[infinitesymphony]

Speaker isolation seems like a reasonable tweak. What sort of results have you experienced before and after providing isolation for the speakers?

Examples include speaker stands, foam isolation platforms (ex. MoPads), spikes, etc.

 

[Chopha]

Under my floor speakers it looks like this;
Speaker - Spikes - cement plate (used when making sidewalks) - Soft rubber

This way, the speaker is mechanically bound to the cement plate which makes the speaker weight more, which is good since it reduces vibrations.
The rubber prevents the vibrations to spread down to the floor.

/Chopha

 

[infinitesymphony]

Thanks for the reply, Chopha. Can you make a comparison of what the sound quality was like before and after your isolation tweaks?

 

[Chopha]

In my room I have parquet floor and since there isn't to much more than that (I live in a detached house) the space under the house and my room became a really big resonance chamber. So at that time my whole room was playing along with the speakers and the bass was really bloated. You could say that the floor in my room was a big flabby part of the speakers. But now I don’t experience the same thing at all since the vibrations from the speaker goes straight down into the concrete stone and stays there. Huge improvement!

You will notice a great improvement if your floor is like mine, “hollow”. The difference won’t be as big if you live in an apartment though, where the floor is concrete in the foundation. Don’t get me wrong, it does improve the sound on hard floor to, but the difference isn’t as huge.

A good way to test how “hollow” your floor is to stand in front of the speakers and stomp with your heels on the floor. If it sounds a bit boomy and you get the feeling that the floor is bending under your feet’s, then this is definitely something for you.
If it doesn’t sound too much and the floor is rock solid, then you’re not in the same need of this setup, but do it anyway since it helps tightening up the bass and improving is fun!

/Chopha

 

[dura]

I've got a suspended floor; isolation of my dynaudio 122 is very critical.
The best result is this: added metal feet (~10 kg ps) attached 'hard' with screws to the dyns to make them heavier and more stable. On the floor concrete slabs, ~10 kgs each, painted black, with a very very tin rubber isolation on the corners, so the contact with the floor is good, no more. Even adding some thin vilt here chances the bass significantly.
But the most important coupling is between the metal feet and the concrete:
- spikes: sharp sound, god tight bass but unpleasant treble.
- rubber dampers: pleasant treble but bloated bass
- vibrapods: bingo, not one problemarea, all around very good.

Basically it seems to boil down the this: the bigger the freedom of movement the lower the problem freq.
(Which can be explained with hindsight with fysics, the amount of energy remains the same, the smaller the max. amplitude possible, the higher the system will vibrate. I find this explanation acceptable, YMMV).
Vibrapods seem to disperse the energy over more then one preferred freq perhaps. Whatever, I love them.
However, on a concrete floor with carpet I would go for coupling the speaker to the floor with 3 good sharp cones, adding massloading if possible, thus creating a system where the floormass is partially added to the speaker.

 

[Old Pa]

My B&W 800 Nautiluses are spike connected through the carpet, pad, and tile to a concrete slab which is part of the foundation of the house. I've been spike isolating speakers for over a decade. The major improvement is clarity, which aids in resolving soundstage. Speaker isolation must be combined with appropriate speaker placement in the listening room.