How to treat a room notch between 125-90 cps.?
- Thread starter raanan
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This can be caused by several things, mostly the relative placement of the speakers vs the listeners.
But you've basically discovered a serious room mode at that frequency.
if you run your room dimensions through a room mode calculator (like this one), you'll probably find that frequency band prominently listed.
the fix is to either move the listener out of the Null, or to treat the room with bass absorption products.
My recommendation is look into treating the room and with CLS, treating the rear wave with a product like a RealTraps MiniTrap HF placed behind each CLS panel. that will help dempen the rear wave cancelations in the mid-bass and down into the region you mention as well.
But the big impact will come from treating the corners with products like Mondo traps.
Ethan Winer
Well-known member
Yes, it's the room. No competent loudspeaker would have a response like that. Jonathan gave you the right answers. Changing speaker placement can help, but you'll likely just move the null frequencies around. The more appropriate solution is bass traps as well as optimized placement.
--Ethan
Corner traps can help tame a room , . However some rooms have a null at certain frequencies. You have shown that yours does with other speakers as well. Placement of CLS is CRUCIAL. To the 1/8 inch or cm . There are many videos on line on how to MAKE bass traps very cheaply.
Search You tube! There are a few but this one is easy and cheap and works. Bass traps are not brain science as you see. You can get real detailed and make them lined in the back with 6 mil polyethylene so not to trap midrange and highs .
http://www.youtube.com/watch?v=iyYUpkpL0gw&feature=related
http://www.youtube.com/watch?v=iyYUpkpL0gw&feature=related
Bernard
Well-known member
Thanks for moving this post.I was unaware until now that there was a special section for acoustics and placement.In addition,I received good advice on the Tweaker's asylum.After fooling around with speaker placement,namely placing them without toein in order to avoid reflections from a side wall,and interavction with a sub placed adjacent to that side wall,I have narrowed the notch to 113-120,and the corresponding 226-240.
At the cost of losing depth to the soundstage everything sounds more natural and right.I reckon that the wider notch in the midbass region contributed to the subjective sensation of hearing the CLS's sound as thin.
Things are better now.
I am not sure how big your room is but I am experimenting now with MY CLS and wide positioning with very near wall set ups. I am noticing as you found with NO toe you can place them closer to the side walls and still retain center image. It actually sounds like a Huge venue when done this way and the bass reinforcement is a welcome factor. The CLS is amazing at imaging. I have put these things as close as 1 foot from the side walls and am moving things as we speak. The corners may need a little trap but I will let you know. What I have found with CLS is toe usually centers the image at the expense of width and airiness. These things throw sound sideways like no other ML design.(Excluding the CLX) . I am actually running them with NO subwoofer and am getting some great bass. Bass how it should sound, tight and snappy, not bloated and boomy.
I really think that with room reinforcement and such these things will do a solid 40 hz. Its not gonna happen in every room but rooms with hard surfaces floors and walls with treatment will help.
I really think that with room reinforcement and such these things will do a solid 40 hz. Its not gonna happen in every room but rooms with hard surfaces floors and walls with treatment will help.
The size is 6 meters by 3.5 by 2.8 high,roughly 21 feet by 11.25 by 9 feet high.If I place the speakers too close to the back walls ,bass is greatly reinforced but I lose HF and resolution and imaging.I have been searching for the best placement for about 19 years.
Laughing my ass of hard as I totally under stand. I am constantly moving them a bit hear or there. I should have stock in Blue tape I use so much. Your room is damn near identical to mine. Where are they placed NOW? Mine are currently 137.2cm from the front wall and 25 cm from the sides , (wood frame to wall). my chair is about 370.8cm back from the center line of the speakers with NO toe. If you look at my system link you can see I have a knock out behind each speaker where the fireplace sticks out(that is a nightmare in itself for sound) but I have a corner trap I am experimenting with. Do you run stands ? If so I HIGHLY recommend them. It was night and day with clarity and image detail.
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I will measure the distances later and post them here.Because no toe-in has such a good effect on taming the room modes,I have decided to remain with no toe-in.
Would you like to make a pair of stands for me?
From a state of crazy room modes,I have gone,with the new positioning, to a notch between 125-113,and between 250-226.My guess is that at these frequencies I am about 10-12 db down-but that is just guesswork.
Room acoustics determine the end result more than choice of equipment.
Can't find my tape measure but,it seems that we may have the same distance to the front wall,may differ by one centimeter.
Found it. 136.7 cms.
Its amazing that we have damn near the same measurements in almost identicle rooms with differing ears. It goes to show that the CLS has common consistency in its sound, and we have good taste
! Try and go wide I have been running mine close to the side walls and get a HUGE stage. NO Toe is the way. What are you using for amplification and upstream gear?
PM sent about the stands.
! Try and go wide I have been running mine close to the side walls and get a HUGE stage. NO Toe is the way. What are you using for amplification and upstream gear?PM sent about the stands.
Its amazing that we have damn near the same measurements in almost identicle rooms with differing ears. It goes to show that the CLS has common consistency in its sound, and we have good taste
PM sent about the stands.
The CLSs are driven by an ARC VS-110 with GL reissue KT88s.The preamp is custom-using 7233 triodes=made by a friend.
Sources are Marantz CDR620,EMT950,and a tube tuner,occasionally joined by a Revox RTR and a Nak cassette player.I use a Tascam DVRA1000 for archiving recordings of concerts from reel and cassette.
I am the first one here who admits to conducting a love-hate relationship with my CLSs.
But,although there were many times when I thought of returning to more conventional speakers with more "slam",I was never able to give up the CLS's
magic.The longest that I was able to put other speakers in my main system was a week.And this meant schlepping stuff with a bad back-both ways.
There were times when I added on good ribbon tweeters,and only recently was I able to incorporate a sub with good results-after trying for almost 20 years,in addition to another few years trying to do this with the QUAD 57s that I had before the CLSs.
I also must admit to always having tried to make the CLSs sound like the 57s-by playing with the associated equipment and cables.
