Advice requested on CR re-build for 5.1...

I would like to ask for your ideas and opinions on a proposed re-build design of an existing 230 sq. foot control room we hope to modify for stereo tracking and video synced 5.1 mixing. The pre-existing walls were solidly constructed to fairly high TL levels, but the room currently lacks both symmetry and any sort of acoustic treatment other than some Auralex panels that the previous occupants placed here and there. After reading many posts here and on other sites, and a consultation with a local architect, I have come up with what I think may be a reasonable retrofit requiring a minimal amount of additional wall, soffit, slatt resonator and bass trap construction. Attached are images of the existing CR, and a possible layout using for the new left side CR gyprock wall, which I intend to splay 10.5 degrees in order to match the existing right side wall. I expect to use tilted 703 hangars under the existing 10' high flat RSIC-1 hung ceilings and a combination of Ethan Winer’s Deep Bass Absorbers for the rear corners and John Sayers' varied gap Slatt Resonators at the splayed pointy area just behind the sofa.. I am still unsure if I am missing any other important elements, and what other types of acoustic treatments may be helpful to build onto the walls on both sides of the mix position. I am also not certain if I can leave a reflective surface (painted gyprock) as the face of the proposed new left side CR wall,? Any suggestions or criticism would be helpful... Jon E.

This is refreshingly short. :lol: I don't see anything that you missed. Yes, you can leave the rear left wall with the surface. Have fun! Andre

Thanks Andre, It's good to know I have the basics covered somewhat well. My questions are.... 1) Would it be advisable to install slatt resonators on additional (not illustrated) "False" 703 covered walls with just 3" airspace, adjacent to the left and right splayed gyprock walls, forward and alongside the mix position, or could I potentially get away with just using slatts only along the front speaker soffit zones and along the rear CR wall? 2) As the existing CR to Live Room windows are situated exactly where my center channel speaker for 5.1 should ideally be located, should I stick the center channel speaker on a stand which blocks my window view, or should I opt instead for a soffit mounting of the center channel speaker just above or just below the window (which would require the angle be somewhat incorrect as per AES/BBC/EBU 5.1 positioning diagrams. - Thanks for you input, Jon E.

Joe - the center speaker si very important in 5:1 as it usually takes the dialogue. The correct layout is that all speakers are the same distance from the listener. Here is the correct layout for your room using the proper 5:1 geometry :) cheers john

John: Oops, I missed that entirely. :oops: Andre

Hi Mr. Sayers, Thanks for the advice. Looking at your suggested changes to my 5.1 layout, I am unclear about the soffits shown in the front and rear in your plan. If possible, could you help me to understand the following.... 1) In terms of soffit mounting all 5.1 speakers as you seem to suggest, I have seen some of your plans that show very compicated wall soffits with complex venting and 703 hangars built below the speakers, but that would a massive construction task which I would prefer to avoid. Since my 5.1 monitors are not rear vented, could I perhaps get away with just enclosing each speaker within a tight fitting MDF box that in turn is built within slatt resonator walls which will mask the corners of my CR room??? Jon E.

Jon - I was just pointing out what the correct method is being that each speaker should be the same distance from the sweetspot and that each speaker have the same baffle around it. You can add a baffle the way you suggested - the additional bass trap etc is only a way of utilising the space behind the baffle. cheers john

Thanks for the great advice!. I have yet one more question to ask regarding the center channel speaker placement, which will end up a few feet heigher than the other speakers in the CR.... There will be a retractable HDTV screen built just above the CR window which will be pulled down when necessary for film scoring and mixing, and will completely cover up the main CR to Live Room window area while in use. In order to achieve equidistant placement of all speakers, and not block visability of this front projection HDTV screen, the center channel speaker will need to be soffit mounted higher than the other speakers, most likely just above the top of the window's center point and angled drastically down towards the mix position. Since this center channel speaker will therefore need to be elevated about 2.5 feet above (and then angled downward) the other surrounds and mains (which will all be elevated to about 4' height), will this single higher elevated and angled center channel speaker potentially mess with the surround image, even if it is actaully equidistant??? Jon E.

will this single higher elevated and angled center channel speaker potentially mess with the surround image, even if it is actaully equidistant???

No it won't - but you can see why there is a tendency to operate the control room sideways so the whole front wall can be used for speakers and monitors. ;) cheers John