Difference between bass traps?

[Tom Higgins]

My question is basically: What's the difference between 'normal' bass traps and superchunk/triangle type traps.

I am describing as 'normal' the bass traps 6 inch thick panels.

I am guessing that the superchunk ones are more effective at lower frequencies. I am planning to treat my room (as in the photo) so what would be better for the corners, in general? Would the 'normal' bass traps work as well?

Thanks,

Tom

[Tom Higgins]

Bump

[Ethan Winer]

Given a fixed 24-inch wide front face, a fully filled corner is a little better than a 6-inch thick panel. But only a little better. If the cost of materials is not an obstacle, definitely fill the corner. Otherwise, use the same amount of material to cover more total corner surface.

--Ethan

________________
The Acoustic Treatment Experts

[Tom Higgins]

Hi,

Thanks for the reply. It would use the same amount of rockwool so it's fine in that respect. There might be a little more wood needed

Anyway the triangular ones, got it

[Glenn Kuras]

Originally Posted by Tom Higgins

Hi,

Thanks for the reply. It would use the same amount of rockwool so it's fine in that respect. There might be a little more wood needed

Anyway the triangular ones, got it

Correct. With the 6" panel you are going to get a bit of a "spring" action (if built right) which will give a bust in absorption around 80hz, but with filling the corner it will absorb more at around 50hz. Both will work fine so either way would not be "wrong".

[Tom Higgins]

Great! Thanks for the help guys!

FYI I can make two corner and one wall bass traps for the same price as making three of either shape. A small amount extra for some wood, but it's pretty much negligible.

[Tom Higgins]

From looking at costs of building, I have decided to make flat broadband absorbers.

I'm thinking of building 6 in total (for now ): 2 X 8" (20cm) to straddle the corners, a 6" cloud, a 6" on the rear wall (reflection point), and 2 X 4" on the side walls (reflection points).

Can you see anything wrong with this?

[DanDan]

If material is limited I would rather see 4x4" than 2x8"
However twice that amount would be advisable.
I consider treating the four vertical corners, from floor to ceiling, as a starting point.
There was a test which compared corner straddling panels with superchunks. The corner straddler did remarkably well, perhaps for the reason Glenn stated.
However, a SuperChunk consisting of less dense fibre was not tested.
There are some reasons to think that this would be a much better performer at LF.

A 4 inch cloud with a four inch airgap is a common recommendation.

DD

[fdc]

different types...so what about these ones:
Auralex Acoustics 12 Cornerfill Charcoal
do they have any positive effect?

[DanDan]

Various types are tested here.
Acoustics Forum • View topic - Absorption Data - Four Devices
The MegaLenrd is foam so you should be able to broadly guess the performance
of the Charcoal's from that.
DD

[Tom Higgins]

Hi all.

DanDan. From what you've said, could I make 6 6" panels?

Also I can't do vertical corners (as shown originally) so instead I was thinking to do the wall/ceiling corners as much as possible (see picture).

From looking at the picture, would the asymmetrical bass trapping be bad? I'm not able to take out the furniture on the other side Wish I could though - a row along each side would look nice

[Tom Higgins]

Bump

Just need to know about symmetry

[DanDan]

I see no side reflection controlling panels. See RFZ, Mirror Trick etc. at the usual websites, or search here.
Such panels would greatly enhance the stereo imaging and horizontal HF symmetry. Bass symmetry is elusive, we often see just one sub for instance.
Generally more bass trapping trumps, as long as it is placed where bass is actually gathered. You can find this by playing sine waves at the room's modal frequencies and listening or taking levels using a meter.
Panel bass traps can be used in corners, flat to either wall. Not as good as straddling but still very usefully in the corner. Also axial modes cause a pressure rise over the whole boundary, the centre of the wall is part of this....
The flat Modex Plate would probably be very useful in your room.
DD

[Starlight]

From what I have been reading I understand that the four superchunk corner traps and first relection point traps would be symmetrical but beyond that your traps will probably be asymmetrical so that you do have too much exposed parallel wall faces and thereby reduce potential flutter echoes.

[Tom Higgins]

Hi guys,

I realise that reflection point absorbers should be symmetrical.

The broadband traps along the horizontal edges are used for absorption/bass trapping in order to make the room flatter, obviously. None of these panels are meant for reflection points, as you noticed. This question is only intended for bass trapping and I will sort out reflection points a bit later.

So from what you two have said, it should be fine to have bass trapping asymmetrical as long as they are placed correctly in the first place?