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Bass: Bass-systems, subwoofers, how-to, what is it, how does it work.

I have a lot of text and information on bass and subwoofers and bass-systems. This content is not organized, it is difficult to find information you may be looking for, and it is spread around in both articles/documents and threads in this forum.

I will now try to organize this by posting links to this content in this thread.

Much of the content is available in norwegian language only. Some may have a browser with built-in translation. I will post google translation links, so everyone can access the content. While this auto translation is far from perfect, it has become good enough to make it possible to understand the text.

Bass and sound quality - discussion and examples

We start here, with this sort of discussion-summary of an article on bass-systems and calibration:


This is the article on bass and calibration:


This link provides a page where you can browse all articles with bass and bass-systems related content:


Most of this is very technical, and it may not be obvious what each article covers. I may try to add some simplified information in this thread, to make the content more easily accessible.

This is what you need to get great bass:

  • Bass-system with decent subwoofers and enough capacity for intended use
  • Calibration of bass-system done properly
  • Integration with good main speakers done properly

We will look into each part, and see how it is done. A bit more complicated than to just buy a subwoofer and put it in the corner, but still manageable.

For the easiest solution, a complete system solution has everything necessary, all necessary sound processing is built-in, and much of the calibration is already completed out-of-the-box:



Subwoofers and the bass-system

The bass-system must have enough output capacity and low frequency extension to meet requirements for its intended use. The quality of the subwoofer units is important for sound quality, and the sound character of the bass.

Compact Horn Subwoofers thread:


About subwoofer specifications:


About horn bass:




Requirements: Capacity and frequency range

  • 100-105dB, 30Hz for normal reduced volume level listening
  • 110-115dB at least, full <20Hz extension, for music at full/live playback level
  • 125dB, 15Hz for movies

This is measured at the listening position.

The articles on sub-bass gives some insight into how this works, and why those numbers are representative for requirements for bass-systems.

Part 1 is about sub-bass in general and perception:


Part2 is about sub-bass content in movies and music, and goes more into detail on requirements:


Capacity requirements for music, in general, for the complete system:




Bass frequencies are influenced by reflections inside the boundaries of the room, which results in frequency response deviations and resonances. This can be fixed. The bass-system has signal processing that allows for equalization, where filters are implemented with help from acoustic measurements.

It may not be possible to achieve a perfect result, but fortunately that is not necessary. When the response is shaped reasonably smooth and according to a chosen target and all resonances are removed, bass sound quality will be good.

Having a bass-system with subwoofers placed close to boundaries like floor and wall, helps a lot.

Fixing the room for low frequencies usually is not a viable option, even for dedicated rooms, because the dimensions of the acoustic absorption needed will simply be too large. Using EQ to fix this instead, is a practical solution that works very well, is quick and relatively easy to do, at low cost.

Relevant articles:



Also see the articles linked to in port #1.


The integration part requires signal processing on both main speakers and the bass-system. For those interested in the tech, links to articles already posted in this thread provides that. This is a solved problem, and the result WHEN DONE PROPERLY will always result in perfect integration where there is no overlap or missing parts of the frequency range, and timing is not compromised. In fact, using the technique with asymmetric slopes for filters and proper time delay on the mains, a prefect flat group-delay and phase response can be achieved.

Now the bass-system is calibrated and integrated, and the bass is solved. With no need for excessive acoustic treatment that would never be viable to implement in a normal room.

More about capacity:

V110 is 5x larger in size compared to T6. If size is proportional to capacity, the V110 should then provide more than +12dB output capacity. And indeed, the numbers are quite close. So how is the rationality behind this, if the T6 is enough, what is the purpose of something like the V110.

It all depends on use. How loud, what content, how large is the room.

A bass-system with 2x T6 is always plenty if volume is always low, say -30dB. In any reasonable room. With any possible content. Even -20dB, a level a bit louder than casual conversation, is still good. On most content, in most rooms, even -10dB works fine. Turn it up to 0dB, and it depends, how the system is tuned, the room, if program material is bass heavy.

The T6 works, in a very small cabinet size, because it has limited extension down to around 30Hz. Limiting bandwidth gives more output capacity. And that works very well for all but loud volumes, because due to how hearing and perception of bass works, it is not necessary to reproduce the very lowest frequencies.

When louder volume is requested, it is necessary to increase bandwidth to include bass down to below 20Hz, and this requires a larger cabinet size for same output capacity. So louder means larger size to increase both bandwidth and capacity. This is why it is pointless to install a subwoofer with slightly more output, you need much more, to make a meaningful difference.

Louder, more powerful and deeper bass, means a much larger bass-system. Not twice the size, more like 4x, to make a real difference.