Quadraspire QX7's -a revelation

[YNWaN]

To be honest, the 'shifting more air' idea (widely promoted) is rubbish (IMHO); there just isn't enough air displaced by the drivers to move the mass of the cabinet. I believe the reason is much more to do with grounding the vibration that the drivers feed into the cabinet - now that is a significant amount of energy. Completely stopping the cabinet from vibrating is very difficult indeed - effectively it is like a balloon that the bass driver is trying to modulate - the air inside is continually being compressed (even in a vented enclosure). Even very thick and stiff cabinets often show some sign of vibration at some frequency. Depending on the resonant frequency of the cabinet, overall output can be reasonably substantial.

How that energy is coupled to the surroundings definitely makes a profound difference. Some time ago I fixed small 5mm aluminium pads to the underside of my speakers and the three stand spikes make contact with these - this definitely sounded different to when they made contact with the wood directly.

I think you have put your finger on it when you write

stopping any energy being sort of dissipated into the ground.

. They won't entirely stop it (0.5 of some damping compound and your carpet isn't going to be a sufficiently broad filter to do that) but they will reduce it. Whether keeping that energy in the system, rather than grounding it, is a good thing is another matter entirely. To be honest, the carpet will be doing most of the filtering and the footer is just stabilising the contact with the carpet (I am deeply sceptical that any damping between the metal components is doing anything of real value within this context).

[Peter Stockwell]

Just installed a set under my main Hutter rack. I had RDC buttons before. The effect is positive.

[Steve Toy]

To be honest, the 'shifting more air' idea (widely promoted) is rubbish (IMHO); there just isn't enough air displaced by the drivers to move the mass of the cabinet. I believe the reason is much more to do with grounding the vibration that the drivers feed into the cabinet - now that is a significant amount of energy. Completely stopping the cabinet from vibrating is very difficult indeed - effectively it is like a balloon that the bass driver is trying to modulate - the air inside is continually being compressed (even in a vented enclosure). Even very thick and stiff cabinets often show some sign of vibration at some frequency. Depending on the resonant frequency of the cabinet, overall output can be reasonably substantial.

How that energy is coupled to the surroundings definitely makes a profound difference. Some time ago I fixed small 5mm aluminium pads to the underside of my speakers and the three stand spikes make contact with these - this definitely sounded different to when they made contact with the wood directly.

I think you have put your finger on it when you write Quote:
stopping any energy being sort of dissipated into the ground.
. They won't entirely stop it (0.5 of some damping compound and your carpet isn't going to be a sufficiently broad filter to do that) but they will reduce it. Whether keeping that energy in the system, rather than grounding it, is a good thing is another matter entirely. To be honest, the carpet will be doing most of the filtering and the footer is just stabilising the contact with the carpet (I am deeply sceptical that any damping between the metal components is doing anything of real value within this context).

Mark, I agree 100%. I think dissipating energy within the cabinet to ground is likely to be more effective than isolating all the energy and trapping it within the cabinet.

[Peter Stockwell]

Just installed a set under my main Hutter rack. I had RDC buttons before. The effect is positive.

By positive, I mean quieter calmer presentation. Now to get some for the sprakers and the other stand.

[SteveW]

Glad you have an open mid Peter, and tried them out. I'm still astonished by the difference.
I now want to experiment with them under my Mana equipment stands...

[Peter Stockwell]

I'm persuaded that the floor stand interface is a neglected area. My hutter is now on the QX-7s and on a hardword over concrete floor. I live in a flat in a pretty big building so there has to be a lot of structural born vibration getting into the equipment via the stand. The hutter stand has two power supplies and a power amp that would be feeding equipment generated vibration in the stand too. I have to say that the difference brought by the QX-7s was not at a must have level, more of a detectable step in the right direction, and given the cost of getting audible gains with the level of kit I have, i felt it worthwhile.

[Marco]

Glad you have an open mid Peter, and tried them out. I'm still astonished by the difference.
I now want to experiment with them under my Mana equipment stands...

That'll be an interesting one, Steve. It may interefere with the 'Mana effect' though so be careful of that, as the various preconceived interfaces with different materials (wood or concrete floor > metal spikes > MDF board > glass, etc) are integral to its function as a vibration sink.

Your Mana supports might not like to 'see' an alien interface material in the chain which has not been factored into the equation in its design principles, if you see what I mean. Coins, screw heads and Linn 'Skeets', have all been tried before in the past and found to be inferior to direct coupling to the floor surface via its metal spikes, and nothing else.

Keep us posted, though!

Marco.

[SteveW]

think in the case of the Mana, you may well be right Marco.
My two Mana equipment stand spikes sit on philips screws, through carpet into a very uneven victorian wooden floor. I had to use the screws in the first place to get the things near level in the first place. However...now curious as to what the effect might be if somehow I can get the quadraspires actually sitting on the wooden floor, as I can see that just resting on top of the carpet would have the Mana moving all over the place.