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Pioneer DEQ-S1000A sound processor

The compact, versatile DEQ-S1000A sound processor is designed to improve the sound quality of the original audio system without replacing the head unit or changing the look of the interior. All you need after installation is a smartphone with the free Pioneer Sound Tune app installed to help you make all the settings.


More and more modern head units are tightly connected to other systems of the car, so much so that it is physically impossible to remove or replace them – why should you stop using parking sensors or air conditioner for the sake of clear sound? This situation is not the first year and many companies offer professional processor-integrators for its solution. Their task is to receive the signal from the original source, process it and send it to additional external amplifiers. Since the capabilities of professional sound processors are overdesigned they are often excessive. It is justified for expensive professional systems, but it affects the cost of processors and prevents their wide application.

For ordinary tasks it is possible to refuse from rarely used functions – then the device has all chances to become mass-market. And such a democratic solution is offered by Pioneer.

Although the processor is very compact (its dimensions are 170 x 40 x 95 mm), its capabilities are only slightly inferior to the professional models, and are more than sufficient in most cases. At the same time, there is a clear focus on the upgrade of regular systems: high-level inputs and built-in amplifier “magnet” type. Not forbidden to use it with external amplifiers – for this purpose is a full set of line outputs with output voltage to 4 V.

In a number of functions processor – the obvious heir to the head units Pioneer, differs only interface. It was completely transferred to the smartphone application, and only “processor” functions are left, which are absent in OEM head units – crossover, delays, equalizer and spatial effects. The last ones, by the way, for unknown reasons are absent in professional processors – although in the car imitation of space considerably enriches the sound. So let’s count it in the merits of DEQ-S1000A as the first point. But far from being the last…


The package includes the processor itself, remote control sensor, remote “nut”, cable for power and speaker connections, wire to connect the parking brake sensor (or “mass”, which is more likely), an extension cord and USB brackets for mounting.

All connections are on one side of the case. From left to right: power and speaker jack, parking brake sensor jack, three pairs of line outputs, line input, remote control sensor input (minijack) and USB connector with load current up to 1.5 A. On the right is the reset button and power-on indicator

One switch on the bottom of the case allows you to select the configuration of the system: standard (front – rear – subwoofer) or network (channel-by-channel). The assignment of line outputs and built-in amplifier outputs changes accordingly. The second switch assigns an input for the OEM GU signal (high level or RCA)

Time loop and signal processing structure in the processor is optimized to the maximum, completely eliminating signal distortion associated with jitter, dual-core DSP with bit depth 48 bits processes digital signals without loss of quality. The amplifier chip with a maximum output power of 4 x 50 watts is mounted on a heatsink


In-house developed software, with a well-designed graphical interface. It’s a free Pioneer Sound Tune app, it exists in two versions – iOS and Android version 5 or higher, and is already available for download on AppStore and GooglePlay. After installing the application and connecting to the processor, it is proposed to register the car (make, model) and the location of the steering wheel in it. In the future, it will be possible to connect to a database of typical settings created by users – but at the time of testing, I was only the third person to install the app, so it wasn’t worth trying.

Let’s run through the user menu items.

The app analyzes the content of the smartphone and generates a list of songs with different selections. The sorting is alphabetical.

The second position sets the Todoroki sound effect settings. This is a dynamic tone compensation that enhances the low-frequency components of the signal. Tone balance is adjusted according to the hearing physiology and the volume setting.

The third position is the equalizer. Seven preset variants of correction and two user variants, which we will return to a little later. The fourth position is for recreating the acoustic atmosphere of a certain type via controlled reverberation

You can draw the user’s AFC with the stroke of a finger (I almost wrote -pera) on the screen. The user mode equalizer is 31-band, and if you press the fine-tune screen button, the screen “stretches”.

Here you can fine-tune the AFC to within tenths of a decibel.

But, like in a good detective story, the most interesting part is at the end. The last position in the menu is actually the first one to start with. It is the choice of signal sources, entering the settings of filters and delays, and even the mode of automatic tuning of the processor by measuring signal. And a separate measurement microphone is not necessary, you can use your smartphone’s microphone as well. But in absence of a microphone (and a car too, by the way – taking it to the lab seemed too tiresome) we will make all adjustments manually.

The router allows you to select the signal source and calibrate the levels

For the standard configuration (with broadband amplification) we offer five options for speaker placement. The choice is not comprehensive, but the missing options (rear shelf, torpedo) with some stretch can be reduced to available

For channel-by-channel configuration there are only two options: with or without a subwoofer

Depending on the chosen configuration of the system and speaker positions next to each speaker, the mimic diagram will display the set values of filter cutoff frequencies, signal levels and delays – according to the listener position chosen in a separate menu. Naturally, the system configuration must be set with a switch before starting the program.

Although in the settings I registered the car with the left hand steering wheel, the program for some reason drew me a “Japanese” one… In the right bottom corner of the screen you need to touch the symbol in the shape of three knobs, resembling an equalizer, to get to the filters and delays. Why that symbol? I guess the pictogram just seemed like a good one.

The values are relative, but close to the statistical average. And what of these pictures turned out in reality – we will see in the section “Measurements”.


As usual the faultless CLIO complex was used for measurements. The distortions on the line output at the nominal 1V output signal are not more than 0,005%, this is at the level of the measurement error. When you increase the signal at the output to the maximum value of 4 V distortions increase to the passport 0.01%, and at the slightest overload instantly jump to the units and tens of percent. So it is better not to be fanatic, two or three volts at the output will be just fine, and it will not affect noise immunity in any way. The signal/noise ratio according to the passport is 105 dB, below the sensitivity limit of the devices.

Now let’s look at the frequency characteristics. It is announced bandwidth of 10 Hz-20 kHz at -1dB. The upper limit is confirmed, above 20 kHz it looks like it was chopped off with an axe (at 22 kHz it is -16dB). At the bottom the bandwidth starts almost from DC – compare graphs of EQ settings.

In order not to multiply illustrations, the graphs are paired “in a related way”. All factory presets are implemented on a 13-band EQ platform – count the “humps” on the third pair of graphs. For custom settings, a 31-band equalizer is already applied, with the bottom graph reproducing the AFC previously set “with the stroke of a finger”

In standard mode, the frequency and slope of the subwoofer LPF and front and rear LPF are set independently. Butterworth filters, the cutoff frequency is chosen from a frequency range of 50, 63, 80, 100, 125, 160, 200 Hz. The slope is chosen from the range of 0, 6, 12, 18, 24 dB/oct. The value “0” corresponds to the deactivation of the filter, although the mnemonic chart continues to display the set cut-off frequency. Subwoofer level is adjustable from -24 to +10 dB, the default setting is -6 dB.

In the three-band mode (called “network”) the frequency and slope of the filters are also set independently. But the range of values is different. The front channels now work with non cutoff HPF for tweeter, cutoff frequencies are 1.25, 1.6, 2.5, 3.15, 4, 5, 6.3, 8, 10, 12.5 kHz. The rear channel LPF (now a midbass) works with the same range of values, but it can be turned off. The rear channel and subwoofer LPFs (both switchable) operate with a range of values of 25, 3.5, 40, 50, 63, 80, 100, 125, 160, 200, 250 Hz. The steepness of all filters is the same as before, but 30 and 36 dB/octave values are added in the subwoofer channel. The subwoofer level is adjustable from -24 to +10 dB, the default value is -6 dB.

Time delays in each channel are set independently, the adjustment range is up to 350 cm in 2.5 cm increments.


The experience, it should be noted, was informative and rich in impressions. Since the listening was done with a high-quality “home” set, all adjustments were reset to zero and the processor worked as an external DAC. The tonal balance with the settings off is neat, soft, nothing hurts the ear or sticks out. With the settings, however, it does not get worse. The focus of the stereo images in two-channel mode is excellent, then the “car” landing was simulated and a little play with delays allowed to bring the scene back into place.

The game with the equalizer and crossover settings turned out to be no less fascinating occupation, with fifty screenshots alone – I had to select only the most expressive ones for publication.

It is worth noting that the power of the built-in amplifier is not great, but quite enough to work with sensitive acoustics, especially in channel-by-channel mode (there it is divided between the speakers, though not evenly). A sensitive subwoofer can also be connected to one of the outputs, the load of 2 ohms promises power up to 70 watts. Thanks to the line outputs you can “power up” the processor with external amplifiers, and in any combination. For example – a 4-channel amplifier for the mid-bass and subwoofer (in bridge connection), tweeters – from the built-in one. In this case, the power distribution will be particularly favorable, and the additional costs will be minimal.


The processor is more than successful. Subjective impressions are favorable, noise and distortion – at the limit of measurement, configuration options – quite sufficient not only for upgrading the regular system, but also for independent use. The most serious simplification in comparison with professional processors (even some of them) is the only type of filters and absence of subwoofer in the subwoofer channel. But the spatial effects will allow you to liven up the sound of even wretched regular speakers. If you replace them with good quality speakers, it will be just great. The processor will be an excellent basis for multimedia system using a smartphone or tablet, and its price is more than humane nowadays.

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