What do I gain if I choose DSP instead of analog monitoring?

As the logical extension of the 8000 and 7000 Series, Genelec has employed sophisticated digital signal processing in the new 8200 Series loudspeakers and 7200 Series subwoofers to achieve the next level of resolution in accurate reference monitoring.

The GLM DSP Genelec Loudspeaker Manager Package provides all necessary components to establish connectivity to 8200/7200 Series DSP monitors. Complete network system setup and control of up to 30 loudspeakers is possible via standard CAT5 cabling.

The GLM includes simple to use step-by-step setup wizards to ensure a pain-free and thorough installation, access to extensive Acoustical Settings in each loudspeaker, and System Setup files for saving and recalling of all settings.

As an essential part of the GLM software, Genelec AutoCal is a fully automated acoustical calibration tool for a single room multi-loudspeaker system which combines decades of acoustic research along with our proprietary DSP and network control. The AutoCal system produces loudspeaker-generated test signals recorded by a calibration microphone to determine correct acoustical alignments for every loudspeaker and subwoofer on the GLM control network. 

Do the DSP products sound the same as the analog products?

The enclosure shape and material, internal acoustic design, radiation and driver characteristics are the same in the 8000 Series monitors and 8200 Series monitors. When used in the same way, the sound quality of the 8200 Series is almost identical to that of the 8000 Series. The differences are in the steepness of the crossover filters and the slightly tighter on-axis response. When using the GLM control network and AutoCal, the loudspeaker can be integrated into the room with greater precision and the differences may be significant. The same is true of the 7000 Series subwoofers and 7200 DSP subwoofers. 

What are the advantages of DSP products compared with analog ones?

If digital outputs are available at the source, the signal remains in the digital domain until after all the processing in the subwoofer or loudspeaker is complete. The signal is finally converted to analog just before the power amplifiers. This ensures that the best gain staging is used to maximize the signal-to-noise ratio, dynamic range and overall filter quality in the signal processing.

AutoCal ensures that the Acoustical Settings in the loudspeakers and subwoofers are optimally set for a large variety of acoustic conditions. This enhances consistency of reproduction both within and across facilities.

All aspects of an acoustic system of multiple loudspeakers such as response flatness, time of flight, subwoofer crossover phase, and level alignment are fully automated and optimized.

Wizards ensure a pain-free and thorough setup together with extensive system documentation

Eight EQ stages (four notch filters and four shelving filters) in each loudspeaker and four EQ stages (four notch filters) plus a Bass Roll-off control in each subwoofer.

System compensation delays for use with video displays.

System Setup files for saving and recalling all settings.

Key Technologies:

  • Genelec 8200 and 7200 systems have employed DSP to allow for all standard AES/EBU formats of digital audio.
  • The 8200/7200 Series will accept sampling rates ranging from 32 kHz to 192 kHz.
  • 8200 Series will also accept traditional analog signals and perform with all the features and benefits of Genelec 8000 Series products.
  • The Genelec Loudspeaker Manager (GLM) is a computer program that provides control of all loudspeakers on the network.
  • Up to 30 loudspeakers can be defined and controlled via standard CAT5 cabling.
  • Functions and settings are stored in System Setup files or directly into each loudspeaker.
  • AutoCal is an automated algorithm that runs within GLM using a calibrated Genelec measurement microphone (included).
  • Correctly sets levels, distance delays, phase (for subwoofers) and room response equalization.
  • SinglePoint and MultiPoint microphone locations for one, two or three-person mixing environments.
  • Interactive Response Editor provides visual readout of measured and corrected response curves.

Are DSP products compatible with analog products? Can I mix analog 8000 Series with the DSP loudspeakers?

The analog input sensitivity of 8000 and 8200 Series loudspeakers is the same so product substitution is possible. The back panel acoustical controls are also identical so copying the settings will achieve the same acoustical response in the room. However, DSP systems exhibit a short throughput latency (<5 ms) whereas analog products do not, therefore analog and DSP loudspeakers should not be mixed in the same system. An exception to this rule is where analog 7000 Series subwoofers are integrated with DSP loudspeakers using the analog inputs.

Are there any advantages if I use DSP with an analog mixer?

In the case of the 8200 Series DSP loudspeakers, AutoCal, the GLM control network and user interface work for both analog and digital input signals.

There are no analog inputs on the 7200 Series DSP subwoofers, so if only an analog source is available, analog 7000 subwoofers must be used together with the 8200 DSP monitors. GLM network control is not possible in the 7000 Series subwoofers but the 8200 DSP monitors Acoustical Settings can still be optimized using AutoCal. Alternatively it is possible to use an 8-channel analog-to-digital converter in front of a 7200 subwoofer and run the system in whatever way is most suited to the application.

Is there a chance that I will ruin the sound with all the features DSP offers if I don’t understand what I am doing?

As the system is very flexible and powerful, there are many ways to configure the systems and huge possibilities to modify the loudspeaker responses, phase, crossover, etc. To avoid time consuming adjustment procedures and provide the correct parameter settings in a very short time, Genelec has developed simple to use Setup Wizards and AutoCal to help quickly and painlessly setup and calibrate the system.

How good are the A-D and D-A converters in the DSP loudspeakers? I am using Brand X and want to be sure that the quality remains throughout the signal chain.

The A-D and D-A provide sufficient dynamic range (122 dB and 117 dB respectively) so as not to be a limiting factor in the sound quality of the system. Correct use of dither and gain staging ensure that noise and audible distortions have been minimized.

How can I recognize the DSP loudspeakers and subwoofers from the analog 8000 Series?

The 8200 DSP loudspeakers are available in black colour only. The speaker rear panel will indicate clearly the model type. The 7200 DSP Series subwoofers have two champagne coloured bars on the upper part of the subwoofer to aid differentiation.

How does Genelec justify the additional cost associated with DSP loudspeakers?

Genelec has spent the last 30 years designing active loudspeakers for professional production studios and listening rooms. All the latest manufacturing techniques have been employed to ensure that these are the best products available in the market today. In addition Genelec has been visiting customers, measuring their loudspeakers, and tuning them using acoustical measurement equipment and the Room Response Controls. All of this field knowledge and experience has been incorporated into the Acoustical Settings features and AutoCal algorithm to ensure that the loudspeakers and subwoofers are able to perform at their very best. No other company has such an extensive studio track record to draw upon.

What is the network for?

The GLM Control Network allows for communication, control and monitoring (telemetry) between the GLM software and the loudspeakers on the network. The GLM Network Interface translates information between the GLM Control Network and the computer hardware acting as the network master and managing all the loudspeakers. The GLM Control Network was carefully designed for robustness ensuring that audio continues even if the network is disconnected or the computer running the GLM software crashes.

Why are there no analog inputs on the subwoofers?

There are no analog inputs on the 7200 Series subwoofers for a couple of good reasons. Firstly, adding eight channels of XLR connectors and A-D converters adds significant cost to the product. Secondly, there is a lack of space on the electronics panel, especially on the smallest DSP subwoofer.

What is the delay (latency) through the loudspeakers?

For a digital AES/EBU input, the delay is 3.75 – 4.5 ms (>400 Hz), depending on the sample rate (shorter delay for higher sample rate). For an analog input the delay is fixed and is about 4 ms. So the delay through the loudspeaker using digital or analog inputs is about the same, and short enough for musicians to do live tracking, as well as significantly shorter than half a video frame. Such loudspeaker latency should hence not be a problem for most practical applications.

On a more academic note:

These DSP loudspeakers (like all analog loudspeakers) have an increasing delay towards low frequencies. The loudspeaker delay increases below 400 Hz because the loudspeaker is a minimum-phase high-pass system and all such systems exhibit an increasing delay towards low frequencies. The limit of 400 Hz is there because the human auditory system is not very sensitive to the system throughput delay increases at low frequencies while in mid frequencies delay variation as well as absolute delay can be audible. The human auditory system is used to large delays at low frequencies presumably because all physical systems, including listening rooms, behave like this, and therefore increase in delay at low frequencies is not very audible. The specification reports the delay variation above 400 Hz because there it can be significant for hearing.

Are network terminators required?

No, not unless the total network cabling exceeds 300 m (1000 ft). If this is the case, contact your distributor for solutions.

What D-A converters are available?

The D-A converter is built into the DSP loudspeaker or subwoofer and cannot be changed. It has very high performance and sufficient technical specifications not to adversely affect the sound quality of the product.

What about the phase shift from the filters?

All filters introduce phase shift. The properties of the phase shift depend on the filter type. The filters used inside the loudspeakers and subwoofers are designed to complement the rest of the electroacoustic system so that the overall response is as good as it can be.

Well-treated listening rooms and good quality loudspeakers can be considered to be minimum-phase systems (no energy storage due to resonances). In a minimum-phase system the magnitude response and phase response are directly linked. Any change in the magnitude response affects the phase response and vice versa. Generally, the object of equalization is to flatten the magnitude response. This has the side-effect of improving the linearity of the phase response. Listening rooms introduce phase shifts and corresponding changes to the magnitude response, so the filters used to equalize a loudspeaker in a room do affect the phase response but in a constructive way.

Does the quality of today’s soundcards and the Genelec 8200A microphone affect the measurements used for AutoCal?

The basic soundcards seen in laptops are now of sufficient quality for making in-room measurements which may be used to equalize loudspeakers and subwoofers. AutoCal compensates for the low frequency response of the soundcard during the initial input calibration procedure. The high frequency response of the loudspeaker is not affected by AutoCal, so there is nothing to be gained by compensating for the high frequency response of the soundcard. All Genelec 8200A Calibration Microphones are serial numbered and each comes with an individual equalisation curve which is automatically used by AutoCal. This ensures reliable system calibration for doing accurate acoustical measurements.

Do the switches sum with the internal settings?

Loudspeakers and subwoofers are under network control when there is an operating GLM Network connected to them, in which case the settings in the System Setup file loaded into GLM apply. If there is no network control, the settings stored inside a loudspeaker, or subwoofer, are used when one of the switches is set to “Stored Settings”. The switches on a loudspeaker or subwoofer are only operational when one of the switches is set to “Manual Control”. These three modes of operation are independent of each other – one set of controls does not sum with another.

Where does the volume control happen?

Genelec DSP loudspeakers and subwoofers implement the volume control as a part of the DSP processing. The volume control decreases the values in the digital audio data just before the data is written into the DA converter to turn the digital audio signal into an analogue audio signal. Decreasing the value makes the sound level lower.

The command to set the volume to a certain level is created in the computer user interface software GLM and mediated into all loudspeakers and subwoofer using the Genelec loudspeaker control network. No audio data travels on the control network.

What happens to the idle channel noise level of the loudspeaker?

The idle channel noise in the Genelec loudspeakers and subwoofer has been designed to be low enough to render this noise inaudible under all normal listening conditions. This is true in all settings of the volume in DSP products. 

What is the quality of digital audio when attenuated using Genelec volume control?

It is well known that attenuation of the digital audio signal in a DSP processor decreases the number of significant bits representing the data. This is called quantization. Coarse quantization (very few bits representing the data) can lead to distortion if the data is not processed properly

There is a standard technology that eliminates this quantization distortion in digital signal processing. This technology is called dithering. Genelec uses proper dithering at the volume control operation to ensure that the signal after the volume control is a perfectly linear digital audio signal, and no distortion is generated. There is no increase in the audible or measurable distortion level in Genelec DSP loudspeakers and subwoofers when the volume is reduced, and the signal maintains its original linearity and smoothness. The only audible consequence of lowering the volume setting is that the sound level decreases.

What is needed to properly implement digital volume control?

Genelec uses the best electronic components, high quality design standards, and maintains wide dynamic range and large word length at all signal processing steps to ensure uncompromised linearity. Furthermore, proper dithering is applied as a part of signal processing to guarantee linearity of the whole digital audio processing chain. During the product development Genelec has conducted extensive testing to ensure linearity under all operating conditions and control settings.