X4 Bass Behavior — Significant Difference Between Sofa and Staircase Position

ertorque

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Hi all,
I’m running the X4 in my living room and I’ve encountered a very interesting bass behavior that I’m hoping to get some insight on.
I’ll attach a diagram of my living room layout (not to scale), but I’ll try to describe the key points here.

🏠 Room and layout
Room is approximately 24 ft (length) × 21.5 ft (width), opens up to the dining hall
Ceiling is ~10.5 ft for most of the room, but opens to double-height near the staircase at the rear (the last 6 ft of the 24 ft boundary)
Speakers are:
~3 ft from front wall
~2.5 ft from left side wall
~6.5 ft apart

🧱 Left side boundary
The main left boundary runs the full 24 ft length and consists of:
Solid wall (front section)
~8 ft sliding glass door
Short solid wall section
Wooden door
Short solid wall near the rear
In addition, there is a 6 ft solid staircase wall, positioned about 4.5 ft inward from the main left wall, running parallel to it near the rear of the room.

🎧 Listening positions
Main sofa (normal listening) which is situated from a varying 9 to 11 feet from front of speakers:
Bass is weak making the sound more pronounced on the mid/highs and hence missing out on balance.

When listening from the staircase position (so basically sitting on one of the steps of the staircase), the sound changes significantly to one that is pleasing; bass suddenly appears. It sounds fuller/stronger, more natural and well-balanced. I now finally understand what the fuss about OB bass is.
This position is about 3 ft from rear wall
Very close to the 6 ft staircase wall on the left
Right side opens toward the staircase / upper floor (no close boundary)
Ear level would be around 12 inches elevated compared to sitting on sofa.

The staircase position appears to benefit from:
Very close proximity to a solid side boundary (left)
Some rear wall reinforcement (~3 ft)
Ceiling opening
Overall asymmetrical boundary condition

Even when the sofa is pushed back to the max (where the stairs begin, about 6ft from the rear wall), the bass is till missing. When you descend from that heavenly staircase position, the bass simply weakens.

❓ Questions

Would it be fair to say that this staircase location represents a locally optimal pressure zone (reduced cancellation / better modal balance)?
Clearly, listening to the system from the staircase isn't exactly practical, therefore would incorporating a subwoofer helps when listening from the sofa ?

I’m not chasing more bass quantity per se — I’m trying to understand how to reproduce the quality and balance of bass I hear at that staircase location at the main listening seat.

Appreciate any thoughts, especially from others running OB in non-ideal or irregular living spaces.
Thanks in advance!






« Last Edit: 23 May 2026, 05:19 pm by ertorque »

veloceleste

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I also have quite an irregular shaped room and experienced bass cancellation/reinforcement issues. Can you center the system and listening position more along the front wall? That will help with first reflections and may balance out some bass issues. If you can do that, next I would again experiment with speaker placement and listening position. Play some music with a nice bass line, on repeat if possible, and walk the room focusing on bass response in different areas of the room to hear where the bass sounds best.
If you are happy with the quantity of the bass you have now, subs may or may not help. Bass traps may also help.

Early B.

Can you center the system and listening position more along the front wall?
That was my first thought, as well. Also, consider placing the speakers catecorner, on the right side, if possible. Oh, and you'll certainly benefit from multiple subs, but not yet.

Tone Depth

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I'm wondering if you're getting bass resonance at the stairway.

In my family room, I have a vertical entertainment center for my audio equipment angled diagonally across the corner of the room. The lower part of the cabinet is enclosed, and the upper part is open both front and back. I've noticed prominent bass in the space behind the cabinet when I've stuck my head back there, as compared with the rest of the room. I think in my room, that empty space is concentrating those lower frequencies, maybe like a bass trap.

Could you be getting a similar result?

ertorque

  • Jr. Member
  • Posts: 6
That was my first thought, as well. Also, consider placing the speakers catecorner, on the right side, if possible. Oh, and you'll certainly benefit from multiple subs, but not yet.

Alas, it is not possible to move the speakers further to the right as that space is occupied by a long cabinet. There is also a tall bookcase along the right wall, though neither item is shown in the layout.

I have tried moving the speakers about a foot further from the front wall and also experimented with sofa positioning, but I still have not been able to replicate the kind of bass I hear from the staircase position. The stronger bass there makes the overall presentation sound more balanced, whereas from the sofa I sometimes feel the mids and highs slightly overpower the lows.

When I say the bass is weak, I only mean relative to what I hear from the staircase. Having said that, OB bass still sounds more natural to me despite lacking some of the "heaviness" many box speakers exhibit (we OB lovers already know that, don't we? 🙂).

A friend has loaned me a REL T9i, and I am currently waiting for some connectors before setting it up. I’m curious to hear what changes once the REL is up and running and whether the REL helps fill in the missing weight , yet maintaining the "natural" bass at the sofa position

ertorque

  • Jr. Member
  • Posts: 6
I'm wondering if you're getting bass resonance at the stairway.

In my family room, I have a vertical entertainment center for my audio equipment angled diagonally across the corner of the room. The lower part of the cabinet is enclosed, and the upper part is open both front and back. I've noticed prominent bass in the space behind the cabinet when I've stuck my head back there, as compared with the rest of the room. I think in my room, that empty space is concentrating those lower frequencies, maybe like a bass trap.

Could you be getting a similar result?

I believe so. Not sure if the spot is a bass trap but I think that is where the low frequencies has greater amplitude compared to at sofa, thanks to room acoustics. I am not complaining though as the sound of the X4 when listened from that position is marvellous, at least to my ears!

AllanS

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Tools are geared towards symmetric spaces, which few of us are fortunate enough to occupy, but they can provide some insight. I like the visual offered by the hunecke.de Room Eigenmodes Calculator which may help understand the/a problem in your space.

https://www.hunecke.de/en/calculators/room-eigenmodes.html

The given dimensions are meant to estimate your room.  Assuming your sofa is in the middle of the space and recognizing the model doesn't accurately model your space, your listening position appears to be in a null-ish position for most frequencies.

The rule of thirds might help some but I'm thinking sub crawl.  Place a sub in the listening position and crawl the room till you find a position(s) that sounds the best.  In a perfect world you could place subs in those positions to fill the nulls.



In my case I gave up on fighting the room and settled on near a field-ish set up and headphones.

WGH

I'm not surprised at the lack of bass at your seat, you are sitting exactly in the center of a null. The Harman Room Mode Calculator is not designed for open baffle speakers so it is a rough estimate of what you are hearing. You are getting some reflected bass at your seat so it's not all bad. Bass is a wave and you are sitting at the bottom of the wave.

Place the REL sub in a corner, it's designed for corner placement. Move the sub toward and away from the corner until bass is perfect. REL has instructions and setup videos on their website:
https://rel.net/


Take your time and study the chart, it will eventually make sense what is happening




The Harman Room Mode Calculator if fun. The download link is at at the bottom of the first post:
https://www.audiocircle.com/index.php?topic=58304.0

If you don't have a spreadsheet program, use the free Libre Office:
https://www.libreoffice.org/

Cloud.sessions

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Pull your speakers out into your room a bit more. Even 1 more foot can be a big difference for bass quality in OB. Try 4 ft from the front wall and also try 5 ft even if they can’t stay out that far long term. It can give you a good gauge for what to expect.

I agree with the others about your listening position. Try to stay out of the middle of your room for the listening position.