Creating Configurations Using the Configuration Wizard
MSO works by evaluating many different combinations of filter parameter values, finding combinations that give the lowest error it can find. However, during the optimization it does not alter the number of filters or the types of the filters used for each sub. It only alters the parameter values of existing filters within the parameter limits that you specify. Therefore you must specify the number and type of filters used for each sub. Fortunately, the Parametric EQ (PEQ) filters are the only filter types you'll need to worry about most of the time. Their role is to counteract room mode effects. The other filter types are mostly used just for frequency response shaping.
To determine how many PEQs should be used per subwoofer channel, some experimentation is useful. For each experiment, you'll want to keep the results to compare with other experiments. This is one problem that configurations are intended to solve. Instead of having a separate project for each experiment, you create multiple configurations within a given project. This allows for comparing the results of multiple configurations in several ways. You can either put all the results to be compared on a single graph in the project, compare different graphs in the project with one another, or compare the various error values that MSO computes by using the Configuration Performance Metrics dialog.
The ability to choose the number of PEQs to be used per sub also accommodates personal preference. Some people don't like the idea of having too many PEQs per sub, and might wish to limit that number to two or so. Then, they let their room correction software take care of the remaining response flatness errors. An example of a commercial implementation of this idea is the Harman SFM system, which uses only one PEQ per sub.
Configuration Types
Depending on your application goals, two types of configurations are supported.
Subs+Mains Configurations
Subs+Mains configurations require that you have measurement data for both subs and main speakers. When you specify this type of configuration to be created, the Configuration Wizard will create a configuration for you that contains the required elements. The integration of mains and subs will then be a part of the optimization.
Sub-Only Configurations
Sub-only configurations do not require that main speaker measurements be imported The optimization does no integration of the subs with the main speakers, but only optimizes the subs as a group. This can be useful when you want to use another tool such as Dirac to EQ the low-frequency response of the system or integrate the main speakers and subs. When you use MSO in this way, it minimizes the seat-to-seat variation of the sub responses, while also flattening the sub response at the MLP as much as it can, given the number of PEQs that you choose. Other software, such as Dirac, can apply more powerful filter resources to flatten the overall response more than the simpler DSP hardware ordinarily used with MSO can do.
The Different Methods of Creating Configurations
Broadly speaking, there are four different methods you can use to create configurations.
- Use the Configuration Wizard.
- Create a configuration by cloning an existing one.
- Create a configuration from a configuration template.
- Create the configuration manually.
The discussion here will be centered on creating your first configurations using the Measurement Import Wizard and the Configuration Wizard, then creating subsequent ones by cloning. Manual creation of configurations is only necessary for non-standard configurations, and is discussed in a separate topic.
Using the Tutorial Measurement Files as Sample Files to Import
In order to illustrate the measurement import and configuration creation techniques described on the next several pages, some sample measurement files are needed. These examples will use the sample measurement files from the tutorial.
Creating Your First Configuration With the Wizards
When you first open up MSO, you are presented with a blank project. In order to do any optimizations, you must add a configuration to it. To add a new configuration, you can invoke the Configuration Wizard. This is done by choosing Config, New From Wizard... from the main menu. If you run this command when no measurement data has been imported yet, MSO will inform you that data needs to be imported, and you'll be presented with a message box asking you if you want to launch the Measurement Import Wizard to import the data. That message box is shown below.
Choose Yes to launch the Measurement Import Wizard.
Importing Your Data With the Measurement Import Wizard
The other way of launching the Measurement Import Wizard is to choose File, Measurement Import Wizard... from the main menu. No matter which way you launch the Measurement Import Wizard, the last page of the wizard gives you the option (enabled by default) to launch the Configuration Wizard when it's done. Choosing this option is strongly recommended, as the creation of your first configuration then becomes a completely wizard-driven experience from start to finish. This provides much-needed structure to a process that can otherwise be confusing, especially to new users.
The Choose the Type of Data to Import Wizard Page
When you invoke the Measurement Import Wizard, you'll first see the Choose the Type of Data to Import wizard page shown below.
If you are creating a sub-only configuration, choose Only sub data. For a subs+mains configuration, choose Both sub and main speaker data. Press Next when done.
The Measurements to Import Wizard Page
After choosing Next on the Choose the Type of Data to Import wizard page discussed above, you'll be presented with either one or two wizard pages, depending on whether you chose Only sub data or Both sub and main speaker data. Both of these are identical except for some text labeling. The Sub Measurements to Import wizard page is shown below.
When you click Add files..., you'll be presented with a standard Windows File Open dialog as shown below. Select the files you wish to import, then click Open to add them.
When you choose Open, the files won't be imported yet, just added to the File Import wizard page as shown below.
Since the files haven't been imported yet, you can add files you may have missed using the Add files... button, or remove files you may have accidentally added by selecting the files to remove, then using the Remove files button.
If you chose Both sub and main speaker data on the first page of the wizard, you'll be presented with a second File Import wizard page for importing main speaker data. Repeat the steps above to import the main speaker data.
After clicking the Next button on the final File Import wizard page, you'll be presented with the following wizard page.
The Choose Whether to Run the Configuration Wizard Page
In almost all cases, you'll want to choose the option to run the Configuration Wizard. Doing so is the easiest way to create a new configuration.
When you click the Finish button, the files will be imported. You'll see a progress dialog as shown below.
Running the Configuration Wizard
When the progress dialog completes, the Configuration Wizard will start.
The Specify the Configuration Type to be Created Wizard Page
If you imported both sub and main speaker data in the Measurement Import Wizard, the Specify the Configuration Type to be Created wizard page will appear as shown below.
This wizard page gives you the opportunity to create a sub-only configuration if you wish, even though you imported both sub and main speaker data. If you only imported sub data, this page will not appear, as the only logical choice is to create a sub-only configuration in that case.
In the following discussion, the wizard pages that appear when you've chosen a subs+mains configuration on the first Configuration Wizard page will be shown. Some of these pages will not show up when you've chosen a sub-only configuration. It should be clear which wizard pages do not apply in that case. Showing the pages that appear when a subs+mains configuration is chosen allows for the most complete discussion.
The Enter Subwoofer Count Wizard Page
When you press Next on the above wizard page, the Enter Subwoofer Count wizard page appears.
The Enter Main Speaker Count Wizard Page
If you chose to create a configuration with both subs and main speakers on the first page of the Configuration Wizard, you'll see the Enter Main Speaker Count page after pressing Next on the wizard page above.
Choose the number of main speakers you've independently measured, then press Next.
The Enter Count of Listening Positions Wizard Page
After you've specified the number of subs (and main speakers if applicable) you've measured, you're presented with the Enter Count of Listening Positions wizard page as shown below.
MSO automatically calculates the number of listening positions as the number of sub measurements imported divided by the number of subs. You can change it to a number less than that if you wish.
Choose the number of listening positions you've measured, then press Next when done.
The Choose a Unique Name for Each Sub Wizard Page
After choosing the number of listening positions you've measured, the Choose a Unique Name for Each Sub wizard page will be shown as below.
MSO automatically generates subwoofer names for you. If these are similar enough to the subwoofer names you chose earlier when exporting the measurements from REW, you can leave them as-is. Otherwise, you can edit the names in place to get them to match the names you chose in the exported files. To edit a subwoofer name, you can either select the name and press F2, or click twice on it (without double-clicking) to activate the edit mode.
Edit the subwoofer names to make them what you want, then press Next when done.
The Choose a Unique Name for Each Main Speaker Wizard Page
If you chose to create a configuration with both subs and main speakers on the first page of the Configuration Wizard, you'll see the Choose a Unique Name for Each Main Speaker wizard page as shown below.
Change the main speaker names as needed, just as you did with the subwoofer names. Press Next when done.
The Choose a Unique Name for Each Listening Position Wizard Page
After choosing the subwoofer names (and main speaker names if applicable), you'll be presented with the Choose a Unique Name for Each Listening Position wizard page as shown below.
Just as with the subwoofer and main speaker names, the names of the listening positions can be changed to match the names you used when exporting the measurements. Press Next when done specifying the names of the listening positions.
The Measurement Associations Wizard Page
After you've specified the listening position names and selected Next, the Measurement Associations wizard page will appear as shown below.
The image above shows this wizard page before any measurements are assigned. You assign a measurement to each combination of listening position and sub/speaker by using the combo box associated with each item in the right-hand column. This is the most important page in the wizard, as it brings together file names, listening position names and sub/speaker names to enable MSO to perform its calculations correctly. The image below shows this wizard page after most of the associations have been made, and demonstrates using the combo box to choose measurement names for the associations.
Notice that the careful choice of the measurement file names made filling out this wizard page easier. When the listening position is placed first in the file name (rather than putting the sub or speaker name first), the order of the file names in the combo box shown above is the same as the order of the items in the left column of this wizard page. This approach speeds up filling out this wizard page and lessens the chance of error.
Select Next after making all the measurement associations.
The Create a Configuration and a Template Wizard Page
After making all the measurement associations and clicking Next on the previous wizard page, the Create a Configuration and a Template wizard page will be shown.
Choose the Create both a configuration and a template option. The default name for the template is usually fine. Configuration templates can save you time by allowing you to create new configurations without needing to run through the wizard again. They are discussed in Creating a Configuration from a Template.
After making your choice, choose Next to continue.
The Specify the Configuration Properties Wizard Page
After choosing to create a configuration, you'll be presented with the Specify the Configuration Properties wizard page as shown below.
An MSO configuration uses zero or more parametric EQ filters (PEQs) in each subwoofer DSP channel, along with zero or one gain blocks and zero or one delay blocks per subwoofer channel. This wizard page allows you to specify how many PEQs you wish to use per channel, as well as whether or not you wish to use gain or delay blocks for the subs. Main speaker channels cannot have gain or delay blocks.
PEQs are used to simultaneously fight room modes and flatten the overall sub response.
Gain blocks are used both to control the level of the subs relative to one another in order to minimize seat-to-seat response variation, and to establish a target SPL level that you'll specify later.
Delay blocks are used to control the interaction of the subs with one another, and provide a way to ameliorate or eliminate response "suckouts" without using a boost at the frequency of the suckout.
Specifying the Configuration Name
Choose a name for the configuration here. There must not be any other configurations with the same name. Choose a name that's short, yet descriptive enough so you'll remember what it is.
Specifying Whether to Use RBJ or Legacy Q Definition for PEQs
Users of miniDSP hardware that will be exporting biquad text files from MSO to set up their filters need not be concerned about this option, as these differences in definition of Q all "come out in the wash" of the biquad coefficient calculations. Users of hardware requiring manual entry of PEQ Q values, such as Behringer DSP amps, need to take care with this option. The Behringer DSP amps use the RBJ Q convention, while the Behringer DCX2496 uses the legacy Q convention. More information can be found in the filter compatibility section. The most commonly used Q convention in modern hardware is the RBJ Q convention.
Specifying the Number of Output (Per-Sub) PEQs
The purpose of each per-sub PEQ (output PEQ) is to counteract the effect of a room mode on the seat-to-seat variation of frequency response. You can think of it as one individual PEQ per sub channel per room mode, so that N PEQs per channel can counteract N room modes. Thus the number of PEQs per subwoofer channel that you choose roughly corresponds to the number of room modes that have a non-trivial effect on the sub responses over the frequency range of optimization (which defaults to the range 20 Hz to 150 Hz).
If you haven't done so yet, I highly recommend getting the third edition of Floyd Toole's Sound Reproduction book. Chapter 8 alone is worth the price of the book. His Figure 8.8 (d) and (e), which I can't reproduce here, nicely show the relationships between room mode frequencies and response peaks and dips at a given listening position. This insight, along with a room mode calculator, can help guide you in your choice of the number of PEQs per sub to use.
The spin button control shown in the figure above allows you to pick the number of PEQs per sub to use.
Specifying the Number of Sub Input PEQs (Strongly Recommended)
Input PEQs perform conventional equalization of sub frequency responses. If your subs have large frequency response peaks in the absence of equalization, conventional equalization is efficient at knocking these peaks down, especially if the effect of the peaks does not change much with position, as is the case for the example on the MSO home page.
Using input PEQ together with per-sub (output) PEQ can often help improve system SPL capability compared to a configuration that uses only output PEQ. In the latter case, the output PEQ is used for both equalization and reduction of seat-to-seat response variation. Beginning with version 1.1.14, MSO can use separate constraints for overall sub input and output PEQ responses during optimization to limit the maximum allowed total boost and cut of these paths separately. By allowing the input PEQs as a group to have a large maximum cut, while only allowing a modest maximum cut for the PEQs in the sub output channels, the possibility of driving the subs at widely differing levels can be greatly reduced. This keeps the drive levels to each sub more consistent, improving the maximum output capability compared to the case where only output PEQ is used.
Beginning with version 1.1.14, MSO allows you to specify input PEQs for your configuration in the Configuration Wizard as shown above. If you do so, MSO will automatically apply a technique that allows large response cuts for the input PEQs, and only modest cuts for the ouput PEQs. This improves the chances that you'll get both low seat-to-seat variation and high SPL capability after the first pass through the wizard, with minimal tweaking needed after the wizard is run. For this reason, specifying sub input PEQs in the Configuration Wizard is strongly recommended.
Specifying Whether to Add Gain and Delay Blocks
Gain blocks are necessary for establishing the response reference level that you specify in the Optimization Options dialog, while delay blocks are very useful to minimize response "suckouts" as mentioned earlier. The default checked option for both of these is recommended.
Specifying Whether to Launch the Graph Properties and Optimization Options Dialogs
Although this is the last page of the Configuration Wizard proper, you can get additional wizard-like behavior by choosing the Launch Graph Properties dialog when done and Launch Optimization Options dialog when done options. By selecting these options, you'll be able to set up your graphs and optimization options right away, speeding up the process. The default checked option for both of these is recommended.
Finishing Up
Press the Finish button to complete the wizard.