Help with Subwoofer Integration Using MSO

[MikeP]

Hello everyone,

I'm seeking advice and support for properly integrating subwoofers into a 2.2 system using MSO.

I've linked the relevant REW measurements along with my current MSO configuration. (Cannot directly attach the files due to their size.)
There are three sets of individual measurements for all four speakers, labeled as follows:

• MLP: Main Listening Position
• LLP and RLP: Left and Right of MLP (~60 cm offset to the left and right of MLP, with slight intentional variations in height and depth)

The two subwoofers are labeled:

• SF: Front
• SR: Rear

The MSO configuration is somewhat unconventional. The main speakers are allowed to overlap with the subs in the 40–80 Hz range to increase the number of bass sources in the room, aiming for a smoother overall response up to ~160 Hz. Filters are applied to the main channels as well, which deviates from the more common approach.

All speakers are placed in their best possible positions within the room, though still far from ideal (as verified with REW). DSP is managed via a MiniDSP SHD unit. A limited Dirac calibration may be applied later, once the configuration is fine-tuned.

I’d greatly appreciate any feedback or suggestions you might have!

Thanks in advance,
Mike

Relevant files:

• REW measurements - Link
• MSO configuration - Link

 

[MikeP]

Just checking back in with a couple of clarifications and an open question:

The intentional overlap between mains and subs is actually in the 50–80 Hz range (not 40–80 Hz as I initially wrote). The goal was to increase bass source count and smooth modal response — but I’m wondering if this approach might be causing unexpected phase issues, especially around the crossover points.

I'm now thinking of adjusting the MSO optimization to give more weight to secondary listening positions (LLP & RLP) in addition to MLP, rather than optimizing solely for MLP. Still exploring whether this trade-off helps or complicates things in practice.

If anyone’s had experience with overlapping mains/subs or balancing multiple seat responses in MSO, I’d love to hear how you approached it. Still super open to feedback — thanks!

 

[DaveBoswell]

Suggest you repost this in the main MSO thread at ASR here: https://www.audiosciencereview.com/...imizer-mso-lessons-learned-tips-tricks.39953/

 

[TheZebraKilledDarwin]

Here I never could get the theory work, that the best setting for subs would result in the flattest frequency response even at modal cancellations.
The room with the HT setup has not optimal dimensions for a listening room. I have big modal cancellations @80 and 100.

By following the REW or MSO setups, the goal is to maximize the frequency response flatness: here the bass became indeed more, "fuller" - but something was not sounding right.
I did sweep and steady state measurements and the flattest response sounded off. A kind of fuller bass, but also with flabby, washy, undefined components.

To find out why things were only partially improving, I used sinetones of constant frequency in 5 Hz increments. Also pulsed versions.

It was a surprise to hear how bad the flatter response curve was sounding at these "filled up" frequencies.
Now bass was there, but with a strange feeling in the ears, like anti-phase, a pressure feeling in the ears, sometimes in one ear "first", like a Haas effect. With one sub the bass was just much lower, but not sounding awkwardly.

Once I had tuned my ear how these frequencies were sounding, I listened to music and I knew this was not for me. Once you hear it, you can't unhear it. The cancellation of the bass was sounding better, than that kind of nauseating "bass" components.

Therefore I decided to ignore these approaches that are looking only at the frequency domain and instead used the spectrogram in REW to have a look at the time domain too: using the 2nd sub on the rear wall like a sink to reduce resonances once the first wave from the 1st sub has passed and therefore smoothen the spectrogram's envelope, in a way that it rises more gradually towards lower frequencies with longer standing waves sticking less out. I vastly prefer that kind of shorter, more punchy bass.

 

[levimax]

Here I never could get the theory work, that the best setting for subs would result in the flattest frequency response even at modal cancellations.
The room with the HT setup has not optimal dimensions for a listening room. I have big modal cancellations @80 and 100.

By following the REW or MSO setups, the goal is to maximize the frequency response flatness: here the bass became indeed more, "fuller" - but something was not sounding right.
I did sweep and steady state measurements and the flattest response sounded off. A kind of fuller bass, but also with flabby, washy, undefined components.

To find out why things were only partially improving, I used sinetones of constant frequency in 5 Hz increments. Also pulsed versions.

It was a surprise to hear how bad the flatter response curve was sounding at these "filled up" frequencies.
Now bass was there, but with a strange feeling in the ears, like anti-phase, a pressure feeling in the ears, sometimes in one ear "first", like a Haas effect. With one sub the bass was just much lower, but not sounding awkwardly.

Once I had tuned my ear how these frequencies were sounding, I listened to music and I knew this was not for me. Once you hear it, you can't unhear it. The cancellation of the bass was sounding better, than that kind of nauseating "bass" components.

Therefore I decided to ignore these approaches that are looking only at the frequency domain and instead used the spectrogram in REW to have a look at the time domain too: using the 2nd sub on the rear wall like a sink to reduce resonances once the first wave from the 1st sub has passed and therefore smoothen the spectrogram's envelope, in a way that it rises more gradually towards lower frequencies with longer standing waves sticking less out. I vastly prefer that kind of shorter, more punchy bass.

While multiple subs tend to smooth out measured LF response they also tend to make a mess of the time domain. DBA strategies like you are trying can be effective if you can get them to work. For now I have given up on multiple subs and have 2 co-located subs and am happy with the sound. When DIRAC ART for PC comes out I will give that a try.

 

[dualazmak]

Suggest you repost this in the main MSO thread at ASR here: https://www.audiosciencereview.com/...imizer-mso-lessons-learned-tips-tricks.39953/

I too suggest you repost there.

By the way, even though being independent from MSO, my post here would be of your reference and interest, I assume.
Summary of critical factors in integration of subwoofer(s) and main woofers in our individual acoustic environments