The Legacy Wavelet II (Part 2)

by Bill Heck

In part 1, I introduced you to a radically different product, indeed a different product category: the Legacy Wavelet II, a music DSP processor. If you've not read that article, check it out here. In part 2, I discuss the results of deploying the Wavelet II in my system and suggest how it might work in yours.

Results

DAC and Preamp: Yes, these functions work well and sound excellent, as expected. There may be subtle differences relative to other products of this sort, but again we’re looking for big changes, not subtle ones. For us today, it’s go big or go home.

Crossovers: As my Legacy Signatures are bi-amp capable and I had an extra older but excellent amp lying around, I figured why not go for it? To make a longish story short, things never sounded quite right with the two different amps, so I eventually sprang for a second PowerBloc2, and all was well. I still don’t know just why the original amp did not work out, and Legacy assures me that other customers have successfully integrated two (or more) different amps. YMMV.

So, is bi-amping worthwhile? On one hand, the effects, while real, are not the sort that revolutionized my listening experience. In other words, we’re back to subtle – although certainly real – improvements, and then there’s the expense of a second amp. On the other hand, amps are getting less and less expensive, and bi-amping is another way to wring a last, noticeable bit of performance from bi-amp-capable speakers. That performance included slightly deeper bass, as confirmed by using test tones, and a subjective sense that the midrange was “cleaned up” a bit. For those already into multi-tens of thousands of dollars territory, it certainly makes sense; if you’re in for that kind of money, you can afford an extra amp or two. In my case, I don’t foresee upgrading the speakers, so my final available avenue for optimum performance was indeed bi-amping.

Oh, about those two channels reserved for subwoofers: I do have a subwoofer and in theory I could use it to fill in extremely low bass (mid-20’s Hz and down); I’ll give it a try when I have some extra free time.

Room Correction / DSP: Here’s where things get really interesting. With apologies to Captain Kirk, DSP is the final frontier, at least for stereo listening. I said that I didn’t want “subtle”; the effects of room correction and other DSP processing are anything but.

I’ve had considerable experience with at least one well-regarded room correction system: Dirac Live (full range version), which was built into my previous preamp. Although I felt that Dirac involved a few compromises, I found that overall, it almost always made noticeable improvements in the reproduction of live music, particularly in the areas of imaging and the reduction of resonances in the nether regions of the spectrum. (I should add here that there are room correction approaches that require multiple additional speakers or subwoofers. I have enough difficulty with the economics and aesthetics of a stereo pair, so for me such systems are not real world options.)

Because I had both the Wavelet II and my older preamp during the transition from my old speakers, Waveform Mach Solos, to my new Signatures, I was able to compare the effects of the Dirac and Böhmer systems within fairly short time periods with both sets of speakers: not true blind testing by any means, but enough (I hope) to develop fairly reliable impressions. To my ears, the Wavelet II’s Böhmer room correction was smoother and more effective, with fewer compromises, than Dirac’s. For example, Dirac tightened bass but at the expense of lowering the perceived bass level; an acceptable tradeoff for me, but Böhmer manages the tightening part without the perceived reduction part. Moreover, Dirac correction works for a specific location; as you (or just your head) start to leave that location, the correction breaks down. To be clear, while you do not need to keep your head locked as though in a vise, moving even a short distance across the sofa is problematic, and moving several feet away is somewhere between disappointing and disastrous. In contrast, the Böhmer correction is constant throughout the room; indeed, I’ve found that I can get a reasonable stereo image while lying on the floor in front of the speakers. (Not that I recommend that listening position in general, but after a long day with an aching back….). Finally, to my ears, the Böhmer correction just sounds more “right”, more “natural”.

Microphone in front of
speaker for room correction.

Meanwhile, the Böhmer correction is far easier to set up. Typically, room correction systems require multiple closely spaced microphone measurements in a listening “window”; the Böhmer approach uses just one measurement per side with the microphone at about tweeter height 48” in front of the speaker. After my first time running the Dirac process, I could replicate it in something between 45 – 60 minutes; replicating with true precision was difficult and demands something like a boom microphone stand to do properly. I can run the Böhmer in under 10 minutes, including positioning the microphone with truly anal attention. Complicating any measurement regimen is the fact that you should conduct any measurement regimen with as little environmental noise as possible; the shorter the process, the less likelihood of interruptions from plane flyovers, trucks passing by, and furnace or AC systems kicking in. The bottom line: it’s easy to set up the Böhmer correction initially, and also to rerun it you change anything in or near the system.

Now let’s zero in on details of what the Wavelet II does for music. Fortunately, it was easy to switch the Wavelet II’s room correction on and off instantaneously to evaluate its effects. (The switch did insert a fraction of a second of silence, so it wasn’t literally instantaneous.) Here’s are some results:

Orff: “0 fortuna” from Carmina Burana, Seji Ozawa / Boston SO: The most obvious effect of room correction was that the words sung by the chorus were more intelligible. (Sadly, room correction did not translate those words into English. No doubt the Universal Translator Upgrade will take care of that.) The orchestral backing and male voices also had slightly more weight.

Quarter Chicken Dark Yo-yo Ma:Room correction brings up the mid to lower bass without changing the overall volume.

Given that I ran these tests around the Christmas holiday, it seemed appropriate to try some passages from Tchaikovsky’s Nutcracker ballet.

Act 1, No. 7: The Nutcracker Battles the Army of the Mouse King, Gergiev / Mariinsky Orchestra: The crack (gunshot?) just after the movement begins seems a little louder with room correction off. But, with room correction on, the initial pop, meaning the leading edge of that shot, is more startling, distinct, realistic, and exciting. (Seriously. I jumped.) Similarly, at the very end of the movement, the repeated plucked double notes on the basses are deeper and more resonant. In general, turning on room correction clarifies the various instruments; it also brings the orchestra forward slightly.

Piano transcription by Stuart Goodyear, TH14, act 1, tableau 1: With room correction on, the lower registers of the piano have more body, as does the big chord at the very end.

Waltz of the Flowers, Los Angeles Guitar Quartet: The contribution of room correction was particularly noticeable with this recording. The guitars not only have more body, but it also is easier to tell that there really are several different instruments playing different parts. With room correction off, you still hear all the notes, but it’s not so clear where each line is coming from. Metaphorically, with room correction off, we have a caricature of some guitars; with room correction on, four people are playing individual guitars.

Nutcracker Suite as arranged by Duke Ellington and Billy Strayhorn; played by the Harmony Ensemble of New York, conducted by Steve Richmond. I promised classical music, and I suppose this just sneaks in under the wire, but this wonderful arrangement sounds more delightful with room correction on. Without correction, the sound is noticeably two-dimensional on a plane in front of the speakers. Turning on room correction opens it up, adds a little punch, and just helps things fly along.

The second form of DSP offered with the Wavelet II is the aforementioned “Omnio”. Subjectively, the effect is obvious, and here’s my best effort at description: Imaging is “solidified”, made more three-dimensional and precise, with instrumental and vocal positions clarified. The image also is deepened front to back, while the overall sound fills out, with instruments and voices having more tonal depth or body. For example, in orchestral music the brasses and woodwinds are more clearly behind the strings, and the sound of the orchestra is “thicker” (in a good sense), as though more of the full sound of each instrument comes through. An abbreviated way to say all this is that the sonic “picture” of performers in space became significantly more believable, which is not the sort of thing that one normally hears by simply flipping a switch.

These benefits can be recording dependent. Omnio really rescued some recordings: for example, without Omnio, the Supraphon recording of the Dvorak Symphony 6 with Mackerras leading the Czech PO had the violins plastered to the left speaker. With Omnio, the sound was not perfect, but the violins managed to move back toward the rest of the orchestra. In contrast, in the Vox recording of Rachmaninoff’s Symphony 2 with Slatkin / St Louis, now remastered and reviewed on Classical Candor here, things sound more confused and messy with Omnio on. (Apparently, this is because the recording originally was mastered for 4-channel – shades of Quadraphonic! Omnio is stumped when trying to figure out what to do.) Fortunately, a simple tap on the control app turns Omnio on and off, so it takes only a few seconds to decide whether to use it or not. When you do turn it on, note that the perceived volume increases, so adjust accordingly. In any case, over the months I found myself happily using the Omnio feature for most recordings.

But wait, what about that Omnio+ thing that I mentioned earlier? With the current firmware, you now can choose Omnio Bypass (meaning off), original Omnio, or Omnio+. As I hear it, Omnio+ is indeed "plus": Omnio, only moreso. In particular, with the original Omnio I occasionally felt that the central image might be a little “clogged up”; Omnio+ eliminates that issue while providing even clearer imaging with a more natural feel. Omnio+ also seems to work a little more reliably, although not always perfectly, with problem recordings.

One editorial comment: product descriptions and other reviews that I have seen of both the original Wavelet and the Wavelet II generally give but little attention to the Omnio feature. I find this surprising. I said earlier that Omnio/Omnio+ make an immediately noticeable change, i.e., one that is not subtle. This is just the sort of improvement that you can obtain only with advanced DSP, and as such, it is a big deal. It’s why one would be interested in a unit such as the Wavelet II – and it may be a harbinger of even bigger changes to come.

Minor Gripes

Lest I be accused of seeing only the bright side, I will admit to a few minor gripes.

On the hardware side, the USB connectors on the rear panel all are USB 2; I wish they were USB 3.1 to help future-proof such a premium device. The USB digital audio input connector could be a micro-B, an A, or better yet the new universal C standard connector rather than the old-style original B-connector. WiFi connection is by means of an adapter plugged into one of the USB communications ports; that’s fine, but the adapter is restricted to WiFi 802/n, using only the older 2.4 GHz band. Finally, although WiFi setup is done only once (unless something changes in your network), the process is a little cumbersome.

In Böhmer/Legacy’s defense, one can argue that they should allocate development resources to hardware and software improvements, which is exactly what they have done – but a few minor tweaks still would be nice. Anyway, that’s the end of my nit-pickng.

In Summary: The Wavelet II

The Wavelet II is an extraordinary product with powerful sonic capabilities. I’ve barely touched on the technology involved, preferring to concentrate on the more accessible features and sonic outcomes. But there’s no doubt that we are operating here at a frontier of sound reproduction.

In my earlier overview of the Legacy Signature speakers, I stressed how “real world” they were; in a different way, the Wavelet II also is a real world product. A simple, intuitive user interface combines serious processing power and control flexibility to work with real systems in real rooms. Sure, it’s nice that the Wavelet II is suitable for use with superspeakers in purpose-built audio rooms that already are full of treatments and tuned to perfection, but it’s really exciting that it works even for lesser speakers in plain old real rooms in real houses, condos, or apartments. (One hesitates to think of the prodigious capabilities of big Legacy speaker unleashed in apartments with unsuspecting neighbors...but I digress.) Obviously, the room correction is front and center, but don’t forget the Omnio / Omnio+ processing. And, of course, there’s the bi-amping capability if your speakers support it.

But what about the price ($7950)? By the rarified – feel free to pick a less flattering adjective – standards of “high end” audio, with folks shelling out well into five figures for everything from phono cartridges to cables, the Wavelet II is not particularly expensive. However, by more down-to-earth standards, it’s a significant investment.

Meanwhile, though, a lot of audiophiles spend a lot more on equipment and accessories that return a lot less than the Wavelet II provides. Also, the price is easier to swallow when you remember that the Wavelet II obviates the need for a separate preamp and DAC. In my own system, given that it would be difficult for several reasons to upgrade my speakers, the Wavelet II is by far the single most significant upgrade that I could have made. In fact, I would speculate that, in many (most?) systems, investing in a Wavelet II could make a bigger difference than an equivalent investment in new speakers. Here’s the point: at the least, you really should try to hear a Wavelet II in a system fully set up to use it. DSP truly is the final frontier of audio; the effects are immediate and obvious.

The Crystal Ball

I suppose that I shouldn’t even mention this last bit, as Legacy has plenty on their plate already, but here’s a dream: could there be a less expensive “mini-Wavelet”? Dump the analog inputs and maybe even a digital input or two, make the output just four channels (for bi-amping) or even two channels (single amp), maybe back down the numeric processor to original Wavelet standards (it used a lower bit depth and a shorter processing window), all to bring the price down to a level that might be accessible for those earlier on the curve of building their audio systems. Böhmer room correction, Omnio processing…it’s a dream of bringing this kind of power to a wider audience. I hasten to add that this is my dream; I certainly can’t speak for Legacy or Böhmer. But wouldn’t it be nice?

Meanwhile, take a listen and imagine what the Wavelet II might do in your listening room. If you are tired of swapping similar components to eke out tiny gains, maybe it’s time, as Monty Python would say, for something completely different.

A Beethoven Odyssey: Volume 8 (CD Review)

by Bill Heck

Beethoven: Piano Sonatas Nos. 13, 16, 18, and 22. James Brawn, piano. MSR Classics MS 1472

It’s been over ten years since James Brawn’s “A Beethoven Odyssey” series began. Like the rest of us, Brawn is ten years older, but it’s a pleasure to know – by the evidence of this volume – that we have the same artist, with fingers as supple as ever and musical sensibilities very much intact.

Note that Volume 8 is the second of the most recent pair of releases in the series. If you’ve not read our review of Volume 7, please do so now for some helpful background. I’ll wait.

I have to admit that, after spending time with Volume 7, which includes the majestic last three sonatas (30, 31, and 32), it's a little difficult to come back down to earth and review the “mere” middle period works here, numbers 13, 16, 18, and 22. But then the word “mere” is inappropriate when speaking of any of Beethoven’s creations; these are lovely works, perhaps less demanding of either the artist or the listener, but also more approachable than the final triumvirate. They also offer fascinating glimpses of Beethoven’s musical progression.

Number 13

The liner notes for this release quote a Beethoven letter from 1801: “I’m not satisfied with what I’ve composed up to now. From now on I intend to embark on a new path.” In sonata 13 (Op. 27, no. 1) – not to be confused with its opus mate number 14 (no. 2), the famous "Moonlight" – we see that Beethoven is indeed heading off in a new direction. The movements are not in the usual order for a sonata, as the opening movement is a slow one, and they are played straight through without pauses. (Putting the slow movement first happens again in the “Moonlight”.)  Even within movements, tempos and moods change radically, seemingly without warning at times. One of the joys of listening to Brawn’s playing is that these changes and differences seem perfectly natural in the moment; although lively and expressive, the playing does not call attention to itself.

Beethoven circa 1801

Number 16

We next hear an odd pair: sonata 16 in G (Op. 31, no. 1) and 18 (Op. 31, non. 3). By the time of these compositions, in 1802, Beethoven was fully on his "new path", moving beyond restrictors of classical composition. But even more: at about this time, Beethoven wrote what has become known as the Heiligenstadt Testament, an extraordinary document in which Beethoven begins with the tone of despair befitting a suicide note but ends up saying that “…only Art held me back…”, that he could not leave this world without producing the music of which he was capable.

And yet we have number 16, hardly a lament of despair! The first movement is filled with twists and turns, metaphorically not signs of danger but more like the joyful careening of an amusement park ride. The second movement seems to recall a more formal, backward looking charm, while the third ends with a flourish indeed. At least to me, none of this seems particularly “deep” (by Beethovenian standards), but it is lovely all the same, and Brawn plays it gracefully.

Number 18

Sonata 18 is a romp all the way through, with no slow movement at all. Perhaps the nickname "The Hunt" was bestowed (by someone other than Beethoven) because it reminds the listener of the energy of that pastime; other sources say that the name came from the resemblance of one passage to a sound of a horn commonly used in hunts. Although this is a "jocular" work (a word from the liner notes), shadows do occasionally cross the sunny landscape, hinting at unseen depths.

As for the playing, the first thing that one hopes for is enough energy to keep things going all the way through, and Brawn certainly brings that. As usual, moreover, he makes it all sound quite natural, giving the music space to breathe but never losing the momentum. I particularly enjoyed the two fast movements: the second (Scherzo, but in two beats rather than three) and fourth (Presto con fuoco, i.e., quickly, with fire). In both, especially in the second, the term "rollicking" came to mind; Beethoven and Brawn carry us along with the vivacity of the music.

Number 22

As we arrive at the final work on the disk, sonata 22, I'm trying to think of a word to describe the first movement. It starts conventionally enough, a short motive being handed off here and there, then more energetically - and then the whole thing grinds almost to a halt only to restart in the same overall plan, but with more ornamentation; this happens a few times. Some commentators have seen this movement as a parody of "uncreative composers ", and I can buy that! The second movement is built on similar ground: Beethoven takes us up through octaves with a rather simple scale, then down the same way, then shifts the same pattern to multiple keys, then we do it all over again with sort of a rocking motive, all at high speed, making for a virtuosic workout for the pianist. Physics tells us that there can be no perpetual motion machine but if there could be, this would be it. (I hesitate to say it, but I even hear precursors of minimalism in stretches in which the music changes only subtlety.) Overall, there's considerable humor here but, given that it's Beethoven, it's not merely a musical joke. Brawn gives us a convincingly energetic and, yes, humorous reading, an appropriate ending for a most enjoyable album.

Overall, I’ll simply summarize what John Puccio and I have said about previous albums in this series: playing that consistently just sounds right, combined with exemplary recorded sound. What’s not to like?

The Legacy Wavelet II (Part 1)

by Bill Heck

As music lovers with nice stereo systems, many of us are subject to periodic fits of “upgradeitis” – the desire to change something, anything, to tweak our systems for that next level of sonic improvement. But looking at the many upgrade options in the audio world, especially the front end electronics, I think that we’re aiming too low.

The prices that we might pay certainly aren’t too low: anything but that, when the cost of fancy versions of the most basic products soar into tens of thousands of dollars. No, I’m dissatisfied because the rewards that these products aim for, and maybe even sometimes deliver, are so small. You don’t need to believe that amps, preamps, or DACs, much less cables and such, “all sound the same” to suspect that the differences among them are mostly subtle, regardless of the sometimes rapturous reports of certain reviewers. (Speakers are a different story; I’m talking about everything up to that point.)

Hey, I appreciate subtle improvements as much as the next music lover. But if I’m spending big bucks upgrading audio components, I don’t want subtle. I don’t want something that I can identify 80% of the time in a blind test; I want something that no one could possibly miss even once. If we spend serious money, shouldn't we get serious returns? Not on the edges, not tiny changes, but major upgrades, differences obvious to the most casual listener. We try to get excited about little gains, but maybe that's because it's been so long since we've had any big gains.

Let’s take a moment to think about why the effects of changing front end components might be subtle. The issue is that these components are mostly pretty doggone good already: electronics with vanishingly low levels of various distortions and digital signal sources that already provide fidelity beyond the limits of human hearing. Moreover, despite audio folklore, human hearing is not particularly sensitive to the kinds of differences (distortions, if you like) that remain at this stage of the audio reproduction chain.

So, if making the musical signal even cleaner is not where advances lie, how do we improve matters? How about changing the signal, not accidentally but with purpose, changing it so that the sound that arrives at your ears better reflects that sound that the performing musicians made originally? In other words, we can modify the signal to correct for, or adapt to, the listening room and to recover or enhance information otherwise lost in the recording process. Yes, that’s Digital Signal Processing (DSP).

Legacy Wavelet II

Enter the Wavelet II. (The original Wavelet has been replaced by the Wavelet II, which is the one that I have and am discussing.) This product, the result of a partnership between Legacy and Böhmer Audio, is a rare beast in the consumer stereo market, one properly characterized as a dedicated DSP product. Sure, there are DSP capabilities built into other products, such as AV receivers, mostly to provide room correction (with varying degrees of success) and to synthesize spatial effects in multi-channel systems. In the two channel world, the aim usually is room correction only, often as an “add on”’ for preamps and such. In contrast, the Wavelet II is primarily a DSP processor offering a unique approach to advanced room correction, plus features aimed at what we might call “music restoration”. The Wavelet II is one of a very few components that does not just sneak across the DSP frontier but bounds fearlessly past it.

To clarify, the Wavelet II does provide the functionality of a preamp and a DAC, not to mention a multi-way crossover. But these features come along for the ride, so to speak: the functions provided by the Wavelet II are built on an advanced processing platform to provide a complete front end, allowing optimization of the entire package while making things convenient for the user. (You can get an idea of how it hangs together from this block diagram at the Böhmer website.)

In what follows, I’ll focus on the unique features of Wavelet II. This means that, in the interest of keeping the length of this article under control, I’ll give short shrift to some aspects; please excuse those omissions.

Description

As with my earlier review of the Legacy Signatures, I won't go into the specifications that you can easily read here on the Legacy website, but a quick summary and orientation may be useful.

Wavelet II Rear Panel

The Wavelet II is both figuratively and literally a black box. I’ve not tried to open mine; you can get an idea of the contents by reading the description on the website. The details are proprietary, and of course with a unit like this, the real action is in the software.

Externally, the digital and analog inputs are more or less typical for a preamp. The output side is more interesting: each of the eight (not a typo) output channels sports balanced and unbalanced connections. Why eight output channels? The short answer is crossovers: I’ll describe their use below.

Wavelet Controls on Android Phone

As to the controls, there are physical buttons and a dial for basic functions on the front of the unit; I hardly ever use them. In addition, a small remote control for basic functions is included with the unit; I’ve never taken it out of the box. The obvious way to control the Wavelet II is with the browser-based app. My own daily driver is a repurposed old Android phone; my Microsoft Surface Pro works well, too, and the Legacy folks swear by iPads.

It was the work of a few minutes to figure out the control app. I particularly liked the clever “fine” volume control, which makes the kind of adjustments that you are likely to make a matter of a few taps. Another nice touch is that the apodizing filter, room correction, and Omnio functions (described below) are turned on or off with simple checkboxes, all of which are located on the main dashboard page – very handy for quickly assessing the results of each function.

Functions

Let’s walk through the major functions of the Wavelet II.

Digital-Analog Converter (DAC): Yes, the Wavelet II includes a DAC. (Do any digital products these days not include a DAC?) Of course, you could connect your source to your favorite DAC and connect that to one of the Wavelet’s analog inputs. But given that the Wavelet II digitizes analog inputs to do its DSP thing, why bother? By the way, you can switch on the fly between linear and apodizing filters (the latter to reduce pre-ringing) but that’s one of those subtle effect items that I’ll not spend time on here.

Preamp: The Wavelet II functions as a preamp. Not to insult the Legacy folks, but there are oodles of preamps on the market, a lot of them are very good, and in real world conditions, the differences among them are, well, subtle. (The Wavelet II does provide a neat set of “Contour” sliders that are unusual and particularly handy. You can read about them in the Wavelet II manual.) Subtle is not what I want to write about today, so again I’ll move on to what makes the Wavelet II unique.

Crossover: Although electronic crossovers are hardly new, finding one integrated into a single component with all this other functionality (preamp, DAC, DSP) is unusual, so I’ll spend a little time on it. Of course, a crossover is relevant only if you have something to cross over, either speakers that allow bi- or multi-amping, or perhaps regular speakers plus subwoofers.

For those readers unfamiliar with the concept of bi- or multi-amping, here’s a brief introduction. (You other folks can skip ahead.)

You probably know that your speakers contain crossovers that divide up the frequencies of music and send them to the appropriate drivers, e.g., bass frequencies to the woofers and high frequencies to the tweeters. In “bi-amping”, the idea is to insert an active (electronic) low-level crossover before the amplifier instead of relying on a passive one contained in the speakers. The active crossover thus directs bass frequencies to one amplifier and higher frequencies to a second amp. At the speaker, the bass amp connects to inputs (binding posts) that feed only the low frequency section of the speaker; the high amp connects to what remains of the speaker crossover to drive the midrange and up. To make this work, you need three things: (1) bi-amp capable speakers, i.e., having separate inputs for bass versus higher frequencies; (2) an active crossover in or after the preamp; and (3) a second amp.

Why mess with the complications of bi-amping? There are several theoretical reasons, including providing more total power to the system; moving the stress of higher power handling to just the bass amplifier; improving crossover accuracy and consistency; keeping large back EMF out of the amplifier handling the higher frequencies; and isolating distortion to low frequencies. (Details about the benefits of bi-amping can be found on the Web.)

So with the Wavelet II, the crossover characteristics specific to your speakers are programmed in before the unit it is shipped to you. If you are using Legacy speakers, the Legacy crew already knows how to program the unit for optimal performance in your system. If you are using other speakers – and indeed you can use the Wavelet II with non-Legacy speakers – you would need to supply information, such as crossover frequencies, so that they can program the unit properly.

For example, to work with my Legacy Signature speakers, two pairs of channels are set for bi-amping (L-R for highs and L-R for lows); another pair is set as full range L-R in case I didn’t want to bi-amp; and the final pair is reserved for subwoofers(s). Higher-end Legacy speakers, such as the Valor, would use all four pairs of channels for the different sections of the speakers, i.e., multiamping. If I later trade in my Signatures in favor of some other speakers, I can return the Wavelet II to Legacy for reprogramming as needed.

By the way, for those deep in the weeds on crossovers, note that Wavelet II digital crossover is itself quite sophisticated, supporting multiple parameters (slopes, delays, filters, etc.) per channel.

Room Correction: Certainly, there are other room correction systems (rather a misnomer, as it’s more like “room adaptation”), whether from makers of receivers or independent ones such as Dirac, but Legacy is the only vendor I know of offering the Böhmer system.

The Böhmer approach differs from most, perhaps all, other room correction systems in that it is primarily based on time rather than frequency, compensating for room effects within a 50 millisecond (ms) window. That long window – in audio processing terms, 50 ms is a long time – allows the Böhmer analysis to “look at” and deal with the results of multiple room reflections.

To cover the process in any detail would take us far afield; I’ll stick to reporting the results below, and suggest that you look at the detailed Böhmer website for more information.

Creating the correction algorithm for any given audio system and room is computationally intensive, so during setup you run a measurement process and the data thus collected is submitted via the internet to a high-powered server. Within a few minutes, the calculated correction algorithms are sent back to the Wavelet II. Although execution of the algorithms while playing music requires less processing power than their initial construction, the load is hardly trivial, which is why the Wavelet II contains a serious numerical processor (an Analog Devices chip with associated hardware support components).

Other DSP: Room correction is the most obvious form of DSP, but the Wavelet II offers another, or rather two others: “Omnio” and “Omnio+”. These are Legacy’s names for algorithms that “improve channel separation and restore the directional vector relationship to depth and position cues”. As the names imply, Omnio, which has been around for a few years, was the first iteration; “Omnio+” is a matter of months old, having been added in the recently released version 2.0 of the Wavelet II firmware.

Note that existing Wavelet II’s can be upgraded with this latest firmware; in other words, the functionality of the Wavelet II can improve after you buy it. We’re used to that with smartphones (and electric vehicles); how nice to see it in an audio product.

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So what’s the result? What does advanced DSP do for the sound? Does it improve our listening experience? Part 2 of this article has now been published here.