Product & Application Support
Where are the Tabular Processing Settings for My Loudspeaker?
Tabular processor settings for EAW loudspekeakers can be found on our Documentation site, please see the links below. Processor settings for current product are listed under their respective product folder. For legacy products, processor settings are consolidated to a single folder.
If there are no tabular settings listed, this means that tabular settings are not available for this product, for one of two reasons:
This product is optimized for full-range operation and does not require processing (other than room EQ and perhaps a high-pass filter). To determine whether this is the case for your product, examine the Specification Sheet.
This product requires Greybox processing. Tabular settings are not available because conventional EQ filters are not sufficient for optimal performance. In this case, the product’s Specification Sheet will indicate that the product requires ‘DSP w/EAW Focusing’
Why Does EAW Require Greybox Processing For Some Products?
To understand why EAW releases Greybox-only processing for some products, it is necessary to understand what a Greyboxe provides and why this cannot be replicated with third-party conventional processing. A Greybox provides the following critical features and functions:
1. EAW Focusing™ – Proprietary impulse response corrections to eliminate horn “honk” and “smear”. This cannot be recreated with third-party processors using conventional parametric filters.
2. Greybox Limiting – Utilizing user input regarding amplifier gain and output capabilities, Greybox-enabled processors and amplifiers automatically calculate the correct limiter parameters for each passband of a loudspeaker.
3. Gain Optimization and Alignment – Like Greybox Limiting, Greybox-enabled processors and amplifiers automatically account for gain differences between passbands. This ensures correct crossover alignment and system tonality, even if amplifier gain varies from passband to passband (i.e. more gain on LF channels than on HF channels). EAW Pilot will alert users to situations where headroom is constrained due to low gain, or where system noise may be elevated due to high gain.
Because all three of these functions are integral to loudspeaker performance, EAW requires Greybox processing for premium-level products. For questions about your specific application and needs, please contact the Application Support Group.
What should I do now?
If the product you wish to use is identified as requiring “DSP /w EAW Focusing” on the Specification Sheet, you have three options:
1. Utilize a UX Series digital signal processor – Per output channel, users can select whether to utilize conventional processing or load a Greybox.
2. Utilize a Lab Gruppen PLM-Series amplifier –One Greybox (up to 4 legs) can be loaded per PLM amplifier.
3. Utilize a Powersoft K-Series amplifier with KDSP card installed – One Greybox leg can be loaded per channel.
All three of the above platforms can natively load and implement EAW Focusing™ for Greyboxes that include it (indicated by a “GF” in the Greybox file name).
Selecting an Appropriate Amplifier Size: The amplifier for your loudspeaker should be sized according to both the sound levels required and the type of audio signals that will be reproduced. If you are unsure of how to determine these things, consult a qualified professional or contact EAW’s Application Support Group. As a rule of thumb, where the full capability of the loudspeaker is needed to achieve appropriate acoustic output levels, EAW recommends an amplifier that is twice the loudspeaker’s power handling specification. This allows the amplifier to reproduce peaks 6 dB above the specified power handling. However, this recommendation does NOT guarantee trouble-free operation, and assumes that operation of the loudspeaker can be properly controlled. It is the responsibility of the audio system operator to ensure that all equipment in the system is operated within its capabilities. That is the only way to ensure that loudspeakers do not get stressed beyond their limits to the point of damage or failure.
Loudspeaker Power Handling Rating: The power handling rating in EAW’s specifications means that the loudspeaker has passed our standard power handling test. In this test the loudspeaker is “exercised” to a point of damage or failure. The power rating resulting from this test is intended to be used as a point of comparison with the power ratings of other loudspeakers. This rating does not necessarily correspond to the best amplifier size to use nor is it a measure of the “safe” amplifier size to use under actual operating conditions.
Preventing Loudspeaker Damage: Preventing damage to or failure of a loudspeaker is not a function of amplifier size nor the loudspeaker’s power rating. Preventing damage is a function of operating an audio system so that a loudspeaker is not stressed beyond its limits. If an audio system is operated improperly, damage to or failure of a loudspeaker can occur even with an amplifier sized well below the loudspeaker’s power rating. Contrarily, if an audio system is operated properly, damage to or failure of a loudspeaker can be avoided even with an amplifier sized well in excess of the loudspeaker’s continuous (or RMS, average, etc.) power rating.
For a more detailed discussion of this topic, please download our Amplifier Power Paper.
HPFs and LPFs are generally defined by three characteristics: a cutoff frequency, a topology, and a slope. The cutoff frequency is the frequency where the response of the filter falls to some level below that of the unfiltered (“passed”) frequencies. This level is generally 1/2 the voltage of the unfiltered frequencies or -6 dB. The topology determines the shape of the filter’s frequency response. The most commonly used filter topologies are Butterworth, Linkwitz-Riley, and Bessel. The slope of the filter defines how fast the level is reduced beyond the cutoff frequency. This is usually defined as dB per octave (dB/oct). Common filter slopes are 6, 12, 18, and 24 dB/oct.
HPFs and LPFs have two distinct applications: As Bandstop filters and as Bandpass filters. A special use of Bandpass filters is for crossovers.
Bandstop Filters: These are used to eliminate frequencies above or below a certain frequency that are not useful for reproduction. This may be because the loudspeaker is incapable of reproducing them or the frequencies do not exist in the audio signal.
For example, speech contains very little information at frequencies above about 8 kHz and below about 150 Hz. This means these two frequency ranges essentially useless for reproducing speech. In this case you would set a HPF for about 150 Hz and an LPF for 8 kHz to eliminate them from the microphone signal path.
Bandpass Filters: In the example above, the combination of the HPF and LPF created a single band-pass filter. A bandpass filter always consists of an HPF and LPF working together to pass a range of frequencies and reduce the level of any frequencies above and below this range.
Crossover Filters: Crossovers are filters made from HPFs and LPFs. They divide up the frequency spectrum into the various frequency ranges (bands) needed by the transducers (also commonly referred to as a “drivers”). Crossovers provide high and low frequency bands for 2-way systems and high, mid, and low frequency bands for 3-way systems.
Typically, crossovers are used in conjunction with bandstop filters. These are used to filter out frequencies near to and beyond the high and low frequency limits of the human hearing range. This is a highly recommended practice.
The bandstop filters are usually engaged in the mixing console, main equalizer, or the electronic crossover. For example, in a 2-way system the high pass crossover filter works with an LPF, set near the highest hearing frequency. Working together, these two filters make up a bandpass filter that passes frequencies from the crossover point to the upper limit of hearing. The low pass crossover filter works similarly with an HPF that filters out unwanted very low frequencies.
In the case of a 3-way system, the mid range crossover output is also a bandpass filter. It is formed by the midrange high and low pass crossover filters themselves. This bandpass filter passes only the mid-range frequencies.
Thus, in most instances and applications, a loudspeaker crossover as used in a complete audio system, is really made up of two or more bandpass filters, each consisting of an HPF and LPF.