Print this page

Sound Adjustment Mode

About Sound Adjustment Mode

The system has several features that allow you to adjust the acoustic characteristics inside the cabin.

PEQ (Parametric EQ)3-band setting, the frequency, and the Q curve pattern can be adjusted.Parametric equalizer adjustment (PEQ)
Position(Position selector)A preset speaker level for each seat, and the balance can be selected. Position selector
X-Over (Cross over)Specified frequency bands are allocated to each speaker for improved sound integration. Crossover adjustment (X-Over)
Non-F setting(Non-fader setting)The sub-woofer phase can be switced.Non-fader phase (Non-F Phase)

About parametric EQ

A variety of materials are used inside a vehicle to manufacture the seats and windows, and because these materials absorb and reflect sound in different ways, the parametric equalizer lets you adjust the peaks and dips of the frequency characteristics inside the vehicle to compensate for this.

An “equalizer” is a function that corrects these peaks and dips in order to flatten the frequency characteristics. However with a normal graphic equalizer, the median frequency and the Q (sharpness and band width) are fixed, so that when neighboring bands are corrected, there is a limit to the amount by which distortion in the peak and dip characteristics can be corrected. A “parametric equalizer” lets you adjust the median frequency, Q (sharpness and band width) and gain to variable levels, so that you can make fine adjustments to spot areas of the frequency band.

[Parametric equalizer characteristics]

1.Median frequency can be varied.

2.Gain can be varied.

3.Q (sharpness/band width) can be varied.

About position selector

From the preset speaker level and Balance/Fader value, the position selector easily provides the listener optimum phase by selecting the seat position.

About crossover

The frequency band that is stored by audio media such as CDs is a fairly wide range from 20 Hz to 20 kHz, and it is difficult for a single speaker to be able to play back all frequencies in such a wide range.

Because of this, several speakers can be used, with different frequency bands (such as treble, medium and bass) allotted to each speaker so that wide frequency ranges can be played back. The “Crossover” function is used to allot the frequency ranges that are to be played back by each speaker in accordance to the installed speaker units and the layout of the speakers, in order to obtain the maximum level of performance from the speakers and to provide the most stable frequency characteristics.

The crossover function includes a high-pass filter (HPF) for playing back treble sounds, and a low-pass filter (LPF) for playing back bass sounds. In addition, the HPF and LPF are used in combination in order to play back sounds in the mid range.

For example, when adjusting the HPF, frequencies that are lower than the specified frequency are progressively dampened, rather than simply not being played back at all. The “slope” adjustment function is the function that is used to adjust these dampening characteristics.

The slope characteristics of a filter are such that with larger slope values (for example 12 dB/oct), the slope becomes steeper, and so the amount of sound mixing in with neighboring bands becomes less so that only the target band is played back. However, it also causes the merging of sound between speakers to become poorer and can result in greater distortion.

  • The crossover function is a filter that allocates the specified frequency bands.

  • A high-pass filter (HPF) is a filter that cuts out frequencies that are lower than the specified frequency (bass range) and allows higher frequencies (treble range) to pass through.

  • A low-pass filter (LPF) is a filter that cuts out frequencies that are higher than the specified frequency (treble range) and allows lower frequencies (bass range) to pass through.

  • The slope is the signal level at which frequencies that are one octave higher or one octave lower are dampened.