Bass is a difficult creature. Any room almost inevitably wreaks havoc, no matter how good the speaker is. Below 100Hz, the speaker's sound is reflected around the room and the direct sound arrives to your ear in one big lump with the room effects. The phenomenon of a bloat somewhere below 100Hz and a large dip between 100Hz and 250Hz is more common. These negative room effects can be somewhat tamed by careful placement. Any listening room, regardless of size and how carefully placed the acoustic correction panels are, cannot make this "room mode" completely disappear.
When the room acoustics have been treated, a good part of the remaining room resonances should be and can be corrected electronically. There are devices to do this correction that have become increasingly popular in recent years. There are also a quite number of subwoofers that now come with such adjustments built in, namely the Paradigm DSP-3200 with its Perfect Bass Kit add-on system, which is one of, if not the, best bass correction unit out there.
But what about with an existing system? Not everyone wants to buy a new subwoofer system. To varying degrees, the standalone Audyssey system is rather effective. But in Canada, it costs around $1,200. Alternatively, if money is no object, there is a very effective Rives PARC, but at $3,000, it is still a bandage solution.
Enter the DSPeaker Anti Mode 8033-SII add-on unit. Yes, it is a bandage, but unlike the other bandages, this one costs around $500, a far more realistic price. I bought one directly from Finland, and received the unit in less than a week.
Installation is as easy as plugging in a power cord. The device puts a signal into the subwoofer, letting the supplied microphone "listen" to the result at your intended listening position. The device then analyzes and remembers what should be done to make the bass response measurably better.
For the best results, as mentioned, start with a proper placement that avoids large or broad peaks and dips - especially dips. The Anti-Mode 8033-SII only pulls down peaks and will not push the dips up. After you're done, you may need to set your overall subwoofer level slightly higher to get the same subjective effect as before, since the system will have removed the boominess that arises from room resonances.
So how effective is it? It works like a charm. The calibration program self-generates sweep-like measurement signals and picks up the data with the included microphone. The process will automatically define parameters of the room modes, such as centre frequency, Q-value, gain, frequency anti-symmetry and apply up to 24 custom-fitted Anti-Modal Filters. The boominess in my listening room practically disappeared, yet the bass response is now audibly clearer, cleaner, and much more precise. My combination of PSB 300i satellites and PSB Subseries driven by a Pioneer Elite SC-LX801 is now is better than ever (reminder: Pioneer's Advanced MCACC only employs Finite Impulse Response 3-band paragraphic EQ below 80 Hz which is already a lot better than most receiver's room correction - with the exception of Anthem's Infinite Impulse Response's Anthem Room Correction - but a lot more EQ points are necessary).
The 24-band Infinite Impulse Response automatic Anti Mode Filter with the resolution of 0.5 dB on the 8033-SII makes the low frequency smoothness extremely close to the recommended SMPTE curve. I should add that according to the manual, the DSP induces an approximately 3ms time delay. So you'll need to set your receiver's subwoofer distance by an additional three feet. Note that the DSP only works on the subwoofer signal. If you want the unit designed for the front left and right, you'll need to buy two more Anti Mode 8033-SII or Anti Mode Dual Core 2.0
For the first test, I used my nearly antiquated yet trusty Disney's Bolt (chapter 2). The scene literally opens with deep bass. I've always had problems playing this track because of some bass bloat, especially in the 25Hz area that rattles my screen. I usually have to dial no more than -20dB from reference level with LFE set to -5dB. After 8033-SII calibration, I can now set the volume to -17dB (this is as loud as my ears can handle) with LFE set to 0dB. That's an overall 8dB improvement in the overall 25Hz bloat that's been reduced from my room. Not only that, there must also be some bloat around 80Hz because some of the bad-guy characters' voices were somewhat muddled. Again, with the 8033-SII in-line, the dialogue clarity was much improved. Even the synthesizer bass line that underlines the entire chapter 2 also benefitted from the depth and precision of the bass and the excellent pitch definition.
My second test was with Celine Dion's Live in Vegas Blu-ray playing the iconic track "My Heart Will Go On." This track opens with an insane amount of bass that tends to make me feel ill. I usually have to remember to turn the volume down before this track plays, then bring it back up once it gets further into the song. The 8033-SII fixed this problem too. I listened both for bass extension and especially for how the Anti-Mode correction improved bass pitch, definition, and precision; and it did a superb job. The bass still feels as deep and as loud but without the mysterious resonance frequency that literally made me ill. Transient precision was excellent in various problematic spots of this concert Blu-ray, and pitch definition improved tremendously. What was really going on with the bass instruments was surprisingly clarified by the 8033-SII correction. There is a bypass mode so one can do an A/B easily.
Should You Buy One?
Was this the best bass ever in my listening room? I suppose the very top honours for value and performance for that would still have to go to Paradigm DSP-3200 subwoofer coupled with Paradigm's Perfect Bass Kit, possibly due to the calibrated and serial-numbered microphone that comes with the kit. However, the set would cost about $1,200, and I have to use a laptop to do the calibration. Further, that's not a small change considering my PSB Subseries 450 is only slightly more than a couple years old. Still, the results here were mind bogglingly good, among the best ever. The overall effect was surprisingly natural, be it with a movie scene with synthesizer-laden bass tracks or a concert recording that uses acoustics, electric, and synthesized bass.
On the plus side, the AntiMode 8033-SII works so well and costs so little that if you have a subwoofer system that does not do detailed adjustments to the room on its own, there is really no doubt that you should buy the DSPeaker Anti Mode 8033-SII. On the negative side, it is not as good as the Rives PARC that also pushes the dips up. But keep in mind that this is a $500 press-a-button unit I'm comparing to a $3,000 unit that is also big, heavy, and freakishly complicated to use. And the Rives PARC is definitely not $2,500 better than the DSPeaker Anti Mode 8033-SII.
Device type: DSP corrections for subwoofer using Infinite Impulse Response system, automated setting, non-calibrated microphone included, to be inserted on input signal to subwoofer
Frequency range: 16-250 Hz divided into 36 Anti Mode Filter points with 0.5 dB resolution Features: Three user selectable additional equalization filter (flat, boost 25-35 Hz, boost below 25 Hz), one or multiple measurement point calibration
Dimensions: 5" x 1.1" x 3.2"