I don’t know much about speaker spikes as I have never used them, but when I used svs isolation feet on my subwoofer (raised about 1 1/2 inch from the carpet) it made a big difference in sound. The bass was more, cleaner, with more room gain. Can someone explain why that could be? I have tried the test with other people and they all can detect a difference in bass with 3 different svs models(PB-16, SB13, SB3000). Why is this the case? My room is 13 x 15 feet with carpet.
I've speculated about the effect of mechanical vibration on suspended wood flooring quite a bit. I don't know anything about your home construction, but my flooring is overly spongy: I jokingly refer to it as trampoline-like. (Though I have a high mass, I taught myself from a young age to step lightly, move quietly. When I walk through my room, everything shakes. I don't know if my landlord spec'd wide joists or used thinner floor boards, but the ability of my floor to transmit energy is quite high.)
Because of this, I was led to research isolation. It started innocently enough, but it's a complicated subject, and more knowledgeable people than I have made convincing counter-arguments to my hypothesis. Yet when I try to work through why they may be right, I keep coming up against my own experience.
I stated before, in this thread, that I make no claims about Sound Quality. Rather it is my @$$ in a chair that I am using to identify the level of vibration being transmitted, that and what I experience walking through the house when I am not seated in my room (doors two rooms down vibrating, glass doors on gas stove rattling in a separate area of the house, etc).
Short story long...
In my experience it is a matter of damping the mechanical vibrations being conducted through to the structure of the house that has an impact on perceived Bass SQ. In a manner of speaking, it is distortion that is not quantified in the build of the Subwoofer. Many will say that modern cabinets on good Subs are largely inert.
OK... I would agree... but for me, the Outlaw X-13s (Claridy Audio designed and manufactured) still created an amount of mechanical energy that was transmitted through the stock feet of the Sub. I have carpeted floors, the carpet and padding do not privide enough damping to stop a 100# sub from conducting energy through 4 small rubberized cone feet.
Applying Soundpath Feet and still leaving the Subs on the carpet allowed for mechanical energy to still be conducted through to the structure.
In my case.
It took a combination of a damping platform being coupled directly to the flooring using Spikes, along with the isolation feet to remove a majority of the vibrations. Now, it is purely an impact of very-high-mechanical-energy and LF wavefronts working on the room that will break my system.
The conclusion is that the "tightening" of the Bass is a function of cleaning up mechanical distortions that are resonant in the structure.
My suspicion is that if my flooring was common (16" joists on center with appropriate floor boards) the Soundpath Feet would have sufficed at alleviating my rather extreme situation.
I am still left questioning why people on Concrete flooring have climed a benefit from any type of isolation. That said, I think the higher usage of concrete mix to lower ratio of aggregate material increases the ability of concrete to receive and conduct (perhaps even amplify) mechanical energy...
My damping pads are concrete, from rejected countertops, and they are high in aggregate material. The full piece countertop was completely inert. However, once cut to size, the smaller pieces did demonstrate the slightest ability to ring... just a hint.
This was only noticeable to me as I had also checked a local quarry dealer and experienced the difference between some high quality granit and other "mineral substrate." The granite was completely inert... though I do not recall the other quarried material by name, I do remember well the fact it rang like a bell, almost; which is to say that rapping on it with my knuckles created a sustained vibration in the product.
Long story longer...
Anybody that has focused any time at all on positional EQ (finding proper placements for Speaker or Sub where each item performs at its acoustical best in-room will know that an inch can make a significant difference in performance. This applies to SBIR, breaking up a reflected wave cancellation, etc. While I do not discount completely that raising a Sub or Speaker by 1-1.5" won't affect the perceived SQ, it would stand to reason that any so inclined manufacturer would glom to this and use it as a marketing ploy.
We have not seen this.
While raising the Sub, in our cases, may have some impact, i do not think it is the main reason for the perceived effect we have on SQ.
Thus, I am still leaning toward a simple (Occam's Razor... anybody wanna shave?) explanation that it is a damping of mechanical energy conductance at play, and that the success of which is subject to the specific architecture of the structure in question when being challenged by a high energy, low frequency source.
(FWIW, I experimented with my Subs as follows:
Stock feet on carpeted floor
Stock feet on concrete pad directly on carpeted floor
Soundpath Feet on carpeted floor
Soundpath Feet on concrete pad directly on carpeted floor
Soundpath Feet on concrete pad coupled to structure using Outriggers with Spikes.
The only thing I did not test was stock feet on pad with spikes.
From a subjective standpoint, I have claimed previously an approximate reduction of mechanical vibration of approximately 85%, in my specific use case.
My only instrument of testing was, as stated above, my @$$ in a chair. No battery of lasers, accelerometers or other device of scientific measure was employed.
Of note: this does not preclude or prevent the actual wavefront from wreaking havoc as it will. I have, of note, felt the Sub cabinet vibrating at times, without that conducting through to the structure.
)