Designing My Soffit Mounts

#61

you can leave the top open however as the bottom is close, you extend the baffle with plywood behind the face insulation (which you may have done already). this provides the baffle extension needed and because it's (mostly) soft, you help with absorbing reflections off the front of your desk/console.

yes, its interactions are complex and it's expected to function as a unit, not parts. :-)

#62

Hi Glenn
Sorry to jump in on someone else’s thread with a question about my own design, but it seems appropriate as it might impact on the choices made here too.

In my design I have hangers underneath the soffit shelf open to the room, much like this design. I didn’t put a piece of ply or MDF over the front of the like some other designs and I’m now wondering whether this was a mistake (albeit one that can be easily fixed)…

What is the purpose of putting a solid panel in front of the hangers underneath the speaker shelf? (I realise an air gap must be left for the hangers to function btw)

Thanks
Gareth

#63

the shelf for the speakers is just one option for mounting. i prefer the entire stack open top to bottom. speaker box mounted on frame and speaker decoupled from that, or speaker box decoupled or even on mass stand. the plate below the speaker is to extend the baffle to match the sides and top of the baffle plate.

#64

gullfo wrote:Source of the post the plate below the speaker is to extend the baffle to match the sides and top of the baffle plate.

Yeah this was my understanding, plus the lower panel catches reflections from the desk (not much of an advantage in my case as the desk will be very small).
As I understand it, the pitfall of making a baffle plate that extends all the way to a foot above the floor is the speaker could very well reinforce resonances due to modal actions of the baffle plate due to the speakers symmetrical placement (exactly halfway down). Read post #16 in this thread (or gullfo's explanation in my JS thread: https://www.johnlsayers.com/phpBB2/view ... =1&t=22675) for more detail

garethmetcalf wrote:Source of the post In my design I have hangers underneath the soffit shelf open to the room, much like this design. I didn’t put a piece of ply or MDF over the front of the like some other designs and I’m now wondering whether this was a mistake (albeit one that can be easily fixed)…

Could do an REW test without and without the panels to see which one is better?

#65

Btw I forgot to mention this earlier but I carried out several REW tests with slightly different mic-positions to determine which one was the most balanced. I got this idea from a post by Stuart in Stadank0's thread over on JS: http://www.johnlsayers.com/phpBB2/viewt ... &start=345

Here are the results (mic was moved left/right in increments of 2.5cm):

It seems like the original position ('L/R Diff + 0' i.e. the green one) is the most balanced/flattest, so I'll be taking all the REW tests from that position from now on

(For those of you who wish to obtain difference graphs for your own studios I would strongly suggest reading posts 48-56 of this thread as REW will need some adjusting or else your measurements will be very distorted)

#66

yes, the baffle plate should ultimately be non-symmetrical for purposes of limiting resonances, but also close enough to approximate an even distribution as well :-)

so 6 inches or so should suffice

#67

Hello. I am new here and been studying this soffit build for some time.

What happened to this project?

Anyhow, I have 2 questions and wondered if the OP or anyone knowledgeable on the forum could reply to my questions

1.

In this picture the soffit is divided into 3 horizontal sections. 1: The bass hangers at the bottom with the port. 2: The middle part with the monitors and 3: The top part with more hangers. I understand that the OP wanted the top section exposed to the room to improve absorption of the room so he left it open but I dont understand why there is a "shelf" dividing the top section and the middle section of the soffit. Is there an acoustic reason why you can't remove that shelf and have just the one shelf that the monitors rest on?

2.
Regarding the box around the speaker. If you seal the the box I realise there must be a cooling path and that is what those holes are in the picture. I was thinking of sealing the box but having it extend back slightly and connecting a round ventilation duct at the back using something like flexible duct and then fill the whole "compartment" with insulation. Is this common practice?

anyhow, would love to know if this build actually continued or not

thanks to everyone for their help because I learned a lot from this thread

Soundman2020 - Studio Design Forum