Shock Mount for Speakers?

Green House · Post by **Green House** » Sun Feb 22, 2004 3:44 pm

So I am going to soffit some nearfields. I am going to mount them so that they are not touching the control room wall. I was thinking of building stands behind the wall with rubber feet and sand etc. Then I had an idea...

Would it be possible to "hang" the speakers between two structural members inside the wall. I am thinking the way a shockmount works (some sort of elastic like bungee or something). Maybe build a little frame for the speakers that has mounting rings built into it. Then suspend it from several directions. Adjust to get it in just the right place. Then put your outer bezel around the speaker.

Seems like this would completely decouple the speakers from the room...and it would be cheaper than building good stands. Am I crazy?

Thanks,
Richard

barefoot · Post by **barefoot** » Sun Feb 22, 2004 6:21 pm

I think this would be a lot more trouble than it's worth.

In order to get good isolation the bungees would need to be fairly soft and rubbery. So the speaker would tend to sag over time. Wires wouldn't sag, but they would transmit vibrations like guitar strings.

I think a solid base with a firm neoprene pad would work fine. Remember, some sound from the rear will come through the gap in the bezel. So, extreme isolation would be wasted. The main point is to prevent the vibrations in the speaker box from exciting that large soffit baffle.

If you really want to get rid of the vibrations, then go directly to the source. Modify the speaker box by gluing some thick slabs of MDF or granite to the sides!

Thomas

Green House · Post by **Green House** » Sun Feb 22, 2004 6:52 pm

Thanks for the reply. So I will probably build a column style speaker stand with a neoprene pad for the speaker to sit on.

If the neoprene is under the speaker itself, is there anything wrong with screwing the stand directly to the floor?

Thanks,
Richard

omegaarts · Post by **omegaarts** » Tue Apr 27, 2004 1:59 pm

Thomas,
What about spikes mounted to speakers and sitting in small disk on stands or console extensions?
Thanks,
Larry

AndrewMc · Post by **AndrewMc** » Tue Apr 27, 2004 4:57 pm

Gives me an idea

it would be fairly easy to make some concrete slabs the size of the monitors base/top and sides. Maybe make a small frame using 2x2 wood - lay on a sheet of plastic and pour in some mortar with a bit of rebar. Then use these in the soffit after binding them around the monitor.

Would only take a few hours to make the slabs - would it be worth it?

barefoot · Post by **barefoot** » Wed Apr 28, 2004 3:18 am

Green House wrote:If the neoprene is under the speaker itself, is there anything wrong with screwing the stand directly to the floor?

Sorry for the very late reply GH. This one slipped through the cracks.

Yeah, screwing the stands to the floor is fine, especially if the are fairly massive and have good internal damping... like sand filled.

omegaarts wrote:What about spikes mounted to speakers and sitting in small disk on stands or console extensions?

Spikes are fine. They're just another way decupling the vibrations. But, it's not any kind of mysterious "transmission line" effect like many suggest. Consider this schematic of how a cabinet vibrates:

The walls flex about the corners. If the cabinet just sits on a surface, the full amplitude of the bottom panel is transmitted. Since the spikes are typically mounted near the corners, the amplitude is much less. They act as fulcrums. So spikes or rubber feet are simply another way of decoupling the center of the cabinet bottom.

AndrewMc wrote:Would only take a few hours to make the slabs - would it be worth it?

Yeah, I like this idea! I don't think you need rebar though. Sand or stone aggregate would be fine. And the thicker the slab the better, because it will wall have more inertia.

Here's another idea for a completely overkill speaker stand. Just cut a piece of 16 inch sonotube to whatever height you need, cap off the bottom and fill it with concrete. It might only weigh a few hundred pounds or so!

Thomas

dk01 · Post by **dk01** » Tue Aug 31, 2004 8:47 am

Thomas,

I did this with cement and tube columns.... they were super dense. What I do not get is that UNLESS you completely isolate these cement columns from EVERYTHING else - they resonant anything on the floor they sit on and anything within many feet around sitting on the same floor.

It seems that its forgotten that sound travels through this material quite easily... it used to be thought it didn't or something?! Or am I just confused - ??? Read it in one of Forest's books...

The cement things were a lot of work - I guess if superiorly isolated (straight into the earth or properly spec'ed neoprene floaters) they would work... but, I just don't see how it really is the best way for an overkill speaker stand - my results did not prove this at all. Curious as to what I do not understand and how or why these were not effective... People think your nuts too when you are buying cement (and NOT laying a foundation or mounting a mailbox!)... they think you did something illegal like you killed someone....

best,

David