Thanks Beoaus. I shall try them this weekend. Only problem is I understand it is not advisable to have a shiny reflective surface underneath the speakers ??....

Here is my room with speakers positioned. I have now brought them away from the walls by about 1.5 feet. 

peterjacobs:

Thanks Beoaus. I shall try them this weekend. Only problem is I understand it is not advisable to have a shiny reflective surface underneath the speakers ??....

 

Here is my room with speakers positioned. I have now brought them away from the walls by about 1.5 feet. 

 

The image is not coming up on my browser. Try storing it in jpg? Go to Options, next to Compose above. And add the image with the Browse function, if you haven't already done so.

And shiny reflective surfaces can't be much of a problem, as most of the photography by B&O of these speakers goes against that bit of advice. But the marble doesn't have to be smooth polished - and it could look quite beautiful - imagine dark marble slabs underneath? (Damn, I'm going to get curious and be wondering about getting my own, now.)

Dave, could you please share some more details of your expirience with the audyssey device? You mentioned that this could not be a promising solution for the problem of  the starter of the thread.

I have treated my room with some acustic elements after consulting an acustical expert and looking now into the last step to imptove the sound.

So the Audyssey is on my list as I heard from owners of very well acustical treated rooms that this device the "cherry on top of the cake" . I have two lab5, lab 7-4 and two lab 3 with a BS3 in my 3,60 by 4m room

Karsten 

The disadvantage with Audyssey is that it processes the signal, and therefore reduces its resolution a little; the advantage would be that it treats the entire frequency range relative to the room, and not just the bass.

I can attest to the BL5s being able to move walls and floors. When we were watching the latest Bruce Willis Die Hard movie, and we got to where it's the truck against the jet fighter on the highway overpass, the entire apartment building seemed to be shaking as the overpass was falling apart.  

Stiffening up the floor from underneath is a good idea, with possible a higher WAF than the slabs! 

Die Hard 4.0 with the Lab5 is the best! My sofa vibrates...and not only a little bit :-)

Karsten 

not wanting to go too off topic but the bridge scene in Mission Impossible 3 is awesome (volume 70)

much better with lab 5s than beolab 2..

Dave,

would setting a cross-over with Audyssey or another system above that handled by the BL5s for the rest of the frequency range be advisable?
 

Peterjacobs did you find a solution?

Ok all, thanks for all your responses and debates especially Dave Moulton. 

 I went off to our local DIY store and got 4 650 mm square concrete pavers.Two sandwiched together to make a concrete plinth about 5 inches high. Placed the Lab 5s on these. Re calibrated and then used a couple of B&O demo CDs to test any change. I also played the DTS DVD Terminator 3. Not much change at all. Interestingly I did noticed by standing right next to the lab 5s that (when they were on the concrete plinths and without being on them too)  that when the calibration sequence started for the bass frequencies I could lliterally feel the floor boards deflecting.

Now Dave Moulton asked a very focussed question. The size of the joists supporting the floor. Well, (don't do this at home) I had to go off to our local pest control, get some "spider dispersal bombs" let them off under the house. Then wait an hour before crawling underneath. The gap is just over 24". The floor joists are solid hardwood, 6" x 8". The floor itself is solid hardwood boards 3/4" thick.

So, I took the lab5s off the plinths, then placed the US "Big Fat Dots"  speaker vibration damping pads (note these can be used for speakers up to 90 kilos). Re calibrated, then played the same tracks and DVD.

 Result - A HUGE DIFFERENCE, POSITIVE of course. I anticipated that it would be better, as when I started the calibration I stood next to the speakers and did not notice MUCH deflection of the floor boars all though there was a hint of it. I re calibrated again and this time sort of leaned on the larger aluminium disc of the lab 5s. Now no deflection of the floors.

End result, the 5s are back to their best. !!!!!!!

 I actually took a day off work today to enjoy them, just to celebrate.

Herbies Audio Lab. They are on the web. $ US 70 + $US 25 postage to Australia. for 10 discs. $ placed in a square and one in the centre.

Hope this helps anyone else with the same problem.

Peter