tweak, do they realy bring improvement?

Repends on the capabilities and deficiencies of your system. I had one of the great ears in audio come to my home from New Jersey this weekend . My friend Dave said my system lacked one critical component. It just happens to be from a company that posted above. He said his friend Barry from Bright Star Audio makes incredible and affordable isolation devices that will breathe life into my system. Disclaimer : I am NOT a dealer but I Am going to buy a product or two from them asap. This hobby and especially this site is too damn much fun . Tweaks... and do they work?.... What do you think ?

I absolutely agree with Barry - I don't get anything until I eventually get a clue how it supposed to do what it claims. For me understading adds fun, this is not about money at all. So far I couldn't find clear enough explanation how vibration may affect well designed SS devices... so no isolation platforms nor coupling devices have found their place in my shelfs yet. Cables, spikes under speakers are quite obvious... Power conditioners - the funny thing is that the better designed the power supply of the component, the less effect AC tweaks produce. For some reason I haven't heard about so well designed components yet...
However, all this is not about savings, it's about fun, so I don't see a reason why not to buy and try even if it doesn't work? If it makes fun, consider it working!

i use anti vibration devices under my cdp but thats as far as ill go with tweaks.

mike.

Yes they do work to a very minor degree in most cases,HOWEVER,what people are trying to do with them is to fix what are room tune problems. To do that properly, unfortunately, you need a pro with experience and the proper equipment to do it right. All the tweaks are just shots in the dark. Sometimes you can hit a few targets in the dark, but you can't really kill the beast. Go to www.bobhodas.com and then click on publications. Read all of the articles and you will see what is involved in properly tuning a room.

Most tweaks (Cables are not tweaks, since the system will not work without them) are designed to do one thing: reduce vibrations. Without getting into a big discussion about physics, vibrations prevent audio gear from functioning at their highest level.

The more these vibrations can be reduced or (not likely) eliminated, the better the equipment is able to sound. Vibrations come from the ground, and from the air, each of them have a detrimental effect on the sound. The battle for the last twenty, or so, years has been to minimize them. All kinds of items have been used with varying degrees of success. In overly simplistic terms vibrations are absorbed with items like Sorbothane or vibrapods, or dissipated with items like cones, and stands. Some work in certain environments, while others work better in different environments. The buyer needs to know what he is trying to accomplish when buying the different types of products.

Just like, not everyone will need an AC line conditioner, not everyone will need every type of vibration treatment.

Hospitals, observatories, and science labs have been the main source of understanding the effects of vibration. These places require accurate measurements to do their research, and small vibrations will have large effects on micro measurements in science. Again I hope I am not being overly simplistic in my discription, I'm trying to make it as understandable as possible, but everyone here is above average, so it should not be an issue.