Speaker stands question (platform small and speaker big)

pennylane · « **on:** 17 Oct 2005, 07:20 am »

I have Polk LSi9's for speakers. They're area is 8-5/8" W x 15-1/4" D (and about 15" high), and are 30 lbs each.

I'm thinking of these 2 speaker stands:

http://www.audioadvisor.com/store/productdetail.asp?sku=ATLPRO28P&loc=5
That platform is 6.5" W & 7.5" D. They're 28" high.

http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=240-744&DID=7&raid=45&rak=240-744
That platform is 8-3/4" W x 9-3/4" D. They're 25" high.

I prefer the Atlantis stands. I prefer their height and their color and their look, but I'm a little concerned about their platform area. Should I be?

Another option is to go get Skylan Stands customized, but that's $200. Should I be willing to spend $200 on $700 speakers? That seems a little unreasonable to me. What do you think I should do?

(btw, I live in California, where earthquakes are possible, if that makes a difference)

jules · « **Reply #1 on:** 17 Oct 2005, 07:50 am »

yes, neat enough stands but I'd be worried about the size of the base too.

With 30lbs on top a slight knock could easily push them past the point of no return and it really wouldn't be something you could quickly grab and save.

Maybe it depends on how busy your listening area is.

edit: sometime it can be cheaper to design something yourself and have it made up ... but I confess to being a DIY fan.

jules

andyr · « **Reply #2 on:** 17 Oct 2005, 09:49 am »

Hi pennylane,

I have no idea whether he was bullshitting me but, FWIW, my local dealer said to me when I asked him about his stands (after buying some similar-sized speakers to yours) that stands with a large base area were sonically worse than a stand with a smaller base area?

So I would say go for the Audio Advisor stands. You should put a small blob of "BluTak" (say 3/8" diam) at each corner under your speakers - this will squash flat but will couple them well to the stand. Your only concern is then ... is the base of the stand stable?

Regards,

Andy

pennylane · « **Reply #3 on:** 17 Oct 2005, 05:32 pm »

jules,
I don't mind the DIY route but the only place I know that would is Skylan Stands and it's pretty expensive. Do you know of other places?

MerRev · « **Reply #4 on:** 17 Oct 2005, 10:34 pm »

Here is a stand I have had my eye on for quite some time. The top plate dimensions are 7"W by 8"D. I believe your Polks are almost 55lbs!
I had a pair of the Polk RTi-35's which measure similiar to the LSi9 and had no problems with the typical top plate dimension (6"x7").

http://www.lovanusa.com/product_info.php?cPath=60_66&products_id=115

Good luck with your search.

-Chris B.

jules · « **Reply #5 on:** 17 Oct 2005, 11:30 pm »

pennylane,

I'm in Australia so I can't help you on a constructor but I've found that the best approach can often be to find a local person who isn't well known and over priced. There have been many occasions when I've put together a drawing of something I'd like made and taken it to a local fabricator to find that the cost is less than something that is part of a commercial run. [The floor on my amp was pretty much a one off but still cost a lot less than many simpler commercial designs]

I suppose the point that Andy's dealer made about base size would hinge on the idea that a larger base could be more prone to potentially harmful vibration. Expressed in another way it's resonance frequency would be lower if it was the same thickness. If that's the problem good design should offer a solution. Strength is roughly proportional to the square of thickness here so an ugly monster doesn't have to be the solution.

I'm using milk crates at the moment

jules

Scott F. · « **Reply #6 on:** 17 Oct 2005, 11:47 pm »

Quote from: pennylane

jules,
I don't mind the DIY route but the only place I know that would is Skylan Stands and it's pretty expensive. Do you know of other places?

Hi pennylane,

Since you don't mind the DIY route, you may want to think about the old Stubby design. You can have Home Depot (or Lowes) cut all the wood and PVC for you, that would leave you with some staining and drilling. They really are easy to build and are dead quiet.

You wouldn't have to use a single piece of 3" PVC as the stanchions. I've talked to lots of guys that have used (say) three pieces of 1 1/2" diameter PVC on an enlarged base. Several of them have used MDF rather than hardwoods with good results too.

Anyway, heres a link to the original article.
http://www.tnt-audio.com/clinica/stubby_e.html

Like somebody has in their tag line,
DIY or die trying!

pennylane · « **Reply #7 on:** 18 Oct 2005, 06:24 pm »

Scott F.,
That's a great link. Thanks! I'm not that experienced with DIY but wood working is something I've always wanted to get into and I know people that could help me. I think I'll try that route. I don't want something ridiculously high class, just something that looks nice. If I screw up a couple times and it gets expensive, I can always chalk up the extra costs to "learning experience" expenditures.

andyr · « **Reply #8 on:** 19 Oct 2005, 10:58 am »

Quote from: Scott F.

Hi pennylane,

Since you don't mind the DIY route, you may want to think about the old Stubby design. You can have Home Depot (or Lowes) cut all the wood and PVC for you, that would leave you with some staining and drilling. They really are easy to build and are dead quiet.

You wouldn't have to use a single piece of 3" PVC as the stanchions. I've talked to lots of guys that have used (say) three pieces of 1 1/2" diameter PVC on an enlarged base. S ...

Hi Scott F,

I've only juz realised you must be the author of that great TNT "Stubby" article!

Did you ever try filling the plastic pipe with lead shot instead of sand?

I'm sure it makes a different sound but whether it's better or worser, I have no idea!!???

Regards,

Andy

Gordy · « **Reply #9 on:** 19 Oct 2005, 12:51 pm »

Quote from: pennylane

jules,
I don't mind the DIY route but the only place I know that would is Skylan Stands and it's pretty expensive. Do you know of other places?

Chris at Timber Nation does beautiful work and will do custom work. His prices seem extremely reasonable to me! http://www.audiocircle.com/index.php?topic=8249&start=100

Scott F. · « **Reply #10 on:** 19 Oct 2005, 02:04 pm »

Quote from: andyr

Hi Scott F,

I've only juz realised you must be the author of that great TNT "Stubby" article!

Did you ever try filling the plastic pipe with lead shot instead of sand?

I'm sure it makes a different sound but whether it's better or worser, I have no idea!!???

Regards,

Andy

Actually no, I've not tried lead shot. Just thinking out loud (which can be dangerous on an audio board), using lead shot in the stanchion would probably result in a lower resonant frequency than the sand due to its specific gravity.

The real question there begs, is the resonant frequency of sand in the stanchion lower than the lowest audible output of your speakers. Considering they are bookshelves, your lowest output is probably somewhere near 40Hz.

Guessing (and leaving the hard math for somebody with a CRC Property of Materials book), I'd say the resonant frequency of the sand filled sand is some where between 10 and 20Hz (maybe a bit higher). The lead has somewhere near twice the specific gravity of the sand (3600 #/cu m vs 1600#/cu m). Again guessing, that would put the RF around 10Hz.

The next question is the lower RF of lead worth the monitary costs? Only your hair dresser knows for sure.

My vote......try 'em both and let us know whcih you like better!

Have fun building!

andyr · « **Reply #11 on:** 19 Oct 2005, 08:13 pm »

Quote from: Scott F.

Actually no, I've not tried lead shot. Just thinking out loud (which can be dangerous on an audio board), using lead shot in the stanchion would probably result in a lower resonant frequency than the sand due to its specific gravity.

The real question there begs, is the resonant frequency of sand in the stanchion lower than the lowest audible output of your speakers. Considering they are bookshelves, your lowest output is probably somewhere near 40Hz.

Guessing (and leaving the hard math for somebody ...

Thanks, Scott,

Yeah ... makes sense!

Regards,

Andy

JohnnyLightOn · « **Reply #12 on:** 20 Oct 2005, 04:20 pm »

Great thread! I only need a single speaker stand to match a cabinet that holds the other speaker, and with the TNT DIY plans I can build a good looking stand at the exact height I need for pennies!

brj · « **Reply #13 on:** 20 Oct 2005, 05:06 pm »

Quote from: Scott F.

Actually no, I've not tried lead shot. Just thinking out loud (which can be dangerous on an audio board), using lead shot in the stanchion would probably result in a lower resonant frequency than the sand due to its specific gravity.

There is no doubt that lead is denser than sand, but don't you want the greatest total mass? The much smaller particle size of sand would allow a far more complete filling of any given volume, as there would be practically no air gaps. I wonder if this might provide a greater total mass for a given volume, especially if you can locate some very fine grained sand.

I suspect that there is another benefit to small particle size... surface area. Because sand grains are so much smaller than lead shot, the combined contact area of the particles will be significantly larger. Ignoring surface roughness for the moment, this greater contact area results in more friction, which means that vibrational energy is more readily turned into heat.

Of course, I'm just thinking out loud as well, so I'm in just as much danger as Scott!