Has anyone here set up a system with tiered subwoofers handling different bass spectrums?


Has anyone here set up a system with tiered subwoofers handling different bass spectrums? I currently have bookshelf speakers fully crossed over to a pair of smallish symmetrically placed, force-canceling stereo subwoofers at 160Hz, and I am thinking about adding a big, ported sub and fully crossing that over to the stereo ones at 60Hz. My setup will easily allow me to do it (I have a miniDSP Flex that is applying DIRAC Live room correction to my current 2.2 setup downstream and that preamp is handling the full bass management duties right now, so the miniDSP only sees a pure 2.0 system at the moment--I can just attach the new sub to the second pair of outputs and use the miniDSP to handle this level of the bass management). Am wondering if anyone else has tried this? I am looking to improve bottom end impact and extension with the big ported woofer (looking at SVS PC-2000 Pro) since the stereo ones are not currently reaching down as low as my previous sub (currently a pair of SVS 3000 Micros; before these, I had a single SVS SB-3000).

-Ed

eddnog

I think you need to change the oil in the car before going for the expensive engine upgrade.

I don’t know why in the world your subs are crossed all the way up at 160hz.  Any bookshelf speaker worth keeping shouldn’t need this.  Your best path forward should be to get the crossover point as low as possible.  This will likely be repositioning your speakers.  Even a couple of inches can make huge differences.

KEF LS50 Metas. They have rising distortion under 200Hz at higher playback levels.

-Ed

eddnog

... bookshelf speakers fully crossed over to a pair of smallish symmetrically placed, force-canceling stereo subwoofers at 160Hz ...

That's a very high crossover frequency and almost guaranteed to muddy up your sound. I agree with @rick_n - you'd be much better off lowering that to 100 hZ and experimenting with placement to perhaps improve the LF of the mains.

Lower your crossover point, look at AM Acoustics room mode simulator for guidance on placement and refer to the miniDSP application notes on using multiple subs. 

Let's face some facts. The KEF LS50 don't do bass well. On their own they lack bass extention and begin to distort.  You are compensating for their inability to produce bass and dynamics by pushing the sub into upper bass territory @ 160hz.

IF you had speakers that could properly handle bass down to say 50hz then your subwoofers could be adjusted properly to give a dynamic low end and operate as they were designed.

Bottom line... if you want great bass and dynamics these aren't the right speakers. The subs are fine. No need to buy another one.

These speakers are great for near field, low level listening for classical music. But if your looking for some punchy Jazz tunes or electronic chill music the little drivers in these things can't handle it. 

 

 

 

 

 

 

Here's what Chat GPT said...

Yes, what you're describing is essentially a tiered or hierarchical subwoofer array, and it can absolutely work if implemented thoughtfully—especially since you already have the tools (like a miniDSP Flex and Dirac Live) to manage crossover points and timing alignment properly. You're not alone in exploring this kind of setup, though it's still relatively rare in the home environment due to complexity.

Summary of Your Idea:

  • Stereo subs (SVS 3000 Micros): Currently crossed at 160Hz from your mains, symmetrically placed in a force-canceling configuration.

  • New sub (e.g., SVS PC-2000 Pro): Crossed over to the stereo subs at ~60Hz to handle the deeper stuff (<60Hz).

  • System architecture: miniDSP Flex will apply Dirac Live to the mains and stereo subs as one logical system, while independently managing crossover and EQ to the big ported sub.


Why This Can Work:

  1. Stereo imaging & upper bass clarity:

    • The 3000 Micros near your mains can localize bass more accurately up to 160Hz, maintaining imaging integrity.

    • By keeping them in a higher crossover zone, you're allowing them to handle upper bass where directionality starts to become perceptible.

  2. Deep bass impact:

    • The PC-2000 Pro, with its larger driver and ported design, will fill in the <60Hz range where the Micros fall off.

    • This can yield more tactile slam, weight, and room pressurization without compromising clarity.

  3. You have DSP control:

    • The miniDSP Flex gives you delay and gain control over each output, which is critical for aligning arrival times between subs and mains.

    • Dirac Live can flatten phase and frequency response at the listening position, further optimizing integration.


Considerations & Tips:

  • Timing Alignment:

    • Carefully align the ported sub’s delay with the stereo subs. Group delay in ported designs can cause integration issues if not corrected.

    • Use REW (Room EQ Wizard) with UMIK-1 to measure impulse responses and adjust delay in miniDSP accordingly.

  • Crossover Slope and Type:

    • Consider using steeper slopes (24dB/oct or more) to cleanly separate the responsibilities between sub types.

    • You might want to experiment with Linkwitz-Riley or Butterworth filters depending on how they interact in your space.

  • Phase & Polarity:

    • Check polarity and group delay interactions between the ported sub and the stereo pair.

    • A misaligned phase can result in comb filtering or cancellation around the crossover point.

  • Room Modes:

    • A large ported sub can exacerbate room mode excitation, especially below 40Hz. Placement will matter here. Corners vs mid-wall may yield different outcomes.

    • Dirac Live can help smooth this, but using the ported sub to strategically excite low-frequency nulls may also be useful.


Others’ Experience:

Yes, people have done this in high-end home theater or 2-channel listening setups, particularly:

  • Mastering studios that use a large sub below a smaller nearfield sub setup.

  • DIY audiophiles using multiple subs (e.g., swarm arrays) often tier them by frequency to mitigate room interaction.

They generally report:

  • Improved deep bass feel and cleaner imaging up top.

  • Occasionally some integration challenges, which are solvable with measurement tools and DSP.


Final Thought:

You're on a promising path. You already have the right equipment and understanding to try this successfully. The PC-2000 Pro is a great choice—high output, ported depth, and fits nicely below 60Hz without stepping on the Micros’ strengths. Just be methodical in integration, and you’ll likely get the best of both worlds: tactile deep bass and responsive, musical upper bass.

If you'd like, I can help guide the exact crossover and delay settings once you get the new sub.

Ask ChatGPT

@gdaddy1,

When you take the 'advice' of a chatbot, you should be somewhat skeptical of the response. Mostly because a bot doesn't know everything, just what it has been fed.

Introducing DSP can introduce time and phase issues, using steep slopes, can introduce the same problems.

These issues have been understood by many speaker manufacturers.

Trying to make a bookshelf speaker perform like a tower speaker, by adding subwoofers is unrealistic. You would be better served by buying a speaker that can perform to the standards you are looking for. 

If that isn't in the cards, because of budget. Then just enjoy what you have and save your money. I don't want to p*ss on your dreams, but, speaking as a fellow audiophile with limited means, I think I know what you are trying to do.

I'd be happy to help you with your journey. PM me.

Bob