Slate under speakers?


My system - listening area is on a suspended floor loft. Wood floor with carpeting on it. As a trial/experiment I currently have formica covered countertop sink cutouts under each of my Snell Type AIII's. No spikes...just sitting on top of the carpet. The difference was an easily noticable tightening up of the sound...more resolution...so I'm looking for a more permanent solution.

I came across some slate slabs (1 inch x 22 x 34 inches) that would would fit under the speakers nicely. Has anyone used slate in this way? If needed I could spike the platforms into the floor.
fishboat
After much experimentation, I ended up with a similar solution for my previous room. The speakers were spiked onto slate for stability, which was then resting on carpet/pad which provides decoupling. Decoupling the speakers from the suspended floor reduces the ability of the speakers to drive the floor's resonant frequency. Do not spike the slate to the subfloor, as it will negate the decoupling.

Incidently, I kept the same slate in place over carpet in my current room despite the fact that the floor is concrete. It still provides the best and tightest bass.
OK no laughing. A few years ago, I wanted to raise my Hales Rev 3s a bit as I am tall and so is my chair. I have been using this cheap tweek with great results. I purchased a pair of 12" square cement path stones each about 2" thick. Each is placed on four hockey pucks, one at each corner. The Hales are on top with their spikes. Not only are they higher, but they sounded better to me and the base tightened up as well. Cost probably less that $20. The results: priceless. I did paint them black for that high end look.
Woodman...Get them cryogenicly treated and you'll never have to feel inferior again !!!!!!!!!!!!!
If you're not afraid to move things around, I suspect various types of materials placed between the feet of the speakers and the materials being used atop the carpeting will yeild various results.

Sorry ... hate to put it that way but that's my exp thus far with speakers on similar florring... not attached to a slab.

I've read here everything from exotic woods as platforms, pavers as listed right here, slate, boxes filled with sand and other sutff atop that... with spikes and without... with soft poly materials, even read a thread here where the idea of hanging them from the ceiling was submitted.

yikes.

There will be differences using different methods, as there will be raising and lowering their overall height to that of your own ears... so the deal is to see what's best for you and in your own confort zone of attempting.

I've found adding another piece of carpeting over some new deep dish carpeting I recently had put in, and setting a piece of plywood on top of it all and spikeing the speakers to that does a fine enough job for me... for now.

The bass certianly became less boomy and it did not make the highs thin or etched.

I'm doing that with every speaker in the room, rears, mains, and center (once I get that stand built to the right height)... I'm still figuring that one out.

Enjoy.
Hmm..seems like I might have a solution.

Zargon..sounds good..no pun intended (well maybe a little). Your right, spikes are between the speaker & the platform...I forgot. I haven't thought about this stuff for a while..life got in the way. My speakers don't really have accomodation for mounting spikes like 'modern' speakers. Back in the 70's - 80's the speakers were made with simple medium-hard rubber feet .. about a penny in size. Are there any spike solutions for this type of setup? Something that wouldn't add much height?

Tpreaves/Woodman...cryo...my thoughts exactly as I read Woodman's description. You could market them as "CeMAti Platforms" that are made of the rare ResMAti stone...the one known mineral source of Unobtainium. You could shave the cost of materials down if you buy in bulk and retail a set for..say..$295? (a steal!) All kidding aside..I don't doubt you heard some effect as the sink platforms I tried surprised me. They look like [email protected], but they stay in place until I find a replacement (for the last 18 months).

Jim..the height (without any spikes) will be about the same between the slate and the sink cutout. Hopefully there won't be any downside in the switch. I too have read many solutions to decoupling suspended floor speakers...this is what lead me to try the sink cutouts. My biggest immediate concern is getting the speaker placement back to where they are now. I dialed them in by ear-alone one day (about half the day to do it) and they are just right. I measured them a few days later and, oddly enough, the center of my head is at one corner of a 103 inch equilateral triangle...my hearing must be balanced at least. (distance of my head to left speaker to right speaker back to my head as I sit in my listening chair) I wish I had a little more room, but I'd have to suspend my chair over the great room below. Still, things sound pretty special.
Yes. I have my Dynaudio speakers on 1" thick granite slabs.Tightened up the base
Slate is becoming a favored material for custom turntable plinths due to its characteristic of dissipating micro-vibrations. It is not simply mass as several other materials can offer that as well. Apparently it is the layering process when the slate is naturally created.

My guess is that slate will become more popular for a base under component as more hobbyists learn about it. I would think it could be a superior material under speakers too.
I use Adona 24" X 24" granite/mdf platforms under my speakers & the results are amazing.
Better base is just the beginning as I was able to place the speakers closer to both the rear & side walls.
I must disagree with the use of spikes - I can now position my speakers all by myself - which is a major accomplishment (especially on carpet) as the speakers have 4 spikes & discs attatced to the bottom of the metal bases.
My new listening room has cork floors over concrete & the speakers are further from the rear walls but still very close to the side walls & the sound is still fantastic.
Probably the best $500 I have spent on any tweak!
BTW - The graphite SF Stradavari's look even better on the granite bases which is another plus.
I use the Adona platforms as well for my speakers, granite side face down with speakers sitting on the MDF layer. Have been very pleased with this arrangement.
This is a very interesting thread as I spent last weekend doing a similar project. I too was trying to raise my speakers up a bit to suit there location. I took 1-1/8th MDF I had left over from when I built my house, I spray painted it black and installed adjustable felt feet that I purchased at Home Depot. The felt is very dense and I can now move the speakers by myself which are heavy. My speakers have spiked feet and are sitting directly on the MDF platforms. My floor is porceline tile over concrete slab so it's a very hard surface that the felt feet sit on. To my surprise the base is at least as tight as it was and the sound did improve for me by raising up the speakers.
Got mine on spikes, on top of 1.5 (or maybe 1.25, don't remeber) inch granite slabs (custom cut and polished by a stonemonger down the street), and the slabs each on a trio of those "magic" sliding furniture footers. I've never critically compared alternatives, but figured it's got to be better than sitting directly on a suspended wooden floor and I sure do like the way it looks.
Fishboat. Slate doesn't make sense. You would be better off with less density, surface area etc. Blindjims idea of plywood or even MDF would be much better on carpet. Wrap it with felt to make the wiff happy. The sound will just resonate back through your cabinets if you use slate. It doesn't work.
Donjr

Slate doesn't make sense... The sound will just resonate back through your cabinets if you use slate. It doesn't work.

What is your basis for these statements? Do you have first hand experience or are you just theorizing or imagining what might happen?

In fact, there are sound (pun) reasons for isolation of this type for suspended floors and quite a few AGONers have reported success with this method. It worked extremely well for me and the results were measurable, so I'm concerned your absolute statements might misslead others from trying it.
Zargon. I'm just theorizing. It seems to me that slate or granite would resonate, where as MDF or plywood would not. If I were using slate or granite, I would put it on high density foam and not a lot of it, to cut down on how much surface area is touching the carpet. If you're going from having your speakers spiked to the floor (coupled) to putting them on slate on top of the carpet (decoupled), you will surely notice a difference for the better. Not the best though. You've still got something very heavy and dense, condensing the carpet fibers and slightly coupling itself to the floor, especially because of how much surface area there is with a slab of slate or granite. Companies such as Aurelex have done extensive research on this subject and that's why their line of products for decoupling amps (isolation risers) have very little surface area that touches the floor, yet very large surface area for the amplifier up top. The reason this phenom of slate and granite started was the WAF factor.....really. That's how this all got started. Then everytime somone posted the question, people would reply "I use slabs of granite. It made a big difference and it looks great", and everyone started doing it. I'm not saying it's a bad solution for carpeted floors, but there's better out there IMHO.
..got busy and lost track of this thread..I meant to post back with results. I picked them up and instaled them. Originally the speakers were sitting on the carpet that on top of a suspended wood floor-loft. The next step was to use countertop sink cutouts..and there was a marked improvement in tightness (prat?) in the sound from what I could tell. I then swapped out the sink cutouts for the slate slabs. I gotta say, things still sound pretty sweet. Certainly no loss from what I had and I think it's a bit better. Surely looks 100% better and is still a marked improvement over the speakers just sitting on carpet. All theories aside...I think the slate a keeper.
I put Totem Forests on 1 1/2 inch marble slabs and put 4 hockey pucks under the slabs and I am very pleased with the sound.

I think all of this is as the 'listener' believes it to be.

We're using different speakers, on differing sorts of finished flooring, and applying what we feel or hope will improve things.

I suspect any or all of the above concoctions could be the fix for non solid floors. BUT it seems a no brainer additional attention to those instances is required for better results.

I'd like very much to try a composite layering of Ebony, Mahogany, and granite, totaling under 2in. with the Mahogany on top and stone on the bottom.

Everytime I've used Mahogany wood block footers for devices, the tones gained more harmonic presence and naturalness. Ebony added definition and dimension without inducing artifacts in the upper end.... and Mass, always has a good effect for imaging but it can be too too enhancing and appear either brittle at the extremes or too bright. The two woods would attenuate such ringing as the stone resonates or 'rings'.

Why not then give it a go?

Duckets, gentlemen, just duckets. Pricing out that plan came to well over $250 for 18x18x?.

18x18 will span the 16 on center floor joists, just about regardless their spots. Which BTW, might well be one other consideration. Setting the weight onto the joists directly and not in between them. Thus allowing for better coupling. The added 25-40lbs of each plinth won't hurt much either.

Speckled shiny black, with Ebony and Red Mahog sandwidched atop it ought to please the eye.
02-05-10: Donjr
Zargon. I'm just theorizing. It seems to me that slate or granite would resonate, where as MDF or plywood would not. If I were using slate or granite, I would put it on high density foam and not a lot of it, to cut down on how much surface area is touching the carpet. If you're going from having your speakers spiked to the floor (coupled) to putting them on slate on top of the carpet (decoupled), you will surely notice a difference for the better. Not the best though. You've still got something very heavy and dense, condensing the carpet fibers and slightly coupling itself to the floor, especially because of how much surface area there is with a slab of slate or granite. Companies such as Aurelex have done extensive research on this subject and that's why their line of products for decoupling amps (isolation risers) have very little surface area that touches the floor, yet very large surface area for the amplifier up top. The reason this phenom of slate and granite started was the WAF factor.....really. That's how this all got started. Then everytime somone posted the question, people would reply "I use slabs of granite. It made a big difference and it looks great", and everyone started doing it. I'm not saying it's a bad solution for carpeted floors, but there's better out there IMHO.

naah! I don't you have all the info/the correct info on the use of slate for isolation.
Due to the crystalline structure of granite, granite does tend to ring (& marble also exhibits similar ringing) when suspended (as in a rack). That's why some racks (Adona comes to mind) sandwich the granite between layers of wood. That basically damps the ringing within granite. OTOH, I've found that if granite is placed directly on the carpet there is no ringing in the granite.
Slate, if you look at its crystalline structure, is a very good isolation material. The structure allows for sheer movement & that provides very good isolation. And, as far as I could tell, slate did not introduce any harshness to the sound. Plus, as you stated, it has very good WAF.
Yes, there are many other solutions to isolation (as you stated) but don't discount slate as much as you have.
It might be better for you to stop theorizing & get the material into your system & do some listening?
Being retired from research NOTHING has the density of slate. The lab countertops are usually slate so your balances and micrscopes don't drift from vibration. The tops are complety dead or vibration free. For my own spaekers (been building them for 40 years) I lined my subs with slate. The bass I get with 10" Focals is fantastic. Spiking on carpeting is a must!
i have been using slate and marble under my components for many years. under a turntable is a must. i must admit never thought of trying it under my speakers.