Revel Ultima Salon2 loudspeaker Measurements

Sidebar 3: Measurements

My estimate of the Revel Ultima Salon2's voltage sensitivity was 86dB(B)/2.83V/m. This is slightly lower than the specified 86.4dB but within experimental error of that figure. The speaker's impedance (fig.1) drops to between 3 and 5 ohms between 17Hz and 600Hz, but as the electrical phase angle is generally low in this region, the Salon2 should not be hard for the partnering amplifier to drive. However, the shape of the impedance curve suggests that the speaker might sound a little bright with tube amplifiers having a high output impedance.

Fig.1 Revel Ultima Salon2, electrical impedance (solid) and phase (dashed), switches set to Normal. (2 ohms/vertical div.)

The traces in fig.1 are free from the small discontinuities that would imply the existence of cabinet resonances of various kinds. Indeed, investigating the panels' vibrational behavior with a plastic-tape accelerometer uncovered very little untoward going on. The only mode I found (fig.2) was high enough in frequency and low enough in level to have no subjective consequences.

Fig.2 Revel Ultima Salon2, cumulative spectral-decay plot calculated from the output of an accelerometer fastened to the center of the main cabinet's sidewall 8" from the top (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

The saddle centered on 22Hz in the impedance-magnitude trace suggests that this is the tuning frequency of the large downward-facing reflex port. The black trace in fig.3 shows the port's acoustic output measured in the nearfield. It does indeed peak broadly between 16 and 32Hz, which implies excellent low-frequency extension for the Salon2. There is a slight shelf in its upper-frequency output around 100Hz, however. The three woofers measured identically, and the sum of their nearfield outputs is shown as the green trace in fig.3. It shows the usual minimum-motion notch at the port tuning frequency and peaks between 40 and 120Hz, before crossing over to the lower-midrange drive-unit (red trace) at 150Hz. This unit in turn crosses over to the upper-midrange unit at around 500Hz. The crossover filter slopes all appear to be symmetrical fourth-order, 24dB/octave, and all the drivers appear to be well behaved both in and out of their specified passbands.

Fig.3 Revel Ultima Salon2, nearfield responses of port (black), woofers (green), lower-midrange unit (red), and upper midrange unit (blue), all plotted in the ratios of the square roots of their radiating areas.

Fig.4 shows how these individual drive-unit outputs add up on the tweeter axis in the farfield. Looking through this graph's small ups and downs, the Salon2's response is extraordinarily flat, from the upper bass all the way through its 30kHz upper limit. In fact, the tweeter's output starts to rise just below 30kHz, suggesting that the beryllium dome's primary resonance lies above this frequency. (My measurement microphone is calibrated to only 30kHz.) At lower frequencies, the broad rise in output in the upper bass will be mainly due to the nearfield measurement technique. The speaker's low-frequency response extends almost down to 20Hz. This is a true full-range loudspeaker.

Fig.4 Revel Ultima Salon2, anechoic response without grille on listening axis at 50", averaged across 30° horizontal window and corrected for microphone response, with the complex sum of the nearfield responses plotted below 300Hz.

The measurements taken to generate fig.4 were taken with the Salon2's five-position Tweeter Level switch set to its central, "0dB" position. Fig.5 shows the effect on the Revel's tweeter-axis response when this switch is set to its maximum +1dB and –1dB positions. The Salon2's output in the top two audio octaves is hinged up or down by up to 1.6dB.

Fig.5 Revel Ultima Salon2, effect of HF control set to ±1dB on tweeter-axis response.

The flat quasi-anechoic response on axis will not necessarily correlate with a flat perceived balance in-room because the latter also depends on the loudspeaker's dispersion; ie, on how that response changes to the sides and above and below that axis. The Salon2's horizontal dispersion is shown in fig.6. The loudspeaker's behavior is almost textbook perfect, with smooth, even off-axis behavior up to 8.5kHz or so, the frequency where the tweeter's waveguide begins to restrict its off-axis output. Due to this increasing directivity in the top audio octave, the Salon2 might sound a bit airless in large or overdamped rooms; the Tweeter Level control, set to one of its two boost positions, will help compensate for this. In the vertical plane (fig.7), the Revel's flat response is maintained over a wide (±10°) window centered on the tweeter axis, which is a good thing—the tweeter is a very high 49" above the floor.

Fig.6 Revel Ultima Salon2, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

Fig.7 Revel Ultima Salon2, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 10–5° above axis, reference response, differences in response 5–15° below axis.

Fig.8 shows how all this added up in LG's listening room. To generate this graph, I took ten 1/6-octave–smoothed spectra for each speaker individually in a rectangular grid 40" wide by 18" high and centered on the position of Larry's ears in his listening chair. (I used an Earthworks omni microphone and a Metric Halo ULN-2 FireWire audio interface, in conjunction with SMUGSoftware's Fuzzmeasure 2.0 running on my Apple laptop.) My goodness! Even though there is some lumpiness at the low end of the graph, due to room modes that have not been eliminated by the spatial averaging, this is, to again use the phrase, an extraordinarily smooth, flat response, especially when you consider that it was taken in an actual room rather than an anechoic chamber. As LG noted, the speaker offers full output down to below 20Hz. At the other end of the spectrum, the gentle rolloff in the top two octaves is due to the increased absorption of the room's furnishings in this range.

Fig.8 Revel Ultima Salon2, spatially averaged, 1/6-octave response in LG's listening room.

Turning to the time domain, the Salon2's step response on the tweeter axis (fig.9) indicates that all five drive-units are connected with the same positive acoustic polarity, and that each one's step smoothly hands over to that of the next lower in frequency, this correlating with the excellent frequency-domain integration of their outputs. The Revel's cumulative spectral-decay plot on the tweeter axis (fig.10) is superbly clean in the region covered by the tweeter, but some low-level delayed energy can be seen in the low treble.

Fig.9 Revel Ultima Salon2, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

Fig.10 Revel Ultima Salon2, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

Even so, the Revel Ultima Salon2 offers superb measured performance. It is a pleasure to be able to measure such a well-engineered loudspeaker. It is fair to say that not only do my measurements validate the speaker's engineering, but that the converse is also true: the speaker's measured behavior validates my test procedures! I have asked Revel to send me a pair of Salon2s for a "Follow-Up" review to appear later in the year.—John Atkinson

Theodor's picture

Could any of you please compare the REVEL Salon 2 performance and GoldenEar Triton Reference especially in the music clarity at mid and low levels (assuming both powered with McIntosh MC462)?

JRT's picture

Take a look at what Kal Rubinson, Jim Austin, and Larry Greenhill are using as reference loudspeakers in their own systems. Kal discussed his recent change from B&W 801D in a recent column, and you can see the others' loudspeakers in associated equipment in their relatively recent reviews.

They seem to be using Revel Ultima/Ultima2 Studio2, and are not using GoldenEar Tritons.

As for you choice in amplifiers, you should know that a pair of Benchmark Media AHB2 bridged as monoblocks would play cleaner with lower noise and lower distortion across the full audible spectrum for less money than the McIntosh MC462.

Jim Austin's picture
The GoldenEar Triton Reference is a fine speaker, but speakers with powered woofers/subs are not practical for reviewers. Jim Austin, Editor Stereophile
Ayrehead's picture

Hi Jim:

I’ve owned my Salon 2’s for about three years. When I first set them up, I was in a hurry and didn’t bother with the spikes. A couple of weeks later, while I was hanging around a forum and showing off about the Salons, I casually mentioned the fact that I had not spiked them. A Salon owner and participant in the forum told me that I should immediately spike the speakers and listen.

Frankly, what I listened to when I spiked the Salons was a very different speaker in the low frequency department - night and day. There was audibly ‘less’ bass but what there was was a hugely increased definition in low frequency delivery.

My speakers rest on carpet so, that might have had an effect when I raised them. I see that, in achieving such excellent sound, yours stood on a wooden floor. You mention not having received the spikes and then, later, you mention the blunt end of the spikes. Did you listen to the speakers without and then with spikes? Any impressions about the difference?

mauidj's picture

...and I still love them.
Its so nice to read that some of my favorite audio reviewers still find these to be among the best full rangers out there. Even more so considering the price. I've owned mine for just over 9 years and they continue to amaze me when the music is right. Yes Jim, you are spot on...they do not like bad recordings.
And yes Larry, that D2D Romeo and Juliet is a stunner played through the Revels. One of my all time favorite records.
So the Revels are sensitive to the music and also, as I discovered, very much to the amplification.
Mine originally lived with a full Krell EVO system...pretty damn good but...there was something not quite right with the tonal balance. They did not sing quite like I heard them singe with other amp systems.
Then I changed to a Pass/Esoteric front end and they sounded dreadful. Flat. No life at all.
I had other components to change out and thus discovered it was the Esoteric not playing nice with the Revels.
Could not believe the difference a power amp made in such a negative way. The system bordered on unlistenable.
It was hard to fathom how such a well made and reviewed power amp could sound so bad.
So the Esoteric was then replaced with a Luxman m900u. they are singing so sweetly.
I completely agree with pretty much everything both Jim and Larry wrote.
When time and budget allow the Pass will go, to be replaced with the matching Luxman Preamp.
Looking forward to hearing even better sound from these great transducers.
BTW...mine are on a solid wood suspended floor with the spikes reversed.
A big mahalo for the reviews gentlemen.

aRui's picture

You paired the Luxman M900U with the Revel Salon2s? What do you think about the combo sofar?