Stuart's Insanity Studio: Design phase

ROOM RATIO QUESTION FOR THE ACOUSTIC GURUS: I'm having a real hard time adjusting my room dimensions to be both practical and also matching a good ratio. I'm aiming for Sepmeyer's first ratio, since that's the closest fit to the almost-cubed dimensions of my control room. The goal is therefore 1 : 1.14 : 1.39. I'm getting close by nudging things here and there, but I'm still a bit off in the length dimension, and I cannot extend that any more as I'm right up against the property line. I'm also swapping "Height" for "Width", otherwise my ceiling would be so low as to be impractical and my CR would be so wide that it would eat into the LR space. Right now, I'm at a ratio of 1 : 1.14 : 1.25 (or in centimeters, it is 226 (W), 257 (H), 282 (L) ) However, I'm at the stage where, in order to get any closer to Sepmeyer 1, I'd have to make the control room so narrow as to be uncomfortable and bring the ceiling height down to an impractical level. (OR knock a hole through the wall and "borrow" eight inches from the neighbors garage!!!!) So my question is: How bad is that as a ratio? Do I really need to shrink the height and width more, or is this OK? If I have to, I will, but I'd really like to avoid that, as it is already so small... One thing I could do (but would also like to avoid) is to eat another couple of cm out of my MSM air gap, but I'm already down to 3 1/4 inches (8.5cm). I guess I could drop that down to 6 cm (2 1/2"), which would improve my ratio by two entire whopping tenths of a decimal, to 1 : 1.14 : 1.27!!!! But is it really worth it? Is this ratio terribly bad? Can I live with it? Any suggestions on what to do? - Stuart -

I wouldn't worry about ratios too much. In an already tiny space, it's a shame to make it even tinier just to adhere to the ratio rules. If tiny is what you got, then that what you should/can use. And, ratios are not the holy grail. Making a room exactly like that is a VERY hard job to do. Adjust the room with acoustic materials. (No, Ethan would say "you can't have enough BASS absorption" ;) ).

Hey Stuart, though I'm definitely not the one this question was adressed to but maybe this link (I guess you already checked your ratios with Bob Golds' Room Mode calculator...?!) and/or at least the "Bonello"-curve at the bottom of the page will show you - theoretically - that your room won't become too bad... :wink: From all I have read so far...I'd follow Ro's advice or read again Eric Desart's comments and thoughts about ratios... Greetings, Carsten

Ro wrote:

I wouldn't worry about ratios too much...

I agree with Ro. Your room is already problematic due to its tiny size and any attempt to adjust the room's ratios to be on the spot would be pointless. You got them down close enough, I would stop worrying about them and turn my attention to more important issues that would actually determine the studio's functionality, isolation and acoustic treatment. Just my opinion... Keep a cool head, John

Thanks guys! Your comments are very much appreciated. That's three "permission slips" in three days! :yahoo: I'm on roll here: better go out and buy some lottery tickets... :) You folks have confirmed what I suspected anyway: better to have a functional, practical room that is slightly off on the ratios, than an excellent ratio but impractical room. Thanks for the link to the Bob Gold calculator. That thing is amazing! I'd been using another one (I think it was Eric Desart's spreadhseet? Not sure where I downloaded it from) which is also great, but I like the way the Bob Gold calculator displays and graphs the results. Based on that, I feeling really comfortable with my current dimensions, so I'm just gonna take your advice, stop fiddling around with millimeters, and get on with other, more important design details! Once again, thanks to all of you guys for your input and "permission slips". My next questions will probably be back on the subject of soffits... :) - Stuart -

I Finally Found It! (I think ? ) André, if you are around, this one is especially for you. Regarding the tilt angle of speakers, I finally found the reference for the 10° number. It comes from the EBU paper titled "Subjective assessment of audio quality", which you can find here, if you are interested: http://www.ebu.ch/en/technical/trev/trev_274-hoeg.pdf Page 3, paragraph 2.3: "The height of the acoustical centre of the loudspeaker monitor should be at least 1.2 m above floor level and the inclination angle of its reference axis in relation to the horizontal plane should not exceed 10°." Bingo! :yahoo: Well, if its good enough for the EBU, then its good enough for me! So I'm sticking with my 7° angle for now, and I know I can take it to 9 or 10 if I really need to. I'm finally feeling comfortable with that! Whew! I can sleep again at nights, now.... :) ZZZZZZzzzzzzzz...... - Stuart -

well.... ain't that funny :) dream on Stu :mrgreen: (zzzzz)

Thanks 4 sharing Stuart!!!!!!!!!

Soundman2020 wrote:

I Finally Found It! (I think ? ) André, if you are around, this one is especially for you.

Thanks Stuart! Andre

Greetings Stuart, How's it going? Any updates?

Thanks for asking, Ken! I'm still around, but the studio is on hold right temporarily. Got lots of stuff all going on at once, the economy isn't helping, I'm still trying to finish the bathroom, and I have a couple of albums I need to finish mastering, so that I'll have the time (and money!) to get started on construction. I'm still tweaking the design, and pretty much ready with that (I think!), so stay tuned. There should be some action here shortly, as soon as I can get some of this stuff off my plate again. (I never would have thought I'd need a year to get my head around the concepts properly, and get a decent design together, but I'm soooo glad I did take the time! What I had in mind before I came here would have been a major flop. What I have now stands a real chance of working out, thanks to John, Rod, Andre, Ro, and a whole bunch of others.) - Stuart -

Stuart: This is not meant to affect your build and design. This seems as good a thread as any to add this bit information on speaker angle. Thjis thread has information that I have alluded to in the past about hearing frequency response and angle of incidence for the sound source. Enjoy! Andre

Thjis thread has information that I have alluded to in the past about hearing frequency response and angle of incidence for the sound source.

Oh cool! You finally found that reference! :yahoo: More reading! More learning! This is good. Thanks, André. Much appreciated!

This is not meant to affect your build and design.

Hehehe! You know me better than THAT! If the data says it will make a difference, then I'm all for changing the design! (And not so far advanced that I can't change it: I designed everything in teh SketchUp to be modular, so changing one thing is relatively easy. It won't be "too late" to change it until the room is finished... ) So it looks like 5° max. is what I should be aiming for? The reasoning makes sense. I'm just thinking out loud here, but wouldn't it be the same thing if, for example, you were to tilt the speaker/infinite baffle at 10° but then tilt your head up 5°? Wouldn't that give you the same angle of incidence at your ears? (Not that I'm planning to do that! Just trying to make sure that I understand the principles.) Also, if I'm understanding all this right, then it means that trying to do critical mixing with your head down while looking at your console / keyboard / mouse / coffee mug is not a good idea, as it could potentially mess up your spatial and frequency perception. So even your posture while seated is important for critical listening. Hmmmmm.... never thought of that before. Thanks again, Andre! - Stuart -

Is this in the building phase soon? :D Looks like it gonna be a hell of a thing this :D Good luck

It will be in the building phase soon. It's only on hold right now awaiting an improvement in finances. I'm not going to start until I have enough money on hand to get fairly well advanced, quickly. I still have some design issue to tweak, and I'm still working on the plan for the construction sequence while I wait for money to appear... But I'm hopeful that it won't be too long now, and of course I'll be posting the final plans here for comment and sanity check, right before I start. Thanks for asking! - Stuart -

Soundman2020 wrote:

It will be in the building phase soon.

I am looking forward to your build blog! Anxiously, Andre

This seems as good a thread as any to add this bit information on speaker angle. Thjis thread has information that I have alluded to in the past about hearing frequency response and angle of incidence for the sound source. Enjoy!

Hello andre. Say, I'm having a problem with the PSW site right now. Could you tell me who the AUTHOR of that thread is please? Thanks. fitZ

cadesignr wrote:

Thjis thread has information that I have alluded to in the past about hearing frequency response and angle of incidence for the sound source. Enjoy!

Hello andre. Say, I'm having a problem with the PSW site right now. Could you tell me who the AUTHOR of that thread is please? Thanks.

The thread title is SOFFIT ATC 110. It is started by Vladi. The specific post is by Thomas Jouanjean, a studio designer based in Belgium. It is posted October 25, 2009. Andre

Some questions for John (and others!) about speaker soffit design: 1) On your soffit design, John, you have hangers in the lower part of the soffit, behind the front panel. Would it make a huge difference to substitute insulation instead of hangers? The reason I ask is because it looks like I'm not going to have much space inside that area for hangers, since I'm going to make the soffit panels out of concrete and I therefore need a beefy steel structure with strange angle pieces inside that area to support the weight, and that would make it hard to get hangers in there. So would I be sacrificing a lot by just stuffing that entire space with fiberglass / rock wool, instead of hangers? Or would it be better to re-work the design so that I can get a decent bunch of hangers in there? Or maybe you could suggest some kind of compromise? I think I can rework the structure to give me more space, if necessary, but not sure that I'd be gaining or losing by doing so, acoustically. 2) On Thomas Barefoot's soffit design, he leaves a slight gap (a few mm) between the speaker cabinet itself and the actual soffit panel, and also has the speaker just strapped to the stand, with no box around it. Is it OK to do that with your design too, John? Or should I still go with your tight-fitting box to surround the speaker cabinet? I'm putting together kind of a hybrid design here ("Frankensoffit"!), borrowing some parts from your design and some parts from the Barefoot design, and trying to be sure that I'm not screwing up double by doing so! The basic idea is to use the Barefoot idea of an isolated stand for the speaker with a replaceable bezel to go around the speaker cabinet (in case of using different speakers in the future), but using most of the rest of your design, modified to use steel framing and concrete panel, instead of wood framing and panel. 3) Just checking: The soffit panel itself does not need to be sealed to the front and side walls and the ceiling, correct? I can leave small gaps there (a few mm)? - Stuart -

Hello Stuart, I'd thought I'd be bold and chime in :wink: Anyone, feel free to correct me, since I'm no expert! 1) the purpose (I think) of the hangers, is to dampen the sound behind the soffits. Therefore I would think stuffing the space below and behind the soffits with rockwool or fibreglass, will have the same effect. 2) the reason (I presume) mr Barefoot leaves a small gap in his dsign, is because the speakers are isolated from the front of the soffit panel. Connecting them would compromise this severely. In mr Sayers' design the speakercabinet is reinforced by the box (thightly) surrounding it, and the front of the soffit panel is attached to that box. The idea behind this (I think) is to prevent sideways/backwards radiation as much as possible, and thus projecting more sound into the room. 3) As far as I know the soffit panels act as an extension of the baffle. I therefore would be carefull not to create another wall. In other words I'd leave more than just a few mm's surrounding the soffit panel.

I'm putting together kind of a hybrid design here ("Frankensoffit"!), borrowing some parts from your design and some parts from the Barefoot design,

I sort of combined both ideas also. The speakers and stands are decoupled from the soffits, the speaker cabinet is slightly reinforced. After mr Barefoot's reaction to that, I'm inclined to beef up the clamps, but I haven't don that so far: http://www.gearslutz.com/board/5077364-post6.html Althought not shown in the picture I made of the speaker attached to the stand, I did insert some rather rigid foam between the top clamp and the speaker. (to prevent future rattling) viewtopic.php?p=97943#p97943 viewtopic.php?p=97944#p97944 I hope this helpes. Phybeau

Stuart - the use of the hangers is purely a matter of using the space under the speaker for something :) - you don't have to use it as a bass trap. whether you mount the speaker on it's own mount or incorporate it into the soffit structure is just two options - I have no idea which is the better option.

Stuart - the use of the hangers is purely a matter of using the space under the speaker for something :) - you don't have to use it as a bass trap.

OK, Thanks, John! I reckon I do need it as a bass trap, though, since my room is so tiny to start with, and the front wont have much else in the way of bass trapping (large concrete soffits!). So I reckon I'll just stuff that full of mineral wool, and leave a small gap at floor level, like you do with your design. If I do that, won't that "gap" at the bottom act as a Helmholtz resonator, to a certain extent? Should I worry about tuning it to a suspect frequency, or should I not bother too much about that, and just make it a "convenient" size? Also, I guess that "bass trap" section should be sealed, right? (I mean, if I want it to act as a resonator). But the soffits themselves should NOT be sealed to the walls / ceiling, as Phybeau suggested, correct? What he says makes sense to me too, but I just want to confirm... Sigh! So many questions.... - Stuart -

I seal everything Stuart - the idea is to make the soffit mount as solid as possible to hold the speaker box rigid. The port at the bottom I make @ 1ft (300mm)

Hijacking :shot: John, how you feel about soffit mounting speakers like Barefoot's where they've got a woofer firing the speaker's side?

Someone recently brought to my attention that I was about to hit 10,000 posts on this forum! :oops: :!: Wow! So I thought the most appropriate place to post #10,000 is right here, on my own original thread, nearly nine years after my initial attack of insanity. And nine years ago, I never, ever expected that things would turn out like this! :thu: So, for what it's worth to anyone who cares, this is my post number ten thousand on John Sayers Recording Studio Design Forum. - Stuart -