Loading FIR filters into Lab Gruppen IPX amplifiers
This page describes how to load FIR filters from FIR Designer M, FIR Designer and FIR Creator EX via DTP into Lab Gruppen amplifiers and processors.
Lab Gruppen IPX Amplifier
Connect the amplifier to the same local network as the computer running FIR Designer M, FIR Designer or FIR Creator EX. Both must be on the same subnet.
Start the IPX Controller. Available amplifiers will be present.
Press the “Mixer” button.
The “Input Mixer” view appears.
Press one of the “Output EQ” buttons to go to output channel processing.
On the “Output EQ” view, press “FiR-X”.
To change to the “FiR-X” view, it may be necessary to enter a password in the “Hardware” menu’s “Enter Password” option. Use the password: “ipxopen”.
The “FiR-X” view appears. We will return to this later.
FIR Creator EX
The following procedure also works with “FIR Designer”.
In “FIR Creator EX,” create processing for one or more output channels using one project per channel. Use the “New Window” menu item to open all projects in separate “FIR Creator EX” windows. (“FIR Creator EX” has a limit of four windows. “FIR Designer” has unlimited windows.)
On the “Export” tab, under “Direct To Processor”, select “Lab Gruppen” and press “Open”.
The “Lab Gruppen” DTP window appears.
For one or more output channels, use the drop-downs to select a “FIR Creator EX” window or project.
Note: Lab Gruppen IPX amplifiers require a channel sample rate of 48 kHz and a FIR filter length of 384 samples.
On the “LPIF file” line, press “Save” to save the LPIF file.
The drop-down next to the “Save” button indicates what will be saved to the LPIF file. When set to “System”, information for all channels is saved in the file. The drop-down also provides the option to save a LPIF file for an individual output channel.
Input IIRs
An LPIF file can contain processing for both input and output channels in a multi-way loudspeaker preset. The “Input IIRs” drop-down provides for selecting a specific “FIR Creator EX” window or project, and using just the IIR filters from that project as the input channel IIR filters in the LPIF file. Since “FIR Creator EX” allows for up to four windows or projects to be open at a time, the four projects can be used to encapsulate settings for up to a 3-way loudspeaker design with input filtering.
“Combine input IIRs into all output channels”
Presently it’s not possible to load IIR filters into the “Input EQ” channels using the “IPX Controller.” (This may change in the future.)
If a “FIR Creator EX” multi-way loudspeaker preset design has input IIR filters, rather save them to the LPIF file and have the “IPX Controller” ignore them, it’s possible to combine the input IIR filters with the IIR filters already on all output channels.
When “Combine input IIRs into all output channels” is checked and “System” is chosen, the saved LPIF file won’t contain a specific input IIR filter processing block description, but rather the input IIR filters are combined into all the output channel IIR filter descriptions. Get more information the Loudspeaker Processor Interchange Format.
IPX Controller
Back in the “IPX Controller,” click the “Load LPIF File”. The program will prompt for choosing an output channel name (from the LPIF file) then it loads the IIR filters, gain, delay and polarity.
The loaded output channel gain and polarity settings can be seen on the “Levels” view.
FIR Designer M
In “FIR Designer M” create the desired processing or load a pre-created system file.
On the “Setup” tab, ensure the sample rate for all input and output channels is 48 kHz.
Note: Lab Gruppen IPX amplifiers require a channel sample rate of 48 kHz and a FIR filter length of 384 samples.
On the system “Export” tab, press the “Lab Gruppen” button.
The “Lab Gruppen” DTP window appears. Select the FIR Designer M system to use and press “Save”.
The drop-down next to the “Save” button indicates what will be saved to the LPIF file. When set to “System”, information for all channels is saved in the file. The drop-down also provides the option to save a LPIF file for an individual output channel.
“Combine input IIRs into all output channels”
Presently it’s not possible to load IIR filters into the “Input EQ” channels using the “IPX Controller.” (This may change in the future.)
If a “FIR Designer M” multi-way loudspeaker preset system has input IIR filters, rather save them to the LPIF file and have the “IPX Controller” ignore them, it’s possible to combine the input IIR filters with the IIR filters already on all output channels.
When “Combine input IIRs into all output channels” is checked and “System” is chosen, the saved LPIF file won’t contain a specific input IIR filter processing block description, but rather the input IIR filters are combined into all the output channel IIR filter descriptions.
Get more information the LPIF format here.