Automatic subwoofer calibration that very effectively corrects for acoustic room modes.

A typical listening room exhibits resonances i the bass frequency region, that affects even the best of subwoofers. The inherent details in the music get masked by the room resonances that puts a boomy veil on the sound. The problem is most outspoken when the subwoofer is placed close to walls or in any of the corners in the room. Sound waves for bass are very long and powerful and thus difficult to absorb. The Anti-Mode technology eliminates resonances from both speakers and rooms through automatic equalizer adjustments both in amplitude and in the time domain with very accurate digital sound processing and anti-phasing technology. This way the listener can hear all the way down to the deepest frequencies the subwoofer can reproduce. Even the reproducton of transients gets dramatically improved and the bass gets more controlled.

Isn't the auto calibration in my AVR enough?
No. The frequency sweeps that an AVR uses for measuring are very short (in time) and never gives the system a chance to "hear" which frequencies resonante in the room. The sweeps generated in the DSPeaker Anti-Mode are several seconds long, and can hear and correct the levels of the problem frequencies. The trick is to lower the peaks just enough, and just steep enough, so the output signals together with the room gain land just right. The difference before/after is staggering! It is also very easy to compare the calibrated result with the uncalibrated through pressing the "Bypass" button.

TEST/MEASUREMENT: BEFORE CALIBRATION

BEFORE: The image shows one of our own measurements of the bass response in a typical room with a 12 inch subwoofer without any crossover frequency set. The curvce is meant to be as smooth as possible for the bass to sound good, but since the sound waves for bass are very long, several meters, the whole room acts like a woofer box. Some frequencies get amplified more, while others lose their strength as the sound energy collides and cancelles the sound waves. The result is unnecessary power-increases at some frequencies that can create distortion and boomy sound. And since other nearby frequencies get drowned out, and in some cases get cancelled, you get bass reproduction with fewer details.

TEST/MEASUREMENT: AFTER CALIBRATION WITH DSPEAKER ANTI-MODE 8033 CINEMA

AFTER: This image shows how the bass responce can turn out after calibration with the DSPeaker Anti-Mode 8033 Cinema. The peaks are suppressed so the sound at the problem frequencies are played at lower levels than they normally would, and the room itself helps to amplify them to the correct levels. The dips, or troughs, in the frequency responce have also been smoothed out since more of the frequencies get the right conditions to end up and more even levels. And more even levels over the whole bass range makes it possible to increase the overall sound pressure level without the resonances taking over.

These measurements are made with XTZ Room Analyzer II Pro

EASY TO OPERATE
DSPeaker Anti-Mode 8033 Cinema is very easy to use. The calibration process is fully automated, and generates frequency sweeps for the microphone at the desired listening position (or multiple measurement locations) and measures the combined transfer function of the subwoofer/room system. The calibration is started with a simple button press, and only has to be performed once. Then you disconnect the microphone.

DSPeaker Anti-Mode should then remain connected between the AVR/amplifier's subwoofer output and the input on the subwoofer. DSPeaker Anti-Mode 8033 Cinema has regular RCA connectors (1 in, 1 out), the same as on the majority of all AVRs. The input signal is taken from the subwoofer out on the AVR. The output signal is to be connected to the low level input on the subwoofer.

The DSPeaker has a latency of 2.7 ms, so best practice is to run the DSPeaker Anti-Mode calirabtion first, and the AVR auto calibration afterwards, so the AVR can adjust for the latency and set the correct level.

TWO SUBWOOFERS
It is also possible to calibrate dual subwoofers. Just use an RCA-splitter on the DSPeaker output so that both subwoofers receive the same signal. The measurement is supposed to pick up the sound from both subwoofers as they affect each other.

FOUR SUBWOOFERS
You can even calibrate four subwoofers. Use a total of 3 RCA-splitters on the DSPeaker output so all four subwoofers recevice the same signal.

SPECIFICATIONS
LED color: Yellow
Input connectors: 1xRCA (mono)
Output connectors: 1xRCA
RCA type: Extruding gold-plated
Supply voltage: 9VAC / 12VDC, quiet start
Plug: Europlug (type C) 230V 50Hz
Amplification: 3.0 dB
Power consumption: 1.2 W
Input sensitivity: Line level (1,0 Vrms nominal, 1,75 Vrms max)
Frequency range: (-3 dB): 5-160 Hz
Dynamic range (unweighted): > 90 dB
Correction range: 16 - 160 Hz
Latency: 2.7 ms
Anti-Mode-filters: 28
Lift-filters: 20 Hz, 30 Hz

MANUAL (PDF)