TW Raven Owners: Set Up Questions

I checked with my building engineer who has the building construction
blueprint and that's what he told me, regarding 30cm thickness. I don't
really know building specification and don't know what is considered norm
and standard of high rise elsewhere but overhere 400 kg/m2 is the
standard as far as I know.

Also my next door neighbor bought a unit below him and managed to find a
small space to drill a hole for a staircase between the 2 units who also
mentioned that 30cm thick concrete was what he needed to go through as
well.

I use factory bench with 4 inches slap of black granite right now with my TW. I have a friend that in the past had tried quite a few different types of stone for amp/speaker stands etc before and he found best result using black African granite (supposedly it has higher density than average granite!) In the past I tried slate but the result was not great. At least for those that I could find locally anyhow. I was trying to get a quarry to cut me pool table slate slap and it was a big hazzle and trying to get them to polish slate smoothly was almost impossible (may be I need a pool table factory for this). Anyhow, the one I got was not so great. However, I just located a used Symposium ultra locally that is big enough for my Raven AC-1 so hopefully I will try that in the next few days.
Vibraplane is also something I want to try or perhaps Minor-K. However, I am still thinking that eventually I might try to get BN 3 motors unit for my Raven so until I know for sure what size the turntable platform will need to be, I don't want to invest a lot on platform for my turntable just yet.

I am curious about wall mount shelf. My apartment has solid concrete floor with tension cable runnig through them. The floor is very solid with a layer of MDF and solid oak floor on top of concrete layer and is supposed to support about 400 kg per sq meter. The stereo equipment is placed near outwall of the apartment which is non weight bearing wall with windows and basically a brick wall. In this case, the floor is much more solid than the wall in my opinion. Foot fall is never a problem. In this case, would I still expect the wall shelf to be more benefitial? The factory bench/granite top that I used weight in at almost 100 kg.

I wonder if anyone knows the weight of Rave AC-1? I could not find it anywhere and can't find it on TW website either. One review mentioned that AC-3 is 70 kg. I email TW and asked about weight of AC-1 and total weight if I upgrade motor to BN motor. All I got for the reply was that with BN motor, it would be 6 kg more but no weight for Raven AC-1! I could try to weight it myself but afraid of getting a hernia doing so. So I wonder if anybody actually know the actual weight.

I don't know anything about concrete floor, bounce and such. The concrete floor is 30cm thick, is that thick or thin I have no idea though. Since it can support 400 kg/m2, how much weight or force do you need to make it bounce?

I agree that something like vibraplane is something that I would like to try. Unfortunately there is nothing locally similar available so I think I will have to wait until I know for sure what I will do with my tw regarding motor option before I will invest in vibraplane or minus k. In the meantime I probably will try symposium since I can use it with other equipments later and thy are not so expensive.

I just have a lead on Minus-K locally but it probably will be closer to the end of the year before I could try one (just in time for Chrismas, I suppose!). I wonder if something like Minus-K or Vibraplane is good only for non suspended table or also equally good for suspended table like Linn?

Thanks for the information. It was really strange. Initially I sent eail Mr Woschnik and he answered within a couple of hours but without the actual AC-1 weight. I sent another email back to him and no answer now for 2 days. I think 50+ kg is more like it rather than 70 kg I saw in one review for AC-3. Now I found a local dealer for Minus K platform so I tried to figure outhte total load that I need. I understand that Minus K works best when you are closer to maximun load rather than being at the lower end of the range.
So I am looking at either 125BM-8 (40-59kg) or 150BM-8 (57-70kg). AC-1 definitely will fit 125BM-8 if the custom top (with larger surface area) does not add too much to the cost.

Thanks for the input. If I go Minus K route, the custom top plate would be quite a bit bigger than the footprint of AC-1 exactly for the center of gravity issue. It is a bit unclear to me at this time though if there is an easy way to see if the center of gravity is properly aligned. If it is a matter of distributing weight until say, leveling bubble level on the platform, I think it can be done easily enough using additional weight

Wall shelf is not an option with my current setup as the nearest wall is not weight bearing and the location would not be anywhere close to weight bearing column.

Pcosta, since you have Raven AC, I assume that you used Minus K with your Raven AC?

Vibraplane was something that I looked at initially as well and it seems that ebay is the best source. The price is right but there is not a lot of information about it. Most sellers only shipped within the US and some will only sell it as is with no guarantee that it is actually functioning :(
I am also worried about servicing if the unit has a problem overhere! So Minus K seems like a safer choice for now.

I think that using separate platform on top of Minus K will also allow for easier centering of the mass rather than using a larger custom top. I am a bit worry about using aluminium as top plate as well. In the past, I experimented a bit with aircraft grade aluminium platform under speakers, turntable, amps etc. I find it to give better impact, more focus bass, extended top but at a cost of adding hardness and edge to midrange. Of what I could find locally here for TW, I find black granite (one of those with higher density than regular granite) to be better than local pooltable slate slab and both better than aluminium by a bit. I wonder what would be a good footer for the slab of slate/granite on Minus K since there is a little screws on top on K Minus so I can't lay a platform on top directly.

I see. So the top plate is totally flat then?