Pioneer SP-91D

Commentary

Surround processor with built-in Dolby Pro Logic Surround, with built-in 16 sound field programs in 50 bitDSP.

By using a unique computer simulation method and inputting detailed information such as the shape of the concert hall, the sound absorption coefficient of walls, floors coefficient of walls, floors and ceilings, and the distance between the sound source and the listener. The sound field information is obtained by making full use of sound technology and LSI technology developed over many years and is gathered at 50 bitDSP.

We have developed and adopted the I ・ E ・ R ・ S (Integrated Early Reflection System) mode in which frequency characteristics are adjusted by digital signal processing. This mode classifies programs with high and low reflection frequencies by taking advantage of computer simulation into consideration that the difference in the materials of reflecting walls and ceilings affects the attenuation factor in the high frequency range.
This method takes into account the subtle frequency characteristics of walls and ceilings in the actual venue and reproduces a realistic sound field.

Equipped with a total of 16 sound field patterns created by computer simulation and refined.
You can experience the world of a stereo sound field by selecting the sound field according to the music genre and performance style of the music source.

You can easily arrange 16 types of sound field programs.
You can adjust the depth perception (initial delay), the size of the room (room size), the volume of the room (liveness), the duration of the rear reverberation (reverb time), and the attenuation characteristics of the high-frequency range of the reverb time (H ・ F ・ Reverb).
By changing the settings of these parameters, the desired sound field can be created, and up to 16 original sound field programs can be registered.

It is equipped with a total of 8 types of surround mode such as Dolby Pro Logic Surround, theater, stadium, studio, etc., and you can freely choose your favorite realism according to the character of the video source.
In Surround mode, you can adjust the delay time according to your preference (except in Dolby 3 ch Logic and Studio mode) to enhance or reduce the sense of surround sound.
Up to 16 types of arranged surround patterns can be stored.

Equipped with a 7-element digital equalizer, you can freely control the processing signal for sound field control and the equalization level of the rear signal of the rear in a round.
As with the parameter arrangement of the built-in program, the newly set equalization pattern can be stored.
It is also possible to equalize stereo signals in the same way as a normal graphic equalizer.

It features a 16-bit stereo A/D converter, an 8 x oversampling digital filter and a 4-channel independent 18-bit D/A converter for D/A conversion.

Honeycomb copper plated chassis and honeycomb insulator are used to prevent sound quality degradation due to vibration.

It uses a 7-row motor drive volume. In addition, the power supply circuit separates analog and digital circuits, prevents interference between blocks, and uses high-conductivity gold-plated input pin jacks for terminals, taking sound quality into consideration.

It comes with a wireless remote control that can perform all operations in the listening position.
It is also equipped with a test tone function for channel balance that can be controlled by remote control.

Model Rating

Type	Dolby Pro Logic & Digital Sound Field Processor
Input Sensitivity / Impedance	Input : 150mV/41k Ω
Output Level / Impedance	Front Out : 1V/1k Ω
A/D converter	16bit Sampling frequency : 48 kHz
D/A converter	18 bit, 4 channel independent
Digital filter	8 x oversampling digital filter
Frequency characteristic	Front : 5 Hz ~ 100 kHz + 0 -3dB Processing Front, Rear : 20 Hz to 20 kHz + 0 -3dB
Distortion Factor (1 kHz)	Front:0.002% Processing Front, Rear : 0.006%
S/N ratio (S = 2 Vrms)	Processing Front, Rear : 90 dB
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	26W
External dimensions	Width 457x Height 92x Depth 335 mm
Weight	6kg
Attachment	Remote Controller CU-SP002