Comparisons

The Ultima Studio/Voice speakers have served as my reference setup for some time now. When the Performas arrived, I knew that they had a tough act to follow, but I was eager to see how the Ultimas would stand the test of time given that the Performa series had evolved over time, the F52 series being the 3rd flagship generation.

My preference, as stated earlier, is to use a subwoofer with both the Studio and the F52. In the limited testing that I did do to compare their bass reproduction capability, I would say that they performed about the same. The stated -10 dB point for both speakers is almost the same, so this is no surprise. If anything, I would give a slight edge to the F52 which had a bit more punch in my room. This, however, I attribute more to the speaker and room interaction than to the speaker itself. Even if the F52 did not fare well in this area, one can add a subwoofer to take control of the 20 Hz - 30 Hz region. The resulting system cost is still going to be lower than the cost of the Studio alone; plus you get the benefit of placement flexibility.

When it comes to treble reproduction, I found the new tweeter to be just wonderful. In fact the new tweeter design with the waveguide does provide a more focused presentation. It is crisp and detailed, without being bright. But the Studio has the rear tweeter which optimizes the power response, resulting in a more airy presentation. I want a speaker with this new tweeter and a rear tweeter! Both speakers also provide level controls. On the F52, I applied a 0.5 dB boost at times, but left it at its default position most of the time. In comparison, on the Studio, I trim the levels of both the front and rear tweeters using their respective level control. In general, I prefer the F52's treble reproduction even without the rear tweeter.

The mid-range reproduction capability of the Studio and voice has been the primary reason they have served as my reference speakers. In this department, the F52 and C52 come very close. In the lower midrange, however, my preference is for the Ultima series, particularly with regards to the voice. There is a level of smoothness and transparency in this range which is just exceptional. It is quite remarkable that even after all these years, the Ultima models compare favorably to the newer generation in some areas, but when it comes to the tweeter and midrange driver integration, the F52 does better.

The performance gap between the two lines has closed considerably. In many areas, the new speakers perform comparably well or even better. There were times where I wished that I could swap the tweeter and midrange transducers between the two speakers to see what I would end up with. If only it were that simple! Given how well these new Performa models perform, and taking the price difference between the two lines into account, they are an extremely attractive option.

On the Bench (JEJ)

At 21" from the middle of the subwoofers, I could get 98 dB maximum at 31.5 Hz, and THD+N was very high. This is why a good subwoofer is necessary with these, and most speakers in general.

At 50 Hz, THD+N was well under control at 100 dB output.

Measured 6" from the midrange driver, THD+N was a mere 0.33% at 1 kHz.

Using 1 kHz and 1.5 kHz signals, the A+B peak at 2.5 kHz was at - 66 dB from the fundamentals, and the B-A peak at 500 Hz was at - 49 dB.

At 5 kHz and 6 kHz, the A+B peak at 11 kHz was at - 67 dB, and the B-A peak at 1 kHz was at - 71 dB.

At 10 kHz and 6" from the tweeter, THD+N was 0.4% at 1 kHz input.

Using 10 kHz and 11 kHz sine waves, the A+B peak at 21 kHz was - 50 dB, and the B-A peak at 1 kHz was - 77 dB.

The room response was quite flat down to about 50 Hz, then rolled off.

Conclusions
 
This ensemble of speakers from Revel has been set up in my listening room for about three months now.  Over this time, they have provided the enveloping experience that makes surround sound exciting.  Whether it was watching movies or listening to music, there presentation across the frequency range was excellent. In two-channel mode, the F52s are delightful.  They are delicate in the treble, lush in the midrange, and bold in the bass. With the waveguide, the tweeter and midrange blend into a single unit. I am going to miss them, particularly their treble reproduction, when they are shipped back.

Revel continues to provide acoustic controls on their speakers, and some new controls have been added here. These controls allow one to tailor the sound characteristics that best match the listening environment.  A customer can place the center-channel speaker where it works best for them, be it a stand or on top of a monitor.  The same is true of a floor-stander where it may have to be placed in close proximity of a boundary (wall). The acoustic controls allow either option while minimizing the performance penalty.
 
Whether you are a two-channel or a multi-channel aficionado, this new Performa lineup has something for everyone.  Revel has now reduced the prices on these new models. The price reduction in conjunction with the performance improvements make this superb set of loudspeakers a very appealing choice.


- Sumit Chawla -

Associated Equipment:

DVD/CD playback: Teac Esoteric UX-1
Preamplifier: Lexicon MC12B v5
Amplifier: Proceed AMP5
Cables: BetterCables/Monster interconnects/speaker cables
Power: P600 Power Plant
Room: ASC SoundPlanks, ASC Iso-Wall

Q&A with Kevin Voecks, Director of Technology, Harman Specialty Group (9/6/06)

1. Compared to the Ultima models, which are still in their first generation, the Performa models are now in their 3rd generation. Why has the focus been on this line?

We continually update models as time permits. The Performa series is in its second generation, although some models have gone into their second generation later than others. There wasn't an intentional focus one way or the other. The current Ultima Series is a very hard act to follow! We still have not found speakers that outperform them in double-blind listening tests. However, we have been working on a follow-up series, "Ultima2," for a number of years. I am confident that it will be received as having been well worth the wait both in terms of performance and appearance!

2. The Performa models have been updated every two to three years. Is this the planned life-cycle?

Generally speaking, we will update models on an approximately 4-year cycle. The Ultima2 Series has clearly taken longer than that. (I promise they will be well worth the wait!) The change from F50/C50/B15 to the F50a/C50a/B15a was strictly cosmetic.

3. The F52s employ newly designed transducers.  What are some of the improvements that have been incorporated into this new generation of transducers?

The woofers and midranges all utilize very sophisticated motor systems with dual-Neodymium magnets inside the voice coils.

The F52/C52 woofers and midranges utilize both aluminum and copper flux stabilization rings to lower distortion. The copper inductance modulation cap dramatically reduces 3rd-order harmonic distortion, which is an especially sonically-degrading form of distortion. Each woofer and midrange has an aluminum flux stabilization ring to provide a consistent magnetic field as the voice coil moves through the gap. The result is lower distortion – and over a wide dynamic range.

The deep-anodized metal cones are stiff and relatively light – resulting in first breakup modes far above their passband. In other words, the first resonance is well above the frequency at which the transducer is "crossed-over" to another transducer. Combined with good self-damping characteristics and high-order filters, the audible impact of cone-induced coloration is eliminated.

The use of multiple woofers contributes to the F52s very low dynamic compression. The effect of dynamic compression is that the timbre is actually different at different output levels, and also changes with time as the speaker is played. It is a result of heating of the voice coils, which changes their impedance and subsequently results in mis-termination of the filter networks. The multiple woofers spread the heat out over a very large area, essentially eliminating this clearly audible phenomenon.

The tweeter is a sophisticated, low-distortion design with an aluminum dome. It behaves as a piston well beyond audible frequencies. Ferrofluid ® is utilized to help minimize dynamic compression. The real "story" of the F52 tweeter is its waveguide (below).

4. The tweeter has a "Controlled Acoustic Impedance" waveguide.  Could you please talk about its effect?

The basic concept of the "Controlled Acoustic Impedance" waveguide is to match its dispersion in the crossover region with that of the midrange. We have always taken great care to minimize the discontinuity between our tweeters and midranges (or woofers in 2-way systems). We have done so by judiciously choosing crossover frequencies, utilizing high-order (steep slope) filters, optimizing woofer/mid diaphragm shapes, minimizing the midrange/woofer diaphragm sizes, and designing tweeters with extremely low fundamental resonances that are then capable of operating at lower crossover frequencies.

We have gone to all that trouble because our research indicates the importance of making the off-axis response as similar as possible to the on-axis response. That of course helps assure that the audibly-critical first reflections will be as uncolored as possible, and contributes to smoother and more natural power response.

Our new waveguide designs provide a major leap in audible performance by providing a much better match in the crossover region than could otherwise be achieved; even with all of the precautions mentioned above. The sonic result is a seamlessness – as one might image from a non-existent one-way loudspeaker that had none of the real-world limitations of an actual one-way system!

5. How does having this new tweeter plus midrange compare to a coaxial transducer mounting?

Coaxial configurations result in off-axis response that is consistent relative to horizontal versus vertical responses. However, coaxial configurations do not imply good off-axis response. In fact, the vast majority of coaxial configurations clearly indicate a trade-off of linearity – both on- and off-axis – for consistency of vertical and horizontal off-axis responses. In other words, such designs almost always degrade the sound everywhere, albeit potentially in a similar manner both on- and off-axis!

6. Performa models other than the F52/C52 use a different tweeter.  It is a 1" titanium dome tweeter.  Is this the same tweeter that was used on the F50?

We have the luxury of using transducers that are optimum for each application. The F50 tweeter is different than the tweeters in any of the other models. Note that simply using the same driver in various speakers does not amount to "timbre matching". Other issues, such as the effects of the enclosure, nearby transducers, and of course the filter networks can easily outweigh tweeter differences. Sometimes there are overriding reasons to use a different tweeter in a center channel than the L/R speakers. For example, it is important that a center channel tweeter motor assembly is small enough to minimize the height of the speaker.

7. Are there any plans to update the remaining Performa series models with the new tweeter found on the F52/C52?

While we continuously upgrade every Revel product's performance, there are no near-term plans to change other Performa models. As mentioned above, the cycle is typically in the 4 year range.

8. The C52 uses larger woofers compared to the woofers used on the F52 and C50.  What was the motivation in moving to the larger sized woofers?

One objective in the design of the F52s and C52 was an extraordinarily wide dynamic range – with very low dynamic compression. That improves the sound in any environment as well as assuring the F52s/C52s are suitable for unusually large home theaters. The use of two 8-inch woofers in the C52 helps assure that it can "keep up" with the F52s. There is typically a lot of low frequency content in the center channel which is still significant – even with a electronic crossover.

9. Shifting gears a little bit, I would like to talk about the Concerta series.  I think many folks were pleasantly surprised to hear of Revel's plan to enter the value market segment.  What were the driving factors in creating this new series?

The most frequently heard request from our dealers and international distributors has long been to provide "real" Revel loudspeakers at price points that are attainable for a larger number of music and film lovers. The response to the Concerta series has been tremendous. The comment I have heard most often is, "They truly have the Revel sound."

10. Trying to preserve the Revel sound while having to meet a lower price-point must have presented several challenges. What were some of the challenges that you encountered during the design process?

It is more challenging to make speakers that are true to the music at an affordable price range than if "cost is no object." The Concerta series is a wonderful example of the many advantages that we enjoy as part of such a large audio specialty company. As with all Revel loudspeakers, our transducer specialists utilized sophisticated design techniques, our system engineer took advantage of our state of-the-art anechoic measurement and analysis facilities, and we voiced the systems in our unique "Multichannel Listening Laboratory" under blind listening conditions. In addition, our company-owned production facility helps assure our strict quality standards while producing the speakers in an efficient manner. It is our philosophy to spend the customer's money wisely at every price point. Our world-leading research groups provide information that helps us target what makes an audible difference, without chasing after misguided audio "fads." The enclosure is the largest single expense for any loudspeaker. In the

11. Thank you for taking the time to answer these questions.