Best's Studio

It has been a long time since I have post. I actually looked it up and it has been 5 years! I designed this studio with much help from the people in this forum but because of time constraints it has not happened. I have also taken a journey into speaker design and building in that time which I plan to incorporate into the design. Building started about two weeks ago. I am building the live room first, then moving everything from that side of the basement into the live room and building the control room. Here is the design. The back wall of the control room is from a design by Philip Newell, with a combination hangers and membrane absorbers. The sawtooth walls in the control room were done to extend the splayed walls so all first reflections are put past the mixer into the rear absorber. This will be hollow with rockwool inside and open to the front. The ceiling will be treated the same way up to the mix position. I have spent a lot of time learning about building speakers. The crossover will be designed based upon speaker measurements of the individual drivers after they have been mounted in the wall. Here are some other views The ceiling and the walls are going to be covered with moveable and removable panels so the acoustics can be adjusted. There is a large bass trap by the window with hangers. The next post will have pictures of the construction. Eric

Welcome BACK Eric! Just wondering why you have the listening position in roughly the worst possible spot: the geometric center of the room! :shock: Also, how come your isolation seems to be incomplete? (around the stairwell): Is that just a mistake on the SketchUp? - Stuart -

Hey Stuart, The listening position is at 8' and the room is 18' deep. The back 2' are a bass trap, not a wall. The isolation under the stars is complete. The area under the stairs will be storage/ isolation area. The views I'm showing don't show what I'm doing with it. The sketchup model also doesn't show the airspace between the two rooms either.

Here are some pictures of what has been done so far. I'm hoping to get all of the insulation in the ceiling and put the drywall on the ceiling this weekend.

Nice to see you. I like what you are doing here...the angled treatments should be pushing the sound in the other direction. As they are currently they push the sound directly back into the listeners sound area...

Brian, what do you mean by the other direction?

The listening position is at 8' and the room is 18' deep.

That's 44%. Still pretty far back. Lean back in your chair a few inches, and you are in all the first order nulls for the room, and all the second order peaks! Wouldn't it be better to move the listening position (and desk) a foot or two further forward? I'm curious about the purpose of those "sawtooth things" on the side walls (the same ones Brien is talking about). What are they, and what do they do? You did mention that "The sawtooth walls in the control room were done to extend the splayed walls", but you don't have any splayed walls! The room is rectangular! I guess I'm just confused by the design concepts here... How are those sawtooth things built? Absorbent on one, reflective on the other? Diffusive? Tuned? Not tuned? You did say "This will be hollow with rockwool inside and open to the front", which basically makes it a bass trap of sorts, but how is that going to work at roughly 1/3 of the room depth? I'm also curious about the "extended sidewalls" that seem to be eating well into the outer edges of your infinite baffles: I would expect that angling one half of each baffle different from the other half like that is going to have some major effect on the low end, surely? Wouldn't it have been better to just built slot walls as an extension of the infinite baffles, angled suitably for an RFZ? With the desk and listening position in the more common location towards the front of the room, it seems to me that the whole room would have worked out a lot better, and easier to build, too. Is this supposed to be a modified LEDE design? Maybe you could explain the design principles involved here, since everything seems to far out of the usual way of doing things these days. - Stuart -

The theory is explained here. http://downloads.bbc.co.uk/rd/pubs/reports/1995-04.pdf The idea is to build a false wall to reflect past the mix position to simulate a much wider control room and absorb in between. The BBC used an idea from Everest and expanded on it. If done correctly (I don't think I have the angles drawn correctly, the angles should be 30, 50, 70) it can simulate the results of a much wider control room.

Cool! I hadn't seen that paper before (still a whole bunch of BBC stuff that I need to get through) Looks pretty interesting though! Time to read... :) Edit later: OK, looked at it: Its just CID, but those devices on your walls, 1/3 way down the room, don't seem to fit the bill. That's what is confusing me... - Stuart -

Here is another picture of the sawtooth reflector, absorber idea from Phillip Newell's book. I'm also going to use this on the ceiling. I'm thinking about hanging the ceiling panels so they can be fine tuned in place after it is built.

Eric Best wrote:

Brian, what do you mean by the other direction?

If you review your design and compare it to the BBC document, you will notice that the way your sidewall treatments are versus the document, the BBC document treatments do not come up to and go past the listener position, as yours do. Even though it is an absorbent area, the ability to push frequencies back into the mix position exists...so I would not do it nor suggest it NOR suggest it based on a document that is being incorrectly interpreted...

Here is a more accurate drawing.

the CID design is pretty cool and if you note in the paper the large overhead space in front - this is often what i try to use clouds for (hard back or other), to form the shape and then use that space (assuming there is some) to add additional absorption - superchunk, hangers, etc. it's interesting to note the Jensen room sawtooth approach and the CID front and the Newell wave guides and Hidley/Sayers' hanger traps are all compatible... i have a couple of generic CID components for SU. if you push/pull and intersect the shapes you can see the 3D effect... nice work Eric!

Thanks Glen. I've spent about ten years reading everything I could get my hands on about control room design, and this is what I came up with for a small room. Thanks for the vote of confidence. Hopefully it will react like a much bigger room. The Big Problem is ceiling height (same as many other have). It is 7' 8" so I figure I have about 15" to work with (one of the guys I work with is 6'4". I've been kind of thinking about doing this on the ceiling. (the angles haven't been worked out yet). I figure that I really need to do it over the mix position then absorb the rest of the front half of the room. The back half of the ceiling I want to leave open for now until I take measurements after the room is built to allow for treatment to adjust the rt60 of the room. Glen, I think this is along the idea of what you are talking about. What do you guys think?

Looking at the picture, I think I would want to have the second panel a lot higher.

Have you considered using a flat hanging cloud with a Louvered back? Each of the louvered cuts can be a different angle much as you will do with the larger individual panels. Such a design could concieveably save you a bit of headroom

Cool idea! A lot of calculations involved, but I think it would be pretty good.

Brian, is this what you had in mind?

Looks kind of like the CID concept? - Stuart -

Yes pretty much. Put in the context of a single cloud, the lower portion could be filled with absorption as need be, with a cloth covering. Suspended as a cloud the louvres would not even be seen.

I kind of like how they look. :mrgreen:

Have you spent any time with ray tracing, as Mr. Walker and his staff did, in order to approximate what you can expect from this design as it is being superimposed over your build? Seems to me there are a lot of things that can go wrong if the concept is not being fully adhered to. Like you may throw the reflections, from where every you are and from where ever these rays are coming from, back into your face and not around you as is the goal of this CID project. I dunno, I would stick with tried and true, unless I had a real team with real ray tracing ability and a whole lot of time to ponder this concept. Even the room dimensions would need to be approximated on your side, to simply "copy and paste" this concept, a ten foot tall ceiling,16 feet wide, etc., etc. Just something I'm thinking about as you may have already. Still, good luck with your work,

He Brien, I came up with the angles for the ceiling by ray tracing and by including the ray and a 15 degree cone of error (even though these would be low frequency and have no effect on imaging or just go through the surface and be absorbed and extremely high frequency because of bumps in the drywall which we can't hear). It is pretty easy to do in sketchup. Here is a simple example with color. You can see the lines coming straight out of the reflective surface, those are a reference angle to make sure the angle of incidence matches the angle of reflection. All you do is take a line from the source (if you want to be very accurate, multiple lines because a speaker isn't a point source) to the base of the 90 degree reference line. Use the protractor tool to find the angle between the two, then match it on the way out. Go to the other end of the surface and do the same then you have the cone of reflection.

I dunno, I would stick with tried and true, unless I had a real team with real ray tracing ability and a whole lot of time to ponder this concept.

What would be the fun in that :mrgreen: The tried and true with all of the research is not done for someone with an 8' ceiling and and 1800 cu. ft. control room. We have to be creative in how to make it work. The ceiling angles I came up with in this manner. The wall angles were stolen from the BBC Document. They have dimensions. I just created the ratios and applied them to my room so it matches exactly just on about a 10% smaller scale. Eric

On the first plan you show on this thread, you have rather large sawtooth surfaces about 1/3 way back in the room, and I still don't see how they fit into a CID design. Are they just for the near-fields on the desk, or are they for the mains, way up front? I didn't ray-trace those, but just eye-balling it, the angles don't seem to add up... Or was that just an early concept, that has now been updated more precisely? - Stuart -

Don't look at the control room on the first plan. I hadn't done the measurements yet, look at the control room plan later in the thread. The second one was done using ratios that I created from the BBC White paper. This one. Tracing the rays, there is a lot of room for error (ie 15%)