Control Room remodel to control low frequency problems...

Hello, (Note: I've attached the Sketchup file at the end of this post) I have recently tested the low frequency response of my control room and have found that I have some pretty large peaks and nulls. The largest is at 137hz. It turns out, and I know this from reading this forum for the past year, that foam acoustic products just don't do anything for low frequency problems. So I am on a quest to design and implement the best solutions to this problem. I don't really have a budget limitation per say. However, I'm not thinking this will be very expensive. Maybe $1,000.00 I'm guessing. Although I could be way off there. I am in no way concerned about isolation as I have already got my M-A-M walls where I want them and am very satisfied with their performance. I am just focusing on low frequency control for my room. As far as I've read, you really can't have too much bass trapping and I intend to flatten my low frequency response as much as I can. Please note that this control room is in a basement and there is a whole floor above what you'll see in the pictures. The following are some pics and more info on what I'm planning... First off, the low frequency response of the room. As you can see, there are some pretty serious problem areas. This is what I am trying to flatten as much as possible with my remodel. Next, here is the room's raw dimensions. Here is the room in its framed state. Please notice the left hand wall. Halfway up, it sinks in about 4". This is because behind the wall is a concrete wall about halfway up. They then framed in front of the concrete so they could put in electrical. I don't know why they didn't just put studs straight up to the ceiling, but they didn't and there is this sunken top portion of the wall. Behind this left wall is a 4' deep crawl space. It is very large back there with open space underneath the rest of the house. The top floor extends out further to the left of the Control Room, leaving the 4' crawl space. The basement where the control room is, is only half the width of the house above. (16 ft below, 32' above). So the 4' crawl space extends another 16 feet to the left of these pictures. This is important since I may use this to my advantage with bass trapping... I'll explain a little further in this post. Also notice, the large door on the right is a sliding glass door that come in from the outside of the basement. The door at the top right goes into a soundlock (double wall/door) which leads into the live room. The other door at the bottom of the picture, leads to the stairs that go upstairs. There is wood on the side by the doors and carpet in the rest of the room. It's not pictured here, but all these walls have pink insulation in them right now with drywall over the top. Next, here is what the room looks like right now. Notice the foam treatment and the foam corner traps which are doing nothing... The last picture is of the back wall. I'm guessing I'll do the same treatment to the back wall as I do the front. Next, to combat and flatten my low frequency response, I have devised the following solutions. In these pictures, you'll see corner traps added to the corners and the ceiling/wall junction on both the front wall and the back wall. These will simply be framed with 2x4's and covered with fabric. Inside will be solid rigid insulation or maybe the pink stuff if that will do. This is where I need some help. I'm not sure exactly how, or with what, to fill these cavities. I have read the differences between the different types of bass traps and I think these will be the best since I don't think I need tuned traps. I am going for broadband absorption here to suck up as much low frequency across a large bandwidth as possible. I'm guessing this will be the type of trap referred to around here as the "Mondo Chunk". I'm guessing 703 or 705 cut into triangle wedges and stacked solidly from top to bottom, side to side would be the best. Anyways, here's the pictures of what I'm thinking I'll do... Please throw in here at any time to suggest alternatives or improvements. (please note: these pictures do not show the insulation in the cavities) The other option here to add even more bass trapping, is to utilize that left wall where it's sunken in about 4". I was thinking it might be possible to remove the drywall on the top portion and cover with fabric instead and add several layers of 703 in the stud cavities and let the low frequencies just pass through that wall and right into the 4' crawl space that extends out 16'. Would this be a good idea or not. I know this might cause problems with not having a symetrical room from left to right of listening position but it would suk up the bass if I'm thinking correctly??? And the room already isn't symetrical. Or would it be better to add some 4" deep "Box" traps (sealed plywood with 703 inside) into the top portion of the sunken wall? This would keep the high frequencies more similar in the room from left to right... I'm guessing here and this is where I need some help. I'm just thinking I want to put in as much bass trapping as I can. The high frequency stuff is already handled pretty well with the foam. I can still utilize some of the foam for that purpose if I need to around the rest of the room. I also thought it might be necesarry to put a 4" thick cloud with 703 in it above the mix position. Again, I don't know if this will be necesarry for the bass issues or not. If not, I can use the foam I already have for the High frequency issues there. Will the corner/ceiling traps on the front and back wall be enough or would a large cloud over mix position be needed as well for bass issues? And then there's the sidewall option... I know that the control room is not symetrical from left to right, but I don't have too many options there right now. Am I right in assuming that getting the low frequency issues solved will be a much larger improvement at this point? Or is there anything I can do fairly easily at this point to help with the symetry? Of course, without switching the direction of the room around... I appreciate, in advance, this forum and all the help that is available here. I hope I've provided enough info. Please let me know if you have any other questions. Thanks, Brook

You might want to check out these links http://www.moultonlabs.com/main/ especially this one http://www.moultonlabs.com/more/nick_ba ... interview/ and, while you're reading maybe think about how attached you are to the sliding glass door, and how much easier it might be to rotate your CR 90 degrees clockwise, achieving a true median plane and putting your "uber bass trap" wall BEHIND you (just a thought, symmetry is important to stereo imaging) - also, you'll definitely want a "cloud" overhead and may (or not) want side absorbers at first reflection points (read the article) Also, especially with those rear passive radiators in the mackies, you'll want heavy 703 or MW on the wall behind the speakers (preferably with a fair amount of AIR behind the insulation) - Just some initial thoughts off the top... Steve

some nice outboard gear you have :shock: :shock:

Brook - I agree with Steve - here's a spot you could add some bass trapping as it's only a walkthrough area. cheers john