Nashville Studio Build (need design help first!!!)

[Shybird]

Also, do you have any input for the questions posted along with layout 14? I really need to know if I'm designing/calculating the front half of the CR correctly.

Does layout 14.2 comply with what you are saying about the back half of the CR? It angles in only a little bit at the very back...is even that much not acceptable?

Thanks
Trevor

[Shybird]

Here is a John Sayers design that appears to do what you are talking about in the rear of the CR. http://www.johnlsayers.com/Studio/Mainp ... rriage.htm

What is the acoustical difference between that design and one like mine (14.1) where those angled rear walls extend up a little further into the room? I really need to understand this concept!! I'm sorry but I'm really confused on this one...

Trevor

[Shybird]

Hey Stuart...here is another one that demonstrates similar "inward" angled rear walls. Can you see why I'm confused??

http://www.johnlsayers.com/phpBB2/viewt ... f=2&t=1929

[Soundman2020]

Can you see why I'm confused?

Yep!

OK, I'm not saying that you absolutely cannot reverse the angles at the rear. What I'm saying is that it can be a problem if not done thoughtfully, and it also eats up space that could be put to better use. Every cubic foot of volume inside a room helps a tiny bit, acoustically. But a cubic foot inside the wall doesn't do a lot! And more angles means a bit more complication in construction, too (a practical issue, not an acoustics issue).

But there is one more big point here: both of those studios you linked to are 5.1 studios, but it doesn't look like yours is. Yours seems to be a normal 2.0 setup. 5.1 brings some interesting new factors into the equation, like first reflections from the rear speakers happening behind you, off the back walls, not in front of you, space for the rear soffits, and suchlike.

There's probably not too much of an issue in your case, and I'm sure you ray-traced all of that meticulously, so you are probably fine, if that's the way you want to go.


- Stuart -

[Shybird]

Hey Stuart thanks for the reply...that makes sense to me now.

Can you answer my three questions regarding the front half of the CR?? I need clarification here to know that I'm on the right track.

1.) How far behind the engineers head should the first reflections from the side walls intersect? What's the safe zone?

2.) Do the baffles of the soffits count as the reflection surface when calculating the RFZ? Or do you have to think of them as "invisible" and calculate using the angle of the drywall behind? I'm assuming that standard soffits are constructed in such a way that they will reflect the frequencies needed for an RFZ...but I wasn't sure so I'm asking. This applies to the left speaker reflecting off the right baffle and vice a verse (I provided a picture below to demonstrate what I'm referring to here).

3.) Is 5'6" enough distance between the ear and the speaker (direct signal)? And is 5'5" enough space between the engineer and front glass of the CR?


Getting closer I think...I really appreciate all the help. I think there should be a sticky that demonstrates ray-tracing and RFZ design at a more detailed level. It would be a great help for us newbies!

Trevor

[Soundman2020]

1.) How far behind the engineers head should the first reflections from the side walls intersect? What's the safe zone?

Hard to say: depends on the Q (directionality) of the speaker, off-axis response, the angle, the frequency, etc. Probably a foot or so is about as close as you'd want to get, but two feet would be better. (I'm not aware of any actual research to back that up: just my own personal hunch.)

BTW, is that a Sony console you have there? Kind of looks like it, but then again, it doesn't...

2.) Do the baffles of the soffits count as the reflection surface when calculating the RFZ?

Ohh yes! The front baffles ARE the new wall of the room, as far as the speakers are concerned. That's why you have to build them massive and rigid.

I'm assuming that standard soffits are constructed in such a way that they will reflect the frequencies needed for an RFZ...

Exactly, which means "as low as the speaker goes, and then a bit more, just in case". Their main purpose in life is to force the low frequencies (below the baffle step point) back into half space, so they have to appear very solid, very massive, very reflective to those low-frequency sound waves. Of course, that also means that they appear even more solid and reflective to the highs! Thus, they absolutely must be taken into account for your RFZ ray tracing.

This applies to the left speaker reflecting off the right baffle and vice a verse

Exactly. But take a look at your speaker manual, and specifically at the polar pattern (dispersion pattern, or whatever it is called: the one that shows you the SPLs around the speaker for each frequency range). You need to take that into account when you check your reflection angles, ray tracing, etc. For example, at 60 degrees off axis, you won't find very much 20 kHz at all, but you might find a lot of 200 Hz, for example. And just to confuse you even more, don't forget that highs bounce like light rays, while lows bounce like expanding balloons... So for lows you really should draw a cone that expands out from the point where the ray hits, and check how that cone is with respect to your ears...

(Hey, I DID warn you that things are a bit more complex than they look at face value!)

OK, put down the gun and suicide note, and don't sweat things too much: if your ray tracing gives you a couple of feet clearance all around your head, and the reflection point is a reasonable distance away, you should be fine. So go with the largest angle that gets things a few feet clear of your head, and that's about all you need to worry about.

I think there should be a sticky that demonstrates ray-tracing and RFZ design at a more detailed level. It would be a great help for us newbies!

That would be useful, wouldn't it? One day when I have time, I'll see if I can write up something... (Hmmm... checking my calendar, I should be able to fit that in some time in early 2058... )

What I would REALLY like, is a free plug-in for SketchUp to do all the ray tracing for me!!!! Oh yeah! (Well, dreaming is free, at least).


- Stuart -

[Shybird]

Stuart thanks so much!! That helps a lot...and yes, after that explanation, I was about to go find a wall to bash my head against..

Thanks for calming me down...

Anyways, I added a third question to that post, but I think I must've done it while you were typing up that detailed reply...so sorry to trouble you once more but here's my, dare I say, final question for the CR...

3.) Is 5'6" enough distance between the ear and the speaker (direct signal)? And is 5'5" enough space between the engineer and front glass of the CR?

Thanks!!
Trevor

P.S. The manuals for my Event speakers do not provide the information you are talking about I've tried contacting Event by phone and email for over a week and have had ZERO luck!! Really bummed about this...

Also, I just got that console off the 3D warehouse...I don't have a huge console. Just a Mackie Onyx 1640 and a MOTU 896HD. Someday I hope to purchase a console but for now I'll be focusing on buying more outboard gear and mics.

[Shybird]

I'm asking question number 3 because you provided documentation earlier in the thread that stated the EBU recommendation was 6'5" from ear to monitor...so now I'm wondering if less (5'6") is a bad idea.

[Soundman2020]

3.) Is 5'6" enough distance between the ear and the speaker (direct signal)? And is 5'5" enough space between the engineer and front glass of the CR?

It's fine. EBU recommends a distance of between 2 and 4m, (6'7" to 13'3", roughly), but you are close enough, I reckon. If you try to get another foot away, you'll be too far back in the room, I think, and/or the speaker angels/position will get a bit weird. You might be able to tweak things to gain a few inches, but you are not far off the ball park. And the EBU recommendation is for rooms that have have more than 325 square feet of floor area, which is also a bit more than you have.

Rod has a very accurate rule of thumb for these situations. It goes something like this: "You have to live with what you've got." (My paraphrase). In other words, if that's the area available to you, then that's what you can do with it. It ain't Abbey Road, but it sure ain't bad at all! In fact, I think you've done a darn good job to get where you are already, and you are probably getting it to about as good as you are going to get it. That place is going to sound really good, I think. There's probably a bit of room for tweaking still, but it loos like you are at the stage where anything you move to make one aspect better, is also going to make another aspect worse.

- Stuart -

[Shybird]

Ahhh!! Thank you so much Stuart!! I think I'm finally seeing a light at the end of the 2D tunnel...I hope soon I will be starting my journey in the pitch black of... 3D

First...I'm going to nail down this design and make all necessary compromises in order of priorities. I will post back when I think I've got it so I can get the "go ahead" on starting my 3D model...woo!!

I really could not have made it this far and this quick without you man! You've been an absolute life saver!

Thanks a ton
Trevor

[ironman]

I think there should be a sticky that demonstrates ray-tracing and RFZ design at a more detailed level. It would be a great help for us newbies!

Say no more, Trevor!

Have to say, I've been following your thread since you started it, and got to say that i love the progress you've had with it.

I actually got in mind putting together the information I've gathered over the past months from internet/forums in a A-Z form for newbies like myself, who are considering to build a homestudio.
But before that I have to get to home from HERE, where I've been working for past month. It's hard to try to design a studio on a hotels bed with a laptop from almost 700 miles from home

-Juho-

[Shybird]

Ah Juho that would be awesome!! I've been thinking about how much time it would save the moderators on the forum if everything were neatly compiled like your saying (I realize this is no easy task)...so newbs could search within something more concrete and organized rather than searching the entire forum which oftentimes is more frustrating than rewarding ...

Anyways, thanks for the encouragement on the progress! Sometimes I feel like I'm moving at a snails pace with this stuff but I just keep reminding myself how important the entire design process really is...I'm hoping for "smooth" sailing once construction begins.

You gotta get back to a desktop so you can do some real work!! You're waaaay out there...what kind of work do you do?? Also, let me know how I can help you with this "sticky" idea or whatever it turns into...I'd love to contribute however I can.

Cheers
Trevor

[Shybird]

One other thing I forgot to mention...

I've been measuring the distance of first reflections behind the engineers head using a listening position that is 18" in front of the monitor intersect point...so even when I get the reflections to be about 20" behind the engineer's head...they are really only 2" behind the intersect point of the monitors...is this ok? Or should I be designing so that the reflections are 1-2' behind the intersect point?

Glenn had told me awhile back that he uses 18-24" in front of the monitor intersect point as a guide for where the engineer should actually sit...just wanted to make sure that applies to what I'm doing here with the ray-tracing.

Thanks again...sorry for so many questions!
Trevor

[Soundman2020]

using a listening position that is 18" in front of the monitor intersect point...so even when I get the reflections to be about 20" behind the engineer's head...they are really only 2" behind the intersect point of the monitors...is this ok?

That's fine and correct, yes. Just think of it this way: the entire control room is built around and for your EARS. They are the most important focus of the entire design, so that's what you should reference everything to. Here's a hint I have used on a couple of designs: In SketchUp, create a couple of vertical planes that run through the center of your head. One runs forwards and backwards along the center line of the room, and you can use that to test symmetry, while the other runs left-right exactly through the place where your ears will be. I have found that to be very useful in setting up room geometry. I make those planes translucent, so I can still see what I'm doing on the other side, and I put them on their own layer, so I can turn them off when I don't need them.

Glenn had told me awhile back that he uses 18-24" in front of the monitor intersect point as a guide for where the engineer should actually sit...just wanted to make sure that applies to what I'm doing here with the ray-tracing.

Yep. Glenn likes to have the intersect a bit further back in the room. Or rather, the listening position a bit further forward on the room. With me, it seems to end up as about 12" to 18", so at least we all agree on 18" as being a good! Actually, I'm slowly moving in Glenn's direction too for a number of reasons.... He might just persuade me to get to 24", one day!


- Stuart -

[RJHollins]

Glenn had told me awhile back that he uses 18-24" in front of the monitor intersect point as a guide for where the engineer should actually sit...just wanted to make sure that applies to what I'm doing here with the ray-tracing.

Yep. Glenn likes to have the intersect a bit further back in the room. Or rather, the listening position a bit further forward on the room. With me, it seems to end up as about 12" to 18", so at least we all agree on 18" as being a good! Actually, I'm slowly moving in Glenn's direction too for a number of reasons.... He might just persuade me to get to 24", one day!


- Stuart -[/quote]

Certainly NOT to derail this thread ... which I have enjoyed the progression !

Glenn [Gullfo] designed my Control Room [along with wonderful support and insights from Stuart, xSpace]. I've also positioned the 'focus' of the mains 18" behind the ears at the seating position.

It is not so easy to move monitors around to test/ measure ... and I am certain that I could improve response by experimenting further ... it's just that I've been enjoying the room too much

If a separate thread was ever started to discuss/ educate us students on the theory/ philosophy of monitor focus depth in relation to the 'mixer seating' position ... I would certainly attend that thread ! Stuart ? in your 'spare time'

On topic ... Shybird ... more words of encouragement to continue the percieved 'snails' pace ... you will thank yourself for years later !

Looking forward to the 3D