Where do you find slabs of granite to use under speakers/subs?

jcaut

I need something more massive than just a floor tile, no? The Home Depot guy just looked at me like I was nuts...

I just set up a rig in my new (old) home and it sounds terrible. I'm used to being on a concrete slab with my speakers spiked to the floor. This house I'm going to be moving into is old, and is built on a crawlspace. I've got lots of hardwood floors, however the particular room I set the system up in is carpeted. Obviously lots of energy being transmitted through the floor and walls. Everything resonates. My bass is all chesty and boomy! I CAN"T LIVE LIKE THIS!

Any ideas? As many speakers as I have, I may have to spend a fortune on granite.

Jason

brettw22

I think i remember faster checking with his local garden shop and they were selling that stuff off pretty cheap comparatively to other places such as Home Depot or anywhere like that

dorokusai

J - I have a 12x12x1 1/2 piece of black granite for you if you want it. It's heavy, and rough cut, but the cost is free for you. We can work out shipping, if I even do that at all. Let me know if you are interested....you will just have to send a thank you email to my homeboy, who hooked me up, on this end, how's that for a deal?

Home Depot = No.

Local Granite/Stone Cutter = Yes. Scraps are normally available, and sufficient size for us audio nuts, but you have to be regular and friendly.

GregBe

I have hardwood floors over a crawlspace and was thinking of trying this as well. Is the use of granite for looks only, or can I use something else. Home Depot has a 12" x 12 " x 2" concrete paver that would fit under my sub. I don't care about looks, my sub is hidden.

I would love to hear about positive or negative experiences. Also, My sub has spikes that I currently do not have installed because of the hardwood floors. Would this make a difference on top of the concrete/marble, or would this just cause more vibration problems.

Greg

faster100

i used 16x16 step stones from walmart, painted them black for the pb2, for my pb1 i used a A/C slab 24"x24 painted... that went with the sub when i sold it to spastic, both work great for getting rid of vibrations, i have wood floors with a space underneath also... dirt ground.

Willow

to protect your HW floors you could use non-skid tool boxliner is thin and non skid and will protect your beautiful floors

sorry that was to sit under whatever type of slab you use

dorokusai

I wouldn't buy granite from HD simply because of price, and it's just a piece of tile essentially. Concrete pavers are available from HD, and 100% functional for this purpose.

I experienced better performance from my subwoofer, prior to the SVS, with the use of granite. I only used granite because it is free for me, a concrete paver would have been fine.

johnny_utah

I was interested in a slab as well. I was thinking of making my own cement slab with a bag of concrete from HD and some black spray paint. Will this be the same thing as "Concrete pavers"? Thanks

jcaut

I think I'll try the concrete paver idea first. I'm pretty sure my local Wally World has those, so that's probably the easiest. Thanks for the offer on the granite slab, Mark. And thanks for the good ideas, everyone. I'll give it a shot and report my findings.

GregBe,

The difference I'm hearing is huge, and though it's probably not ALL attributable to the difference in the floor construction, I'm convinced that it's at least 80% of it. Perceived QUANTITY of bass is greater, but it's because the walls and the floor are resonating, and it really sounds sloppy. I think that, for you, getting that sub up on a piece of massive stone would really tighten up the bass. Use the spikes, too, I believe.

Jason

jcaut

j-u,

My wife suggested that last night while I was describing the "problem" to her. I like to build speakers, so she suggested that I could build a box, fill it with concrete, and then finish it to match the speakers. Probably not a bad idea, but for now I'd like to find something that will work without being so much WORK..:p

jdeej777

This may be a stupid question..

I have a PSW404 on a carpet and so I think I get some of the vibrations I read on this thread. Just want to know if there's any size of slab (whatever it's made of) that I need to consider. Does it need to be bigger or smaller than the size of the bottom of the sub?

Is there a preferred material to be used like granite or a simple tile or "book" will do..

Thanx.

dorokusai

It should be big enough for the feet to make solid contact. A concrete paver is typically 12x12.

jdeej777

Thanks for the prompt response, dorokusai.

So any material will do as long as it's solid?

dorokusai

I wouldn't say that. You want something that will create a solid, non-resonating base. A concrete paver is as cheap as you can get, and will give you the ability to determine if you want something more aesthetic later, without the investment.

The paver will also show you whether or not this idea is going to help you....and if it doesn't you are only out $2. The sonic improvements will be subject to your interpretation. I can't say that it will help you, but it helped me and others. SVS, for example, has a integrated, rigid base for a reason.

The concrete can be sealed and painted any color you want, just as a side note.

A piece of wood for example, in this application is not a good choice.

jcaut

I got a couple of 16x16x2 concrete pavers from walmart this afternoon for $5.14. They're brick red, so I think I'll paint them flat black. I haven't had a chance to try them yet, but they're bound to help.

Jason

scottnbnj

that's good they're 16", might help if they span two joists(at least come close) instead of balancing on the floor/subfloor over only one.

)

dorokusai

If you want to get into the distance between joists, and the associated spec's....your getting extremely involved, and into the "why bother" area. Room tweaking, is a one on one excercise.

The original question was concerning a simple tweak of solid slab vs nothing at all.

Joist width? Are you kidding me?

VR3

Just curious...but

What would you accomplish with knowing the distance between the joist? And yes, they are 16" apart - if the house was built on center.......

Do you plan to set the slab on each side of the joist....

Just curious what you think this will accomplish?

Now if you set it over a pillar -- I could probally understand

johnny_utah

Originally posted by dorokusai The concrete can be sealed and painted any color you want, just as a side note.

Does concrete have to be sealed before it is spray painted for inside use?

jcaut

Probably doesn't HAVE to be sealed, but it might make it easier to paint.

I was actually thinking of using some of that spray-on truck bed liner. I've used it on home-built speaker baffles to give a textured finish. It covers even the routered edges of MDF pretty well in one coat and dries to a tough plastic-like finish. Smells bad for several days though....

faster100

I painted smooth concrete, and it does pick off if you bump into it at first, once its cured it was pretty good.. The pavers are very poarse and they took the paint right on, no peeling or problems from the get go,

steveinaz

JCAUT- I know your pain, I have a concrete slab home and love the sound I get. A large ceramic tile isn't doing the trick? You might consider a large concrete paver spryed with one of those simulated "rock" spray paints--you can get some pretty neat results with experimenation.

jcaut

Thanks, Steve

Yeah, I was really surprised at the difference in the sound. I've got the concrete pavers. I'll probably get around to trying it this evening.

Jason

Willow

could you maybe lay some marble looking vinyl tiles over the slab ??

GregBe

jcaut,

I am sure you know this, but there is a lot that goes into the sound of the sub. If the concrete does not work, don't get frustrated. It may be the room peaks and dips, and moving the sub around may help considerably.

Hopefully it will be your answer though. I am going to try it myself tonight. For $.98, what do I have to lose.

Greg

scottnbnj

Originally posted by dorokusai
If you want to get into the distance between joists, and the associated spec's....your getting extremely involved,

not really, if you're familiar with construction, or know someone that is, it's usually a alot quicker than running to home depot and easier carting slabs of granite around.

and into the "why bother" area.

not really, what are you trying to accomplish by putting a slab of granite on the floor anyway? crush the carpet?

Room tweaking, is a one on one excercise.

The original question was concerning a simple tweak of solid slab vs nothing at all.

not really, here is what jcaut says:

"...Obviously lots of energy being transmitted through the floor and walls. Everything resonates. My bass is all chesty and boomy! I CAN"T LIVE LIKE THIS!

Any ideas?..."

i just offered the *best* way in ~probably~ 99% of all cases of placing a slab on a wood framed floor w/ joists on 16" centers, where the flooring/subfloor thickness is anything less than a good bit thicker than average, with the material he already had to help reduce, as he said, resonance created by a sub transmitted through the floor and walls.

Joist width?

i don't think i mentioned joist width. based on what jcaut said, it's more than likely that his floor joists are spaced on 16" centers. it could be different, but then, if he came back and said that and that what he was doing wasn't working, i'd have different advice.

in any case, the joist width is something altogether different.

Are you kidding me?

no. not really.

his problem might well not need the *best* placement method. that's ok too, but, does that mean that i shouldn't offer it in one sentence or less if i know it?

btw, did i just waste all this time because i missed the point that you were just kidding the newbie?

darn, i hate when that happens.

)

dorokusai

Who's the newbie? It can't be you, you've been here. It was meant to sound lighthearted, not offensive BTW.

The joist comment, was in relation to the lack of not having to think about the issue that far. It simply doesn't matter, he's not building anything.

Whether he uses a 16x16 or a 12x12, it's going to create the same end result....it may help him, or it may not. It should help because the energy is not being directly transmitted into the subflooring....then the walls, blah blah. Placement is up to him, no kidding, it's a given.

Excuse me, "span two joists". I'm sure everyone was completely befuddled by my incorrect qoute :rolleyes:

If you want to find out more about subwoofer design and build theory, do a search on Yahoo. As an example, SVS has an integrated baseplate on their subwoofers to create a stable firing platform.

The slab under subwoofer is a common tweak in audio.

jcaut

I had no idea this query would get this many replies
I appreciate everyone's suggestions!

Technically I wasn't even talking about a sub, just some little 'ol RT55i's on some fairly cheap wood stands. They sound great at my present house and really bad everywhere I put them in the new (old) house. If I take my PSW1200 over there, I'm afraid I'll shake the whole house down!

dorokusai

Oh....LOL

scottnbnj

oh,.. nevermind.

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