Speaker Spikes - do the shake test


Everyone by now knows that speaker spikes improve the sound. The theory is that the tweeter excursion is so short, that any speaker cabinet front to back movement creates Doppler / intermodulation distortion. That movement can exceeed, by many times, the excursion of the tweeter. So, the effect is most pronounced up top and then towards the bottom most frequencies. Or so they say.

I have some C4 series II speakers that come with four “spikes” in the plinths. But, the people in Denmark seem to think we all have hardwood floors. The so-called spikes are dull “lugs" that really are meant to sit into four small aluminum floor bot dots, for any better term for them. Many have speakers on carpet, and the so-called spikes sitting on those four round aluminum discs still are pretty wobbly on carpet.

Last week, I pulled all eight of the spikes (not nearly sharp enough, with a 30 degree rounded tip, to be called a spike) and had the guys in the machine shop at work lath them to 60-degree POINTS!

OK, re-installed and speakers leveled (four point level is a pain). WOW, now they are stable as a rock when you push and tug on them. What was NOT expected, was that the BASS response is significantly better. Not that bass is easy to do, but the contribution to the C4’s bass that spikes that are now planted into the concrete floor and under the carpet is amazing. The bass can now place a black dot on a white background as needed. Everything isn’t a shade of gray in the bass. I always felt that the C4’s weakness was bass definition, but the weakness is that Dynaudio doesn’t supply two sets of spikes, those for hard surfaces and those for carpet. That’s too bad, as the supplied spikes don’t cut it on carpet. My spikes are now good enough to pierce down below the carpet and rest on the concrete. But, real spikes should be like half-inch ten-penny nails that don’t chew-up the carper as much as my 60-degree spikes. But, I can’t find this spikes for the C4’s.

If you are like me and haven’t given your speakers the shake test, go do it! If they wobble around any at all see what you can do to fix it. The rewards are well worth as close to free upgrade as I’ve ever done. Don’t think for a second that it seems, “good enough”. If they move around, it isn’t.
rower30
My experience is quite similar to Mrmitch.

I have a suspended floor. My best results with my monitors is on Vibrapods. This decoupling without much absorption retains the microdynamic energy of the music and results in more presence and better bass definition and heft. Amazingly clarity did not suffer like it did on blue tack. Brass cones gave the most clarity.

Vibrapods on my floorstanders resulted in sloppy bass. I compromised by using cork/rubber isolpads which gave the best balance of warmth, microdynamics and clarity.
The factory spikes made the floorstanders rather cold sounding in comparison.
Interestingly, or not, the "pods" under my speakers isolate them somewhat from floor vibration from the front firing (older) REL sub that is has small felt skid pads under it...right behind one of the main speakers. That may be part of what's making the whole thing work. Tight, pitch correct, and well defined bass.
One thing to be mindful of as you experiment is that any change you make in the height of the speaker or its rake angle will affect the sound.
OK, Spiked my DD10+ subs. I used Dayton Audio spikes into the concrete floor beneath the carpet. Here, like the speakers, the spikes force the speaker / subs to become "one" with the floor so the speaker can't shake near as much. The hand on the cabinet test say so big time, too.

The AUTO EQ shows less boost at all frequencies suggesting that more energy is going into the room than before.

The soft feet are more than likely best for keeping vibration FROM a unit where the sharp steel spikes adhere the object INTO the substrate below them, and that in turn determines how hard the spiked object is to move relative to the surface it is spiked into. When they are spike into a conctere floor, they have too "push" the whole house around to move, which is kind of hard to do. Sitting on the carpet? They shook away on that springy surface.

Anyone with Velodyne subs, the Dayton Audio DSS3-BK spike kit fit perfectly. Screw out the old insert with the wrong threads / inch, screw in the same type inserts with the right threads / inch that come with the kit, and screw in the spikes. Done.

http://www.daytonaudio.com/index.php/loudspeaker-components/speaker-cabinet-accessories/speaker-spikes.html
I have commercial carpet over a cement basement floor. The floor is not even, not even close to even. My tower speakers have integral plinths beneath open-bottomed cabinets, and are designed to sit flat on a flat floor. When I first set them up, they wobbled a lot. The manufacturer provided pads and shims, but even with these, they were not really stable. I had Sound Anchors custom build heavy cradle bases with three-point adjustable spikes (the sharp kind), ~$325/pr shipped. Once leveled, the speakers improved significantly in transient reproduction, image stability and overall clarity. A friend who designs isolation devices feels strongly that spikes, which couple, but do not isolate, are preferable for speakers, which ought to be coupled to the floor in most cases. Electronics, OTOH, he prefers isolated with vibration absorbing devices. But hey, there is more than one way to skin a cat.