Music in the Round

Using the Anti-Mode 2.0 mostly as a room equalizer with a pair of full-range loudspeakers, the Bowers & Wilkins 800 Diamonds, I tried a number of ways of inserting it into the system. Most obvious and useful was to put it between preamp and power amp, using the XLR ins/outs and full A/D/A conversions. I also tried it between the Oppo BDP-95 universal Blu-ray player's TosLink S/PDIF output and the Meridian 861's TosLink input. This meant no A/D conversions, but confined the EQ's effect to the Oppo. I also tried, briefly, the Anti-Mode 2.0's digital input and analog XLR outputs, thereby inserting no additional conversions but relying on the Anti-Mode's own D/A converter. All those options made no difference in how I operated the DSPeaker, but I preferred the sound with the XLR in/out—it seemed marginally more transparent. It also let me place the Anti-Mode 2.0 where it would process all the signals fed through the system, at least for the L/R channels. I used a similar arrangement with the DSPeaker running the two subs in my weekend system, where it did the job of integrating their outputs with the main loudspeakers/into as well as any other add-on sub EQ I've tried.

On initial power-up, the Anti-Mode 2.0 asks for your speaker configuration. I chose 2.0: plain-vanilla stereo. It then invited me to do a Typical room calibration, to which I agreed. I placed the provided calibration microphone at the listening position, adjusted the output to an acceptable level according to the display, and let 'er rip. The Anti-Mode 2.0 performed several slow sweeps up to few hundred hertz; following the first sweep, it displayed the raw room response as a red trace. After another 10–20 minutes of generating signals, measuring the response, and correcting for it, the DSPeaker displayed the overall corrected response in black, overlaid on the raw response. I hit "OK" to accept the correction, the display reverted to the home screen, and I sat down to enjoy the results (see fig.1).

This automatic, single-mike-position, "Look, Ma, no hands!" correction made a significant improvement in the sound of my system. I'm guessing that most users won't need anything more. More, in the case of the Anti-Mode 2.0, can be more mike positions and/or more advanced options in measurement and correction parameters. DSPeaker says that the Anti-Mode 2.0 can "add as many points as you want to the calibration," but recommends a maximum of seven additional points, the results of which are automatically weighted "by comparing them to the main calibration data." Interestingly, these really are "added" measurement points—you can do the single-point measurement/correction, evaluate the results as you wish, then do more measurements post hoc. I like this, and found that adding five or six more points around my personal main listening position smoothed the system's sonic signature. It changed the measured response a bit, but of course that depended on where I placed the measurement mike.

To address room-EQ challenges that don't easily succumb to a Typical calibration, the Anti-Mode 2.0's Advanced calibration offers three more tools. First, one can adjust the bass-level compensation from Off—which provides no dip compensation, and allows more headroom for those who'll be applying custom "house" curves—to Max, which adds about 2dB gain for the filters, but with the reminder that one "can not, will not, and should not" attempt to correct true nulls, which will require infinite amplifier power. Between Off and Max is Norm, which provides a mild dip compensation, and is the default setting in a Typical calibration.

The second Advanced calibration tool is the time-alignment options. These include Auto Detect, which is most useful for subwoofers and corrects for different arrival times at the listening position, and Manual, which is, well, a manual adjustment. The third tool is the ability to set the upper limit of automatic correction anywhere from 80 to 500Hz. Notably, the Anti-Mode 2.0's firmware corrects the two channels monophonically at low frequencies; the correction becomes channel-specific as the frequency rises. Details aren't provided, and I didn't test these parameters, but this seems appropriate.

On top of all this, the Anti-Mode 2.0 can also measure, but not correct, the frequency response in ranges of 16–200Hz (Bass), 16–500Hz (Mid), and 20Hz–24kHz (Full). The results, like those of all the other functions, can be displayed on the DSPeaker's own screen without the need for any additional hardware or computer. Of course, you can plug the Anti-Mode 2.0 into a USB port of a PC, which will recognize it as a simple storage device, with all of the data of the configuration currently selected available for download as text files.

The DSPeaker Anti-Mode 2.0 Dual Core is a remarkable product. It may not display or describe time-decay information, and it's not entirely unique as a two-channel digital room equalizer. However, aside from products aimed at musicians or commercial applications, it's significantly less expensive than other, similar stereo products such as those from McIntosh, Trinnov, DEQX, or TacT (none of which I have tried). It's similar in operation to the all-analog Rives PARC parametric equalizer (see my review in the July 2003 Stereophile), which offers only three bands of correction, is not automatic, lacks all the DSPeaker's bells and whistles, and costs more than three times as much as the Anti-Mode 2.0—though the PARC may have the edge in transparency. As a subwoofer room equalizer, the Anti-Mode 2.0 is as potent as the SVSound AS-EQ1 ($799, now discontinued; see my September 2009 column, or its sister under the skin, Audyssey's Sub Equalizer ($799; see my January 2010 column), but provides infinitely more tweakability. The DSPeaker Anti-Mode 2.0 may be a small and unprepossessing black box, but for $1099, its performance and power are huge.

MSR Dimension4 SpringTrap Bass Absorber
I want to clear up any confusion I may have caused in the September installment of "Music in the Round," in which I quoted two different prices for MSR's Dimension4 SpringTrap Bass Absorber. Actually, I mentioned only a single price, $909, but first stated it as the price per pair, and later as the price for each. Unfortunately, the latter is correct, which means that the SpringTrap costs twice as much as I thought it did. However, after living with a pair of SpringTraps for another two months, I have no doubt that it's worth its actual price of $909 apiece. The SpringTraps have made more of an impact on my room/system acoustics than any other passive acoustic product I have tried. The magnitude of improvement in bass clarity and impact is the equivalent of that of a few of the best electronic equalizers, but with none of the complications, such as the introduction of additional circuitry to the signal path or the restriction of the improvement to a small part of the room around the primary listening position. My enthusiasm for the Dimension4 SpringTrap continues unabated, even at $1818/pair.