Changed the subs around for LCRS sub bass extension that are placed on the JBL 18".
Had a few snags with resonating rattle/buzzing that I managed to sort out where the plastic box of the flat screen tv (any) would resonate rattle/buzz. I placed some carpet tile behind it where it reduced resonate rattle.
Pinched a few holes in a spare carpet tiled and poked a few cable ties though it.
To reduce port air turbulence turned the sub around so its port isn't firing towards the back of the tv and that seemed to work. If this was a CRT the colour would be instantly de-coloured with blotches of red pink and green, flat screen LCD are great.
Placed one of second best subs behind the back row as seen with resting on back seat raiser that is joined to front seat raiser. the sub is merged with the JBL 18" for LFE.1 or SW for analouge Lt-Rt soundtracks.
Lows are filling though below 20Hz to 120Hz with just a few minor peak dips not critical but I'm looking at this Mini-DSP EQ for subs sometime in the future as there's only so much I can do with 1/3 EQ and my Behringer FBQ2496 packed up with a failed power supply two years ago and was a useful parametric EQ. So hope the Mini-DSP can restore balance to sub bass galaxy.
Least lows are filling above 38Hz though 40 to 50 where most of the bumps and bangs are on film soundtrack low end. 60Hz still same. Though 70Hz is a bit peaky and can do with little minimizing up to 80Hz where it levels out.
Back row is thrilling with the sound of the Millennium Falon from Return of the Jedi (1983) Laserdisc AC-3, kicking bass into the back of the seats while it whooshes from behind surround to front channels.
Re-EQ the room due to seating position change. Measured for flat on the TrueRTA 1/3 then applied equal EQ cut with secondary 1/3 EQ to each LCR channel while applying equal cut to surround channel zones so's to warm up the bass mid so that its felt a bit more often with less middle highs harshness while leaving the upper high EQ flat so that the higher highs can be heard on the odd few films above 8KHz though to 10KHz and 16KHz.
Ran repeated frequency sweep of the LFE.1 sub on its own at varies fader levels to check for resonate rattle/buzzing and see what needs tightening down?
Very few items rattle.
TV not as much
Light fittings are free rattle/buzzing
Windows free from rattle/buzzing
Radiator free from rattle/buzzing after tightening down a lose part.
Seating free from rattle/buzzing (expect for bass shakers that I'm still working on) but airborne sub lows the seating is free from rattle/buzzing.
Rack system is free from rattles expect the laserdisc player that creates a nice vibration due to spindle motor speed acceleration and takes a little adjustment to stop the rattling. The players are due for refit elsewhere in a fourth rack in the kitchen with (remote IR emitters).
kitchen rattles a little bit from sink to a few cupboards and projector fitted to the wall brackets (that I managed to secure) but the sink rattling sounds cool thou I keep the fader at normal level where it would be rattle free, its when the fader is up at +10.0db which is hardly ever used above 0.0db "7".
Generally the room is quiet down to about 30db at night time with some equipment turned ON there is a rise of 10db that I like to reduce back down from 40db to 30db A C weighting.
Fan cooling and transformers inside certain gear can be heard elsewhere in the room if listening! To most other people they might not be so bothered by it as its so quiet.