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Beginner question on hollow concrete block stands

Posted: Tue Jan 26, 2016 11:46 pm
by javamad
Hi,

I am about to embark on a fit out of a (very small) spare room as a mixing room and recording studio. Mostly myself recording and I'd like to get the best listening room I can to be able to mix other peoples music.

The room is 264.5 cm long x 168 cm wide x 248 cm high. Carpet on floors, plasterboard walls. I will post drawings and ask for some advice on treatment in a separate thread. I want to concentrate on the speaker stands for now.

I am considering using concrete construction blocks as per this link: https://www.goodwins.ie/p-196-215mm-9.aspx

They are 9" high so I am thinking I can stack 4, add a recoil stabilizer and place the monitors on top of that. The monitors will be the Adam A7x.

I am attaching some mock ups of the stands.

My question:
Will the holes in the blocks align up to form a sort of tunnel that will affect the room sound?


Thanks,

Re: Beginner question on hollow concrete block stands

Posted: Wed Jan 27, 2016 1:45 am
by Eric Best
I was planning on using concrete block to support my speakers that will be mounted in the wall.

I wonder what these would do?

http://www.fendtproducts.com/products/c ... -cell.html

It wouldn't do me any good, but it might be very good in your situation.

Re: Beginner question on hollow concrete block stands

Posted: Wed Jan 27, 2016 4:44 am
by javamad
Eric Best wrote:I was planning on using concrete block to support my speakers that will be mounted in the wall.

I wonder what these would do?

http://www.fendtproducts.com/products/c ... -cell.html

It wouldn't do me any good, but it might be very good in your situation.
Hi Eric,

I don't see any international delivery on their site but I'll contact them to see do they have a dealer in Europe.

The concept though is quite good. I might try breaking off random bits off the sides to 'open' the chimney and avoid any resonance.

Re: Beginner question on hollow concrete block stands

Posted: Wed Jan 27, 2016 9:27 am
by Eric Best
Or just look local for a similar product.

https://www.roadstone.ie/products/soundblox/

Re: Beginner question on hollow concrete block stands

Posted: Wed Jan 27, 2016 10:22 am
by javamad
HI,

Thanks for that link. I'll call them tomorrow.

I have also being applying lateral thinking to the idea and I think I will first try standing up 2 blocks vertically which will give me 34" (2 x 17") which when I add 2" for the recoil pad and, say, 11" to the tweeter .. gives me 47" tweeter height instead of 49".

I am a little concerned though that these tweeter heights are very close to half the room height... is the rule that it can't be exactly half the room height? Or that it can't be near half? Any clarification appreciated.

Re: Beginner question on hollow concrete block stands

Posted: Wed Jan 27, 2016 1:29 pm
by Eric Best
You need to be more worried about the woofers than the tweeters. They are the speakers that will produce the lower frequency waves that will interact with the modes of the room. I think you would like to be close to 38% (someone else chime in if I am wrong) if possible, or have very heavy absorption on the ceiling.

Re: Beginner question on hollow concrete block stands

Posted: Thu Feb 11, 2016 9:36 am
by javamad
Just wanted to get back to show my final (for now) solution ...

As you will see form the photo my room is impossibly small ... but I have to make do for the moment.

I simply didn't have room to have the bass trapping in the corner and then the monitor stands and then the desk .. because it pushed me beyond the halfway mark and the bass was all over the place.

My thinking on this solution is as follows.

I have a rubber doormat under the blocks to isolate somewhat from the table.
The blocks weight 25kg and will not be moved much by the monitors
Auralex ISO separator between the monitors and the blocks.


The monitors I have at the moment will be replaced soon by Adam A7x and I will be replacing the Auralex foam separator with ISO Recoil pads. To be hones the Auralex foam doesn't seem to isolate much at all.

As an added bonus my desk gets 50 kg of ballast on it so I have noticed that it vibrates less than before.

I will post more photos in the acoustics section when I get the room better treated but for now I am happy with the rolls of rockwool in the corners (floor to ceiling) .. it has made a huge difference and I haven't had to do any DIY. I'm calling it the lazy man's bass trap :D