# Idea for my own sub-dude



## Rancho5 (Aug 20, 2009)

Instead of making a DIY sub-dude out of MDF, carpet and foam, wouldn't it work just to place my sub on a few of those 1/2 thick foam, interlocking floor tiles I have left over from my kids karate room?

My SVS cylinder sub already has the MDF bottom to bounce the waves off of, so making a sub-dude from MDF would be redundant, right? All I am missing is the foam.

Is this too simple? Just stacking a few 1/2" high density foam mats?

PS. I have hardwood floors.


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## bpape (Sep 14, 2006)

The idea with the hard top is to spread the weight of the sub over the entire surface.

The mats will likely do something - just hard to say what exactly. Certainly free and easy to try.

Bryan


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## Rancho5 (Aug 20, 2009)

But considering that the mats are as large as the sub is, wouldn't just resting the sub on the mats distribute the weight?


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## bpape (Sep 14, 2006)

If they're the same size, yes. If the mats are bigger, you can distribute it more with a hard surface on top of the mats for the sub to sit on.

Bryan


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## Alen K (Aug 27, 2010)

Bryan, what kind of foam would you recommend? The idea of the subdude is to isolate the subwoofer from the floor so that all the energy goes into vibrating the air, right? If so, some materials are going to do that better than others.

Also, is such isolation good for the LCR speakers too? IIRC that is recommended in one of Ethan Winer's videos.


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## bpape (Sep 14, 2006)

It's really more a matter of sound isolation rather than changing in-room sound - though, there are cases where what the sub sits in is actually causing problems due to resonation.

The foam would be something that's stiff enough to support things without being overly compressed yet still has enough give that it will absorb some of the vibrations. The more surface area you spread the weight over, the more there is per unit area to 'give'.

The downside is that this does let the cabinet of the sub move a bit rather than forcing all the motion to be the driver itself. It's the old equal and opposite reaction thing. When the cone wants to move forward, the force wants to push the cabinet backward. The foam will allow this to a certain extent whereas something like spikes resists that counter motion.

The only time I've seen benefits for L+R is in a studio environment where monitors are sitting on a desktop and causing resonances from the desk itself.


Bryan


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