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
How heavy are those Dunlavys? I suspect that heavier speakers benefit less from spikes. Or, to be more specific, I think weight vs. driver size is likely key.
On the other hand Dunlavy speakers did not come with spikes at all. However, my SCIVs had no problem with imaging or bass. My CLS only had spikes in the front, no spikes on Maggies, but Vandersteen 2 and 3s are sensitive to spikes and the type of stand that is used. This list could go on and on, but what it comes down to is speaker design.
Rrog you are so right. Snell supplied weak, wobbly spikes that were prone to bending with their models. You had to crank a lock nut against the bottom of the cabinet and they would still wiggle. Replacing them with outriggers made a huge improvement.

I just experienced a similar jump in performance after spending a few days placing my new (to me) Von Schweikerts. When I put proper spikes in them the bass blew me away. Never mind the soundstage. :)
Rower30 Aren't your C4's fairly new. Not sure if the dealer mentioned it but check the screws holding the drivers (not tweeters) and make sure they are snug. They do seem to get a little loose after a while. That reminds me I'll need to check mine again.
"C4 cabinets have next to ZERO resonance even when played hard, so it's the WHOLE unit being moved by the woofers in my case."

Then explain why the spikes make a difference at any volume level.
...If Dynaudio only supplies one type of spike for their speakers they have apparently voiced their speaker that way...

No way that's true as big a difference as it makes in the sound based on the coupling to the floor. That, and you won't like what you hear when the speakers are perched-up on carpet verses firmly in place on a solid floor material.

C4 cabinets have next to ZERO resonance even when played hard, so it's the WHOLE unit being moved by the woofers in my case.

I do agree that different methods will diminish either cabinet resonances or the entire speaker moving about. What ever keeps things still is going to be best.
I think spikes have more to do with bass energy in the cabinet than movement. Take a look at Vandersteen model 2 speakers while playing music with a lot of bass energy. Even with the speaker sitting on stands with spikes the top of the speaker has an enormous amount of movement. There used to be a product on the market called Microscan. It was a resonance control device that attached to the back of the speaker cabinet. The perceived improvement was better upper frequencies, however, this was due to draining resonance from the cabinet and removing unwanted lower frequencies.
Spikes have different affects in different situations depending on the speaker, system and the type of floor. If Dynaudio only supplies one type of spike for their speakers they have apparently voiced their speaker that way.
Starting with the CD3 MKII Audio Research has built in isolation so their CD player sounds the same regardless of what the CD player is sitting on. I guess this is their way of controlling the sound since the sound of a component can change dramatically depending on what it is sitting on. Maybe this is what Dynaudio is attempting to do also.