Do you have any questions about the repair procedures of DAS products or audio in general? Here you´ll find answers to those question.
Do you have any questions about the repair procedures of DAS products or audio in general? Here you´ll find answers to those question.
What types of connections can be found in DAS Audio systems?
To answer this question, it is necessary to differentiate between powered and externally powered systems.
For externally powered systems, there are several types of connection solutions:
Powered systems use three types of connectors for power supply:
Is it possible to rotate the diffusers in DAS Audio installation systems?
Yes, all the DAS Audio installation systems, such as those from the Artec-300, HQ and WR series, have rotatable diffusers:
What do the acronyms CX and DX in DAS Audio systems mean?
For fixed installations, DAS Audio offers two types of weather-resistant finishes.
The CX finish protects the wooden enclosure with polyurea paint and includes stainless steel fittings and mounting hardware. This finish is recommended for applications where the cabinets are partially covered or protected.
CX: covered exposure.
The DX finish protects the wooden enclosures by employing a fiberglass exterior and stainless-steel fittings and mounting hardware. This finish also includes a triple protective coat behind the grille of the systems, including a water-repellent fabric. This finish is recommended for systems fully exposed to extreme environments.
DX: direct exposure.
¿What is the IP rating of DAS Audio systems?
Live sound systems, such as the powered Event/Aero/UX, are IP-43 certified thanks to the integrated rain cover that protects the amplifiers.
Fixed installation systems, such as the HQ and WR series, are generally IP54 certified.
Can the portable sound reinforcement systems from the Action-500, Altea-400, Altea-700, and Vantec series be reset to factory settings?
Yes, all systems can be restored to factory settings.
The procedure is the same for all series. Navigate up to the options sub-menu and select the reset device option:
Is it possible to update the firmware of systems that include a wireless connection?
Yes, all the series that incorporate this technology (Altea-700 and Vantec) can update their firmware wirelessly using the DASlink™ application. See user manual for more information.
Can DASlink Group Manager™ send audio wirelessly?
No. DASlink GM™ is designed to control groups of systems from the Altea-700 and Vantec series. The maximum number of systems that can be controlled ranges from 4 to 16 depending on the tablet or smartphone version the user holds.
This application cannot update the firmware of the systems.
See the series user manual and the DASlink GM™ tutorials for more information.
When do you recommend using the DASlink™ wireless application?
In locations with no Wi-Fi connection, DASlink™ can be used for music streaming and for controlling a small number of systems from the Altea-700 or Vantec series.
Please note that Wi-Fi networks can cause interference with audio streaming.
DASlink™ will be necessary to update the firmware of the Altea-700 and Vantec systems.
See the series user manual and the DASlink™ tutorials for more information.
How many curves or presets can be loaded onto the Altea-400, Altea-700, and Vantec systems?
There are 5 types of pre-recorded frequency response curves: Live, Dance, Bass Boost, Monitor and Vocals. The Live Mode curve appears by default.
The Vantec-20A models do not feature these 5 presets. However, there is one parameter that can be modified, known as Number of Units, which depends on the number of cabinets in the array. Blue Number of Units: Blue =1, Green =2, Red =3
How many curves or presets can be loaded onto the Action-500?
You can load 3 curves: Live, Dance and Monitor.
The Live curve is loaded by default onto the systems, except for the Action-M512A model which includes the Monitor curve.
The display of the Action-M512A, is it off during operation?
Yes, the display is set in Monitor mode. The screen automatically shuts down when the encoder is not in use, so as not to disturb the audience.
Do the systems from the Altea-400, Altea-700, Vantec, and Action-500 series have configurable delays?
Yes, from 0 to 9.9 meters.
Which high-pass filter should I choose when combining tops and subs from the Altea-400/700, Action-500, and Vantec series?
In the same way that it is possible to select the preset (frequency response curve) for the tops, you can also select the high-pass filter (HPF) when using SUBS+TOPS together.
For the Altea-412A, Altea-415A, Altea-712A and Altea-715A models, select the HPF option: At-18A
For the Altea-718A model, select the low pass filter (LPF) option: AlTop
For Vantec-12A, Vantec-15A, Vantec-215A and Vantec-20A, select the HPF option: V18A
For the subwoofers Vantec-18A, Vantec-218A, Vantec-118A, set the LPF control to 100Hz (number 9 in the figure):
For Vantec-20A, select HPF: V118A
What is the number of units parameter for?
In a powered line array or curved source system, it is used to compensate the excess of energy in the mid-low frequency range produced when hanging the systems one under the other. The graphic shows the curves for different values entered in the “number of units” parameter for the Aero-20A. The pink curve shows the number of units = 1.
This parameter can also be found in the Event-208A, Event-210A, Event-212A, Vantec-20A, Aero-20A and Aero-40A models.
Very important: For this parameter, use the same “number of units” value in all the cabinets of your system. For example, if you have an array with 6 x Event-210A per side, the same value of the “number of units” parameter must be used for each and every system.
For the Event-208A, Event-210A and Event-212A models, the parameter “number of units” can be adjusted on the rear panel of the amplifier.
For the Vantec-20A model, it can be done via DASlink GM or hardware.
For the Aero-20A/40A systems, via DASnet or hardware.
See the user manuals for more information.
How do I set up a cardioid subwoofer array?
With the powered Event-218A, Event-121A, UX-218A, UX-221A, UX-30A and LX-218CA systems, just by positioning two/ three subwoofers with ONE of them facing backwards in the same stack. The back-facing subwoofer must have the cardioid preset button on:
When the parameters of a powered system are modified, are they saved after the amplifier is off?
Yes, any change of presets in the Altea-400, Altea-700, Action-500, or Vantec powered series is stored in the internal memory of the systems.
Similarly, in the Aero and UX series any changes or parameters entered via the rear panel of the amplifier or via DASnet is stored in the internal memory.
What is RMS power?
“RMS power” is a misnomer derived from the usual method of calculating speaker power, which is to divide the RMS voltage squared by the impedance (V²/Z). RMS is the acronym for root-mean-square, which relates to the mathematical equation that obtains the average of the modulus of an alternating signal (that is, with positive and negative cycles). The correct expression for “RMS power” is average power. The ratio between RMS and peak values is different for each signal.
What is average power?
It is the result of deriving power from an RMS value of voltage or current. It is the correct way of writing “RMS power”.
What is programme power?
Programme power is an archaic term dating back to when power tests used sine waves. Many manufacturers, including DAS Audio, apply a convention whereby programme power is twice the average (“RMS”) power, although other manufacturers may use different power ratios, which may even vary from product to product. Nowadays the term “programme power” has no specific meaning, although it might be used as a power amplifier recommendation for controlled applications.
What is peak power?
Peak power is the power that corresponds to the signal peaks that the amplifier feeds the speaker during a power test. Typical test signals have peaks that carry four times the average signal power, which is why peak power is normally four times the average (“RMS”) power.
What is AES power?
The AES (Audio Engineering Society) publishes a standard for the measurement of loudspeaker component parameters. Generally speaking, this standard calls for a 2-hour test using pink noise with specified dynamics and with a frequency content that matches the component`s frequency range. Although it is a standard for components, it is often extended to the different ways on an active system. The rating always derives from RMS voltage or current measurements, therefore the rating corresponds to average (“RMS”) power.
What is IEC power?
The IEC (International Electro technical Commission) publishes standards for loudspeaker measurement. We can speak of IEC power by following those standards. Specifically, IEC 268-1 defines a signal with specified dynamics and a frequency content that tries to resemble that of real music. The rating always derives from RMS voltage or current measurements, therefore the rating corresponds to average (“RMS”) power. DAS Audio utilises IEC shaped noise for enclosure power testing.
Can I run the amplifier with 2 ohm loads?
Virtually all professional amplifiers will accept loads down to four ohms safely in stereo mode. Many are rated for 2 ohm loads but often will run into overheating protection when used with 2 ohm loads, particularly in high ambient temperature and high output power applications. Check the user`s manual of you amplifier to find out the lower impedance it will take. Never use a total impedance load that is lower that the lowest impedance that the amplifier will take (for instance, hooking up too many enclosures in parallel).
Should I enable the amplifier´s high-pass (sub-sonic) filter?
It is good practice to use a high-pass filter for the lowest frequency component in your system (i.e. a full-range enclosure; or a subwoofer if using subwoofer reinforcement). If your electronic crossover has a high-pass filter, use it, and disable the amplifier´s. Use the amplifier´s high-pass filter only if there is no other filter of this type anywhere else in your system chain.
Beyond their operating ranges, speakers produce little sound. Instead, they radiate large amounts of heat. In addition, frequencies below a speaker´s operating band will generate a lot of cone movement. By using a high-pass filter, we can put the low frequency energy that would otherwise be wasted into usable amplifier power for the speaker´s operating band. We also prevent mechanical damage from excessive cone movement. Thus, high-pass filtering maximises acoustic power and makes systems more reliable.
We recommend enabling a high-pass filter that is equal or higher than the system´s lower usable frequency. For instance, for an Vantec-215 used as a full-range box, set the high-pass frequency no lower than 40 Hz. No lower than 60 Hz for a DAS Factor-8.
DAS signal processors provide system specific high-pass filtering. DAS IA series amplifiers also provide sub-sonic filtering with useful cut-off frequencies.
What amplifier should I use with transformer loudspeakers?
There are specific amplifiers for 70/100 V lines, sometimes referred to as constant voltage. For applications where little power is required, these amplifiers are appropriate. As the power requirements for the system increase, conventional amplifiers are often used. For instance, a conventional amplifier delivering 1200W per channel at 4 ohm can be considered a stereo 70 V amplifier. Likewise, an amplifier delivering 600 W per channel at 4 ohm can be considered a monophonic 100 V amplifier in bridge mode. Similarly, an amplifier delivering 300 W per channel at 4 ohm can be considered a monophonic 70 V amplifier in bridge mode.
To calculate the required amplifier power for a 70 or 100 V line, simply sum the power for the amplifiers connected to an amplifier channel. Example: if we want a 100 V line with 50 DAS Factor-8T enclosures (with built-in multi-tap transformer to select different power levels for 50, 70 and 100 volts) such that 25 of them use the 30 W tap and 25 of them use the 15 W tap, we would need an amplifier delivering a minimum of 25×30+25×15=1125 W. In this case, assuming all speakers share the same signal (zone), it may be worthwhile, and probably more economic, to use a conventional 500 W output per channel at 4 ohm amplifier in bridge mode, such as a DAS IA-1002.
What is the damping factor?
Damping factor is related to amplifier output impedance, and can be explained as the ability of the amplifier to control the movement of a loudspeakers` voice coil. For a given speaker load, the damping factor is, in practice, given mostly by the cable impedance, so that one should not place too much importance on this amplifier parameter. It is also important to note that damping is directly related to the speaker load, so that using an 8 ohm load will yield twice the damping factor compared to a 4 ohm load. To maintain a high damping factor, always use cable of appropriate thickness (gauge).
What cable should I use?
To ensure quality sound (high damping factor) and minimum power loss, the speaker cable needs to have a large enough cross section depending on the cable length, number of speakers per channel and speaker impedance. The longer the cable and the more speakers, the thicker the cable has to be. The lower the impedance of each speaker, the thicker the cable has to be. The most important feature for a cable is its wire area; you can discard cables with magical properties and astronomical price.
Amplifier user`s manuals often have tables to aid the selection of wire gauge for different cables lengths and speaker impedances. The DAS IA Series amplifiers` user`s manual provides tables of this type.
In what voltage range do DAS Audio´s powered systems work?
In terms of design, ALL powered DAS Audio systems can operate successfully down to voltages of 180V for nominal power of 230V, and 90V for nominal power of 115V.
The standard only requires a 10% variation from the nominal voltage, but DAS Audio extends this margin up to 20% for the lower limit.
Does this mean that the systems are not affected by voltage drops and peaks?
It means that the systems can run at full power within the following voltage ranges:
For 230 V: Min 180V ; Max 260V
For 115V: Min 90V; Max 130V
What is a third octave?
A third octave is more like a “third of an octave”, i.e. an octave divided by three.
An octave is a frequency band that spans within two frequencies with a ratio of 2:1. For instance, the 1000 Hz octave band spans from 707 to 1414 Hz. Adjacent octave bands are also spaced by a ratio of 2:1, such as the 500 and 1000 octave bands. The octave band centre frequencies have been standardised by ISO (International Organization for Standardization) to rounded figures as follows:
A third of an octave is a frequency band that is three times smaller than an octave band, so that an octave band logically comprises three third octave bands. Thus, the 1000 Hz third octave has a bandwidth of 891-1122 Hz. And the 1000 Hz octave band encompasses the 800, 1000 and 1250 Hz third octave bands. Third octave bands are often used in audio because they relate to the way human hearing (and mammals` in general) works. The most used form of pro-audio equaliser is the 1/3rd octave band “graphic” equaliser, the term “graphic” deriving from the fact that glancing at the fader positions we can (arguably) get an idea of the resulting EQ. Analysers that measure frequency content in 1/3rd octave bands are often referred to as RTAs. The 31 third octave audio band centre frequencies have been standarised by ISO to rounded figures as follows:
For the musically inclined, a third octave is equivalent to four semitones.
What long throw systems for installations are available in the DAS Audio catalogue?
Point Source Systems: The externally powered HQ series which feature 2-way passive or bi-amplified systems for sports facilities, such as football stadiums, arenas, etc.
Line Array Systems: There are two externally powered line array models. The Artec-320 and the WR-320 systems, ideal for indoor and outdoor applications, respectively.
Powered Line Array Systems: The Event and Aero series are available as long throw solutions for installations with powered systems.
What is efficiency?
Efficiency is the ratio between the acoustic power output and the electrical power input to a loudspeaker. Power not converted into sound ends up as heat. Loudspeakers are very inefficient devices that put out more heat than sound.
What is sensitivity?
Sensitivity is the sound pressure level (SPL) which is measured at a distance of 1 metre in front (on-axis) of a loudspeaker which is fed 1 watt of electrical power. If the measurement uses a different distance or power, the result is scaled so that it refers to the standard 1W/1m.
What is this excursion thing then?
On a cone or diaphragm, excursion is the movement outward and back or from the voice coil rest position. It is inversely proportional to frequency, so that low frequencies generate more movement than high frequencies.
Over-excursion takes place when excessive movement causes scratching or deforming of the voice coil, or even fracture when the coil support “bottoms-out” and hits the speaker`s bottom plate. To prevent damage, avoid equaliser gain on frequency ranges below a speaker`s operating range (such as 20 Hz on a SUB218, or 40 Hz on a Factor -5), use a high-pass filter and be careful when utilizing large power amplifiers.
What is the directivity index?
The directivity index (Di) is an expression in decibels of the directionality of a sound source. Narrow coverage systems have a high directivity index, whereas wide coverage systems have a low one. Di is the decibel form of directivity Q factor, so both are related as Di = 10*log(Q).
What do we mean by long / short throw?
A long throw system is one that has high sensitivity and narrow directivity (high Di), whereas a short throw system is one with lower sensitivity and a wider coverage (low Di). These are informal terms without precise definitions.
What is the difference between direct radiation and horn loading?
With direct radiation, a vibratory element (such as a cone loudspeaker) radiates directly into the air.
Horn loading takes place when the loudspeaker couples with air through a horn. In doing that greater efficiency is achieved, that is, more sound and less heat. We also get more directionality. The theoretical size for a horn is inversely proportional to frequency. That is why, for bass bins, the horn of which would be impracticably large, the horn has to be “folded” inside the box, thus referred to as a “folded horn” box.
What is horn EQ?
A compression driver and horn combination exhibits inherent high frequency roll-off. This is compensated at the passive filter network in passive systems, while active ones (with no passive network elements) take care of the correction at the electronic crossover.
What is sound?
In physics, sound (from Latin sonĭtus) is any phenomenon that involves the propagation of mechanical waves (audible or not), usually through a fluid or other elastic medium, generated by the vibratory movement of a body. Without an elastic medium there would be no sound since waves do not propagate in a vacuum.
What is the sensitivity (SPL) of a system and how is it determined?
It is the sound pressure level (SPL) measured at a given distance, conventionally 1 m in front of a speaker (on axis) with an input power of 1W. If the measurement is done at a different distance or power, the result is scaled to 1W/1m:
What is the Peak or Maximum Sensitivity (SPLmax) of a system and how is it determined?
It is the sound pressure level (SPL) measured at a given distance, conventionally 1 m in front of a speaker (on axis) at the maximum power handling capability of the system. It is traditionally calculated using the Peak Power rating, applying the following formula:
SPLpeak = SPL(1W/1m)+10*log(Peak Power)
For example, the HQ-212.95 system has a sensitivity of 105dB. The peak power rating of the system is 3200W. The calculation is as follows:
SPLpeak = 105+10*log(3200)=140Db
What is frequency range and how is it determined?
Given a frequency response measured at 1W/1m, the frequency range is determined by the points where the SPL drops 10dB below the average:
For example, for Aero-40A, the limits are 60Hz – 20kHz
What is the target frequency response curve for a system?
It depends greatly on the application and the type of system. Note that a public address system for voice evacuation announcements is different from a club system, a concert, or a cinema system. For instance:
DAS Audio designs systems, both powered and externally powered with DSP, so the user can benefit from a frequency response curve as flat as possible that can be used as a starting point for a wide range of applications.
What types of acoustic systems are there?
There are many ways of categorizing acoustic systems.
Two- or three-way systems can fall under the passive or active category, depending on whether the crossover point between the signal paths is done with a passive filter included in the system or is done with an external digital processor.
What is the coverage of a system and how is it defined?
System coverage is determined by measuring the system´s frequency response at various positions off the horizontal and vertical axis. When the frequency response has dropped 6dB off-axis, we obtain the Horizontal or Vertical coverage angle of the system. Coverage angles are expressed in sexagesimal degrees. The following would be the basic measurement points to determine the H x V coverage of a two-way system:
The result is typically shown in polar plots or sound pressure graphs (a two-way system of 60º x 40º coverage is shown):
What is the vertical coverage of a line array system?
A line array system does not have a fixed vertical coverage. In terms of a single cabinet, the vertical coverage varies with frequency, so it is common to find in catalogs or specification sheets the coverage of a line array (H x V) expressed as follows:
90º x splay dependent
Asking about the vertical coverage of a line array cabinet is a common question in the professional audio industry. The answer to that is not a fixed and defined number since that coverage varies with frequency. As a matter of fact, the answer is shown in a graph like this one bellow:
Sound pressure level map on the vertical plane of an Artec-320 system. Notice that from 1kHz the system vertical coverage narrows with frequency.
On the other hand, we can talk about vertical coverage when several cabinets are hung at certain angles forming a complete cluster.
What is a cardioid subwoofer setup?
Subwoofers have virtually an omnidirectional radiation pattern. That is, there is the same energy in front and behind the subwoofer.
Cardioid means that power only radiates at the front of the subwoofer.
This can be achieved by combining the DAS Audio powered subwoofers.
How do I calculate the impedance that results from connecting several loudspeakers?
The total impedance for a number of speakers in parallel is equal to the impedance of one divided by the number of speakers. For instance, two 8-ohm speakers in parallel total 4 ohms (8 ohms divided by 2 speakers equal 4).
If the speakers are in series, the total impedance is the sum of the individual impedances of each speaker. For instance, two 8-ohm speakers in series total 16 ohms (8 ohms plus 8 ohms equal 16). In pro audio, series connections are rarely used outside low power applications such as background music, paging, or surround sound.
Why is the impedance that I measure with a multimeter different from the system`s nominal impedance?
The multimeter looks at resistance, not impedance. Impedance is the opposition to the passage of alternating current and varies with frequency. Resistance is the opposition to the passage of direct current. Resistance is normally lower than nominal impedance. For instance, an 8-ohm nominal impedance cone speaker would typically have a (DC) resistance around 6 ohm. See any DAS spec sheet for an impedance curve. Dedicated impedance meters for audio use exist; they typically use a sinewave generator to measure impedance at 1 kHz, so you need to look at the speaker`s impedance chart to see what value you should expect at that frequency.
What is the impedance of a system and how is it determined?
Impedance is defined as the opposition to the flow of alternating current. In a system, the impedance varies with frequency, so manufacturers publish “impedance curves”. Impedance curves are measured using specific laboratory equipment and, typically, a sinusoidal sweep. An impedance curve of a passive two-way system may look like this:
Impedance is expressed in ohms.
The standard nominal impedance for externally powered systems is 8 ohms or, in some cases, 4 ohms.
What is a balanced line?
There are two basic ways to transport an audio signal with microphone or line level:
Un-balanced line: Utilizing a two-conductor cable, it transports the signal as the voltage between them. Electro-magnetic interference can sum to the signal as undesired noise. Connectors that carry un-balanced signals have two pins, such as RCA (Phono) and ¼” (6.35 mm, often referred to as jack) mono. 3-pin connector such as XLR (Cannon) may also carry un-balanced signals if one of the pins is unused.
Balanced line: Utilizing a three-conductor cable, one of them acts as a shield against electro-magnetic noise and is the ground conductor. The other two have the same voltage with respect to the ground conductor but with opposite signs. The noise that cannot be rejected by the shield affects both signal conductors in the same way. At the device’s input the two signals get summed with opposite sign, so that noise is cancelled out while the programme signal doubles in level. Most professional audio devices use balanced inputs and outputs. Connectors that can carry balanced signal have three pins, such as XLR (Cannon) and ¼” (6.35 mm) stereo.
What signal connectors do DAS Audio´s powered systems use?
All powered DAS Audio systems feature analogue audio input(s) using XLR connectors:
The Aero and UX Series systems feature audio input XLR connectors plus additional Ethercon connectors (marked as DASnet in/out) to feed analogue audio and monitoring data (DASnet) via the same cable:
Consequently, in Aero and UX systems, if the Ethercon connector is in use, there is NO need to feed audio via the XLR.
Thank you for your confidence in our products.
If you are an end user of DAS products you should contact your local distributor or dealer. Contact information for international distributors may be found in the Where to buy DAS link.
In other cases, complete the Customer Support Form and send it using the “Send” at the bottom of the web form.
Please remember the following:
-Before sending any materials to DAS Audio you must obtain an RMA (Returns Materials Authorization) number. Fill in the Customer Support Form and you will be contacted with instructions for obtaining service.
-The customer is responsible for transporting the product for repair or arranging for its transportation and for payment of any initial shipping charges. Products received with “freight due” will not be accepted.
-Send your DAS product with adequate protection for shipping. A suitable carton with packing materials sturdy enough to withstand shock or puncture is required. If you need one, request it from DAS when you call or email your RMA form. DAS will not be held responsible for damage done to unsuitably packed products.
-The RMA number should be clearly marked on the outside of the packaging.