No point in mixing in the width center? (nulls too huge)

Hi there! I'm new here, so hello everyone, and thanks for all the info! I am trying to acoustically treat my project studio for two purposes: recording (just vocals) and for mixing, primarily pop and dance music. Obviously, for me bass is critical. My room is concrete on all sides (big apartment building) and rectangular with dimensions: 14 x 9.514 x 8.202 in feet (l x w x h), or 430 x 290 x 250 cm. I have already made two superchunk traps out of rockwool (I live in europe, no OC) and have put up standard acoustic foam around the entire front wall and most of the side walls (all early reflection points well covered). Needless to say, the bass in the mixing position SUCKs. It is just terrible, and the kick/bass is the MOST important part of making dance music. Here's the question: when I align the desk centered between left and right walls, no matter WHERE put it front to back (by the way, 1/3rd from the front wall has my speakers sitting around 1 foot from the wall, and is also terrible, terrible bass response) , whether close or far from the back wall, there is always a HUGE null in the bass at the mixing position. If I move to the sides of the room, I hear all the low bass come back. Why do people say that stereo image (left right symmetry) is so important, ie, more than bass, and suggest sitting in the middle side to side? there is NOwhere that this provides bass for me, so I have to turn the speakers and move around until I finally hear the thump of the kick and bass again. How badly is this affecting my stereo image? I have foam up over most of all the walls and ceiling, so the HFs are covered, when I clap there is no flutter whatsoever from anywhere, will this work? I just can't live without bass, and after installing the bass traps to no avail, I think I need a more creative solution than the 38 percent rule... any advice? Hope someone can help! I gather this is frustrating stuff... Ross

cybeross wrote:

I think I need a more creative solution than the 38 percent rule

You just need more bass traps. --Ethan

That's what I was thinking! Maybe if you were to post a diagram or sketchup model of your room, to scale, showing where your treatment is, your desk, your speakers, etc., then people might be able to make better suggestions.

Hi Ross, Welcome! Yes, more details/pics etc. would be great. Try Google SketchUp - it's free and quite easy. Don't forget nulls between floor and ceiling, too. Geoff.

Ok, I will post more as soon as I am back home. I'll try and take a photo as well. As of RIGHT now, my speakers are sitting on the desk, but this afternoon I am buying monitor stands from a music retailer, since (no meter) my hearing tells me that the desk resonates quite dramatically between 100-150 hz. I'll post pictures after I put in the stands, so I can start doing it right! I will certainly try more traps as it is, but doing these giant chunks of rockwool can be a pain... oh well, all part of DIY I guess :)

Hey Ross, welkom op dit geweldig forum :) If you check Ethan's website (realtraps.com) you'll find much info on that particular subject. It's a great resource.

are you sure your speakers are in phase??

bedankt Ro! Arg! I can't download sketchup for some reason... I can click the link but nothing happens, I will perhaps just post plain photos instead to give an idea. AND, John Sayers, I do *not* know if my speakers are in phase... how can I adjust this? They are krk RP8 g2s, and I am running logic pro on a macbook pro. It's funny... when I sit in the mix position, the stereo field is great and the sound is great, I just don't hear that "i-just-walked-into-a-club" bassline and kick that is so critical to mixing this kind of music. I only hear this on the extreme sides of the room, and mostly behind the speakers and on the edges of the room, but in the center there is this giant area where you hear "bass," but not BASS.

just reverse one of the speaker's leads and compare the difference. http://www.saecollege.de/reference_mate ... .htm#phase

So! It has been a long time coming, but I finally uploaded some photos of my studio (still w/ huge bass nulls in the mixing position. In answer to John's question, everything is in phase, no doubt about that. There are no oddities with what comes out of the speakers, just dramatic differences depending on where you are in the room. Even 40% back from the front wall, I still can't hear deep bass at all, while everything else seems to be ok in my opinion. These are pre/post shots of what I'm doing now. and after... http://img5.travelblog.org/Photos/10019 ... shed-0.jpg So, I have 2 superchunks in the front corners, and I can't really put a super chunk in the back left corner because of a window, but I'm going to try the back right corner as well. As it is right now, I sit to the very side of the mixing desk to hear bass accurately, aside from that position, behind the mixing desk, and in the back of the room I cannot hear the accurate low bass response. Any ideas from here? I really appreciate all the good feedback and help!

and one more thing... my chair has me my ears sitting about 45% of the way from floor to ceiling. It seems like a "good" height for a chair, but should it be higher or lower?

Ethan Winer wrote:

You just need more bass traps. --Ethan

When i look at your photos, i can just quote Ethan`s post. There are 12 corners in your room, which are waiting for basstraps :wink: Also think about a cloud (20cm thick or more) at your celling. cheers Mika

my chair has me my ears sitting about 45% of the way from floor to ceiling. It seems like a "good" height for a chair, but should it be higher or lower?

In addition to what Mika said (which is totally correct: you need more bass trapping in the other in the other 10 corners) it looks to me like you have a problem with your speaker location and your mix position location. As a test, try placing your speakers absolutely up tight against the front wall, with just a tiny little gap of a quarter inch or so, such that they are not actually touching the wall, and at the exact height of YOUR ears when you are normally seated in the normal chair that you use. By "height" I mean the acoustic center of the speakers. If the manual for your speakers does not tell you where that is, IIRC you can guess it as being roughly in between the woofer and the tweeter. You want that part of the speaker at the height of your ears when you are seated. You want the speakers and your head roughly at the corners of an equilateral triangle. ie, the distance between the speakers should be the same as the distance from each speaker to your head, and the angle made by imaginary lines that poke out of the speakers perpendicular to the front faces should be 60 degrees where they intersect at your head position. In this scenario, your head should be at about 38% of the depth of the room, from front to back. Try the speakers in that position, and see how it sounds. If they are up against the wall then they will not be in any nulls that affect the bass range, but where you have them now (according to the photo) looks like they might well be in an area of bass nulls. Also, regarding your "45% of room height" issue: That may nor may not be a problem. After trying the above setup, keep the speakers in the same place against the wall, but now raise them up above your ear height until they are, for example, 76% of the height of the room. (Note: 76% is not a magic number. It's just a different position that might be good and should be better than 45%.) Now, the speakers will obviously be above your ear height, so you will have to tilt them down a bit to aim at your ears. You can tilt as much as 20 degrees, according to some speaker experts, but hopefully, you won't need to tilt that much. If you can keep it to about 10 degrees of tilt, that would be better. More tilt is bad, for several reasons. Try it in that position, and see how it sounds now. I'm, not saying that this should be the final position for your speakers: I'm merely giving you some ideas to try that might improve your speaker positioning, and thus also improve your bass. But you do also need to do what Ethan and Mika said: Install lots more bass trapping in at least some of the other ten corners of your room. Install it symmetrically, of course, and deep. What are the walls, floor and ceiling made of? - Stuart -

great replies! I am going to have to do this in some installments, since each set of bass traps is somewhat of an endeavor for me, not having a car and all ;). However, I think I realize what everyone realizes when they just finish one piece--now what? hahaha So, I'll try the floors, the back corners, and I'll save the ceiling for last since that will definitely be by FAR the most difficult in my case. In answer to your question, EVERY wall is made out of concrete, which is great for the neighbors (they have never complained even once!), but terrible for acoustics. I'll get some more bass traps going, since I have absolutely no intention of arguing with the esteemed pros! As you can see for now, the speakers are at different heights, since that photo was taken as I moved them around. I had them somewhat close to the walls, but then I read somewhere there should be space between them and the walls, which is why I moved them. I then adjusted the height to the range of these particular stands to see where it was better, but height didn't really make a difference. However, I will note that while I don't know the exact range of the speaker stands in CM, I do know that they don't go if anything much higher than 50% of room height. I'll look into some makeshift solutions for height, but I just have to have better bass response. I'll try each one of these tips as time/money allows! One more thing... what exactly does a "cloud" mean on the ceiling? Is there a link or a method of how I can build one? In the netherlands I get the feeling that there aren't many places to buy products that are easily available in the US, owens corning to name an obvious one...

A cloud is simply absorber panels mounted on the ceiling. The general goal is to cover a fairly large area extending from above your head to above the loudspeakers, and at least as wide as the speakers are apart from each other. --Ethan

Thanks, Ethan! Here I am, getting advice from the true pros! Much obliged!