Transcript
How IMPRINT Works Step 1
Typical loudspeaker response, measured in a vehicle, in one seat A typical loudspeaker frequency response will have several peaks and dips at various frequencies. These are caused because the sound from the loudspeaker interacts with the seats and consoles in the vehicle cabin. In some frequencies these interactions add and give rise to a peak and at others they subtract and give rise to a dip.
How IMPRINT Works Step 2
IMPRINT applies hundreds of correction points The first step in correcting the effects of the interior on the loudspeaker response is to generate the control points that will be used to morph the response into the desired shape. To capture some of the finer details in the response fluctuations, it is necessary to use hundreds of points. IMPRINT dynamically applies the points where they are needed most, typically in the lower frequencies.
How IMPRINT Works Step 3
The result is a very good fit to the response These control points allow IMPRINT to form a near-perfect model of the loudspeaker response, which is key to making an accurate filter.
How IMPRINT Works Step 4
IMPRINT creates a precise inverse filter The IMPRINT equalization filter is created by inverting the precisely-modeled response. Everywhere that there is a dip, the filter applies a peak with the same shape. Similarly, every peak is corrected by a dip. The more precise the model is, the better the inverse filter will be. IMPRINT uses several hundred points to create the model and the corresponding filter.
How IMPRINT Works Soundstage improves with IMRPINT Parametric EQ With parametric EQ, the frequency response is corrected, but the speaker-to-speaker match is usually no different than it was before EQ.
Alpines IMPRINT makes each speakers response closely match the desired target curve. As a result, each speaker is not only corrected but also matched to every other speaker in the system. This has a dramatic effect on improving the soundstage because matched frequency response is one of the cues that human hearing relies on for imaging. This is what reviewers mean when they say “The soundstage snaps into place."
How IMPRINT Works 1 1 2
Time Domain Problems In the time domain, the first arrival of sound is seen as a large spike (1) and it corresponds to the sound signal coming directly from the loudspeaker. A few milliseconds later, copies of the direct sound signal arrive (2) after they have been reflected and modified by the vehicle interior (seats, dash, windows, etc). Because these reflected copies arrive so close to the direct sound, the brain blends everything together and this results in audible artifacts such as smearing of transients, ringing, and comb filtering. The result is muddy sound. IMPRINT filters are specifically designed to address these time domain problems and concentrate most of the signal energy in the direct sound. In the graph on the right hand side, the reflections have been dramatically reduced and the first spike is narrower and stronger thus allowing pure sound from the loudspeaker to arrive at each seat.
IMPRINT + GUI
IMPRINT tuning flow GAIN + X-Over setting Select the preferred position Positioning the microphone Measurement and Equalizing (Follow the GUI on the Sound Manager)
No
All Position done?
Yes Target Curve Setting Fine Tuning
Prepare before measurement Before starting the automatic measurement Switch all Amplifier crossover Off:
Turn all filters on the amplifier for the Sub LPF/Subsonic “OFF” If subwoofer Low-Pass Crossover cannot be turned off then select the highest frequency setting (eg. 200Hz) 200Hz If subwoofer Subsonic Filter cannot be turned off then select the lowest frequency setting (eg. 15Hz) 15Hz
Prepare before measurement X-Over Setting Depending on your System Setup. Set the x-over values for each channel. Set the GAIN of each channel at 0dB. The GAIN of each XOver channel is set to 0dB during the IMPRINT measurement. If you have to adapt the volume level use the GAIN controller on the amplifiers. We recommend to store the X-Over settings. For example use Preset 1
IMPRINT GUI
Starts the IMPRINT measurement
Listening area Selection Select which area is your preferred listening position by click. For example Front left.
The first position is the most important position. The time correction and speaker detection will be done in this position.
Prepare before measurement Measuring Position 1. (Preferred Position Front left) 1)
Place the microphone in the Driver’s Listening Position Place mic at normal ear height, centered approximately 15 cm in front of the headrest position.
The Microphone MUST be pointing straight up
2) Exit the Vehicle and Close ALL Windows and Doors.
Position one 1. Click Measure
2. Click Start
3. The countdown starts During the 10 second countdown, go outside the vehicle and close the door. A test signal will be output from the speakers to measure the acoustic characteristics of the cabin. Do not open any doors until the finish message appears on the screen. If external noise interferes with the measurement, click [Measure] again to re-measure.
Imprint measurement
Keep silence Notice: The measurement area must be absolutely quiet. Every noise can degrade the performance. Stop the engine, switch the air-condition and the fan off. Close the doors, windows and sunroof while measuring. In this case...silence is golden...
Position two When the measurement for position 1 is done. Move the microphone to position 2. At the 2nd measuring position, differences between several fine settings are not so obvious comparing to the 1st position. However we still can find out the best position. It is the Center Position of the seat area. The Center Position is smoother and clearer than any other position.
After positioning the microphone push the „Measure“ botton on the GUI.
...following micro positions After the measurement at the 2nd measuring position, it’s OK to follow the indication on the Sound Manager GUI screen for setting position.
Our recommendation is minimum 2 positions. Of course the result will be much more detailed when you do all 6 positions.
Imprint result 1. When every position is done push the result button
2. IMPRINT will show you the results of the measurements
...by the way Here the proof: 1. Measurement with our X5 in the install-bay. Ventilation noise from the aircondition 66dB
2. Measurement without ventilation noise. The impulse response is much better
The measurement area must be absolutely quiet...!!!
Imprint Target curve 1. Press „Target Curve select“ on the GUI
2. You have 4 possibilities
4. The system starts the calculation
3. Select your preferred curve
Select memory... 3. Select the Memory place and push OK.
You can save 2 different curves or you save the IMPRINT measurement in a file on your PC.
IMPRINT Curve USER You have the possibility to save your own target curve Select “User’s” in the “Target curce” section and you will see the adjustment window. Without any modification, name and save it as your own setting. Default User’s setting* is recommended for natural bass sound. Reference is good for more bass enhanced.
Default setting
Customized target curve
IMPRINT fine tuning IMPRINT postprocessing adjustments: If you are not satisfied with the IMPRINT measurement you have several posibilities to customize the settings. TCR is a each
When you feel something wrong with phase matter, TCR would be a solution. Though IMPRINT EQ has TCR function, tweaking with TCR effective to fit your own auditory sense. When your system setup is 3-way active system. IMPRINT will set the same TCR values for channel for example Front left. But you can customize however you want.
GAIN/Sub level When the subwoofer level or another channel is too much or to less. You can decrease in the X-over settings. Increase on the GAIN controller of the amplifiers. Though trying another target curve may solve your Problem, too. EQ parametric/graphic If you want to customize the IMPRINT measurement. You can use the parametric or Graphical Equalizer. Only limitations is increase/decrase +/- 6dB
