# 140 Hz 15 db too loud still not fixed



## truthsurge (Sep 9, 2012)

I have 8 ft ceilings so I ran this mode program and that gave frequencies of 70/140/280 etc and yes, those frequencies are WAY too loud where I sit in the room (roughly 40% from one wall and a tad off center).

So, I made 2' x 2' x 4" mineral wool bass traps and hung 12" from ceiling OVER the speakers and 140 is STILL way too loud. That's roughly C on a keyboard. Everything's grand until I play a bass note on C in the lower registers. I thought by blocking the path from speaker to ceiling, it would mitigate that problem. I didn't expect a flat response but from 15 db too loud to at least say 8 db too loud. It sounds like there was no change. 

So... is it because I don't have enough coverage to block the bass from hitting the ceiling? I think the room is roughly 13' by 13'. I have bass traps in 3 corners (4" thick of mineral wool) and a few just leaning here and there and two directly behind my monitor on the wall.

anyway, forum told me it missed me and so I thought I'd log on and make it happy. 

Any ideas.... thanks!


TS


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## JohnM (Apr 11, 2006)

It takes a lot of treatment to have an effect at frequencies below 200Hz. I'll move this thread to the home audio acoustics forum, where the folk are better able to advise on what might help.


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## truthsurge (Sep 9, 2012)

Man, took me a while to find this. hehe

Well, it may just be that I don't have enough sq footage of the stuff hanging. i have two 2' x 2' and four inches thick so maybe it would need to be several more of those sections up there. I guess I have to just live with it because I don't have the $ to be doing much more and since it's just mainly C notes, I can just always know they are going to be louder. Not good though if my song is in C hahahha.

ts


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## pharoah (Jul 21, 2012)

2 2x2 panels isnt very much room treatment.i have 4 panels that are 2x4 feet.my panels are gik acoustics.my 244 bass traps are 5.5 inches thick,and my monster traps are 7.5 inches thick.so you need more coverage and maybe even thicker.


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## truthsurge (Sep 9, 2012)

Thanks. I have other bass traps in the room but just those 2 right above my speakers and I thought if I blocked the waves above them it would be enough to beat down the 140 Hz waves and maybe help the dip in 100. It seems the answer is no.  So, I have more insulation in the garage. Prob 6 pieces of 2 x 4 4 thick. I could make more and put them up at the corner of ceiling and wall behind the speakers. Anyway, thanks.

t


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## pharoah (Jul 21, 2012)

yes the trihedral corners should be filled first.thats the majority of the strong reflections.


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## Jon10 (Feb 25, 2013)

Chiming in. Since your room is squared, you might have a hard time to deal with resonating/diping. If I understood correctly, you have 4" thick in 3 of 4 corners. I really think you'd need some super chunk style absorbers in the corners behind your main monitors, as big as you can afford. 140hz is pretty low, 4" thick is probably not helping more than 1-3db.

Also, you might consider moving your traps at the first reflection points correctly. You can use the "mirror trick" to find these, according to your seating point. Placing the absorbers "directly over" the monitors will not help much the sound coming to your ears. I apologize if you are familiar with the concept, just trying to help...

And, pulling your absorbers a few inches from the wall, at first reflection points, is also a good and cheap help to efficiency in low frequencies.


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## truthsurge (Sep 9, 2012)

Yeah, I have read up a bit on this but chiming in is fine!

I decided not to do the triangle that fits the corner precisely. Too hard to make and I have no $ to buy. and so I opted to make 4' x 2' slabs and I have those going from floor to ceiling in 2 corners of room and maybe 70% to ceiling in another corner. but i don't have any in the corners where 3 walls meet. plus, now, i have no way to get behind my speakers and put up more traps where wall meets ceiling. I'd have to pull it all out and I have a bit of messed up back.

But the 140 Hz is a direct mode of the ceiling distance to floor (8 ft) which is why I thought blocking that line would help. Yes, I have those hanging ones a good 10 to 12" from the ceiling.

oh well. If I had $ or a local friend.... I might be able to add some more in the corners. I'll just leave it for now. 

thanks!
t


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## AudiocRaver (Jun 6, 2012)

truthsurge said:


> But the 140 Hz is a direct mode of the ceiling distance to floor (8 ft) which is why I thought blocking that line would help.


Right line of thinking, but remember that standing waves can occur anywhere in the room between the floor and ceiling. As an experiment, try putting the aforementioned trap above the measurement mic at the LP and see if it helps at all there.


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## truthsurge (Sep 9, 2012)

My net connection is blowing and of course it loses all the stuff I typed. 

anyway, good idea. I might try a little more testing. 

thanks
t


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