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Sorry Clueless

Posted: Sun Jan 02, 2005 2:10 pm
by John Sayers
Mate I lost your post so could you give the rave again - I've posted your pictures so you don't have to do that agin - sorry ;)

cheers
john

Text that describes the drawings

Posted: Mon Jan 03, 2005 9:51 am
by Clueless
For better or worse, I've decided to upgrade my Mackie 624 monitors with a pair of Thomas Barefoot's MM12s. I made this decision by auditioning another pair of monitors which, while nice, and revealing, have shown (1) there's a lot of bass that doesn't come through the 624s and (2) my room and/or listening position make for a very uneven listening experience. My goal is to have my studio laid out (and perhaps re-trapped) before the MM12s are delivered some time in March 2005.

Here are the pdfs, drawn to the scale of 1 foot = 1cm. Some small explanations...

0. The images, as presented, should be viewed as three pairs of drawings. The first of the pair, the square box, is a ceiling-eye view of the studio. The second of the pair is looking from the back wall, into the studio, with the semi-vaulted ceiling on top.

1. The first layout is the current layout. As you can see, I've tucked my
listening position into the corner with the speakers near mid point of two of
the rooms axes (left/right and up/down) with me mid-point between the speakers and a reflecting wall--not optimal! There's all sorts of challenge right where various programs predict: 70-something Hz and 150-something Hz.

2. The second layout rearranges things with me looking out the window that may be blocked by the MM12s. The MM12s could be above the console (40" min height--9" console on a 30" desk) or perhaps hung from the ceiling. I put MM12 shapes in both potential locations in the view that looks out the window.

3. The third layout has me looking against the knee wall, with the MM12s
projecting the long dimension of the room (and down from a low ceiling). Again, the fit could be just above the console or, for bonus points, soffit mounted into the knee wall. The latter position would require some major surgery as the original wall was not designed to have a soffit, and moreover the ceiling faces south, which may require some thermal shielding against the strong North Carolina sunshine.

In all three considerations (stick with #1 and trap like hell, or move 1000 lbs of furniture and gear for #2 or #3), I'd also be interested to know what folks would recommend trap-wise. I have Auralex foam which has made the room quite bearable for vox and guitar recording, but I know I need better trapping if I want to get my mixes really right down in the 30-125 Hz register. If two speaker positions are equally good from a speaker placement perspective, but one is much better in terms of setting traps, I'd love to know that!

Posted: Fri Jan 07, 2005 4:21 am
by barefoot
I recommend the 2nd layout where you're facing the window. It provides better symmetry and fewer issues with early reflections. However, I would pull the desk and monitors away from the window a few feet. This will help reduce frequency response anomies caused by reflections from the front wall. Then I would heavily trap the rear wall.

Thomas

Ceiling vs. ear-level speaker positioning

Posted: Fri Jan 07, 2005 4:27 am
by Clueless
Thanks for the response. Regarding #2, would you put the MM12s at ear level (and risk being very near the vertical center of the room) or at ceiling level, facing down to the mix position?

Re: Ceiling vs. ear-level speaker positioning

Posted: Fri Jan 07, 2005 12:28 pm
by Jon Best
Clueless wrote:Thanks for the response. Regarding #2, would you put the MM12s at ear level (and risk being very near the vertical center of the room) or at ceiling level, facing down to the mix position?
I agree with Thomas, although you could pull off #3 if you felt you had to, as long as you trapped/damped the crap out of the rear slant ceiling.

Personally, I've always preferred speakers at ear height, slightly above if absolutely necessary. I wonder, actually, if that's a selling point for three-way speakers with the woofer(s) below instead of beside. Never thought about it.

Standing ear height, angled down to point at sitting ear height, has always been about the highest that doesn't feel excessively weird to me.

I'd agree with trapping the rear wall, and if you do pull a few feet back from the window (which I also agree with, I'd get some absorption on the front wall, basically as thick as possible. Maybe 2-4" thick, spaced at least 2-4" off the wall. Then panel trap the rear wall, and just hang some absorption in front of the traps if you end up needing it.

Posted: Sat Jan 08, 2005 5:18 am
by knightfly
Thomas and Jon gave you excellent advice - and you're wise to want to keep the woofers AWAY from dead center, in ANY axis -

Philip Newell's book, Recording Studio Design, has some comments on speaker height that aren't often mentioned - seems that our ears' "pinnae", the little "bumps" in front of our ears, aren't as useless as once thought. They cause us to hear higher frequencies differently when they come from a height different than our heads, to the point that cymbals and other HF stuff don't sound as bright when approaching our heads from above; this is probably responsible for Jon's comment about things not sounding right with speakers at the ceiling.

With low ceilings, speaker height is definitely problematic; but you want the woofer centers AWAY from the half-way point by several inches, either high or low, and the same with your ears; how you get there is just one of the many frustrating things about optimising your space so you can hear AND still reach all the knobs... Steve

Posted: Sat Jan 08, 2005 5:40 am
by barefoot
Since about 2/3 of the ceiling is sharply sloped, vertical room modes won't be very strong at all. And you can improve things even further by putting panel traps on the flat part of ceiling. So I wouldn't worry much about the vertical position. Place the monitors at ear level; preferably on sturdy stands just behind the desk (MiniMains are HEAVY!). I can recommend some stands if you need.

Below I've illustrated some ideas of where to place the bass trapping. I would also put some broad band absorption on the sloped ceilings where the 1st reflections will occur.

Thomas

Fascinating...

Posted: Sat Jan 08, 2005 6:05 am
by Clueless
Why would the traps against the window wall be flat against the wall, rather than angled as corner traps?

Also, for the trap that's against the wall where the entry is (and a sideboard currently resides), I was planning on putting a Mondo Trap on the sideboard, extending up to the ceiling. Is there a reason it's better to have the trap extend to the floor instead of the ceiling?

Thanks again.

Re: Fascinating...

Posted: Sat Jan 08, 2005 11:24 am
by Jon Best
Clueless wrote:Why would the traps against the window wall be flat against the wall, rather than angled as corner traps?

Also, for the trap that's against the wall where the entry is (and a sideboard currently resides), I was planning on putting a Mondo Trap on the sideboard, extending up to the ceiling. Is there a reason it's better to have the trap extend to the floor instead of the ceiling?

Thanks again.
I think Thomas is talking about panel traps, which are designed to do their work sitting flat against the room boundary. Crossing the corner with them just reduces their effectiveness, and my gut feeling is that it reduces it a whole lot.

If you're talking about rigid fiberglass or something, then yeah, cut across the corners with it. The panel traps will do better for you, though.

As far as trapping down low or up high, I don't really recall anyone saying it was going to make much of a difference, but as a rule of thumb, you're going to want two things for wall treatments; 1) the bottom of the treatment below your head while sitting, and the top above your head while standing, and 2) adjacent to at least one room boundary. Don't think it matters much whether it's floor or ceiling, really. If you push them sideways and do floor, however, you are able to put some trapping along the side walls as well, and get some smoothing on that corner-to-corner modal bounce as a bonus.

Placing traps in corners

Posted: Sat Jan 08, 2005 10:27 pm
by Clueless
Jon, I'm thinking about mini-traps (or mondo traps), which I think are panel traps in your lexicon. Here's a lot of examples where panel traps are placed across corners:

http://realtraps.com/placing_mt.htm

In fact, by my read, this is the prefered way to treat corners. As for placing them flat against a room boundary, I also assume you mean "flat, but with 4" spacing behind them". The beauty of placing a mini-trap across a corner is that you get the spacing for free.

Re: Placing traps in corners

Posted: Sun Jan 09, 2005 2:43 am
by Jon Best
Clueless wrote:Jon, I'm thinking about mini-traps (or mondo traps), which I think are panel traps in your lexicon. Here's a lot of examples where panel traps are placed across corners:

http://realtraps.com/placing_mt.htm

In fact, by my read, this is the prefered way to treat corners. As for placing them flat against a room boundary, I also assume you mean "flat, but with 4" spacing behind them". The beauty of placing a mini-trap across a corner is that you get the spacing for free.
Hm. Looked at the site, and it's different that it was last time I looked, it actually doesn't look like his original wood panel traps are in there.

If you're talking about the minitraps on the site, then yeah, follow the instructions. Those traps work on velocity, and need to be out in the air where the wave is actually moving air around. I was actually talking about sealed membrane absorbers, basically a wooden box with a thin wooden face, designed to weaken the pressure where the modes hit the room boundary. Pressure traps *have* to be pushed up flat on a room boundary to work correctly.

The upside is, if you have a room with really serious low end problems, you can stick pressure traps in the corners up against the walls, and get even more smoothing by hanging traps that work on velocity across the same corners.

I've been out of it for a while, anyone know why Ethan apparently isn't selling pressure traps anymore?