[urlhttp://www.htguys.com/news/2010/12/5/auralex-subdude-video-review.html][/url]
From above link:
Awesome! I am SO pleased that you found the SubDude to make a worthwhile improvement. I try not to use hyperbole when recommending that people decouple their subwoofer and speakers, but I do make very strong statements because it typically takes that level of persuasion in order to get people to try it!
So it comes as a great relief when other people discover that decoupling really does improve the sound both inside and outside of your theater! Results do vary, but I have yet to come across anyone who found zero improvement with a decoupling device in place.
One thing that can make the SubDude/GRAMMA's improvement less noticeable is if the subwoofer or speaker was already sitting on top of a very thick carpet pad and carpet. Essentially, a thick carpet pad will already act as a decoupling device. However, most subwoofers and speakers have "feet" or some sort - either "spikes" or just small, rubber feet that stick out from the bottom. These "feet" will typically sink deep into any carpet and will often sink deep enough to still couple the subwoofer or speakers to the floor. So even with carpet, the SubDude/GRAMMA can often still deliver a noticeable improvement.
Ara mentioned that the bass in his theater actually sounded louder with the SubDude in place and surmised that perhaps the reason was because more bass was entering the room due to no longer entering the floor. This isn't actually the case. What is actually happening is that - without the SubDude in place - the room itself is shaking in sympathy with the subwoofer. In essence, the walls, floor and ceiling all end up acting as huge speaker surfaces. They shake along with the shaking of the subwoofer and, as a result, produce sound waves of their own. These sound waves (which are a clear form of distortion) interact with the soundwaves coming from the subwoofer - in exactly the same way that reflected soundwaves interact with the direct soundwaves. In other words, the shaking of the walls/ceiling/floor creates destructive and constructive interference when the soundwaves created by the shaking walls/ceiling/floor interact with the direct soundwaves from the subwoofer AND the reflected soundwaves.
The bottom line is that decoupling greatly reduces one major source of distortion and one major source of additional soundwaves within the room. With fewer instances of either destructive or constructive interference, the result is a somewhat flatter frequency response within the room. To be clear, both the direct soundwaves and the reflected soundwaves still exist, so decoupling is NO panacea for frequency response! But you DO eliminate the soundwaves that were the result of shaking walls/ceiling/floor, so that has an audible effect!
Some people experience LESS bass volume when they add the SubDude. That would be because the shaking walls/ceiling/floor happened to be creating constructive interference at that person's particular seating location. In Ara's case, it is very likely that the shaking walls/ceiling/floor happened to be creating destructive interference at his seating location, so that is why the bass seemed to get louder with the SubDude in place!
Regardless of whether the shaking walls/ceiling/floor happen to create either constructive or destructive interference at your particular seat though, you can expect to hear "tighter" bass with a decoupling device in place. And that is because, regardless of your room acoustics or seating location, reducing additional distortion soundwaves will always result in fewer instances of either constructive or destructive interference. As I said earlier, that means some measure of improvement in the frequency response and you are also removing a major source of distortion, which is always a good thing
Mark, personally from this point forward I will be using Isolation Platforms under all my Subs and Mains even if they are not downward firing or bottom ported. My room benefited when I placed my Klipsch RF-7 floorstanders on platforms. I was able to run my Sub Volume slightly higher without hitting my rooms Low Frequency Tipping point.
Just be careful you don't place your Omega Sub too close to adjacent walls. I find I have to have my Mid Bass Modules at least 12 inches away from the front wall or else they will excite the front wall which transmits vibration into the floor.