics from drums, cymbals more bright than reference. Follows transient attack of trumpet blasts well. Loss on low end where acoustic bass fades into background compared to reference. Excellent energy from piano, but less realistic, lacking in three-dimensional imaging. 

Rhythm and Pace
Johnny Frigo on jazz violin performing I Love Paris. Opens with electric guitar to the right. Airy cymbals and sweet sound of violin. Deep notes of electric bass keeps rhythm to the left. Excellent imaging of high-hat cymbal. Very deep kick drum with visceral impact. Saxophone on left fills soundstage while cymbals and guitar keep pace on right. Very dynamic!

Spectra Silver: 7 points. Overall brightness comes through again, with acoustic bass muted compared to reference. Nice airy cymbals with warm guitar. Decent sense of room acoustics. Good pluck of bass, and full sound of saxophone. Kick drum nearly vanishes compared to reference.

Spectra Black:7.5 points. Good breadth of soundstage, but very bright compared to reference. Retains most of the warmth of electric guitar that emerges on the right. Very good on imaging of high-hat cymbals, but too much sibilance. Good reproduction of blasts from tenor sax, but imaging lacks the depth that makes the reference sound like "you are there". 

Vivaldi Flute Concerto in D. Wide dynamic range with deep bass notes along with high fluttering notes from the flute. Can hear detail of the musician's breaths. Excellent sense of space and realistic ambiance.

Spectra Silver: 7 points. Loses sense of space in opening. Flute melds into background. Echo on high notes. Loss of detail in flute solo. Low end response lacking.

Spectra Black: 6.5 points. Good detail on flute solo, but image and placement are not focused. Compressed soundstage. Attenuation of low end leaves track sounding bright overall. 

Holographic Imaging
Festival Te Deum is a performance by the Westminster Choir in a large cathedral (60' W, 225' L, 90'H) with pipe organ, recorded with a single microphone elevated 35 feet high. This track is challenging for a full-range loudspeaker to image the large space, and presentation of the wide, yet detailed dynamics. The reference system has excellent depth, and fills the room with images of the choir as a whole, while retaining the individual voices.

Spectra Silver: 8 points. Clear depiction of air from organ, but high-end emphasis produces a veil over the sound not heard in reference. Good representation of space at peaks of choir, though with some distortion. Very good imaging of soloists. Loss of some organ harmonics, but overall good job of holographic imaging. Good detail on soloists.

Spectra Black: 7.5 points. Air hiss from organ dominates at the opening, rather than receding into background as in reference. Very good in imaging the breadth and volume peaks of the choir. Excellent detail of individual vocalists. Brightness overwhelms the depth of the organ. 

Stravinsky's The Royal March. This is a very dynamic track, with very deep notes from the kettle drums to the high frequency transients from violins, flutes, and trumpets.

Spectra Silver: 7 points. Initial impact is very bright. Good detail, soft low end. Good dynamic range and transient response.

Spectra Black: 7 points. Initial impact distorts the sense of space in the reference with a much more shallow image. Good on low end horn sounds, but against a background of brighter highs from cymbals and violins. Detailed imaging of kettle drum is lacking. 

Bass Resonance
This is a single standup bass recorded 3' from the microphone. The reference system produces a full, realistic sound of the body of the instrument, along with the string plucks, that never fails to shake something in the room before finally trailing off in a gentle fade out.

Spectra Silver: 6 points. Loses body of bass entirely. Track loses depth and depicts only string plucks without low end.

Spectra Black: 7 points. Good on opening plucks of bass strings, and transients, but lacking in body depth. 

Dynamic Test
This is a wide dynamic range solo drum recording. The snare and kick drum open relatively low in volume, with detailed cymbal hits and clear, deep drum kicks. Excellent holographic imaging of the complete drum kit, along with height of the cymbals. Incredibly realistic!

Spectra Silver: 8 points. snare sounds shallow. good representation of cymbals. bright compared to reference. deep notes of drum hits depicted well.

Spectra Black: 8 points. Opens softly as in reference, but kick drum is muted. Good at distinguishing different cymbals. Drum hits are impactful. 

The Black Spectra provided a discernible improvement over the Silver Spectra. The average of the fifteen tests for Spectra Black was 7.6 points, and for Spectra Silver it was 7.37. By comparison, the original iPod earbuds had a score of 7.2 points. There were three tests where the initial Spectra Silver score was higher than the Spectra Black, seven where the Black rated higher, and five tests where we rated them the same. The overall impression is that the Black do offer an improvement in the musical experience, both over the Silver and over iPod earbuds.

The iFrogz Spectra, with their medium-sized ear tips,  are also much more comfortable to wear than iPod earbuds. They are less prone to move or fall out, and feel lighter. The woven cloth cord is also an improvement over the plastic iPod earbuds.

During the listening tests we noticed that the microphone, which is much higher on the cord than for iPhone earbuds, would rub against and sometimes catch against a shirt collar. We performed only a brief test of microphone sound quality with an iPhone, and found this to be a problem. Once again, users also need to be aware that the microphone lead is reversed from the iPhone. On the Spectra Silver the white on silver labeling was initially not apparent.

At the price level of $34.99, there are many competitors for earbud replacements. The Spectra offer a definite (though small) improvement in sound quality, and a much greater improvement in fit and comfort. We can recommend them over iPod earbuds for listening to music, but not for use in making phone calls.

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