APOGEE DAX ACTIVE CROSSOVER
Arnis Balgalvis auditions the dynamic DAX/Diva duo
Dual-channel, dual-passband, non-inverting active crossover, with external power supply
Crossover frequency: 330Hz. Filter slopes: 6dB/octave gradually increasing to 12dB/octave. SIN ratio: -90dB (A-weighted). THD: 0.01%
Inputs and outputs: balanced and single-ended. Gain: balanced=2, single-ended=l, with internal 6dB gain adjustments in 1dB steps for low- and highpass sections
Input impedance (switch-selectable), balanced: 600,1.2k, 25k, 5k, 10k ohms; single-ended: 5k, 10k, 20k, 40k, 80k ohms. Output impedance: 6 ohms
Front-panel controls (per channel) for mid/tweeter level (0 to -6dB in 1dB steps), woofer and mid/tweeter balance (in 0.2dB steps), rake control ±2dB at 5kHz (in 0.5dB steps) hinged at 1kHz
With six-window numeric LED readout
Dimensions: 2 1/2" H by 18" W by 12 3/4" D (DAX), 2 1/2" H by 6 1/2" W by 11" D (power supply)
Weight: 5.5 Ibs
Price: $3995
"Uh-oh, Apogee is up to something!" I thought when I opened one of the passive crossover boxes for the Diva loudspeakers and discovered some loose wires inside. No, negligence this was not. Not when all the loose ends in question were terminated and carefully covered with heat-shrink insulation, and, not when each wire was found neatly tucked away.
All of it was too deliberate, too carefully. planned. Only one thing to do-call Boston. Not unexpectedly, Jason Bloom fessed up when I confronted him with my discovery.
"Oh, sure, that's for the DAX," he said with a chuckle.
"The DAX? What's a DAX?"
"It's our new Dedicated Active X-over. Were hoping to unveil it at the Summer CES. For now it's only slated for the Divas, but in time the Duetta Signature and the Caliper Signature are to get it."
That was two years ago, and yes, Apogee introduced the DAX as promised.
Jason went on to explain that, in their continuing quest to raise the performance level of their speakers, they have had to look beyond the drivers. He felt that Apogee had gone about as far as they could -especially in the case of the Divas -when it came to the development of the individual driver elements.
But the crossover, especially a passive design, is quite another matter-it's a situation crying out for help. And Apogee responded with a sweeping decision- they scrapped the existing passive network and replaced it with an active electronic design. Hence the Dedicated Active X- over, or DAX for short.
It's dedicated because the DAX is intended to be used with only three of Apogee's loudspeakers-the Diva, Duetta Signature, and Caliper Signature-and even then internal adjustments are necessary to set the unit up properly. The Scintilla and the new Stage are excluded, as, of course, are all loudspeakers by other manufacturers.
The active part refers to the circuitry performing the crossover function. It is much easier to create sophisticated frequency -response contours not only accurately, but also more repeatably, by employing active filter techniques. The required signal-processing manipulations for creating complex low- and highpass filters can be significantly more proficient when powered components with gain-such as operational amplifiers-are used.
But more important, filter designs are unlikely to flourish in the stormy environment found at the outputs of power amplifiers. Here, where the voltage and current levels are very high, resistive values can appear in but the smallest doses. Power here cannot be wasted it's a very precious commodity, in the literal sense of the word. It's something very difficult to attain, since the large inductors called for always have a resistive component. Design considerations are further hampered by saturation and proximity effects, creating conditions that deviate from the ideal by a wide margin.
A far better place to perform the crossover function is at line level, before the power amplifier. To be sure, there is a price to pay in system complexity- remember, additional amplifiers, as well as interconnects and speaker cables, are required for driving the other speaker elements - but possibilities for proper signal processing are significantly more favorable.
Which leads us to the other advantage- the performance of the power amplifiers. For one thing, each amplifier now encounters only a portion of the audio band as determined by the crossover bandpass characteristics. For another, the amplifiers drive the speaker elements directly The reactive effects of passive crossover impedances and loudspeaker voice-coil interaction with the crossover are eliminated. In the Apogee designs, the amp/speaker interfaces are particularly amicable. The Diva's woofer elements get connected directly to the amplifier binding posts; the midrange and tweeter elements do have a minor passive network for dividing the upper spectrum between them. No matter, the speaker elements present very linear and mostly resistive loads to the amplifiers. Apogee tells me the impedance never drops below 3 ohms. All in all, these are conditions that should keep the system as a whole performing better.
Just the DAX, ma'am
Dedicated or not, the DAX is a remarkably flexible device. It's a shame that this product is limited to the Apogee speaker line. It prominently demonstrates just how much more effective crossover filters can be if the processing is performed at the low signal level ahead of the power amplifiers. More important, that additional-and very functional -flexibility can be built into a crossover to make it more than a mere frequency - channeling device.
One of the DAX's main goals, according to Jason Bloom, was to provide the user with the ability to tailor the response characteristic of the loudspeaker in order to compensate for the vagaries of the listening environment, source material, or individual taste. To quote from Apogee's manual, the DAX provides an "exceptional tuning flexibility which enables the user to sculpt a tonal balance to meet their exact listening requirements."
To this end, each stereo channel of the DAX features four controls for modeling the response of the woofer and the midrange sections, as well as the refinements outlined below.
This makes for a rather busy front panel: eight controls spread out across the face of the DAX and arranged in two groups of four, flanking the six centrally located LEDs. The Displays are arranged in two stacked rows, with three LED groups in each.
Starting on the left, the first control alters the bass response of the woofer section. Six increments have been included, each decreasing the output by 1dB.
The second control has been included for fine-tuning the woofer and the midrange response in increments of 0.2dB. A CCW rotation affects the woofer, a CW rotation the midrange/tweeter.
The third control performs the same function as the bass control, except that the response of the midrange/tweeter ribbons is affected-the level can likewise be attenuated in six 1dB steps.
The fourth control is the most interesting, as far as I'm concerned. Apogee refers to it as the Rake Angle, and it affects frequencies above 1kHz. Here's how it works: The response is flat when this control is set to zero, but commencing at 1kHz, which Apogee calls the hinge point, the response can be "raked" -angled, if you will-upward or downward in 0.5dB steps, to create a change in response of up to ±2dBat 5kHz.
The application is obvious. Dull spectral results can be enlivened, or, when things get too bright, the excess can be toned down. The nice thing about this control is its mild mannered approach. The result is never overbearing or prominent. It's a rather subtle effect immediately, but with lasting influence in the long run.
And here's the ergonomic icing: An array of LEDs displays the response changes effected by the front-panel controls. In dBs, no less. Each channel has three sets of LEDs, corresponding to changes in the bass, midrange, and Rake Angle responses.
The LED array immediately conveys the selected speaker response, without having to poll the individual switch settings. An added touch of thoroughness is the choice of two brightness levels for the LEDs. A switch on the rear panel takes care of that.
The display becomes indispensable when the DAX is positioned at the loudspeakers, where I also prefer to keep the power amplifiers to keep cable expenses low by using short runs from the DAX. Now the settings are easily visible from across the room. Of course, accessing the switches is now impossible without leaving the listening position. A remote control is obviously called for.
While it's true that the DAX can only be used with certain Apogee loudspeakers, Apogee nevertheless wants to minimize interfacing problems with associated components such as preamps and power amps. To ease matching, the user has at his or her disposal a number of adjustments. For some of these "set-it-and-forget-it" adjustments the top cover has to be removed to access switches on the main PC board. This complexity is not the rule but the exception-every frequently used control appears on the front panel.
First off, every input and output of the DAX is ready to be used in the single-ended or balanced mode. For the input side-there are two inputs, one for each channel-the desired configuration is selected by an internal switch on the main PC board. So, to set the input mode, all you have to do is tilt a small rocker switch to the required position.
Choosing the output mode is even simpler. Since all the connectors for both configurations appear on the DAX's back panel, it's just a matter of matching each interconnect to the proper output connector. Be it input or output, the design is foolproof - the single-ended connections are Tiffany RCAs, and the balanced interfaces appear on XLR connectors.
Next, we get to select the value of the input impedance using selector switches located on the main PC board. Going balanced, choices of 600, 1.2k, 2.5k, 5k, and 10k ohms are available, while for the single-ended mode the increments appear at 5k, 10k, 20k, 40k, or 80k ohms.
Still sticking with the main pc board, we find four rotary gain - setting switches. At two per channel, these switches attenuate the gain of the high - and low-pass sections of the crossover over a range of 0 to -6dB. This feature accommodates amplifiers with unequal sensitivity ratings when powering the woofer and the midrange/high - frequency drivers.
The last internal adjustment is included to set the DAX for the desired speaker application. Since the DAX can be ordered in the Duetta/Diva or the Caliper/Diva configuration, a switch setting is included for choosing the proper EQ.
How to add a DAX
The easiest way to end up with a DAX in your system is to choose it right away and make it a part of the initial speaker-system purchase. You'll need to double up on the power amps, however. All told, the Divas now require a total of four power amps; that's either four monoblocks or two stereo units. If you're like me and had bi-wired your speakers, no additional speaker cables are necessary.
After that, the DAX can be treated like any other component: just plug in all the interconnects and connect the speaker cables between the amps and the external crossover enclosures at the Divas.
It makes good sense economically to go for the DAX right away. The price of the Divas with the passive crossover is $8995, and the DAX costs $3995 when purchased separately. But if you buy the Divas and the DAX together the total price is $11,350, a saving of $1640. There's no voodoo economics here-the passive crossover is not supplied in this case, and the savings are passed on to the customer. This money can, for example, go toward the purchase of the additional amplifiers.
Converting existing Divas to accept the DAX is another matter. Having gone that route, I would rate it, for the technically uninitiated, a relatively involved situation.
As mentioned earlier, the DAX only replaces the major crossover point involving the woofer and the midrange ribbons; it has nothing to do with the midrange- to- tweeter transition. As a result, the passive crossover electronics box cannot be eliminated-it has to be reworked. *
* It's possible to purchase a simplified passive crossover network at this point, but it results in discarding the complete passive network. For most people that's too much of a waste.
All the work involved is internal to the crossover. In the modified state the passive crossover components for the woofer- to - midrange crossover are bypassed, and the box itself remains in place as the termination point for connecting to the three ribbon elements. It also houses the components for the midrange-to-tweeter crossover. As expected, the MR- and woofer-level switches on the passive crossover are deactivated, with only the tweeter-level control switch remaining functional.
Reworking the passive crossover was not as simple as Id anticipated, and I would not encourage anyone without at least advanced hobbyist experience to tackle the conversion. In fairness, I'd like to mention that the tasks involve nothing more than changing a number of pre-terminated wire connections and terminating a small inductor coil to binding-post screw terminals. As I mentioned at the beginning, it was obvious that Apogee had the DAX planned for some time because the passive crossover for the Divas was carefully prepared to accept the modifications. All parts, including a very special attention to detail - a 3/8" socket wrench-are provided, and the instruction manual is explicit and detailed.
For Divas with SNs below 10360, the instructions call for a soldering operation. Unless you know exactly what it takes to make a good solder joint, don't do it. Since soldering is not as easy as it appears, and a heavy-duty soldering iron is called for, I urge you to defer the modification to the dealer.
Adding the DAX to the Duetta Signatures also involves modifications of its passive crossover. Judging from the instruction manual, these changes are much easier. Since the network is much simpler - the Duettas do not have an external crossover enclosure - and all necessary wires for the modification are in place, I would not expect this conversion to be very demanding.
The Caliper Signatures cannot be modified by the user; dealer involvement is called for.
News worthy item - hot off the presses. By the time you read this, Apogee will have unveiled their new DAX II at the 1990 SCES. This is a more cost-effective version of the original DAX, with a list price of $1995. The DAX II will not have the LED display and the power supply will be internal, but the basic functions will be retained. I'll try to report on this development as more information becomes available.
Down to business
Let's listen.
Suppose a component is around for a long time, performing very satisfactorily. Even if you started out with a rush of excitement, before you know it you're taking it for granted. And that's just about what happened with the DAX.
I've had the Diva/DAX combo singing for me for the better part of a year now. Those of you who read my cartridge reviews in last year's June and July issues might recall that the DAX arrived just in time to be included in the system used to evaluate the cartridges. Its considerable positive contribution was immediately apparent, and the DAX was accorded "essential" status.
But when the going's good, we don't appreciate just how good we have it. The DAX was no exception. With time, its contribution to system performance, though considerable, was taken for granted.
It merged into the system so successfully that its sonic strengths became its liability. Even though the sonic virtues of the DAX were on display constantly-even more significantly, it did not call attention to itself in any negative sense - the DAX assumed a somewhat passive presence.
As a matter of fact, I was much more aware of it while swapping amplifiers or substituting interconnects now that the DAX imposed a doubled component count at its outputs.
This sonically pleasant setting remained essentially unchanged, contributing significantly to unraveling and sorting out the sonic pleasantries of the Esoteric P-1 CD transport and the Wadia 2000 digital processor.
For this review, however, the DAX occupies center stage, and some specific sonic assessments are called for. So I dusted off the passive crossover and reinstated it in the system -the DAX has been in use far too long for me to reliably recall the sound of DAX-less Divas. Only by reacquainting myself with the primeval Divas could I be in a position to sort out the DAX's contributions.
But haste makes waste. If we're not careful, the original setup can end up significantly disadvantaged. It all boils down to the quantity and quality of power. Simply put, equal measures of power, and with the same sonic signature, should be fed to each speaker with and without the DAX. To me that's basic - a simple case of apples and apples.
The problem surfaced when I switched from two identical power amplifiers per side with the DAX in place to a single amp without the DAX. Obviously, that halved the total amplifier power for each loudspeaker. On top of that, introducing the passive crossover into the system produced an additional 3dB loss of efficiency. Consequently, when backtracking from having used four identical power amplifiers with the DAX, the Divas ended up seeing only one quarter of the power when the DAX was removed and the passive crossover instituted.
Fortunately, the flexibility of the Classé DR-9 stereo power amp saved the day. Since this amplifier is bridgeable (see my review in October 1988, Vol.12 No.10), its two 100W channels can be strapped to produce a 400W mono, power amp to drive each Diva sans DAX. With the DAX, the DR-9s can be restrapped to provide dual 100Wpc stereo amps, keeping the before and after power conditions at each speaker the same. **
** Webmaster note - This is not strictly true, it depends on HOW the amp is internally bridged. A pair of Meridian 557 amps I owned sounded considerably different when in bridged mode, much more upfront and "in-your-face" than as ordinary stereo amps. If anyone else has experienced anything like this email me.
And since we're using the same amplifier building blocks, the sonic signature is likely to be the same. Certainly more similar than choosing separate amps with different power ratings.
So why bother with any other amps at all? Two reasons. First, the DAX had to be exercised with as wide a variety of power amps as possible. And second, it represents more of a real-world situation.
To add the DAX, a user would most likely double up on the amps in the system; one would go from two to four monoblocks, or from one to two stereo amps. It's unlikely that someone will start out with two bridged DR-9s, then unbridge them when the DAX is added. If anything, in this instance, two more DR-9s would be added.
The other components in the system were the Jeff Rowland Coherence 1 series II and Krell KSP-7B preamps, the Basis Gold Standard Debut Turntable, the Airtangent tonearm, various cartridges, the Teac Esoteric P-2 CD Drive and S-2 Processor, the Wadia 2000 Digital Processor, and Straight Wire Maestro and Monster Cable Sigma series interconnects and speaker cables. Besides the Classé DR-9s, power amplifiers were Krell KMA-160s, Krell KSA-250s, and Rowland Models 5 and 7.
Do Divas like DAXes?
To set the stage for what the DAX did for the Divas, let me briefly return to my original review of this speaker (August 1988, Vol.11 No.8):
"The strength of these loudspeakers is their ability to communicate the essence of a musical event. It's an all-inclusive concept that suffers considerably when broken down to its component parts. Instead, we have to think in terms of the performance as a whole, and recognize that the constituent aspects have to act in concert, reaching us properly proportioned and mutually enhanced. Only then are we in a position to fully appreciate the significance of these loudspeakers.
"But I'll strike a compromise. Let's say that the basics are all present and accounted for, and I'll try to concentrate on a few of the more involved performance aspects such as spectral balance, dynamics, and soundstage...
As far as I'm concerned, the Divas present a soundstage that is simply phenomenal. Again, it's the total presentation that dazzles. This includes the overall soundspace that seemingly pervades the whole stage in front of the listener, and billows forward from there to envelop the listener as well ...
"The panoramic presentation of the Divas is, in my experience, peerless. They operate with a sweep so broad that it's startling at times. Add to that a keenly developed sense of depth, and we are talking grandiose."
That was then. What about now? Having carefully read the above, and being of sound body and mind, I will now go on to tell you that the contribution of the DAX is significant and, as I will explain shortly, it allows the Divas to perform better than ever.
Did I say perform better? Better than phenomenal? Better than peerless? Better than grandiose?
Absolutely!
Simply put, the DAX allows the Divas to realize their potential. At the same time, let's keep things in perspective and recognize that the inclusion of the DAX does not alter the Divas in any way. It's exactly the same speaker it always was, except that the limitations of the passive crossover have been eliminated - and better associated equipment was used allowing the speaker to perform under far more optimal conditions.
These conclusions were reached by careful listening under the controlled conditions outlined earlier, and by using other amplifiers. It turned out that the DAX was successful despite my efforts to trip it up. Whenever the DAX was included, the music sounded more rewarding and the performers blossomed.
Without the DAX, the presentation regressed. It was veiled and less vivid. The soundstage diminished in size and in the quality of its makeup. It did not convey the same sweeping perspective- the panorama was now restricted as if a set of blinders had been put in place.
Just how dynamic is the DAX/Diva duo? I'll invoke the recent Stereophile High End Show in NYC as an example.
I spent a total of two days listening around and came away very impressed. Taken as a whole, the quality of the sounds heard there was very wholesome and certainly well above average. Many exhibitors had spent a lot of time and effort-the equipment arrived extremely late the night before-to be seen in the best light possible. In general, they acquitted themselves admirably.
I would single out, in alphabetical order, Burmester (with B&W 801s), Definitive Hi-Fi (WATT, Puppies, WHOW, Krell), Bob Graham/Ensemble, Hobson Ultimate Sound (Rowland, Avalon, SOTA), and Select Sound (YBA, Koetsu Eurushi, Roksan, ProAc Response 2) as displays that pleased my ears more significantly than others.
Yet when I returned home that Sunday evening and listened to the DAX, Divas, Coherence 1 series II, four Krell KMA-160s, Monster Sigma cable, and Sony X7-ESD/Wadia 2000 combination, I have to tell you that it was then that I heard the most musically satisfying sounds of the weekend.
Now, it may be unfair to compare a system under development for months to the systems set up under the duress of show conditions. But my listening room leaves a lot to be desired, and the equipment I used was not as up-to-date as what some of the exhibitors were showing. And I was playing exactly the same CDs I had at the show. (Except at Definitive Hi-Fi - they used their own digital and analog sources, a practice I welcome wholeheartedly.) *
* I see nothing wrong with stacking the deck in this manner. The dealer gets to show off the equipment at its best, and the listener benefits.
Excellent as these displays were, I was more impressed by the sound from the equipment at my disposal. Maybe it was the familiar surroundings, maybe the snug comfort of my listening chair, but I came away convinced of the ability of what I heard to draw me into the performance musically and sonically,
That's not to say that certain show exhibits did not outdo the Diva/DAX duo in a particular aspect or two. Certainly the WHOW woofer went lower, the dynamic impact of the WATT/ Puppy combo or the ProAc Response 2s was greater, and the coherence in the lower mids/upper bass of the Avalons was more remarkable. But these were isolated bright spots.
Taken as a whole, the DAX allowed the Divas to encompass more musically pertinent performance aspects. I sit there and I am in the midst of music. The voices and instruments ring very true, the dynamics convey realism, and the soundstage is vivid enough to authenticate the event.
I'm not going to delude you by suggesting that the DAX performed miracles. Far from it! We're still dealing with reproduced sound heard under acoustically compromising conditions. But within the context of these admittedly limited circumstances, the DAX's contribution is very significant.
There's the unmistakable improvement in definition, staging, and coherence. Also welcome is the more agreeable timbral tonality The lower registers in particular are allowed to blossom with newfound energy and control, while the bottom octaves are presented in a more refined, more transparent manner.
This is an aspect that could be misinterpreted unless the listener is familiar with the sound of live instruments. The first impression with the passive crossover in place is of warmth, more power, and energy in the bass region. The sound is somewhat opulent, resounding, and hefty. Not exactly the worst situation to have. And note, I didn't say bloated or leaden.
Revisiting the DAX made me realize that the presentation of the lower frequencies was smoother, more controlled, and with a downward extension that was often visceral. The definition was crisp and distinct, but without shortchanging richness. Instrumental intonations were seemingly more spontaneous and better balanced. The perceived presentation was now more apt, more credible.
Several layers of sonic smog were also dissipated. This reduction of grime, smearing, and similar sonic litter markedly helped to refine the backdrop against which the midrange was allowed to assert itself. And in a manner very profound at that. Performers emerged with remarkable presences now that the unobscured virtual imagery was projected with an assured air.
The glib persuasiveness of what are really sonic infirmities, but are allowed to intrude under the guise of colorations, is now reduced to a faint hue. Even though the DAX employs integrated-circuit op-amps, Apogee must be extracting maximum performance from their circuitry. The DAX's sonic signature is mainly one of neutrality, but if it erred it did so on the side of the analytical. While I have no problem with such performance, those who have developed a dependency on euphonics are not likely to be gratified.
The soundstage was a beneficiary of the DAX as well: wider, extending further back, and significantly more ornate in pertinent sonic details. Instruments within the soundstage had a floating projection. That's not an indication of vagueness or uncertainty, but of more focused presentation and enhanced imaging.
Instruments occupied clearly defined and unwavering positions, but emitted their sounds in a billowing manner. It's as though more air was moved and the dynamics were expanded at the same time. At times I could sense that more of the volume in the recording studio was excited, this energy now transmitted more efficiently. I have a hunch that the significantly enhanced ability to recreate ambient cues played a prominent role here. All I can say is that I heartily welcomed the expansive and exquisitely defined state of affairs before me.
This sonic effervescence can be harnessed effectively to replicate the recorded event very vividly. The Divas continuously dazzled me with their near-uncanny ability to extract very believable sonic images, an aptness that fortunately applied equally to solo instrument, voice, or full orchestra. When enticed with the right source material, the Divas are second to none in their ability to seamlessly depict a vast stage filled with musically and sonically arresting activity. This is action that draws attention to itself by involving the listener. It's an invitation to partake in a rewarding experience.
Last but not least, there's the freedom from strain. This is a significant step in the right direction in our quest for emancipated sound. What I heard was more uninhibited, more flowing, more effortless. Things didn't top out or bottom out; they were less hesitant, less truncated. Transients were allowed to snap into place with speed and energy, and decays died away convincingly. Harmonic richness was not artificially lush, but quite convincing and, at times, very credible.
I mentioned earlier that the sonic versatility very apparent in the DAX/Diva duo can be a liability On a system level, this is true more than ever.
The Divas now replicate every sonic contribution, positive or negative, of the componentry and source material preceding them.
Since the contribution of each component change is easily perceived, it's very difficult - at least for me - to pinpoint the exact nature of the Divas' colorations. I'm of the opinion, however, that what they appear to contribute is far less than what they've been accused of doing.
I believe the speaker was occasionally condemned for misdemeanors that the passive crossover was committing. The book on the Divas in some circles is leaden, bass-heavy performance with subdued treble and highs.
Well, not when the DAX is included, and not when something fast, powerful, and controlled-like the Krell KSA-250s - are driving the Divas.
That the Divas are very sensitive transducers was starkly revealed when the Krell KSA-250 amplifiers arrived. As good as the other amplifiers before this were thought to be, the KSA-250s acquitted themselves remarkably well.
Suffice it to say-since it's not my intention to steal the thunder from a forthcoming KSA-250 review - that the Divas were able to fully reveal the remarkable performance of the KSA-250s. Again, the Divas did not improve when the KSA-250s arrived-they merely got a better chance to display their abilities. My point is that the Diva/DAX duo will only be as good as the rest of the components in the chain.
The sonics here are something to behold, not leaden but tight, controlled, and utterly extended. The highs are not subdued, but instead can be enviable in the way they extend, and in the amount of air and ambience they clearly convey And there's speed, snap, and fidelity throughout the spectrum.
What I had at times ascribed to brightness in the Divas now turned out to have been compromised amplifier performance. How come? 'Cause the Krell KSA-250s don't do it, that's how.
By the way, the Divas can take huge amounts of power without sustaining damage. I have used Rowland Model 7s and the aforementioned Krell KSA-250s with no ill effects. That's at least 600W per each 4ohm panel. Jason Bloom tells me he has used double that amount of power and the Divas stood up just fine.
As a matter of fact, these very high-power experiences have been very gratifying. Not only was the performance effortless due to the extra amplifier headroom, but the added dynamics and some good old heft were welcome. This is yet another instance where the DAX has been a very positive influence in the emancipation of the Divas, allowing them to act more uninhibited.
Peculiarly enough, even though my listening room is asymmetric, I ended up leaving the DAX in its "0,0,0" position most of the time. It could be that the distance to the DAX at its location near the speakers influenced me, but I doubt it. I have no qualms about making cabling changes, a task far more tedious and time-consuming, and they are located in the same area as the DAX.
And it's not as though I never touched the DAX. There were instances when certain equipment did benefit from the adjustments on the DAX. On more than one occasion the balance got too heavy, leading to a congested presentation. In each of these instances the situation could be resolved quite satisfactorily by cutting back on the bass response to -1 or -2 dB. The midrange would open up distinctly, and the bass got tighter.
Two fellow Audiophile Society members, Hy Kachalsky and Bill Brassington, also DAX/Diva owners, report similarly encouraging results. I have some significant firsthand experience with Hy's system, as Society meetings all take place at his house.
Bill, in particular; has fully benefited from the DAX. It was the DAX that made it possible to sonically fit his Divas into a very difficult room. He's convinced that it was the dials on the DAX that made the difference. Instead of merely coexisting with the Divas, he was able to enjoy them.
I did get gratifying results with the Rake Angle set at +2 (+1dB at 5kHz). The sound appears to open up just enough, but without degrading the high frequencies. The treble definition in this case reaps the most benefits. I suspect that the newfound clarity of the KSA-250s contributes significantly Instead of being irked by subliminal slivers of harshness, I can enjoy the easy consequences of refined definition.
Summary
At this point I can reveal that I had some serious misgivings when Jason Bloom and Lee Spiegel first revealed their intentions to go into the electronic component business. What's a nice speaker manufacturer like them doing in a business like that? But I was wrong - I needn't have been concerned about Apogee's ability to compete in this new realm of equipment. The DAX is a resoundingly good product, and an essential complement for the Divas. I recommend it wholeheartedly.
But one essential aspect of the DAX has not been covered. This review cannot be considered complete without addressing the money issue. In my original Diva review I dared to call them a Best Buy. One of the arguments I invoked to prove my point dealt with system complexity. just get a couple of good amps, some commensurate speaker cable, and you were well on the way to excellent sound. No added amps or other equipment. Nice and simple.
That the DAX changes the serenity of that setting cannot be contested. It's not a Best Buy situation, is it? But does the DAX bring enough to overall system performance to make it nevertheless worthwhile? Yes! And a number of DAX/Diva owners - experienced listeners whose sonic judgments I value - echo my sentiments. This consensus endorses the DAX as a worthwhile development entirely justifying the expenditure.
And don't forget the significant saving in amplifier watts delivered by the DAX. For those just on the verge of going for the DAX/Diva combo, this is about as real as a monetary inducement gets.
The ultimate issue has to do with higher performance. If you already appreciate all that the Apogee speakers can give you, then you owe it to yourself to go for the DAX. The rewards are bound to be bountiful.
© Stereophile-Vol. 13, No. 8