Concrete block monitor stands on carpeted concrete floor?

Hi all, I came across this thread yesterday in my search for info on building concrete block studio monitor stands: viewtopic.php?t=10021 which was advice from Gullfo on building them for someone with a wood floor. I was wondering what variations would there be in the same design for a carpeted concrete floor? I'm inclined to assume that I won't need to use foam under either the blocks or the speaker but of course I could be wrong. I just got a new pair of Focal cms 65 and I'm unsure about how exactly to mount them on the blocks i.e. whether I should use the supplied 'feet' and mat or not. I'm having trouble understanding the whole 'coupling/decoupling' issue in this context, especially since there are so many opposing opinions on the subject.

the idea is simple enough - create a stand massive enough to prevent the speakers from moving and from directly vibrating the surfaces it is in contact with. the mass (stand and speaker) ensures the foam (or rubber/sylomer/sorbathane etc) is properly compressed to maximize its isolation value and not shift when the speakers are firing. can you simply put this type of stand (blocks) on the carpet? possibly if the carpet will perform the decoupling job. if not, then adding the foam will be helpful. on the top, there are several options: 1) use a layer of foam/rubber/etc under the speaker, 2) a solid block on top and the supplied feet, 3) obtain a pair of the monitor pads with the steel plate and put those on top of the stand.

sirhenry wrote:

Hi all, I just got a new pair of Focal cms 65 ...

I've been looking at the Focal line of monitors ... I'd be curious what you think of them ? What were you using prior ? thanks

Thanks for your help Gullfo, I just have a few more questions. As regards open cell polyurethane foam/rubber/sylomer/sorbathane, can you give me any tips on where or how to find these materials? Bearing in mind that I live in Ireland, I'd say we don't have many of the U.S. brand names. Even just what in general to ask for in the hardware store.

1) use a layer of foam/rubber/etc under the speaker

If I used this method would it be wrong to use the mat and feet on top of this layer? It's just that the speaker isn't straight at the bottom - all the edges are rounded.

2) a solid block on top and the supplied feet,

When you say a solid block on top, are you referring to the "CMU block Plain 8x16x2" in your Sketchup, i.e. does that denote a solid block? If so, do you think the design would work without it, as the approx height of 4 blocks and speaker/tweeter is pretty close to my ear height when seated. Because of this, how thin could the piece of wood be and still be effective? Also, what in your opinion is the right type of wood?

3) obtain a pair of the monitor pads with the steel plate and put those on top of the stand.

By this, do you mean Recoil Stabilizers? I was surprised to see that the 'spikes' with the speakers are just screws. I was looking forward to using them to really stick the speakers to the top. Focal wrong or my mistake? Patrick p.s. @RJHollins- Sorry, haven't tried them yet - will let you know soon as I have them up.

http://www.proctorgroup.com/Products/Ac ... lomer.aspx - I guessing but probably you will need the one of these if the stack is about 150lbs / 70Kg Sylomer® G Sylomer® SR11 (up to 0,011 N/mm2) Sylomer® O Sylomer® SR18 (up to 0,018 N/mm2) if you need to use the mat and feet - then you need to use them to get the speaker to sit correctly. the top block could be solid, or you could use a 1" (25mm) MDF plate. if you want it finished then some nice hardwood would suffice. then again if your feet are screws maybe the MDF is better.

gullfo wrote:

http://www.proctorgroup.com/Products/AcousticSolutions/Sylomer.aspx - I guessing but probably you will need the one of these if the stack is about 150lbs / 70Kg Sylomer® G Sylomer® SR11 (up to 0,011 N/mm2) Sylomer® O Sylomer® SR18 (up to 0,018 N/mm2)

Thanks Gullfo. I just looked up SYLOMAR and saw that it comes in 5m rolls. Do you know how much it should cost? Do you think the SR11 would be good under the speaker like in your diagram? If so, then it could do under the blocks as well.

no idea on the cost - you can all the local provider and find out if you can get a smaller size or as pads and it shouldn't be too much in the smaller size. the difference with the pad on top versus the bottom would of course depend on the loading. a single 35-50lb speaker on the pad will very likely behave differently than 150-200lb on that pad.

Hi Gullfo, I got this msg today about getting Sylomar: I’ve been forwarded your email by my colleague Pam – it’s possible to obtain Sylomer in whatever pad (or strip) size is required, standard thickness is 12.5mm though thicker – 25mm, 37.5mm etc or thinner (6mm, 3mm) though for the thinner material cost doesn’t decrease from 12mm. Price is determined by the work involved in cutting & the overall volume required; delivery could be 3-4 weeks at this time of year. If you can advise what you are looking for, or send me some details on what you are trying to achieve I can perhaps assist. I just wanted to be sure of what I need before I order. I want my stands to be almost identical to your design so can you help me with the details? It would be much appreciated.

sirhenry wrote:

gullfo wrote:

http://www.proctorgroup.com/Products/AcousticSolutions/Sylomer.aspx - I guessing but probably you will need the one of these if the stack is about 150lbs / 70Kg Sylomer® G Sylomer® SR11 (up to 0,011 N/mm2) Sylomer® O Sylomer® SR18 (up to 0,018 N/mm2)

Thanks Gullfo. I just looked up SYLOMAR and saw that it comes in 5m rolls. Do you know how much it should cost? Do you think the SR11 would be good under the speaker like in your diagram? If so, then it could do under the blocks as well.

why not. i have idea on the cost. :shot:

erikasha wrote:

sirhenry wrote:

gullfo wrote:

http://www.proctorgroup.com/Products/AcousticSolutions/Sylomer.aspx - I guessing but probably you will need the one of these if the stack is about 150lbs / 70Kg Sylomer® G Sylomer® SR11 (up to 0,011 N/mm2) Sylomer® O Sylomer® SR18 (up to 0,018 N/mm2)

Thanks Gullfo. I just looked up SYLOMAR and saw that it comes in 5m rolls. Do you know how much it should cost? Do you think the SR11 would be good under the speaker like in your diagram? If so, then it could do under the blocks as well.

why not. i have idea on the cost. :shot:

If you have an idea that is fine. Please update your profile to reflect your geographical location in the world in order for all of us to be more informed.