Why is good, deep bass so difficult? - Myths and their Busters


This is a theme that goes round and round and round on Audiogon. While looking for good sources, I found a consultancy (Acoustic Frontiers) offering a book and links:

http://www.acousticfrontiers.com/guide-to-bass-optimization/?utm_source=CTA

Interestingly: AF is in Fairfax, CA, home to Fritz Speakers. I really have to go visit Fairfax!

And a link to two great articles over at sound and vision:

https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-1
https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-2

Every audiophile who is dissatisfied with the bass in their room should read these free resources.

Let me state unequivocally, deep bass is difficult for the average consumer. Most audiophiles are better off with bass limited speakers, or satellite/subwoofer systems. The former limits the danger you can get into. The latter has the most chance of success IF PROPERLY IMPLEMENTED.

The idea that large drivers/subs are slow is a complete and utter myth. Same for bass reflex. The issue is not the speed of the drivers. The issue is usually that the deeper a speaker goes the more it excites room modes, which the audiophile is then loathe to address.

Anyway, please read away. I look forward to reading comments.
erik_squires
It’s not really a mass issue for the tops of speakers. It’s placing something that acts like a diode and allows the otherwise trapped energy in the speaker cabinet to rapidly escape to the outside air via a path of least resistance.  This is why things like those Totem Beaks or cones, especially NASA grade ceramic DH Cones, very hard but not very massive, but massive enough, are often so effective placed on top of speakers. 🍦 There used to be a product Tekna Sonic that was purpose built for attaching to speaker cabinets that accomplished the same thing. For the same reason cones can often be placed on top of the electronics chassis or tube traps and accomplish the same sort of thing, dissipate energy rapidly from the system. Crystals also dissipate mechanical energy in similar circumstances.

so...
anybody actually run the curves for your listening position ?
easy to do
but harder than typing this.....
I don’t know but I have a sneaking suspicion nobody ever ran curves for anything from the listening position. That’s not something in an audiophile’s bag of tricks. 👜 What audiophiles do is try something. Listen. Move it a little. Listen again. Try something else. Listen again. Ad infinitum. And they wonder why audiophiles frequently come down with a bad case of audio nervousa. 😬

I’m not sure how many different ways I can type this. If you are thinking of resonance cabinet control it is VERY different than what I am describing.

Imagine an open baffle speaker design of zero mass resting on frictionless rollers. As music plays, the speaker will roll back and forth on the skates, and the acoustic output will be reduced. This is the equal and opposite reaction to the energy of the motor acting on the baffle/motor and motor frame. This is a matter of force, leverage, and mass.

Is it an issue? I don’t know, I have had a number of people whose opinions I trust say they get better bass out of monitors with additional mass, which need not be particularly modern. An antique iron would work if it was heavy enough.



Best,

E
Yamamura used to make some very elegant limited slip plate thingamabobs for speakers. You can actually knock them off if you know what you’re doing. Limited slip plate devices offload excess energy from the speaker cabinet by converting that energy to work performed by the movement of the speaker allowed by the 3 piece limited slip plate arrangement under the speakers As far as mass goes, what can I say? People say things. People talk. Some people swear up and down that VPI bricks work due to increased mass. What else is new?