So is the real problem the coupling of the sub, or the integrity of the floor?All I can say is I have a nasty room. The floor seems loose and rattles, and I have gross room modes at 40Hz and 80Hz with a suckout at around 60Hz. The Gramma makes the sub sound better--no, it makes movies sound better. I don't know why and I don't really care. All I know is instead of hearing the room rattle, I hear the movie. To me, it was worth every penny, but YMMV.
So you are recommending that I:The Doc makes a very valid point!
I am a bit amused by seemingly simultaneous rush to buy the many available 'decoupling' speaker mounts while others rush to buy the ever popular tip toes without a thorough examination of what is actually the problem.
More often then not, we erroneously begin with a solution and then go looking for a problem to solve.
Why would one want to acoustically or mechanically isolate a component? One item come to mind. That being a turntable. But there are not too many turntables being employed in home theaters nowadays...while they are still around in the audio listening world. But my focus would be on isolating the turntable, NOT the speaker.
If the priority was the attempt to isolate a listening space in order to minimize the transmission of sound through a surface into an adjoining space, I could imagine the potential to attempt to isolate a mechanically coupled source...
If we are worried about items in the room 'rattling, the effort would be better spent isolating them, as their mass will likely be small and they will be the victim of some mechanical coupling, but also significant acoustical coupling. And one would be better off utilizing such methods as earthquake anchors for items such as pictures and nik naks..
But again, we need to identify the actual problem to be solved...and additionally we need to determine if this is this a real problem, or merely an imagined one. After all, an optimal answer is predicated upon the formulation of a concise and accurate question.
The mention of room modes will not be be resolved by decoupling of a subwoofer.
And as Doc has mentioned, decoupling the sub will NOT make the sound of the sub more defined.
We could likewise take the opposite approach and examine the notion that rigidly coupling a speaker to the floor will significantly 'tighten ' the response (such as is so often claimed by those selling such devices as 'tip toes') - especially as most are using passive crossovers and the various acoustic centers of the drivers within the speaker - let alone the various drivers amongst the various speakers - are not aligned in time!
Thus, in this case, we are faced with the dilemma where upon we ignore the gross misalignment of the various source signals in the time domain and instead maintain that the minute oscillation of the cabinet measurable in fractions of an inch (and of which the damped system will move out of sync with the cone motion!!!) and the resultant group delay errors are more critical than mis-aligned delays measurable in ms or much greater - equivalent to the offset of acoustic origins ranging from several inches to many feet! Hence, what we have is the **** preoccupation with fractions of an inches while we blithely ignore feet! Hmmm. A clear case of being penny wise and dollar foolish!
Yet how many systems employ passive crossovers which lack the ability to adjust and align the acoustic centers of the various drivers, let alone the ability to accurately align the various separate real and virtual sources such as the speaker and the sub and the associated reflections?
So while a minimum phase alignment is important, such a 'posterior backward' focus of obsessing over minute group delay issues while ignoring issues that constitute orders of magnitude larger signal alignment errors utterly misses the point! Or to put this in a none acoustical POV ...This is like worrying if we have the correct change to pay for a purchase while we lack a thousand dollars from meeting the sales price!
So...to return to the original problem...Perhaps we need to better frame the problem. What is the actual problem, and what are we trying to solve! Simply selecting one variable out of context simply because we can, or because one might have seen a purported solution marketed somewhere is not the optimal approach to addressing issues.
(And in a sardonic effort to contribute to another ever popular cause all sorts of problems (misunderstandings), this topic reminds me of the perennial issues surrounding the seeming endless debates over 'magic' interconnects!..a deceptively simple subject that has assumed an air of mystical significance for many who live in the realm of marketing literature. :raped::devil
So you are recommending that I:
1: Remove my subwoofers from subdudes
2: Place sticky foam feet the size of quarters on the subwoofer
3: Place the subwoofer on the concrete floor, or plywood (insualtion filled) riser.
4: Permanantly seal my PVC ceiling to reinforce it from vibration (as instructions note) prior to wiring my equipment to their home.
1: I will have less support for my subwoofer
2: I will have wires running across my floor
Lets say the OP takes your advise and does his floor over
1: Subwoofer will have unknown improvement. We don't know what the cabinet is
2: Maybe he needs to hire a builder, get permits, all to fix something that is already fixed. Not going to be high WAF if that is of importance. I'm sure the OP is intellegent enough to know that securing something that will rattle will stop it from rattling. Hopefully he is not treating room modes. :heehee:
I see and my bad. I never would have gotten invloved knowing so. Thanks. :TI prefer (and cannot too adamantly suggest!) proper evaluation and planning, combined with results driven feedback and proof of performance verification... Not just buying some new whiz bang market solution 'guaranteed to cure what ails ya' and plugging it in. And that is where this thread began.