A Tale of Two Speakers Associated Equipment

Sidebar: Associated Equipment

Digital Sources: Ayre Acoustics C-5xeMP universal player; Apple 2.7GHz i7 Mac mini running OS10.9.3, iTunes 11, Pure Music 2.0, Audirvana Plus 1.5.10; PS Audio PerfectWave DirectStream D/A processor; dCS Vivaldi upsampling D/A system.
Preamplification: Ayre Acoustics KX-R Twenty line preamplifier.
Power Amplifiers: Pass Labs XA60.5 monoblocks.
Cables: Digital: AudioQuest Coffee, Belkin Gold USB, Kubala-Sosna Elation! AES/EBU, Transparent USB (with dCS Vivaldi). FireWire: AudioQuest FireWire 400 (prototype). Interconnect (balanced): AudioQuest Wild Blue, Kubala-Sosna Elation!. Speaker: Kubala-Sosna Elation!, Nordost Odin. AC: Kubala-Sosna Elation!, manufacturers' own.
Accessories: Target TT-5 equipment racks; Ayre Acoustics Myrtle Blocks; ASC Tube Traps, RPG Abffusor panels; Acoustic Ballasts, VPI Bricks, Shunyata Research Dark Field cable elevators; APC S-15, Audio Power Industries 116 Mk.II & PE-1 AC line conditioners (hard drive, computers). AC power comes from two dedicated 20A circuits, each just 6' from breaker box.—John Atkinson


lo fi's picture

No surprises there really.

OneMic's picture

What a truly exceptional analysis of these two speakers. Technically sound, extremely informative, and very well written. The differences in these two well engineered speakers were expertly elucidated. I think you have set the bar high for the new year and hope to see more articles of this caliber!

Hi-Reality's picture

Dear John,

I think if a new metric (e.g. enjoyment factor) and its corresponding testing procedure for 'Subjective Sound Pleasure' could be standardized it would create a substantial value-add to today's reviews and measurements. This idea is perhaps not new but the relevant technology has been in progress for some years: given we had established this metric we could measure it by today's commercially available brain-wave capturing devices that the reviewer wears during the listening/measurement.

This metric should ultimately indicate the 'level of perceived realism' that a listener experienced subjectively. This would be content-dependent (simple sounds would most likely trigger better values and the opposite for complex sounds, e.g. an orchestra performance); we could perhaps develop a performance grading scheme that would take into account the complexity of the sound content.

Thank you for a great article and for bringing a core issues/topic into focus.

Regards, Babak
Founder, www.Hi-Reality.org

Synthetic's picture

I have owned both the Revel M105s and KEF LS50s for over a year now. The smaller M105 is even more similar to the LS50 in terms of cabinet volume, driver complement, and output ability. But as you've concluded they are definitely not the same speaker.

There are two things about these speakers that I think are really different. The first is the voicing. With the LS50, the overall tonal balance is relatively flat, but there are more peaks and valleys in the on-axis frequency response than in the Revel. This consistently shows up in my own in room measurements as well as in published reviews as a peak at around 2 kHz, a dip centered around 1.2kHz, and a dip at around 500Hz. The Revel, by contrast, doesn't have any notable peaks and valleys in the frequency response. To my ears, this gives the LS50 a somewhat unique character in the midrange and lower treble.

The second difference is in the dispersion patterns. The off-axis sound in recent KEF speakers tends to decline constantly and gradually with increasing frequency. However, based off of a combination of my own measurements, Harman's anechoic data, and measurements of other Revel speakers by Stereophile, it would seem that the Revel target is a sound power that is more constant with frequency. The result is more energy in the room in the treble range. To my ears this does not make the LS50 sound dull or the M105 sound bright, but instead the increased high frequency dispersion results in a wider soundstage and a more spacious presentation. The M105s sound more natural and open, while the LS50s sound more focused with precise imaging.

My preference? I like the more honest and spacious presentation of the M105 for most music. One thing I really like about the LS50 is that it can be used horizontally without issue. This is how I'm currently using them; three speakers with my living room television.

Reference Systems's picture

We have had both of these models (along with the RBH SX-61/R) in our design center for some time being powered by a Primaluna Integrated to show clients that there are upper mid-tier monitors that won't take up a ton of space and look great while featuring outstanding sound quality. A pair of either of these in a family room will enhance TV watching and give beautiful musical reproduction.

While both attractive, my eyes prefer the LS50, but my ears say no contest that the Revel M105 is a much better speaker for typical listening environments that a smallish monitor should be used in. The M105 is a nearly flawless combination of price/performance when used in a properly sized room and with solid electronics. We use a Denon HEOS and a Rega turn table to stream music to it and I find the Revel to be the perfect combination of forgiving poor recordings and excellent at reproducing great ones.

I also love the fact that quality stands made to fit the M105/106 are available through Revel. A rarity today. The bass is surprising - down right incredible - out of the M105 while the upper end is perfectly clear and energetic. Not at all thin or "floaty".

The LS50 seems better suited for near-field monitor listening, which leads me to....

While not the exact same speaker, people often overlook that KEF has very similar self powered (active) models to the LS50 available at a much lower cost than the LS50's $1500 MSRP that also include bluetooth & PC connections that make great pieces for the desk/office area. That's a great step down for those looking for high quality sound with a low parts count. To me, the LS50 and it's siblings are better suited for that type of positioning and listening.