Springs Under My Speakers: What's Happening?

[DMill]

I have speaker stands that can be filled with sand. I never bothered doing it. For one thing it would just make them heavier to move around. For another I doubted
it would make much difference to the sound, which I still tend to doubt. (Though I'm open to the idea).

The only benefit I could ever see was to make them less prone to getting knocked over by kids or pets. But even then, a rolling tackle by a 10 year old is gonna knock them over. I did lose a floorstander once to a cat who like to jump on top. Knocked it over and busted the tweeter and put a giant ding in the side of the cabinet. It was B&W CM4. Cost me close to grand to replace the speaker. Should’ve replaced the cat. Lol

 

[Sal1950]

But it will bug me until the end of days if I don't fill the other one. So I will, of course I will.

LOL, you know you have too.
Then empty one and fill it with lead shot and compare to the sand filled one.
Then empty one and fill it with steel shot and compare to the sand and lead filled ones.
I've read that it all makes audible differences for years.

 

[jdjung]

But did the thread help you to decide if you should fill your speaker stands?

I have a bag of fancy-sand from the days when I sold audio. It was costly when I sold such things, it should suffice for a test. If I see differences, perhaps I will follow up with more materials. I also have a pair of Paradigm Export Monitors, a fine speaker to test the stand-filling hypothesis. They are firmly bolted to steel stands with isolation patches. The stands do ring a bit.

I set up a mic at 1 meter, carefully marking the speaker's position since that is critical.
View attachment 300806

I measured the speaker, then filled it with the sand.
View attachment 300808
I returned the speaker with the stand filled with sand to the same position and (without moving the microphone) repeated the measurement.
Red is with No Sand. Green is with the stand filled With Sand.
View attachment 300811
The differences are tiny. Could it be positioning? I tried to get the speaker to within a few millimeters of original position. I will test for how sensitive the speaker is to position.
I rotated the speaker with the stands filled with sand by moving off axis keeping the distance to the microphone the same. It's only a couple millimeter nudge, about 2 degrees horizontal rotation.
View attachment 300813
A much larger difference is seen due to rotation than can be attributed to sand-filling.
How about vertical? I tilted the speaker back by elevating the front by about 2mm (also a couple degrees of tilt).
View attachment 300814
No surprise the small vertical shift affects the sound more than horizontal:
View attachment 300815

These two results show we can't tell if the tiny differences measured after sand-filling is just tiny changes in placement.

Lastly, how about moving the speaker 8 inches closer to the wall, keeping the mic (as best I can) same distance and orientation to the speaker.
View attachment 300816
This says way more about my room than about sand in my stands. You can see the room mode at 40Hz is unaffected, that's because I moved the speaker closer to the back wall and this mode in my room is transverse to that. I did change the 55Hz mode's depth since that is from front to back wall and the change in position is changing how the speaker is energizing that mode. The peak that moves from 120 to 140Hz and the one that moves from 180 to 200 are cancelation from the back wall. See here for instance:

Monitor Placement - Genelec.com

To create the ideal listening experience, several aspects need to be taken into account when placing the monitors within the listening space. First, you need to identify the listening area within the space and consider where the listener will be placed in relation to the space as well as the...

www.genelec.com

In summary.
I did the time-honored (and slightly messy) task of filling one of my speaker stands with sand. I measured nearly zero difference in sound before and after the stands were filled with sand. I also measured the tolerance of the experiment to speaker and mic placement and showed that tilting speaker position by just a few millimeters in the horizonal or vertical plane made a much larger difference in the sound than the addition of sand to the stands. This gives some confidence that I got the speakers positioned in the same place after filling the stands. I also found that positioning the speakers 8 inches closer to the wall made a much more dramatic impact on the sound than treating the stands with sand.

The room and relative position sensitivities are no surprise. I can't hear the small differences in horizontal or vertical tilt. I can hear the differences in bass as I move the speaker a relative to the back wall. I certainly can't hear the impact of sand in the stands. I can't even measure a difference and the mic is way more sensitive and quantitative than my ear.

Wow thank you! Saves me the possibility of spilling KEF's acoustic innert filler everywhere.

 

[Doodski]

That's a reversed case study of a highly microphonic component.
Engineers have been working on TT isolation since near day 1.
Some change is to be expected and differences easily measured.

It was this tiny little house. I was ~18 and I rented it. I weighed the main floor down with cinder blocks and stopped it from bouncing, rumbling and feedback. There was still air born feedback but it was not too bad.

 

[Ken Tajalli]

I have speaker stands that can be filled with sand. I never bothered doing it. For one thing it would just make them heavier to move around. For another I doubted
it would make much difference to the sound, which I still tend to doubt. (Though I'm open to the idea).

Antibiotics are very effective if one has a bacterial infection. It won't do anything for diabetes ( I guess). Does this mean the drug is a snake oil?
If you have a flimsy metal stand, which suffers from resonances of its own, then filling it with sand or lead shots can help, otherwise it won't .
It is madness to imply that because it didn't work on a good stiff stand, then it must be an old wives tale.
Horses for courses.

 

[Purité Audio]

Any ‘resonance’ must be audible,
Keith

 

[MattHooper]

Any ‘resonance’ must be audible,
Keith

Springs Under My Speakers: What's Happening?

LOL, let's keep going, prove that you have a window. I want proof Purite Audio even made that post before it's worth answering. Could have been hacked. Or his wife posted while he wasn't looking.

www.audiosciencereview.com

Don't leave us hangin'.........

 

[MAB]

Antibiotics are very effective if one has a bacterial infection. It won't do anything for diabetes ( I guess). Does this mean the drug is a snake oil?
If you have a flimsy metal stand, which suffers from resonances of its own, then filling it with sand or lead shots can help, otherwise it won't .
It is madness to imply that because it didn't work on a good stiff stand, then it must be an old wives tale.
Horses for courses.

The stands I tested were not very expensive, steel, and somewhat resonant. Filling with sand made no difference in the sound.
Flimsy does not equal resonant. Bells are not flimsy but are resonant, for instance. You equated the two.
And, sand won't fix flimsiness. Better off upgrading to a better stand, it's not like it's expensive.

 

[Ken Tajalli]

The stands I tested were not very expensive, steel, and somewhat resonant. Filling with sand made no difference in the sound.
Flimsy does not equal resonant. Bells are not flimsy but are resonant, for instance. You equated the two.
And, sand won't fix flimsiness. Better off upgrading to a better stand, it's not like it's expensive.

I said "suffer from".
If it made no difference , or it was not audible or measureable, then iy didn't suffer from its own resonances.
At any rate, dry sand or play sand sells for a few pounds a large bag over here!
Good enough to experiment with and have fun with.
It can't do any harm, as your measurements have shown.
A fancy expensive acoustic sand, is indeed snake oil.
builders dry sand, or play sand is all one needs.