Speaker Floor Decoupling

Dear All,

I'd like to hear your advice on how to solve a problems. the elements involved are the following:

1) Speakers Sonus Faber Grand Piano. They are floor standing on four points. The base is not perpendicular to the floor.

2) Neighbor. Living downstairs, standard model, did not complain yet.

3) Two granit slabs approx 2cm think to be placed under the speakers. Very heavy.

4) Daniel. 11 month terror toddler.

Now With the speakers on the floor I can hear the vibration of the floor under my feet even at low volume. The structures of the building is very elastic here in Japan because of earthquake resistance.

So I thought to put the slabs between the speakers and the floor.

Now the problem is that the metals points can easily slide on the granite if the terror toddler push on the speakers.

I was thinking about drilling small holes in the granite so that the point will sit into them and the speaker will not slide. Do you think this will defeat the purpose of the slabs in decoupling the speakers and the floor ?

What do you think would be the effect of a more intimate contact between the metal base of the speakers and the slabs would be ? What about screwing the speakers to the slabs ?

Thanks for helping,

A granit slab between the speaker and the floor might not achieve the desired mechanical decoupling.

IMHO, what works is:
- good mechanical COUPLING of the speakers to the slabs (yes, you can also screw them, although best coupling is done by very small contact area like spikes)
- and good DECOUPLING of the slabs off the floor: you need some sort of elastic/viscous material (foam, rubber) which can take over mechanical vibration and absorb then

PS: you did not mention what kind of floor you have ?
If you are feeling really brave you could look at the Townshend seismic sink principle. This uses a compliant bladder filled with air underneath a large mass to decouple the speaker.

So you could use an inner tube from an electric wheel chair, or similar, underneath your granite. This would give you the best floor decoupling, but you would have to make it toddler proof with a hard mechanical limit. A shallow box topped with the granite, sandwiching the inner tube within a slightly smaller box should do it.
Thanks, I have a thick carpet. But I will try extra soft material. It's a good suggestion


Maybe just the thick rug is enough. Put the granite on the rug and the speaker spikes in little divots (or floor protectors) on the granite, The granite should be wide compared with the speaker base or the rug might make it unstable.

This is the simplest. I assume you have been using spikes on the rug, so the rug has been doing nothing and you have been coupling directly to the hard floor below.

Before making fancy contraptions with inner tubes and stuff, I would see if this is good enough.
i put eggcrate foam sandwiched between my monitors and the stand. this effectively killed the vibration problem i was having with my faux wooden floor, but does make the speakers wobbly to the touch. i doubt that'll go well with your element #4. cork sheet is another material i have available, and hulk glue- the sticky clay used to hang posters to the walls. the last onen would decouple and secure at the same time, but the foam has been good enough for me not to bother switching out.
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2015-08-05 11:17 pm
Blu- tac or similar in place of the spikes would be thd easiest solution . It gives good de-coupling and will stop the ' terror toddler ' from pushing them around.
On the subject of ' terror toddlers ' from a very early age i explained the danger of electricity to my son telling him it was an invisible force that could kill a person . I told him there was a ' force field ' of it around my system and showed him the point at which it was active , about 6 foot out , he never once went near my precious ' toys ' and i could leave him unattended in the room knowing my gear was safe . He was about eleven before he figured out my deception :)
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