130 hz peak

[petys]

I've got a peak at 130 hz that won't go away. I originally had 18 traps and now have 49 traps and the peak is still there. No difference. I've tried positioning, traps. Any ideas on what could be causing this? The ceiling is 8 feet high and there is a cloud above me. I was under the impression that 4 inch traps could improve frequencies easily above 125hz. The room is 22 by 34 by 8.

[jdg]

try moving your monitors a few feet back/forward until everything evens out as best it can.

[Glenn Kuras]

JDG is on to something. Try moving your mix spot to see if thing change. How are you set up in the room? Where do you have the bass traps placed?

Glenn

[petys]

I've got it positioned the best I can using the RTA. It's actually 38 percent and about 2 feet to the left of center. Does anybody know which walls could be causing this mode. Or what length causes a peak at this frequency?

[nosebleedaudio]

565 divided by the dimension gives the first mode, then multiples of that.
Ex. 565/8' = 70.6Hz, then 141.2. ect..
Why do you have them NOT centered left/right?

[nosebleedaudio]

How are you measuring? Sine wave? How narrow is it?
Can you hear it with a musical note at the same 130Hz?

[petys]

Yes, with REW, RTA and sine wave. For some reason the best response I get is left or right of center about 2 feet. The room is not rectangular and has angled walls. I don't necessarily hear it with music but I definitely hear it as I sweep a sine wave. I don't know what's causing it and therefore I can't seem to fix it with traps.

[Weasel9992]

Originally Posted by petys

Yes, with REW, RTA and sine wave. For some reason the best response I get is left or right of center about 2 feet. The room is not rectangular and has angled walls. I don't necessarily hear it with music but I definitely hear it as I sweep a sine wave. I don't know what's causing it and therefore I can't seem to fix it with traps.

Well, to be perfectly honest a 12dB peak isn't all that bad. I agree that you could probably shave a few dB off of it though...what's the decay time like down there?

Frank

[jdg]

move to the center line for L/R if you can!
2feet is alot IMO

[bi-tonio]

I've got the same problem in my room.

140Hz (and he's brother 280Hz) is too loud there.

my room is 4m x 4,50m (13Ft x 14,5Ft). my monitors are 1 pair of ATC scm 100 and a pair of Genelec 1030. the atc's are backed up to the wall in front of the stereo point. the only place i find to get the bottom.

a friend of me, engineer in acoustic, told me to put a roll of "rock wool" (5x2Ft) on the floor, between the main monitors and the desk's legs.

this is what I'm gonna try.
then I'll tell you if it changed something in a positive way...

[Weasel9992]

Originally Posted by bi-tonio

I've got the same problem in my room.

140Hz (and he's brother 280Hz) is too loud there.

my room is 4m x 4,50m (13Ft x 14,5Ft). my monitors are 1 pair of ATC scm 100 and a pair of Genelec 1030. the atc's are backed up to the wall in front of the stereo point. the only place i find to get the bottom.

a friend of me, engineer in acoustic, told me to put a roll of "rock wool" (5x2Ft) on the floor, between the main monitors and the desk's legs.

this is what I'm gonna try.
then I'll tell you if it changed something in a positive way...

A lot of that stuff in the can be changed by moving the room around some. I've seen 25dB nulls reduced to 5 or 6dB simply by moving the desk and monitors.

Frank

[bi-tonio]

Originally Posted by Weasel9992

A lot of that stuff in the can be changed by moving the room around some. I've seen 25dB nulls reduced to 5 or 6dB simply by moving the desk and monitors.

Frank

definitely true Frank.

BUT, every room, every house, every material have there own resonance frequency.

I tried 3 positions in my square room, i think i found the best spot considering sound and space for a Soundcraft 2400, a pair of ATC, a Sony APR 24 and 3 outboard furniture.

also, i know it's only cheap trix to try.
Antoine

[Weasel9992]

Originally Posted by bi-tonio

definitely true Frank.

BUT, every room, every house, every material have there own resonance frequency.

I tried 3 positions in my square room, i think i found the best spot considering sound and space for a Soundcraft 2400, a pair of ATC, a Sony APR 24 and 3 outboard furniture.

also, i know it's only cheap trix to try.
Antoine

Oh yeah...I'm a big fan of the cheap fixes, trust me. I've still got resonances at 40Hz and 80Hz in my own room to deal with. It never ends.

Frank

[Schaap]

Originally Posted by Weasel9992

Oh yeah...I'm a big fan of the cheap fixes, trust me.

I was in a studio some time ago and there was a peak about 110 Hz. In the end it seemed the whole table/desk resonated on that freq.! Some rubber under the monitors fixed it almost completely. About 5 euro fix .
Now they're using monitorstands.

[Weasel9992]

Originally Posted by Schaap

I was in a studio some time ago and there was a peak about 110 Hz. In the end it seemed the whole table/desk resonated on that freq.! Some rubber under the monitors fixed it almost completely. About 5 euro fix .
Now they're using monitorstands.

Dude, absolutely...and that stuff happens all the time. Occam's Razor is relevant here: the simplest solution is usually the correct one.

Frank

[petys]

I've moved the desk to the corner and know that this isn't the normal or correct positioning of speakers but I've completely removed that peak which I believe is caused by the 8 foot ceiling. The corner has a sloped wall 2 feet up the ceiling. But now there is a dip below 60hz. Which one do you like better? There is some ringing as shown in the waterfall. I'm not sure if I should be that concerned with it, though. Which one do you guys prefer?

[Weasel9992]

It's a little hard to determine with that much smoothing...any chance you could post it at 1/6?

The ringing could be worse...I assume that that was the tradeoff for the 130Hz improvement?

Frank

[petys]

Frank, thanks for the compliment, I guess. But there is no smoothing on those graphs. I'm not sure which position would be better. And do you think I need to be concerned with the ringing down that low? Your right, it is a compromise, either way.

[1320 P.]

The other day I was helping a friend with the treatment of his studio. There was a massive ring at 125. As I ran the peak tone around the room and checked it with my SPL it turned out that the door was ringing. Like 18db ringing. We opened the door and to our surprise the Peak at 125 was gone as well as some lower freq peaks. The room went from +/- 18 to +/- 10. This studio was designed by a major designer as well so it explains why the room became so flat once the door was opened. Since the ringing door was into a storage area at the back of the room it was easy to cure with a nice curtain.

Just a thought but did you try running the peak tone/noise to find out the root cause of the ring or where about in the room it is, while moving your speakers to find the best possible position for the speakers?

Disclaimer:I am not an acoustician, but this method has saved me about 6 times or more while helping friends with bad rooms.

[Weasel9992]

Originally Posted by petys

Frank, thanks for the compliment, I guess. But there is no smoothing on those graphs. I'm not sure which position would be better. And do you think I need to be concerned with the ringing down that low? Your right, it is a compromise, either way.

Yeah, sorry...I wasn't paying attention to the scale. I've got some ringing at 40Hz and 80Hz in my own room which was a trade off for a more even frequency response, just like your situation. Keep working on the issue; sometimes there's a simple fix like the poster above indicated. Other times the only fix is to add as much treatment as is practical, move around until you find the best position in the room, then live with what you can't fix.

Sorry I don't have an easier answer!

Frank