3 replies to this topic

[Valavien.]

Good evening all,

I have been enjoying the progress of the the other DIY projects here and now it's getting closer to the start of mine. I now have three weeks holiday so that should be enough time to finally get my panels made.

About a year ago I bought a pack of Tontine Acoustisorb 3 (2400x460x100) with 6 sheets in a pack.

My room is 6x4m with only a 2.1m ceiling. My plan is to make two floor to ceiling traps for the front corners, first reflection on the sides, the rear and maybe the ceiling if I have enough insulation.

I do hope to take some measurements with REW yet so I am not sure when they will be.

What I am not sure about is how to tackle my corners. I see three options:

1. put two sheets side by side to to make one panel about 900 wide
2. just use the one sheet for 460 wide
3. have two sheets on top of each other to make one panel which is 200mm thick

Does anyone have any thoughts on any of these approaches?


Room Corner by Valavien1, on Flickr

Acoustisorb 3 by Valavien1, on Flickr

[KenTripp]

How much of an effort and percentage of resources you put into the front corner bass traps does depend very much on how much of a problem you think the low frequency (under 200hz) room modes are compared to higher frequency reflection points, RT60 times etc.

Given that the room is essentially 2x4x6 and solid brick means you're going to have some serious room mode issues down low so decent front corner bass traps is what I'd be working on first. The problem is that you only have 6 sheets of material. The obvious solution is that you can always buy more.

Wider panels get them further out from the corner where the velocity is higher and the panel traps would work better. So I'd be voting for two panels side by side, stradling the corner, floor to ceiling.

I'd also be tempted to use the remaining two panels behind the front ones, either directly behind them so the middle of the panel was now 200mm thick for the middle of the wider panel or further back into the corner so you had two panel traps, one 460mm wide and the other 920mm wide.

[Paul Spencer]

Valavien,

A solid brick room like that is going to have some serious bass build up! For corner traps I would suggest 900mm wide with that material x floor to ceiling x 150 - 200mm thick. Four of them and bulkhead traps if you can live with them. If you don't have enough material, then just start with big traps and get more material, buying it later if budget constrains. Thin and narrow traps won't do the job.

You could also consider some membrane traps which have a much power profile, but they are more difficult to design and build, give less predictable results but a normal room would usually have all the walls acting as pressure traps.

Your placement of listening position, speakers and subs will become more critical.

[Valavien.]

Ken/Paul,

You both sure are right about bass build up. I am currently sitting at the rear corner of the room while I type this and the bass is quite full compared to my listening position. Standing 1m away from the speaker/sub isn't so bad either. The difference is quite serious as you say Paul. Damn bricks! My last place had exposed bricks as well, when will i learn.

I think I will stay clear of the membrane traps being an amateur.

I was suspecting that your suggestions would be the answer I would receive. Going from your ideas, for the time being I might make the double wide trap with one behind. Then in the future once I have raised another $350 I can make another piece to make it 200mm all the way through. The side refelections aren't as big a deal to me at this first stage.