Multi-Sub Optimizer (MSO): Lessons Learned, Tips & Tricks

[DaveBoswell]

File attached.

Thanks - I had a look this morning and overall I think your current Confg 2 looks pretty good as is, but I have a few suggestions/comments for you to try if interested and for other's benefit
- you have only measured for 2 positions - recommend that you measure for at least 3 positions to avoid over correcting for very localized issues at any one of them
- in your native unmodified state, your subs are definitely cancelling each other out by up to 15dB (!!) in the 30-90Hz range (as can be seen by the large gap between the green and blue lines in the baseline and baseline SPL penalty of 6.92dB) - time and phase alignment in MSO 2.0 will fix this and really help improve the overall output for sure!
- your HSU sub is rolling off quite a lot below 35Hz (see measurements black lines plot below) which is a bit surprising for a sealed sub - do you have it located far from the walls? If not, check for any High Pass Filter being active on this sub either on the back of the sub or in the MiniDSP. Other wise try to move it close to a wall/corner to take advantage of room mode coupling
- you can clearly see that the HSU sub has different group delay below around 50Hz or so as the black dotted phase line is much shallower in slope than the blue and red ones in the baseline phase plots. This means that the HSU has lower group delay than the SVS subs and definitely you can see improvement with AP filters so good to keep them in your optimizations
- I found that if you try to optimize the SPL penalty between 10 and 180-200Hz, MSO still struggles to find a great solution for SPL penalty between 45 and 85Hz (see second plot below with separation on blue and green lines)
- if you reduce the upper limit to 120Hz, you can materially improve the SPL penalty for the cost of a small peak in the Position 2 location at around 85Hz - if it's just you who cares about the sounds quality, I would try this option and see if it is any better

Maximizing SPL with limits of 10-180Hz leads to signficant null at 72Hz

HSU ULS sub not producing much output below 35Hz

 

[PCSguy]

Thanks - I had a look this morning and overall I think your current Confg 2 looks pretty good as is, but I have a few suggestions/comments for you to try if interested and for other's benefit

No, thank you for your help. Do you mean Config 3? That is the one I downloaded into mini-dsp and it sounds pretty good. Although, I have not compared the sound to any other Configs. That will be one of my next steps. Yes, happy to try suggestions.

- you have only measured for 2 positions - recommend that you measure for at least 3 positions to avoid over correcting for very localized issues at any one of them

Sure I can do 3 positions, however my concern is that my room is not very wide (10.5ft) and didn't want to measure too close to the walls. I can try measurements 2ft' apart. I should have some time tomorrow and will post results.

- in your native unmodified state, your subs are definitely cancelling each other out by up to 15dB (!!) in the 30-90Hz range (as can be seen by the large gap between the green and blue lines in the baseline and baseline SPL penalty of 6.92dB) - time and phase alignment in MSO 2.0 will fix this and really help improve the overall output for sure!

Yes, huge suck out, kind of aggravating! Currently using version 2.0.1. Is it the latest? In your video, where did you find the Performance Metrics popup containing multiple configuration data sets?

- your HSU sub is rolling off quite a lot below 35Hz (see measurements black lines plot below) which is a bit surprising for a sealed sub - do you have it located far from the walls? If not, check for any High Pass Filter being active on this sub either on the back of the sub or in the MiniDSP. Other wise try to move it close to a wall/corner to take advantage of room mode coupling

My sub locations: SVS LF, SVS RR and ULS II RF. In the future I plan to try some different sub locations, starting with both SVS subs in the front corners and the ULS II in the RR corner. Yes, the measurements used are with the HSU EQ2 switch position, it is supposed to emphasize mid-bass response and I tried it because of the "suckout". I did measure with the other EQ position and will rerun configs accordingly. Is there a way to swap sub measurement in an existing Baseline?

- you can clearly see that the HSU sub has different group delay below around 50Hz or so as the black dotted phase line is much shallower in slope than the blue and red ones in the baseline phase plots. This means that the HSU has lower group delay than the SVS subs and definitely you can see improvement with AP filters so good to keep them in your optimizations

Got it!

 

[PCSguy]

- I found that if you try to optimize the SPL penalty between 10 and 180-200Hz, MSO still struggles to find a great solution for SPL penalty between 45 and 85Hz (see second plot below with separation on blue and green lines)
- if you reduce the upper limit to 120Hz, you can materially improve the SPL penalty for the cost of a small peak in the Position 2 location at around 85Hz - if it's just you who cares about the sounds quality, I would try this option and see if it is any better

Ok, I changed to max freq. to 120Hz and I don't see much improvement in the max spl. and minor improvement the multi -opt run below 120Hz vs. 180hz.

 

[DaveBoswell]

Ok, I changed to max freq. to 120Hz and I don't see much improvement in the max spl. and minor improvement the multi -opt run below 120Hz vs. 180hz.

View attachment 427937

View attachment 427938

View attachment 427940

Yes - I meant Config 3, not Config 2.

Looks like you changed the "Frequency range to optimize response" limit to 120Hz instead of the "Frequency range to optimize SPL" in your post above hence the only very small improvement - your settings should look something like this:

And the dialog for comparing multiple optimizations is here (right click):

 

[PCSguy]

Yes - I meant Config 3, not Config 2.

Looks like you changed the "Frequency range to optimize response" limit to 120Hz instead of the "Frequency range to optimize SPL" in your post above hence the only very small improvement - your settings should look something like this:
View attachment 428085
And the dialog for comparing multiple optimizations is here (right click):
View attachment 428087

I checked the options again and the correct field was changed. Is there something else that I needed to change?

My choices for the performance metrics are different.

 

[DaveBoswell]

I checked the options again and the correct field was changed. Is there something else that I needed to change?

View attachment 428114

My choices for the performance metrics are different.

View attachment 428121

Check your version of MSO - should be version 2.1.5 as the latest - looks like andy made a few changes to the menus for the performance metrics.

Also double check your Frequency Range to Optimize SPL/Response on all your new runs - this chart below you posted a few posts back shows that you had changed the FR Response upper limit to 120Hz (as can be seen by the dark red Target line ending at 120Hz) - that's why I had thought you had potentially mixed them up.

 

[PCSguy]

Check your version of MSO - should be version 2.1.5 as the latest - looks like andy made a few changes to the menus for the performance metrics.

Also double check your Frequency Range to Optimize SPL/Response on all your new runs - this chart below you posted a few posts back shows that you had changed the FR Response upper limit to 120Hz (as can be seen by the dark red Target line ending at 120Hz) - that's why I had thought you had potentially mixed them up.
View attachment 428517

I updated to the latest version and ran another set of configurations with 3 positions.

Performance metrics from the previous 2 position run.

I have loaded configs 3 and 5 from the 3-position run and config 3 from the 2-position run into my minidsp. Config 5 of the 3-position run sounds the best to me. It's also the run with the best STSV. I don't know why 3-position STSV for configs 3 and 7 are so high. Any idea?

 

[meeseeks]

You work around this lack of miniDSP input biquads in MSO by first enabling the crossover biquads as shown in the image of the previous post. Then you tell MSO that the number of input biquads per that image is zero. MSO then implements the shared sub filters as filters that are replicated in each separate miniDSP sub channel. Some or all of these will end up in the crossover biquads. When you do this, the number of shared PEQs plus per-sub PEQs must add up to a maximum of 18 (8 in the crossover biquads, 10 in in the output biquads).

I wanted to ask more specifically about this, as there wasn't much discussion thereafter. I've got two subs/mains I'm looking to integration with my miniDSP SHD. As far as I can tell, there's also no input biquad support on this model either, referencing their signal flow. Their dual-sub integration app note shows configuring MSO otherwise, but I'm assuming this was for MSO v1 / custom filter integration that didn't make use of the shared filters or the new Multi-Stage Optimization.

It does seem that the device supports eight crossover biquads, so I think your guidance above might be applicable for me. Otherwise, correct me if I'm wrong, the shared biquads could be placed as output biquads, albeit limiting the total number of input and output biquads to 10. Considering my device's input biquad limitation, would it be wise to perform a Subs+Mains measurement, and handle the LPF/HPF as shared (crossover) biquads, as opposed to a Sub only measurement and handling the crossovers directly within the miniDSP Device Console?

I attempted a quick configuration last night following their app note and finishing with Dirac, but wasn't completely satisfied. Planning to digest more capabilities and process before I give it another go. Also, @DaveBoswell , thank you very much for your recent video; truly insightful!

 

[andyc56]

I wanted to ask more specifically about this, as there wasn't much discussion thereafter. I've got two subs/mains I'm looking to integration with my miniDSP SHD. As far as I can tell, there's also no input biquad support on this model either, referencing their signal flow.

Yes, that's right, so you'll need to emulate input biquads using the MSO biquad export feature that turns the input biquads into identical biquads in the sub output or crossover channels. To activate that feature, go to Tools->Application Options, and in the Hardware category, choose 0 for "Input (shared) biquad limit", and also choose "Use miniDSP crossover biquads if output biquad limit exceeded".

Their dual-sub integration app note shows configuring MSO otherwise, but I'm assuming this was for MSO v1 / custom filter integration that didn't make use of the shared filters or the new Multi-Stage Optimization.

That app note was for MSO v1, before the export was changed in v2 to allow shared MSO filters when there are no input filters in the device.

It does seem that the device supports eight crossover biquads, so I think your guidance above might be applicable for me.

Yes. In the absence of an actual crossover, this would allow the sum of the MSO shared and output sub PEQs (or all-pass filters) to be up to 18 (8 crossover + 10 output). In your case, you'll likely use an LR4 crossover. An LR4 LPF will use up 2 biquads, so you'd have 16 combined MSO shared and output PEQ/APF available (10 output + 8 crossover - 2 for the LR4 LPF).

Otherwise, correct me if I'm wrong, the shared biquads could be placed as output biquads, albeit limiting the total number of input and output biquads to 10.

See above.

Considering my device's input biquad limitation, would it be wise to perform a Subs+Mains measurement, and handle the LPF/HPF as shared (crossover) biquads, as opposed to a Sub only measurement and handling the crossovers directly within the miniDSP Device Console?

The multi-stage optimization can only be done with sub-only configurations. You'd want to do that first, limiting the combined MSO shared and output PEQ/APF to 16.

After this, create a new subs+mains configuration using the wizard. Delete all its shared and output sub filters. Then for each of the shared and output channels of the original configuration, select their yellow channel folder node in the Config View and choose "Copy all filters of this channel". Then you can go to the corresponding channel of the new subs+mains configuration, right-click and choose "Paste filters". Doing this for shared sub and each of the two sub output channels of the original configuration will replicate the filters found in the sub-only multi-stage optimization for use in the subs+mains configuration. Be careful not to swap the individual-channel subwoofer filters.

Once you've done this, you want to preserve those filter values, so go to the "Subwoofer Channels" node of the new subs+mains config, right-click and choose "Lock all sub filter parameters".

After doing that, add a shared sub delay block to the new subs+mains configuration, allowing it to have both positive and negative values. If it ends up negative, that means you add the negative of that (a positive delay) to both main speaker channels. Then add an LR4 LPF to the shared sub channel of the subs+mains configuration, and an LR4 HPF to the shared mains channel. You'll want to lock the parameters of these to the chosen crossover frequency by right-clicking on them and choosing "Lock Filter Parameters".

I attempted a quick configuration last night following their app note and finishing with Dirac, but wasn't completely satisfied. Planning to digest more capabilities and process before I give it another go.

There's a compatibility problem with Dirac and bass management as implemented in the SHD device. This is due to them performing Dirac before the L and R are summed to form the mono bass management signal. I discussed that in detail here.

 

[meeseeks]

Wow, truly appreciate the prompt and thorough response. Excited to play around more with MSO; what a great piece of software.

There's a compatibility problem with Dirac and bass management as implemented in the SHD device. This is due to them performing Dirac before the L and R are summed to form the mono bass management signal. I discussed that in detail here.

Bummer. Well, sorry for being late to the party- I guess bypassing Dirac and working with MSO and REW instead, might be in order.

 

[sveinse]

I've been using MSO since 2022 and are really happy with it. I have a 4 sub setup using MiniDSP DDRC-88A. I am about to do a reconfiguration as I'm excited to learn what 2.2 brings of improvements to the sound. I have one sub that have been loaded heavier than the other from MSO1 and my room layout have changed a bit so I'm looking forward to this.

I see from the docs that having a DSP that provides shared PEQ is beneficial. How beneficial is it really? - The DDRC-88A does not seem to have support for a common input PEQ. Is having a common PEQ so useful that its worth doing an extra loop through the DSP? AVR LFE -> IN CH8 -> PEQ -> OUT CH8 -> IN CH3 -> MATRIX+PEQ -> MANY OUTS -> SUBS. I know this sacrifices both audio quality and latency. I haven't measured the latency of the DDRC so I don't know if it would be a showstopper.

 

[andyc56]

I see from the docs that having a DSP that provides shared PEQ is beneficial. How beneficial is it really?

The multi-stage optimization and conventional EQ of flattening just the MLP (both new to MSO v2) are disabled unless there are 4 MSO shared sub PEQs or more. This might make it seem that you are out of luck if your miniDSP device, such as the DDRC-88A, doesn't have a common input PEQ channel as you mention. However, there is an MSO feature that emulates such shared input filters by replicating the shared MSO filters on the output side of the device in the biquad export. This makes use of the Equivalence of Input Filters and Replicated Output Filters relationship described in the docs.

The DDRC-88A does not seem to have support for a common input PEQ. Is having a common PEQ so useful that its worth doing an extra loop through the DSP? AVR LFE -> IN CH8 -> PEQ -> OUT CH8 -> IN CH3 -> MATRIX+PEQ -> MANY OUTS -> SUBS. I know this sacrifices both audio quality and latency. I haven't measured the latency of the DDRC so I don't know if it would be a showstopper.

To enable the use of replicated sub output biquads as the equivalent of shared sub input biquads for your device in MSO, do the following steps:

• In Tools->Application Options->Hardware, set "Input (shared) biquad limit" to 0.
• In Tools->Application Options->Hardware, make sure "Use miniDSP crossover biquads if output biquad limit exceeded" is checked

The first step tells MSO that your device has no input biquads, and the second will cause it to export crossover biquad files in addition to the output-channel biquad files. The biquads in the MSO shared sub channel are converted to replicated output biquads automatically during export. The crossover biquad files have the same name as the corresponding output-channel biquad files, but with "_xo" appended to the name. You load them in a slightly different way in the miniDSP software. The details of this are device-specific and depend on whether you're using the original "plug-in" software or the new Device Console.

Each PEQ and each all-pass filter ("APF", used for SPL maximization) maps to 1 biquad. In your case, the DDRC-88A supports 8 crossover biquads and 10 output biquads. This means you can use any combination of MSO shared PEQs and output PEQs/APF that add up to 18. A typical way to start might be 9 shared PEQs and 9 output PEQs/APFs.

I discuss this more in post 129 above, and in the series of posts elsewhere beginning here. Those latter posts may seem a bit confusing at first, because they deal with software called "BEQ" that does movie-specific equalization and uses up all the input-channel biquads of devices that have them. But it's the same concept in MSO when you're not using BEQ and you device doesn't support input biquads at all.

 

[sveinse]

To enable the use of replicated sub output biquads as the equivalent of shared sub input biquads for your device in MSO, do the following steps:

• In Tools->Application Options->Hardware, set "Input (shared) biquad limit" to 0.
• In Tools->Application Options->Hardware, make sure "Use miniDSP crossover biquads if output biquad limit exceeded" is checked

The first step tells MSO that your device has no input biquads, and the second will cause it to export crossover biquad files in addition to the output-channel biquad files. The biquads in the MSO shared sub channel are converted to replicated output biquads automatically during export. The crossover biquad files have the same name as the corresponding output-channel biquad files, but with "_xo" appended to the name. You load them in a slightly different way in the miniDSP software. The details of this are device-specific and depend on whether you're using the original "plug-in" software or the new Device Console.

Thanks. The DDRC use the old "plug-in", as it have no network. I've considered writing a Python script and reverse engineer the minidsp xml settings format to upload all the generated MSO biquads in one go.

Each PEQ and each all-pass filter ("APF", used for SPL maximization) maps to 1 biquad. In your case, the DDRC-88A supports 8 crossover biquads and 10 output biquads. This means you can use any combination of MSO shared PEQs and output PEQs/APF that add up to 18. A typical way to start might be 9 shared PEQs and 9 output PEQs/APFs.

In addition the DDRC have 2 biquads per input channel for HPF pre dirac, which I think can be used unless the xover is used. I'm hearing that this should probably be enough and that a creative HW loopback to make an additional pass of the LFE input is not really needed.

This reminds me of another topic I've been contemplating:
I have a Yamaha AVR where the LFE xover is not very steep (and if I'm not misremembering, different order on LPF and the HPF). Would it be an advantage to run the LCR as large and let the DDRC run the xover, e.g. use something steep like LR4 and mix it with the dedicated LFE channel? Does this make a better correction result when using MSO?

Out of pure curiosity since the DDRC88A is not perfect: What is considered the most optimal HW for running MSO with sufficient number of input and output biquads these days? I have a 4 sub setup.

 

[andyc56]

Thanks. The DDRC use the old "plug-in", as it have no network. I've considered writing a Python script and reverse engineer the minidsp xml settings format to upload all the generated MSO biquads in one go.

This is out of my area and I don't know if this would be of any help, but some of the BEQ tools use minidsp-rs.

In addition the DDRC have 2 biquads per input channel for HPF pre dirac, which I think can be used unless the xover is used.

I didn't realize before that these biquads are made available in "Advanced Mode", but the documentation says they are.

I'm hearing that this should probably be enough and that a creative HW loopback to make an additional pass of the LFE input is not really needed.

This reminds me of another topic I've been contemplating:
I have a Yamaha AVR where the LFE xover is not very steep (and if I'm not misremembering, different order on LPF and the HPF). Would it be an advantage to run the LCR as large and let the DDRC run the xover, e.g. use something steep like LR4 and mix it with the dedicated LFE channel? Does this make a better correction result when using MSO?

I guess that would depend on the AVR. If you were to do all the bass management in the DDRC-88A/BM I would think that just knowing what you have in the LPF and HPF of the crossover and being able to control it would be an advantage.

Out of pure curiosity since the DDRC88A is not perfect: What is considered the most optimal HW for running MSO with sufficient number of input and output biquads these days? I have a 4 sub setup.

For 7.1 applications having multiple subs, my guess would be one of the balanced ("Flex") multi-channel miniDSP devices, but using only a single output of it for the subs. That would go into a balanced "Flex" 2x4, allowing input biquads to be used. That would unfortunately give a double A/D->D/A stage, but at least it would only be for the subs.

Also, be aware that SPL maximization only works in MSO for sub-only configurations, so if you're using it to integrate subs and mains, that would unfortunately be a two-stage process. Over the years, usage of subs+mains configurations has dwindled to almost nothing, so there has been almost no development in that area.

BTW, version 2.2.1 just came out this morning. It is a bug fix for an occasional failure of the Multiple-Configuration Metrics dialog to launch.

 

[Pieter1267]

This is out of my area and I don't know if this would be of any help, but some of the BEQ tools use minidsp-rs.



I didn't realize before that these biquads are made available in "Advanced Mode", but the documentation says they are.



I guess that would depend on the AVR. If you were to do all the bass management in the DDRC-88A/BM I would think that just knowing what you have in the LPF and HPF of the crossover and being able to control it would be an advantage.



For 7.1 applications having multiple subs, my guess would be one of the balanced ("Flex") multi-channel miniDSP devices, but using only a single output of it for the subs. That would go into a balanced "Flex" 2x4, allowing input biquads to be used. That would unfortunately give a double A/D->D/A stage, but at least it would only be for the subs.

Also, be aware that SPL maximization only works in MSO for sub-only configurations, so if you're using it to integrate subs and mains, that would unfortunately be a two-stage process. Over the years, usage of subs+mains configurations has dwindled to almost nothing, so there has been almost no development in that area.

BTW, version 2.2.1 just came out this morning. It is a bug fix for an occasional failure of the Multiple-Configuration Metrics dialog to launch.

After 2 weeks of diving into REW with mixing results, mainly to fix XO problems wich I know seem to have found some solutions (not least because of the fantastic depth of knowledge of @Keith_W) I decided to follow the MiniDSP website help for a 2.2 setup with MS and immediatly came into problems because they are using the v1.0 iterations and the mains plus subs solution? They also seem to advise settings that is the previous MSO iteration.

Either way, the mains + subs I somehow managed to get a few MSO solutions , one or two actually sound okay but my main problem with MSO is working out the various graphs. If I had one wish for the next MSO upgrade is a further simplifying of that interface. A Graphics Settings Wizzard perhaps? And make the graph/config buttons left below bigger and or different colours. I almost looked over them. EDIT: scratch that. Ive now read about 85% of the MSO User guide. Much respect for @andyc56 . The weeks, months put into just writing that super extensive guide is a work of art.

 

[Keith_W]

Hey @andyc56 any chance you could add an option to MSO so that we can export linear phase filters in .WAV or .TXT format?

 

[andyc56]

Hey @andyc56 any chance you could add an option to MSO so that we can export linear phase filters in .WAV or .TXT format?

MSO doesn't use FIR filters at all, linear phase or otherwise. So exporting them from MSO doesn't make any sense. If you mean exporting from some other software to import into MSO, then that's not going to happen either. MSO will never support FIR filters.

 

[Pieter1267]

Scratch everything ive said before. After 2 good weeks

-Dumped the subs+mains config. Too difficult to get right;
-Subs only gives much more playroom;
-I think ive trawled through 2000 posts on various forums. The step to v2.0 made a lot of older experiments not necessary. Ive re read the user guide 2 or 3 times. Still a lot to reread again as its so technical. Fascinating.

Im quite at home throughout the interface. Delays, gain blocks, peq input and output set. AP too. I had an error on one of the subs lower frequencies. Turns out UMIK1 doesnt like below 30-20hz. Below it gets worse. REW needs a reset every few hours. Minidsp doesnt like being in 2x4hd plugin.

If there is one major thing i learned is: keep the measurements correct and clean. Thats 50% of making it work.
I wanted to make a new one with bigger spl but messed it up. In the end i think 80-85db spl measurement is good enough to make it work.

 

[Pieter1267]

Ok, finally happy with setup. Things I learned for a 2 channel setup with 2 (passive) subwoofers and 2 main speakers, using MSO in the ''subs only'' mode.

I contemplated and experimented with the "subs and mains" mode but it had up and downsides. For instance the multi run option is not available, wich makes MSO V2.0 such an outstanding kit. Marrying the mains later is no problem and as long as you dont adjust gain and or especially delay, its no big deal. I found adding an All Pass filter to one or both mains was enough to cure any null.

Before going into MSO
- Start by levelling to subs and mains as much as possible, and only then make the measurements for MSO - level both channels and L+R input mono per sub, not stereo as MSO doesnt work for stereo;
- Then make sure you test the subs with only L or R input per sub, as this is how you will do the MSO measurements;
- Measurements is 50% of the work. Make sure to test fixed position and MMM techniques and analyse the results, different SPL's and analyseagain. Look at waterfall and if higher SPL measurements differ from lower;
- Its very, VERY important to recognise what is room influence and what isnt. Do you have the same problem at various measuring positions, or is it just at this or that position? Make a note of wich null or bump is to be left alone;
- Make sure there is at least a 40db difference with floor noise. When you finally happy and familiar with how your un-optimised channels perform, turn on acoustic reference and make the MSO measurements;
- Make sure and then make sure again the output matrix is correctly configured for the acoustic timing MUST HAVE. You have no idea how many hours i lost by making mistakes with importing the wrong measurements into MSO;

Into MSO
Some basic MSO graph settings advised by @DaveBoswell but might as well put it here when you have no time to watch his (fantastic) MSO V2.0 tutorial on youtube

Graphic settings
Axis assigments:
Left axis - Magnitude, Right Axis - Phase
Axis Parameters:
Limits for left Y axis: keep 60 db between up and down.
Limits for right Y axis: min value -360 max value 1800. deg/div: 180

In MSO Application settings make sure you choose the correct sample rate for your DSP.
Change PEQ settings to: max Q 9.0(8.6 is Dave's advice).
Max - db cut to: -15.
Change delay to 0 and 10 (instead of -10).
Change gain to max -5 and 5.
Change All Pass 2nd order max allowable Q to min 0.1 and max 0.6.

Some other usefull personal preferences in his video.

- Subs only config its better to implement an LPF in MSO than later in MiniDSP for instance;
- Every little boost added made it worse to only cut configs;
- Test with different reference SPL's;
- In addition: test where you make the cut low and high, wich window you want optimised. Sometimes its better to set lower limit at 30hz instead of 15hz for instance;
- Try to keep the output PEQs to about 4 or 5 per channel;
- After finalising and exporting still gives problems around the XO region, use REW to investigate wich main is giving problems with phase, then insert one or two All Pass second order filters with max Q of 0.7 AWAY from the XO frequency - put it 20hz lower or high but NOT on top of the XO;
- It helps to create 2 or 3 end result-configs, for instance with 3 different reference SPL's and see how that works in the DSP and the REW final measurements.


Note: the UMIK 1 has deficienies below 20hz. I suspect its not even that good below 30hz. Its very good for general use but remember its limitations.
Also: read as much as possible on the MSO threads at AVSforums and the MSO User Guide at creator @andyc56

https://www.andyc.diy-audio-engineering.org/mso/html/

https://www.avsforum.com/threads/op...-sub-optimizer.2103074/page-168#post-61897597

Another note: MSO was originally built for AVR use, equipment with one subwoofer output. Please note that most help at the AVS forum runs on such use, having 4 subs home theater setups and not 2 channel configs like we use a lot on this forum. Keep this also in mind when watching these great tutorials on youtube.



https://www.youtube.com/@jeffmery


For reference on my setup

Quad 34 pre amp (fed analogue sources) left and Right
into MiniDSP DDRC-24** (downgraded to 2x4HD to use MSO input filters)
output 1 (left) and 2 (right): Quad 606mki to main speakers (Revel F208)
output 3 (left and right) and 4 (left and right): Behringer inuke 6000D (in stereo mode*, all dsp turned off)
MSO config with 90hz LPF LR4 24dB filter, both in MiniDSP input and output 3 and 4
Mains output 3 and 4 has MiniDSP XO HPF filter at 100hz, 24dB LR4 (because F208 is front ported, sounds better unplugged)
2 Dayton Ultimax UMii 15" in DIY sealed 85 liter cabinets.

UMIK1
REW
MSO V2.0

*I can put the behringer in dual mono but it doesnt make any difference.

** The MiniDSp when you use the USB cable into the PC to work the plugin, it can put some unwanted extra distortion and funny noises when you move the mouse. I bought a simple €1 USB isolator and that fixed everything. For Dirac setup it needs the USB cable. Without, you can also use the MiniDSP Wifi dongle. (I use that now since the amps and MiniDSP are a few meters away from the PC and my desk). At the moment I see no added function for Dirac. I dont want the expensive F208 to lose their character and even when tried, I just could never make it work and it also made REW measurements worse.

A very last note: MSO is a very nice very complex program where you can lose yourself for hours, days, weeks with manipulating the tiniest detail. For me as nerd, I love it. When you are not, I hope the above helps to figure stuff out quicker. You dont need to spend weeks like me for basic upgrade results. In fact in a few days I already had good optimisation. I just like to know each tiny detail. Do respect it requires some study. If you figured out REW to a reasonable degree then youll figure out MSO too. Again, the end result is much better than any other correction program. Imo.

 

[Omartian]

hi guys. just watched the 2.0 video and i still have a noticeable dip at about 66hz. right now, I'm using a mini-dsp 2x4hd and for my shared filters, i have 10 peq's. For my per sub filters, i have 2xall pass second order filters, and 8 peq filters w/the settings recommended by the 2.0 video.

Is this just something i'll have to deal with or is there a way to eq it out for my mlp?