Sorbothane under speakers

[Macca]

I didn't give it a thought when I bought my house. It has a solid floor with floorboards on top, with a gap between them of a couple of inches. Probably a worse case combination, but it did mean when I had a dedicated ring main installed for the audio, I could also run the audio cables under the floor. My speakers are 6m from the audio sources, preamps etc. I dislike seeing cables snaking around the room.

Regarding speaker isolation, I have never been disappointed with the soundstage my speakers create: the soundstage width extends beyond the outer dimensions of the speakers with excellent depth. I'm not a bass freak and have to have the volume turned up to very loud levels before I can feel the vibrations through the floor.

The QUAD ESL being well known for it's difficult-to-tame deep bass response of course

I rented 8 places before I bought this one. Old, modern, big rooms, small rooms, solid floors, suspended floors, and ran systems in all of them. My takeaway from that experience was old is better than modern, big is better than small and solid is better than suspended.

Was looking for two years before finding one that ticked all those boxes and that I could actually afford.

[Barry]

The QUAD ESL being well known for its difficult-to-tame deep bass response of course

I rented 8 places before I bought this one. Old, modern, big rooms, small rooms, solid floors, suspended floors, and ran systems in all of them. My takeaway from that experience was old is better than modern, big is better than small and solid is better than suspended.

Was looking for two years before finding one that ticked all those boxes and that I could actually afford.

(Your room displays a distinct echo ! )

The Quad 57s have no deep bass: they roll off at 45Hz, at a rate asymptotic to 18dB/octave. As I said, I'm not a bass freak, if I were I wouldn't be using Quad 57s. To feel vibrations through the floor my system has to be running at 90dBA, measured at my listening distance of 4.2m and at ear level (0.75m), and that is so loud to be uncomfortable.

I would agree with your comments; old is quite likely to be better, as older properties were better built: solid brick internal walls, with the timbers and floorboards of larger size. Old properties often had larger sized rooms, compared to modern properties (in 1950 building 12 houses to the acre was the norm, whereas between 1960 to 1980 it crept up to 10 - 12 per acre. Now (2019) it 12 to 20 dwellings per acre).

[loheswaran]

Has anyone here made diy contrained layer platoforms from aluminium plate and resonant damping sheets?

[loheswaran]

I do not have a lot of space to work in - hence seismic bars are a non starter. I am considering old style rubber tube platforms placed inside a box to tidy the appearance

[bumpy]

Have been doing quite a lot of reading on this topic.

This is the most meaningful graph. It shows the frequencies above which sorbothane is effective vs the frequencies above which Townsend isolators are effective.

The bump on each profile is the resonant frequency if the device. The device is progressively totally ineffective below this and progressively effective above it.

It shows why sorbothane is good, but why Townsend acoustic isolators are much better (but more expensive!)

[Barry]

If that graph is to be believed, it shows the uselessness of spikes/cones when it comes to isolation - something I have known for ages: not from experience but from a basic knowledge of mechanics.

[walpurgis]

It doesn't take much to figure out that cones, spikes or any other kind of hard contact won't isolate anything. They will do the opposite and rigidly couple whatever is stood on them/it to whatever is beneath.

[Macca]

Anything you do to the speaker and it's postion is going to change the sound.

You put spikes under a speaker that was previously sat flat on the stand, you raise its height relative to your ears - sound changes.

You also reduce the amount of cabinet surface in contact with the surface of the stand - sound changes.

Nothing to do with isolation.

[bumpy]

Yep, a transmissibility figure of 1 means no effect whatsoever. In this experiment spikes show no effect on low frequencies until about 400Hz when there is a bit of a squiggle.

[zanash]

like wise .......Barry !

from almost the first year of trying spike. I became more and more convinced of there failings, and that was in the late 70's.