Helmhotz resonators for audiophile at almost no cost and without calculus...

The importance to treat the room if you have speakers, even in nearfield listening like me, is imperative ...

Here is my advice: 

Buy some big  empty wine bottles, or drink them before, it is optional....Or use some carafes, the kind that some display at the center of a table....I use plastic  wrapping sheets to tightly seal the aperture of the bottles and the carafes after pouring in them around 10 % of water in their volume space...You must listen and experiment for your taste and room to determine the exact amount of water to boost the frequencies that will benefit….After that  I peirce the plastic sheet with a needle and I insert a  thin straw with only the extremity of the straw at the top...  That its! You know have an Helhmotz resonator... 

You now have one of the more astounding tweak for a room that will transform your listening space in sound heaven ...I use more than 15 of them in my little audio room and trust me that is one of a kind upgrading...

I wrote that for those who want to experiment, the others can stay silent...My best to all...