PS audio explain how spike at bottom of the speaker works

[gerG]

The answer is, of course, it depends. The original idea behind the spikes is that they couple to the floor, preventing the speaker cabinet from vibrating counter to the cone motion. If this happens, one woulh have out of phase signal cancelling the "correct" signal. Probably works for a sealed cabinet running at low frequency with concrete floors and carpet. It get more vague with bass reflex ports and wooden floors. How to tell what is best? Easy, run a test! Easy enough to put a mic in front of the speaker and do a response sweep, or even pink noise with an RTA. Try with and without. Next level is a vibrometer on the speaker cabinet. More difficult to find, but you could figure out the resonance frequency of your speaker/stand combo. The toughest one is something like Newman's LSR6325P on a tall stand. Those are heavy aluminum cabinets (I have several pairs) and they make a great pendulum. Fortunately they are going to rock, er. oscillate at a low frequency. Keep your crossover above that, and it does not matter much. Taller stands and heavier speakers push the resonance to a lower frequency.
There is a company called Isoacoustics that make stands designed to let the speaker vibrate in space. Their intent is to decouple the speaker from a desk or console to eliminate annoying vibrations. They work for that. I am ashamed to admit that I have not tested them to determine the sonic impact. The company rep told me that they actually improve the sound. I doubt that, but without data I can only conjecture. As far as desk stands go, I really like them.

 

[Newman]

The original idea behind the spikes is that they couple to the floor, preventing the speaker cabinet from vibrating counter to the cone motion.

But they don't prevent that. It's a false premise, like I said.

Fortunately they are going to rock, er. oscillate at a low frequency. Keep your crossover above that, and it does not matter much.

The pendulum Fs for my setup is about 2 Hz back-and-forth, 1 Hz side-to-side. They could be subwoofers and it wouldn't matter, in terms of rocking in response to cone motion. My point.

And if I had spikes, it would prevent nothing: those Fs values would be the same, except it would rock back onto the rear spikes, then (Ker-lunk) onto the front spikes. Which would only be worse. Fortunately it's a false premise.

 

[gerG]

But they don't prevent that. It's a false premise, like I said.


The pendulum Fs for my setup is about 2 Hz back-and-forth, 1 Hz side-to-side. They could be subwoofers and it wouldn't matter, in terms of rocking in response to cone motion. My point.

And if I had spikes, it would prevent nothing: those Fs values would be the same, except it would rock back onto the rear spikes, then (Ker-lunk) onto the front spikes. Which would only be worse. Fortunately it's a false premise.

In your case, I agree. I was guessing about 5 hz, but my calibration must be off.
However, take a system with a light cabinet and a large low mounted woofer or PR, sitting on carpet. No longer a pendulum, but a block sliding back and forth. It is possible, I think, to hit frequencies where the cabinet moves and creates energy losses. You can actually see this in some subs with undersized cabinets.
One real practical application of spikes is wobbly speakers. They are dandy for stabilizing a cabinet that moves around from floor movements.

 

[Newman]

How many pro Subs have you seen that dig as deep as some of us pursue for HT, Organ and Electronic music (ie 10-16Hz)?

Irrelevant in a discussion of speaker stands for standmount speakers.

And yes I am well aware that my pro sound mention is not 100% transferable to home audio, but the real difference is not that their world is uncaring about speaker vibrations: the real difference is that their world is full of trained engineers making purchase and setup decisions, who are slightly less susceptible to internet banter and comments starting with "an argument could be made", or product 'white papers' found somewhere on the internet, compared to home audio enthusiasts telling one another what is what. They just know what actually happens wrt vibration: eg if that suspended event speaker was moving back and forth freely with the (vast) sonic energy going through it, it could lose up to 6 dB of output, requiring a quadrupling of amplification power (and onsite generator output) to meet the SPL targets for the event. Not a trivial matter.

cheers

 

[HiFidFan]

Paul's having a rough week

 

[Holmz]

Yes, my little subs have rubber cover for the spikes, to suit my nice hard oak floor.
Spikes on that floor would lead to divorce.

Stilettos as well?

 

[Ped]

the PS video is back up ...................

To spike or not to spike

httpv://youtu.be/4r5D06Evq10

www.psaudio.com

 

[Holmz]

The hand gesture is enough for me to know the likely answer without hearing the question.
99% of the time it is either:

• It depends.
• One needs to listen.
  

 

[TheBatsEar]

The hand gesture is enough for me to know the likely answer without hearing the question.
99% of the time it is either:

• It depends.
• One needs to listen.

View attachment 252834

I use that gesture when dinner is ready. I see nothing wrong with it and will not apologize for using the same gesture, even between meals for cookies and other scraps.

 

[MattHooper]

I had spring footers under my speakers for a while. The speakers normally sat directly on a carpet over a 1st floor wood floor. When bass content would be present the floor clearly vibrated. I could stand beside the speaker and feel the floor rumbling beneath my feet. And I could feel the vibrations right through the ottoman I’d rest my legs on, as well as sometimes right through my listening sofa.

However with the springs decoupling the speakers, there was zero noticeable vibration. From the floor around the speakers or through the furniture. It did change the listening experience to some degree. Tighter bass, but also lost some “feel” from the music that I’d always liked. Ultimately I left the spring footers off as I liked the connection and feel of the music with the speakers vibration the floor.

 

[TheBatsEar]

However with the springs decoupling the speakers, there was zero noticeable vibration. From the floor around the speakers or through the furniture.

Will the floor "play" all frequencies, or just a few resonances? Would the floor work against or towards room modes? Could a vibrating floor work against nulls by exciting the room everywhere?

How do we ship a room to @amirm and how do we get it into the Klippel?

Ultimately I left the spring footers off as I liked the connection and feel of the music with the speakers vibration the floor.

Apparently people screw these on to their lounges to get that effect, never tried one, but i'm mildly interested and ordered one:

Tactile Exciter

Dayton Audio Exciter

www.speakerbuddies.eu

 

[bodhi]

Anyone know what actually was the original purpose of spikes? For example, carpets and stands for putting things on the have been around a while before speakers. Were they spiked?

Could this be the usual case that something has been around for so long and for mundane reasons that people just assume they are important and when the original reason does not apply (hard floor) a new one had to be invented?

 

[ahofer]

To make getting it in position much harder, and annoy the neighbors more.

 

[TheBatsEar]

Anyone know what actually was the original purpose of spikes?

We may never know, Spikology is a constantly underfunded field of science.

But it's an interesting question for sure. I would think it was for stability only, to couple something to the ground proper.

 

[IPunchCholla]

I did it at the suggestion of an audiophile friend way back when. He suggested it for making the speakers sound better. I couldn’t hear a difference, but the speakers felt much more stable. This was on vinyl over concrete. Now they’re are on carpet and I have left the spikes on for the same reason.

 

[Holmz]

At XMAS floating them in the air on springs is good.
At Easter,… spikes.

 

[Ped]

Anyone know what actually was the original purpose of spikes? For example, carpets and stands for putting things on the have been around a while before speakers. Were they spiked?

Could this be the usual case that something has been around for so long and for mundane reasons that people just assume they are important and when the original reason does not apply (hard floor) a new one had to be invented?

A few decades ago I was advised by a non-technical friend that it was to stop the cabs moving laterally and thereby nullifying the movement of the cones.

 

[thewas]

Guess due to their shape some audiophiles think that spikes are like "mechanical diodes" transmitting vibration in only one axial direction which is nonsense of course.

 

[nerdstrike]

Hmm.... I suppose spikes mean you don't have a big flattened patch on the carpet when you later move your speakers.

You also might find that the speaker is a little harder to tip over on deep pile.

 

[TheBatsEar]

"mechanical diodes"

Brilliant.

Forwarded to the marketing dept.