What type of sand for dampening??

0 Members and 1 Guest are viewing this topic. Read 4790 times.

fu_man

What type of sand for dampening??
« on: 28 Mar 2007, 12:26 pm »
Hi, I want to add  sand to my  DIY  speaker  stands, and around  my (Front)  horn for mass loading/  dampening.  Anyone know what  type of sand I should  use? I have some  clean  "sharps" dry, no fines sand.  Or should I  use a fine rounded  sand?


Any  clues?

Thanks

mcgsxr

Re: What type of sand for dampening??
« Reply #1 on: 28 Mar 2007, 02:03 pm »
I used silica sand in mine - white, fine, clean, and completely dry.  50lb sacks were cheap too, at the local construction supply store.

Same stuff I used to use when doing interlocking brick.

rollo

  • Restricted
  • Posts: 5530
  • Rollo Audio Consulting -
Re: What type of sand for dampening??
« Reply #2 on: 29 Mar 2007, 02:10 pm »
Play sand. For sand boxes.

   rollo

chgolatin2

Re: What type of sand for dampening??
« Reply #3 on: 29 Mar 2007, 02:59 pm »
Regular sand or Silica for sure.  I wouldnt worry too much about that...

DSK

Re: What type of sand for dampening??
« Reply #4 on: 29 Mar 2007, 03:03 pm »
Play sand. For sand boxes.

   rollo

Do NOT use regular play sand ...the moisture content is too high. Use fine kiln dried sand, available at hardware stores and inexpensive.

mcrespo71

Re: What type of sand for dampening??
« Reply #5 on: 29 Mar 2007, 03:07 pm »
Play sand. For sand boxes.

   rollo

Do NOT use regular play sand ...the moisture content is too high. Use fine kiln dried sand, available at hardware stores and inexpensive.

I had trouble when I used this type of sand in the bright star sandboxes.  It was too fine and would get really dusty (would puff out of the crevices) when I moved the boxes.

DSK

Re: What type of sand for dampening??
« Reply #6 on: 29 Mar 2007, 03:13 pm »
Play sand. For sand boxes.

   rollo

Do NOT use regular play sand ...the moisture content is too high. Use fine kiln dried sand, available at hardware stores and inexpensive.

I had trouble when I used this type of sand in the bright star sandboxes.  It was too fine and would get really dusty (would puff out of the crevices) when I moved the boxes.
It is true that it is powdery but it won't dry out and 'cake' or harden like play sand can (losing its damping qualities). You just need to ensure that the welds on the speaker boxes seal the join, otherwise run silicone around them (black silicone doesn't show on black metal speaker stands) or tape or whatever. The other method is to buy regular sand but dry it in your oven first ...not worth the hassle when you can just buy a bag of cheap kiln dried sand to start with.

avahifi

  • Industry Contributor
  • Posts: 4698
    • http://www.avahifi.com
Re: What type of sand for dampening??
« Reply #7 on: 30 Mar 2007, 12:29 am »
Kitty litter works great, as long as you keep it dry and don't have kitties.  :)

Frank Van Alstine

fu_man

Re: What type of sand for dampening??
« Reply #8 on: 30 Mar 2007, 06:31 am »
thanks for the suggestions.
Do you  think  fine sand (and kitty litter)  would  absorb airborne  water ( high humidity )  more  so than  coarser  sands?

DSK

Re: What type of sand for dampening??
« Reply #9 on: 30 Mar 2007, 06:34 am »
thanks for the suggestions.
Do you  think  fine sand (and kitty litter)  would  absorb airborne  water ( high humidity )  more  so than  coarser  sands?
???? Once you insert the sand, you should totally seal the stands as I described above.

HChi

  • Jr. Member
  • Posts: 174
Re: What type of sand for dampening??
« Reply #10 on: 30 Mar 2007, 01:32 pm »
Due to the same moisture reason of causing sand to stick together, I would stay away from sand.  If you could contemplate the micro-bearing steel-fill, but they are expensive; or, you could go to the nearby gun shop and see what is the finest steel shot they carry.

gooberdude

Re: What type of sand for dampening??
« Reply #11 on: 30 Mar 2007, 01:47 pm »
Does anyone remember old Wharfedale speakers (70's) that had sand packed tweeters?  My dad used to be so proud of those.

I remember tearing them apart as tennager & all around the magnet on back was a cake of sand...

is that technique still used today??

Alwayswantmore

Re: What type of sand for dampening??
« Reply #12 on: 30 Mar 2007, 03:36 pm »
I have Skyland stands. They recommended sand used for sandblasting - the smaller / finer size. Advantages: More uniform in size, it has been heat dried, and treated to have very little dust. I bought 100 lbs for under $10.

Tweaker

  • Full Member
  • Posts: 783
Re: What type of sand for dampening??
« Reply #13 on: 30 Mar 2007, 07:55 pm »
Star Sound sells micro-bearing steel fill:
http://www.starsoundtechnologies.com/micro.html
It's $46.99 a quart. It does seem lke a better idea than sand.

Wardsweb

Re: What type of sand for dampening??
« Reply #14 on: 30 Mar 2007, 08:36 pm »
I use bead blasting media. It's finer than sand, pure white and pours like water.


DSK

Re: What type of sand for dampening??
« Reply #15 on: 31 Mar 2007, 01:28 am »
IMHO this is a great example of a tweak that audiophiles obsess over unnecessarily.

The speaker resonates, which in turn excites resonance in the stands, which in turn excites resonance in the floor, which in turn may excite resonance in the equipment rack and your components. So, assuming that you have decently built speaker boxes to minimise their resonance, the main objective is to minimise resonance in the stands. If several methods achieve this, then the secondary objective is to do it with materials that are readily available and as inexpensive as possible.

A real life example.... I built new speakers last October and bought new stands and customised them to ensure optimal speaker height to listening height. Before filling the stands, when I tapped on the metal legs with the metal end of a screwdriver, they would rrrriiinnnnggggg for over THREE seconds. I ran a bead of black silicone around the end of each leg to ensure that the welds were air tight and allowed it to dry and cure for a couple of days. I then filled the legs with fine, kiln dried sand (cheap and readily available at hardware stores) and sealed over the little filler holes with black electrical tap. The black silicone and black electrical tape are not visible on the black metal legs unless you put your head near them. Now when I tap the legs again, there is an extremely short and dull 'clunk' with no audible ring whatsoever. The sand only cost a few bucks and I picked it up at a hardware store less than a mile away from home. So, primary and secondary objectives have been achieved.

As long as your stands are already rigid and stable, adding heavier filling will provide no additional benefits over the sand, except perhaps for being slightly more 'topple proof' if you have large dogs or small children.

So, why over-analyse the problem and spend more money unnecessarily when it can be resolved very quickly and cheaply? I would humbly suggest that you are better off putting your time, thought and money toward areas that will yield potential audible improvements. :scratch:

fu_man

Re: What type of sand for dampening??
« Reply #16 on: 31 Mar 2007, 03:06 am »
Some really interesting suggestions.
DSK  thanks for the detailed  description  -  I agree  with what you are saying, and removing the  ring from the stand and adding some weight is one thing I want to achieve.
 
Quote
assuming that you have decently built speaker boxes to minimise their resonance

This  is also part of  what I am trying to do.  Not only filling the metal  stands  to  stop them  ring but also  dampen the  back/inside  surface of a  fibreglass  front horn.  ( i read someone did it to great effect)  Unfortunately the construction method I have chosen/ended up with wont  let me  try one filling  against  another, I only get one shot.. hence:
Quote
So, why over-analyse the problem and spend more money unnecessarily when it can be resolved very quickly and cheaply?
I  agree the cheapest  way to  achieve the same result is the best way!  I have  both a washed, graded dried bagged coarse sand and some clean  washed and dried  fine smooth sand.  Once it's sealed in there is no changing.  I wondered  whether  there might be some established  wisdom on one over the other.  I might see if I can discern any difference in a trial  container.

Around the  back of the  horns is  wood hence my concern that I may not be able to totally seal out all humidity/ moisture - therefore  any material  which "draws moisture out of the air" might not be best.

Interestingly, one guy I know  suggested that  to much  dampening may  in fact rob the dynamics, so achieving this balance may be my biggest  challenge. 

DSK

Re: What type of sand for dampening??
« Reply #17 on: 31 Mar 2007, 03:45 am »
...Around the  back of the  horns is  wood hence my concern that I may not be able to totally seal out all humidity/ moisture - therefore  any material  which "draws moisture out of the air" might not be best....
Yes, my posts have been concerning speaker stands only. I would not use sand in any areas that cannot be sealed. Over time, it would be sure to harden.

...Interestingly, one guy I know  suggested that  to much  dampening may  in fact rob the dynamics, so achieving this balance may be my biggest  challenge.  ...
Yes, I've heard these claims too ...right down to the suggestion of adding 1" of sand at a time to the speaker stand legs and listening between. However, if you think about it, anything removed by the addition of damping material to speaker stands was an artifact (addition) by the stands anyway and was not generated directly by the speaker.

IME any mods that result in a quieter noise floor tend to produce greater natural detail but also a more effortless and clean presentation. Often some splashiness/tizz in the higher frequencies is removed and the more relaxed presentation that results is initially and incorrectly perceived as a loss of dynamics or detail. However, longer listening reveals that the tonality is more natural and there is actually greater inner detail and cleaner leading edges ... it is just that the artifical emphasis or hyper detail is gone, leaving an apparent loss of excitement in initial short term listening. This may be why some people claim a loss of dynamics when adding damping. Otherwise, we would be deliberately designing added resonance into everything.  :nono: