I thought I would share the details of my design and manufacturing journey on this forum:
The floor in my listening room (AKA sitting room) is concrete with insulation, battens and an MDF sub floor, dense foam underlay and wool carpeting. I have considering the sub-harmonics generated by the floor and shall soon be replacing the dense foam with a proprietary sound absorbing cellular matting ( only $200 per sq foot from the US)
The hollow tubular steel chair legs are filled with kitty litter and spiked through the carpet and underlay to the MDF sub floor, this bothered me a little so I've packed under the spikes with quick set mortar to prevent any vibration. The chair seat has a worm thread rise and fall adjustment to enable proper horizontal ear / tweeter alignment. My wife has made for me a special pair of trousers which have a 2 inch thick butyl rubber padded seat ( only $200 per sq inch from the US ) and to avoid any untoward, unwanted vibrational movement in this area an exhaust pipe vents any gases to behind the chair. Movement in these trouser is very limited so I have a special hoist to lift me into the chair ( only $3000 from the US )
The arm rests have been moulded to my arm shape and to prevent any sideways movement which could affect the soundwaves from my speakers there are leather straps to hold my arms in place, hand movement is rather limited but sufficient to allow me to operate the remote controls of my streamer and amp. I have found it rather difficult to change tracks and I have been listening to Mariah Carey's Christmas album on repeat since yesterday.
The chair back has a spinal support pad and a unique moulded head retaining neck / cranial pan bracket, this is the clever part as it holds the head perfectly steady and aligned, vertically and horizontally. To enable the ears to perfectly receive the sound waves, ear flap position is adjusted by a lever arrangement. With the head thus retained having a drink is only possible through a straw - actually a personal fluid delivery suction tube made from specially recycled non ionic compressed paper ( only $250 for a pack of 12 from the US ) The cup holder fixed to the arm rest has been repurposed from one found in a defunct electric car abandoned in Haywards Heath.
The whole set up has a remarkable resemblance to an American electric chair but hey - I can really appreciate the music.
Merry Christmas and happy listening everyone