Domsmart
Joined: 29/03/06
Posts: 90
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DIY trap for 50Hz problem room mode? Help please!
#985719 - 04/05/12 12:02 PM
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I was wondering if anybody could help...
I'm in the process of adapting the
living room at the apartment I've just moved to, so that it's usable as a studio for my
music production. Unfortunately it sounds terrible at the moment, by far the worst problem
being a massively long boomy tail at 50Hz...with strong modes at 100 and 150.
This is caused by the fact that the "front" and "rear" of the studio/room are hard brick
walls 11.5 ft apart, with the speakers firing right into the back wall. Unfortunately as
this is my living room as well, I can't afford to lose too much space by putting thick
traps on the rear wall...10-15cm would be the absolute maximum, and to compound matters
the flat is rented and I can't go screwing things into the ceiling or wrecking the
walls.
There is however some space to the left and right of the speakers where
I could potentially put bigger traps.
Can anyone recommend the best way to damp
these awful room modes? There's no way I could even begin to mix in the room at the moment
and I need to do something about it pronto!
Help much appreciated Dom
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sheggs
Joined: 16/12/08
Posts: 88
Loc: Bradford, UK
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Domsmart]
#985741 - 04/05/12 01:23 PM
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Hi Dom, With smaller rooms like yours the problem is normally the bass. What
have you got in the corner of the room? Have you the space to put any bass trapping in
there. I realise its your living room but you can either adapt or get some pre made very
good corner traps that are not obtrusive and can be used a s part of the decor? The
corners are gonna be key to trating those lower frequencies. You will want to treat those
immediate points around the speakers as well, some first reflection trapping there would
help in that 100-150 hz range
-------------------- David Shevyn General Manager GIK Acoustics Europe
www.gikacoustics.co.uk
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Martin Walker
Watcher Of The Skies
Joined: 28/02/01
Posts: 16375
Loc: Cornwall, UK
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Domsmart]
#985851 - 05/05/12 12:17 AM
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I agree with sheggs - the corners are your best bet, and you don’t have to screw things
into the walls either. Many musicians simply push their floor-mounting corner traps into
place, or prop smaller traps up against the corners on wooden legs to lift them off the
floor. Martin
-------------------- YewTreeMagic
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Domsmart
Joined: 29/03/06
Posts: 90
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Domsmart]
#986317 - 08/05/12 12:43 PM
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Thanks for the replies...
I spoke to a mate who does studio builds, who
recommended RW5 Rockwool. I'm going to put a few 100mm slabs of that on the rear wall and
behind the speakers to tame the first reflections, and then build some large corner traps
by sticking several slams together...hopefully that'll help...I'll report back with the
results...
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Glenn Kuras
Joined: 22/12/05
Posts: 339
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Domsmart]
#986407 - 08/05/12 08:05 PM
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Quote Domsmart:
Thanks for the
replies...
I spoke to a mate who does studio builds, who recommended RW5
Rockwool. I'm going to put a few 100mm slabs of that on the rear wall and behind the
speakers to tame the first reflections, and then build some large corner traps by sticking
several slams together...hopefully that'll help...I'll report back with the results...
Putting 100mm is not really
going to hit 50hz all that much. If you cover the whole wall it might help a bit but not
cure it. You are much better off straddle the panels in the corner (I would actually fill
the corner to hit 50hz) with thicker panels spaced off the wall (200mm) and or do
something tuned.
BTW are you sure you know you are having the problems in that
area? It might be best to test the room before moving forward. The following program is
free for testing. http://www.gikacoustics.com/video_rew_room_eq_wizard_tutorial.html
-------------------- www.GIKAcoustics.com
Now with offices in the USA and Europe
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Domsmart
Joined: 29/03/06
Posts: 90
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Glenn Kuras]
#986546 - 09/05/12 01:30 PM
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Quote Glenn Kuras:
Quote Domsmart:
Thanks for the
replies...
I spoke to a mate who does studio builds, who recommended RW5
Rockwool. I'm going to put a few 100mm slabs of that on the rear wall and behind the
speakers to tame the first reflections, and then build some large corner traps by sticking
several slams together...hopefully that'll help...I'll report back with the results...
Putting 100mm is not really
going to hit 50hz all that much. If you cover the whole wall it might help a bit but not
cure it. You are much better off straddle the panels in the corner (I would actually fill
the corner to hit 50hz) with thicker panels spaced off the wall (200mm) and or do
something tuned.
BTW are you sure you know you are having the problems in that
area? It might be best to test the room before moving forward. The following program is
free for testing. http://www.gikacoustics.com/video_rew_room_eq_wizard_tutorial.html
Thanks for that, the video is
really helpful - I'll get one of those Mics and download that software and give it a
go.
As for my assessment, I made it by playing tone sweeps as well as
individual notes, and just listening to the results. Although much more low-tech, there is
clearly a long and very resonant book at 50Hz - tones played at this frequency clearly
linger for a long time, and the effect is very pronounced at this particular frequency. I
suspected this was because of the parallel brick walls at the front and rear of the room,
and doing the maths would indicate that this is indeed the case (they are 11.5ft apart
which yields a mode of 50Hz).
I am aware that a 10cm absorber won't do much at
this frequency, but unfortunately I can't afford to lose much more than this off the depth
of the room because it also needs to function as a living room. I was hoping that such
absorbers might at least damp the 100Hz and 150Hz modes and tame the ringy reflections at
higher frequencies, and that I might be able to tame the sub bass a little by building
some chunkier corner traps.
I was wondering however if it'd be a good idea to
build a couple of plywood panel traps for the front wall behind the speakers...but I don't
really know if this would work or where to start. would this be a good idea, and does
anyone have a good design for such a trap?
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Martin Walker
Watcher Of The Skies
Joined: 28/02/01
Posts: 16375
Loc: Cornwall, UK
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Domsmart]
#986813 - 10/05/12 11:37 PM
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Quote Domsmart:
I was wondering
however if it'd be a good idea to build a couple of plywood panel traps for the front wall
behind the speakers...but I don't really know if this would work or where to start. would
this be a good idea, and does anyone have a good design for such a trap?
Hi Dom!
I'd stick to
broadband absorbers if I were you - simpler to implement, and in a small studio you can
almost never have too much broadband absorption
Get traps straddling all the vertical and horizontal corners and you're far more likely
to squash that 50Hz problem IMO than with plywood traps behind the loudspeakers
Martin
-------------------- YewTreeMagic
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Domsmart
Joined: 29/03/06
Posts: 90
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Domsmart]
#987984 - 17/05/12 12:26 PM
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Thanks for the advice...so far I have constructed 3 panel traps from 100mm RW5 Rockwool
with one more under construction for the front/rear parallel walls. These seemed to have
killed the "ringyness" and some of the high bass hump. The next phase will be to add some
deep bass trapping, however I'd appreciate some more advice on this...
Unfortunately as this is a living room, I am somewhat limited as to the amount of space
I can take up with trapping. I could potentially fill the rear-left corner of the room
with a "superchunk" from floor to ceiling, however putting such traps in the other corners
is a no-go (well maybe at a push the front right corner, but definitely not the other two
as they have a door/window respectively).
Would it be a waste of
space/time/money just having a single superchunk, or would it still be useful? Assuming it
is a good idea, is RW5 Rockwool a good material for such a trap? Also would a 60cm square
corner trap work much better than a triangle of half the volume?
Whilst I would
prefer broadband trapping, seeing as space is at such a premium here...I'm wondering
whether panel traps or something similar might be a more effective use of space for taming
the <100Hz region?...Can anybody point me to any good designs for such traps?
Any advice much appreciated!
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sheggs
Joined: 16/12/08
Posts: 88
Loc: Bradford, UK
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Domsmart]
#988013 - 17/05/12 02:51 PM
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Have you had a chance to test the room yet to see where your problem areas you are left
with are? General rule with bass is that even one corner will help as opposed
to having no bass trapping at all. Like Glenn said though you could also use panels to
straddle the corners as an alternative but the square 'soffit' style corner trap will just
be as effective as a triangle tra and bigger will help but definately worth measuring your
room to see where you are
-------------------- David Shevyn General Manager GIK Acoustics Europe
www.gikacoustics.co.uk
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Domsmart
Joined: 29/03/06
Posts: 90
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Re: DIY trap for 50Hz problem room mode? Help please!
[Re: Domsmart]
#988130 - 18/05/12 09:05 AM
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My measurement mic should be arriving today! I'll do some measurements and post...
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