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
...Then explain why the spikes make a difference at any volume level...

Don't need to. It's the same answer as when they are louder. Different people will hear the degradation of sound depending on their ears pleasure center based on driver movement. There is no "magic" to reducing cabinet movement (spikes do not address vibration so much).
"Don't need to. It's the same answer as when they are louder."

I couldn't disagree with you more. Spikes will make a difference at any volume, however, it will require high volume and significant bass energy to move the speakers.
Cabinet resonances are logarithmic with volume. To say they make a difference down low is pointing out the diminishing effect of the cabinet. No one is challenging your superb hearing, but most will hear the difference only when their is enough energy to actually move the cabinet and it doesn't move for free.

The problem with audio, is everyone's challenged to claim they hear everything. So disagree some more as it makes no difference when you do the math. Cabinets are much more inert at low volumes so they contribute little to the sound. Not so at higher SPL's.

But if you're a human phase response / SPL meter...hey, hear away at 30 dB SPL. No one's challenging that.