The ACT 4 also sets a new standard for ease of installation and use. An intuitive, full-color touch-sensitive front panel display simplifies setup and operation. Web-based setup and control enable operation of an ACT 4 powered theater from anywhere within the home via mobile phone or tablet computer. Both unbalanced and unbalanced outputs are included for flexibility in connectivity.
The EQ system in the ACT 4 (as of firmware version 0.9) is easyto operate, flexible, and is very effective at minimizing acousticalresponse errors due to room modes, loudspeaker responsevariances, and loudspeaker mounting location effects. The ACT4 EQ system works with several of the most popular roomanalysis software tools on the market such as Room EQ Wizardor Omnimic.
Acoustic Measurement Software
For consistency in describing EQ operation in this applicationnote, we assume use of a specific tool, Omnimic. While severalother tools can be used with the ACT 4 EQ system, Omnimicischosen for illustration here. Omnimic can be purchased at thelink below:
Global and Channel-based Parametric EQs
Each loudspeaker driven by the ACT 4 can have up to 6parametric EQ filters applied to tailor its room response. Onehigh-pass shelf filter and one low-pass shelf filter is appliedglobally to all channels and is used for tailoring the overall slopeor “tilt” of the room response curve. Additionally, four adjustable“bell-shaped” parametric EQs can be added and adjustedcompletely independently on each channel. Besides these sixparametric filters, each channel also has a defeatable high-passfilter in the form of the “large”/”small” speaker selection in thespeaker parameters page.
Built-in Tone Generators
Internal test tones can be used to quickly set speaker relativelevels or check for correctness of channel hookups. Provided inthe ACT 4 are a sine tone (440Hz for full range loudspeakersand 80 Hz for subwoofers), white noise, and pink noise. Pinknoise provides good results for quickly checking the levels ofeach loudspeaker in the room.
Omnimic, like several other measurement software packages,provides its own recommended sweep-based test signal formeasuring room acoustics. The “EXT” button on the ACT 4 EQsettings page enables the selected input audio source to bemixed down to mono and played through either one or allspeakers depending whether one is adjusting the fourparametric filters or the two global shelving EQ filters. One canalso run music as a source through the ”EXT” function to hearthe sonic contribution of any one particular loudspeaker in thesurround layout.
EQ On and Off (per loudspeaker)
To quickly activate and de-activate the four ACT 4 EQ filters on agiven channel, simply touch the PEQ button in the upper left of theEQ display. When the filters are toggled off with this button, thevalues are still retained in memory for later recall by simply pressingthe button again.
To erase the EQ settings in a particular channel and start over,simply press the PEQ reset button on the PEQ page for thatloudspeaker. To reset all loudspeaker EQ settings, go to thesettings -> factory reset page and press the PEQ reset button.
The ACT 4 web server control (as of firmware version 0.9) enablescontrolling all EQ parameters and signal generators using a PC,Mac, iOS device or Android device. This can be used instead ofthe front panel of the ACT 4, particularly when the ACT 4 is locatedfar from the Main Listening Position (MLP) .