Bedroom Design

Hi Steve, The dimensions you have are right. I'll move the mix desk in there today and start blasting some pink noise to see what's happening in there. Should I have the insulation installed in the slat walls? Thanks for your help, Tom

Try it first without, then measure WITH to see what it's doing... Steve

Here are the results of the pink noise without insulation in the frames of the slat walls. Photo 1: mix position Left channel pointed toward speaker Photo 2: mix position both channels on Photo 3: center in rear 5' off floor both channels Will post more tomorrow when insulation is in slat wall frames. The scale is set to 3db Is there anything else I should check before installing the insulation? ciao, Tom P.S. I did a google search with my findings and found the last picture :P __________________________________ EDIT Images removed for more accurate readings in following posts

Soooo, you're saying your room has more humps than the camel??!? :? Nuthin' new. Just make sure you can EXACTLY duplicate mic and speaker positions in all three axes for the next set of tests, otherwise it's pointless... Steve

I decided to re-test the room setting up mic stands in the locations so I know for sure that we'll be comparing apples to apples once the insulation is in the slot walls. I will update the pictures of the first test and upload some new ones of the insulation tonight. Sorry it's been a while, but this week has been not the best. I wouldn't bore you with the details, but I'm glad to be back on track, little worse for wear. ciao, Tom

-Results- "I" in beginning of file name indicates insulation in slot walls I took readings on a 3db scale and I set RTA to slow release so the readings were easy to capture and because I read is that pink noise is equal power over time . I thought the readings would be more true this way. I can do a momentary burst and capture the peak readings if needed. One thing I thought about were transients in the room that may be combed due to something I am missing doing slow release readings, but maybe I am just thinking too much. :| There are average and peak readings in all positions. 1st Set: Mix Peak Mix position readings -Mix position -Right speaker only -Mic pointed to center of speaker 2nd set: Mix position Average readings -Mix position -Right speaker only -Mic pointed to center of speaker 3rd set: Center room Peak readings -Center of room 4' behind mix position -Stereo sound -Mic pointed forward

4th set: Center of room Average readings -Center of room 4' behind mix position -Stereo sound -Mic pointed forward 5th set: Rear of room Peak readings -Rear center of room -Stereo sound -Mic pointed forward 6th set: Rear of room Average readings -Rear center of room -Stereo sound -Mic pointed forward

I'm going to hit the sack now. Steve, Thank you for all your help. I wish there a way to really convey that, but please know how appreciated you are. nite nite, TOm

Ok, I was able to use the excel file after a friend changed the dimentions and send it back to me. I've been trying to determine, without any success, how to tune the slat walls based on the readings of my RTA. I am really concerned about the notch at 80hz. I added 2 2x4 703 panels directly behind the speakers in the window and it smoothed out the low end a tiny bit. I believe the problem is being caused by the height of the room, so a low absorber would be necessary to correct this, I think. :?: Is there an acceptable flatness a room should be? :?: Meaning withen a certain db range. I noticed the mid range smoothed out once I added the insulation into the slot walls. See the I mix R-ch avg.JPG picture above. So I may only need to build the slot walls as a broad band absorber? :?: I'm really stressing on what to do because I have clients coming in next week. :?

Here are some more results of my research:

Since yesterday I moved the speakers around. Up, Down and left to right thinking they may be in a null and nothing changed. I think I've concluded that the fix for the extreme notch at 80hz would be a broad band absorber above the mix position. I'll let you know how I plan to build it after I get the slats on the wall monday. ciao, Tom

Tom, what was the HEIGHT of your speakers AND mic for the measurements? If the mic was near center of the vertical distance, it could be picking up a first axial harmonic null at 71 hZ - or possibly the second axial harmonic of the length could also do it, if you're near 3 or 10 feet from either end with either your mic or speakers. Thing is, a full modal analysys of your dimensions doesn't show any lack of modal density in ANY of the bands; the tangentials and obliques fill in just fine, so there's no holes shown in a Bonello graph of the room itself. This doesn't mean, however, that PLACEMENT can't cause an axial (or tangential) problem. If you're getting desperate due to the impending gig and you have more absorbent laying around, I'd "shotgun" things for now - add even MORE to your corners, etc, cloud, and save some time to familiarize yourself with the new environment using favorite commercial mixes, etc... Steve

knightfly wrote:

Tom, what was the HEIGHT of your speakers AND mic for the measurements? If the mic was near center of the vertical distance, it could be picking up a first axial harmonic null at 71 hZ - or possibly the second axial harmonic of the length could also do it, if you're near 3 or 10 feet from either end with either your mic or speakers.

The speakers are very close to 3'10 (within an inch). I saw that too, but even when I changed the height of the speaker and the placement of the microphone I still had the notch at 80hz. I'll double check today when I return from work, but I am fairly certain of this.

knightfly wrote:

If you're getting desperate due to the impending gig and you have more absorbent laying around, I'd "shotgun" things for now - add even MORE to your corners, etc, cloud, and save some time to familiarize yourself with the new environment using favorite commercial mixes, etc... Steve

You mean spend time and just add absorbant material instead of finishing the slats :?: Thanks, Tom

Right; slats take more time, and if SOME absorbent helped the notch then MORE should make it even better. I'm mainly thinking of time constraints here, and the need to use SOME of that time to make sure you are "tuned in" to what your room does BEFORE the client gets there. After, when there's less "crunch", we can continue the slower approach of analysis/experimentation. But for now, nearly every room will benefit from the basics; corner absorbers, clouds, first reflection absorbers, and rear traps(absorbers) - Steve

Ok, I'll calm down now. Man, can I stress myself out! :twisted: I am going to build a 3 clouds tonight. 2' x 4' x 4" of 703 to hang over the mix position, burlap the left slot wall, move in the couch, then take a few readings and start tuning my ears to the room. Thankfully the group changed dates that was to come in after the group this weekend so this gives me a few weeks in between clients. :) Thank-you Steve! ciao, Tom

Hi Everyone, Just wanted to check in and send you all a picture of the progress. Sexy eh? :D

I personally like the uncoverd 703 in the lower half of the window! BTW, It sounds pretty good for being a really dead control room. ciao, Tom :mrgreen:

All right, the weekend is over, and my girlfriend and I broke up yesterday :cry: I have more time now then I know what to do with, so I guess it's time to think about getting the slat walls done. I am so disoriented I'm not sure where to begin. So far, the mixes translate pretty good to other systems, so I guess we're on to a good start.

First of all, my condolences on your breakup; I wouldn't recommend doing anything rash - there may be a possibility of reconciliation, and the less said/done the better mended. (OK, Dear Abby is closed for the night ) On the subject of your room, I would start by placing ONE of your speakers in a corner of the room, facing into the corner - play an 80 hZ test tone through ONLY that speaker, and walk the room with a SLM ("C" weighting, slow) - check high, low, and medium throughout the room and make note of where you get peaks and nulls in the sound level @ 80 hZ. I'd really like to know where this is coming from, since it doesn't really match any of your room dimensions - if it goes away when you place your speaker in the corner, it's because this isn't a room mode at all but a product of mic or speaker placement with respect to room boundaries. There is, however, some chance that this could be a Tangential mode @ 82.9 hZ (first one of length + height). If so, you would see peaks at a midpoint of your front and rear walls, again at midpoints of your ceilng and floor, and nulls halfway between any two of those points... Steve

Hiya Steve, It's been a little while since we parted ways. There are still blips of her on my emotional radar, but they are fading away... Thanks for that trick. I have to leave for a family reunion tomorrow, so I will not be able to flip the speaker around for a week. The side walls and rear walls have all the 703 in them. Is it crucial where I point the speaker, meaning to the corner behind the front splayed wall, or where the splayed wall joins the front wall? ciao, Tom

I'd put the speaker facing into the rear corner closest to the two adjacent walls - maybe even pull out the absorbent there if it's not too hard. You never mentioned what mic you used on the RTA - hopefully an omni? For this test, all SLM's are omni (good thing) - and you'd just play the frequency you're concerned with thru the single speaker (in that position it will excite the room fairly evenly) and then look for peaks/dips, and map them out. This will help figure out what mode (if it is a mode) that's causing the problem. I gotta say, your room dim's aren't bad at all and I'd be surprised if this isn't something else entirely. In fact, I'm not sure what frequency to suggest you tune slats to since those dimensions are really well balanced... Steve