To have a great sound from the midrange and up is easy. As long as the speaker is kept reasonably far from hard reflective surfaces and the whole environment is balanced (in acoustic terms), your ears will automatically lock onto the direct arrival sound in the mids and highs (100 Hz and up), and room effects won’t keep the top from sounding good or sometimes even phenomenal.

For the lower frequencies, however, it’s a very different story.  Any room almost inevitably plays havoc, no matter how good the speaker is an anechoic measurement. Below 100 Hz, the speaker’s sound is being reflected around by the room and the direct sound arrives to your ear in one big lump with the room effects. The phenomenon of a boom somewhere below 100Hz and a large dip between 100Hz and 200Hz is far too common.

These negative room effects can be somewhat tamed by careful placement.  However, regardless how one places speakers, there are inevitably deviations from smooth response in the bass, arising from the fact that listening rooms of domestic size have room modes—resonances quite widely spaced in frequency in the lower part of the audible range. Any listening room, regardless of size and how carefully placed the acoustic correction panels are can not make the room mode completely disappear.  Even concert halls, which obviously are much larger, have resonances too, although due to the closely spaced resonances they are now called reverberation that can be quite smooth in frequency response.

When the room acoustics have been treated to the hilt, a good part of the remaining room resonances should be and can be corrected electronically.  There are devices to do this correction and have become increasingly popular in recent years. There are also a quite number of sub woofers now come with such adjustments built in, namely the Paradigm DSP-3200 with its Perfect Bass Kit add-on system as one of, if not the, best bass correction unit out there.  However, what about the existing system?  Not everybody wants to buy a new subwoofer system.  To varying degrees there is Audyssey system, rather effective, but in Canada it costs around $800.  Alternatively, if money is no object, there is a very effective Rives PARC, but at that price, it is still a bandage solution so you might as well buy the absolute best Paradigm subwoofer with Perfect Bass Kit.

Enter DSPeaker Anti Mode 8033 add-on unit.  Yes, it is a bandage, but unlike the other bandages, this one costs less than $400, a far more realistic price for everybody.  From the price point, I’m already gravitating towards it.  Furthermore, due to my notoriety in writing a no-nonsense and politics-be-damned review, some companies have refused to have their products reviewed by me.  This is not the case with this company.   Even after showing them the samples of both my negative and positive reviews they are still very enthusiastic and I received my review sample overnight from the USA.

Installation is as easy as plugging 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 analyses and remembers what should be done to make the bass response to be measurably better.  For best results, as mentioned earlier in the article, start with a proper placement that avoids large or broad peaks and dips… especially dips.  The Anti-Mode 8033 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 arise 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 included microphone. The process will automatically define parameters of the room modes, such as center 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 Century 300i satellites and PSB Subsonic 300 driven by Pioneer Elite SC-27 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 auto Anti Mode Filter with the resolution of 0.5 dB on the 8033 is making the low frequency smoothness to be extremely close to the same system with the Anthem set up.  I should add that according to the manual, the DSP induces approximately three millisecond time delay.  Either you need to put the subwoofer closer to you by three feet (90 cm) to get the time integration correct, or set your receiver’s subwoofer distance by and additional two feet.  Note that the DSP only works on the subwoofer signal. There is no A-to-D-to-A with DSP in between operating on the main speaker signal. The main speaker signal is untouched except, in my case, by the analog crossover inside the PSB Subseries 300 subwoofer.

For the first test I use my old and trusty Disney’s Bolt (chapter 2).  The scene literally opens with a deep bass.  I’ve always had problems playing this track because of some bass bloat especially in the 25 Hz area that rattles my screen.  I usually have to dial no more than -20 dB from reference level with LFE set to -5 dB.  After 8033 calibration, I can now set the volume to -17 dB (this is as loud as my ears can handle) with LFE set to 0 dB.  That’s an overall of 8 dB improvement in the overall 25 Hz bloat that’s been reduced from my room.  Not only that, there must also be some bloat around 80 Hz because some of the bad-guy character’s voice was somewhat muddled.  Again with the 8033 in-line, the dialogue clarity has been 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 is Celine Dion’s Live in Vegas blu-ray playing “My Heart Will Go On” track.  This track opens with insane amount of bass that tend to make me feel ill.  I always had to remember to turn the volume down before this track plays and bring it back up once the music starts playing.  The 8033 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 correction. (There is a bypass mode so one can do an A/B easily.)

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 will cost me about $1,200 and that’s not a small change considering my PSB Subseries 300 is only slightly more than a year old. Still, the results here were mind bogglingly good, among the best ever. The overall effect was surprisingly natural be it a movie scene with synthesizer laden bass tracks or a concert recording that uses both acoustic, electric and synthesized bass.

As per usual my reviews always have pluses and minuses. On the plus side, the AntiMode 8033 works so well and costs so little that if you have a sub-woofer 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. 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 $400 press-a-button unit which 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 $2,600 better than the DSPeaker Anti Mode 8033.

My suggestion?  Buy it.  I know I’m buying my review unit.

Specs & Pricing

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: 16-144Hz divided into 24 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”
Weight: 8.2 oz.
Price: $379