There's a lot more bass in a 6.5" driver than most of you think

Apparently we read different papers from two different universes, each with its own laws of physics. In your universe the definitions of physical states (eg. "steady state") follow circular logic. Let’s leave it there. As a parting note: "room EQ" makes poor systems sound better above Schroeder frequency, in the listening spot, by acting as an ersatz speaker correction technique. It does not improve systems designed properly from the start. That’s how it works in my universe anyway. Toole never really studied distributed bass, he left it to Welti. Geddes had the last word though. He also allowed bass EQ in some circumstances and so do I after him.
www.gedlee.com

Apparently we read different papers from two different universes, each with its own laws of physics. In your universe the definitions of physical states (eg. "steady state") follow circular logic.

@pirad

I’m not feeling very charitable. Did you not understand how Toole used the term? That may explain where your reading went awry. Right up at the top of the paper.

As a parting note: "room EQ" makes poor systems sound better in the listening spot by acting as an ersatz speaker correction technique.

Man, you really can’t read context can you? Like, at all. Toole writes a paper about how hard it is to judge a room response and you claim it proves vaccines cause autism, but later, you claim Toole never said anything.

Toole never really studied distributed bass, he left it to Welti. Geddes had the last word though.

So, you are bringing up Toole as your authority to prove Toole said you can’t fix bass problems .... but he didn’t really study distributed systems, so he couldn’t know, and therefore your use of the paper was to.... blow smoke.

Here, I answered fully this issue in another thread.


I used to work in motion picture equipment industry, including design, installation and set up of some of the best sounding motion picture audio gear in the world. I also make my own loudspeakers and do my own room EQ.

My views are pretty much the same as those posted by JL Audio, though as I posted elsewhere, I disagree with them in some nuanced ways:

https://forum.audiogon.com/discussions/me-vs-jl-audio-an-open-discussion?highlight=me%2Bvs%2Bjl%2Bau...

The problem you’re having rooze, and the mistake you’re making, is the same one I made and everyone makes and that’s following the conventional wisdom, because the conventional wisdom is WRONG! The conventional wisdom is based on the idea that because sound is waves and bass is waves then bass must be the same as midrange and treble. When its not.

That’s not the conventional wisdom, and not what I’ve seen anyone propose. The general solution, as written by and accepted by professional acousticians and installers, for getting deep bass in a room with moderate spend is bass traps + EQ.


http://ethanwiner.com/basstrap_myths.htm


My views and recommendations are also largely in line with what GIK Acoustics would recommend, so please, contact them directly and ask.

https://www.gikacoustics.com/

If you have lots of room, time and money, get more subs, and a custom room. Otherwise, I stand by my advice of using a DSP based solution along with appropriate room treatment and question your judgement and qualifications.

Best,

Erik

You write in your comments to Toole:
"It’s 2020, who on earth uses steady state measurements?? "

Toole does not give a definition of "steady state" in this paper, the readers learn it in EE101. Lacking that , some believe it is better to negate a simple concept like that because it sounds stale in 2020. The rest is just a consequence.

     I'm a big fan of the 3-4 sub distributed bass array (DBA) concept. Although I've only personally used the 4-sub Audio Kinesis Debra DBA system in my system/room, it functions so incredibly well that it's not hard for me to imagine that a 3-sub DBA could function nearly as well.
     I agree with Erik that a single sub properly positioned, with PEQ and DSP correction can provide good bass response at a single designated listening position but will likely result in poor bass performance at numerous other positions in the room.  
     There are a few other downsides with this approach. One is that PEQ/DSP is very good at attenuating bass peaks identified at specific bass frequencies at the listening seat, since it simply decreases output power demand on the amp(s)at these peak frequencies. However, PEQ/DSP is limited in its ability to correct all bass dips and nulls identified at various specific bass frequencies at the listening seat, since these require increasing and not decreasing power at these bass dips and nulls. This takes a lot of power especially at deep bass frequencies to correct and the amp(s) need to be powerful enough to supply power for both the normal deep bass notes and the very sudden and high power demands for bass dynamics at varying deep bass frequencies and amplitudes. So, it's really not a limitation of the PEQ/DSP circuitry itself, but a limitation of the amp(s) that must meet this circuitry's power demands.  
    Further, powerful high quality class AB sub amps, possessing more moderate damping factors, reproduce more accurate and natural deep bass frequency note's decay times than high quality class D amps, possessing extremely high damping factors, are capable of. The use of class D amps to power subs often tends to result in the truncation of deep bass frequency note's decay times which sounds inaccurate and unnatural.
    In my experience, I've also found that 2 subs perform and sound about twice as good as a single sub at a designated listening seat. I believe this is due to two factors:

 1. 2 subs reproduce deep bass that is more powerful, dynamic and seems more effortless than a single sub because the bass output of both subs is cumulative and each individual sub is operating nowhere near its limits.
AND
 2. The use of 2 subs, each optimally positioned sequentially and independently in relation to the designated listening position, begins to provide the benefits of having multiple subs launching bass soundwaves into the room and these benefits increase in degree as more subs continue to be added to the room (with diminishing improvements resulting beyond about 4 subs); these additional benefits are bass that is perceived as being smoother, faster, more accurate, more detailed and better integrated with the main speakers.  
    Continuing on the bass upgrade path,I've found that the use of 4 subs independently positioned in a distributed bass array sound and perform about twice as good as 2 subs, maximizing both categories of bass quality improvements listed above.
    My claim is not that the 4-sub DBA concept is absolutely the best bass system in , it's just definitely the best I've heard and used to date. I believe a linear bass array(LBA?), with multiple subs lined up horizontally along the front wall at precise separation distances between them, could outperform a 4-sub DBA. But the LBA concept has serious downsides like the need for no rear wall for soundwave reflections to reflect off of and its dreaded and awful WAF.

Tim

@noble100

I agree with Erik that a single sub properly positioned, with PEQ and DSP correction can provide good bass response at a single designated listening position but will likely result in poor bass performance at numerous other positions in the room.

What you are missing from my argument is bass traps. I never said EQ alone solves all issues, but rather that EQ and room acoustics are complementary.

In theory, you could fix all room modes with proper bass traps, but few of us are able to afford something akin to the Magico listening room.

The magic sauce is the use of both. The traps stop the ringing, the EQ corrects what’s left and you can get something damn good that works for multiple listening locations.

Of course, a true pro will measure several different listening locations and attempt to use an average to decide what to adjust.

Still, Toole’s argument of "how do we know what is right" holds true. Even after this, the use of a discriminating ear is very valuable.

Also, to reiterate, I have nothing against the swarm besides cost, complexity and space. :) I mean, as far as I can tell from reading it should sound great. It’s the cultishness of the idea it is the ONLY possible way to have good bass. It isn’t.  If you have the money and space for 4 subs, by all means, have at it, but don't compare it to a poorly integrated single sub as proof it is the only way to go.

Best,

E