No it will not be a soffit mounting
You might want to reconsider that. There are many benefits to soffit mounting your speakers, and in your case one of those benefits is that it gets your mix position as far forward as possible in the room, which is something that you really do need to do, as the space is so small.
I am planing to make Helm Holtz resonators modular for lowend(in the corners),
That might not be a good idea. Small rooms need a lot of broadband bass trapping, not necessarily trapping that is tuned to specific frequencies and with a very narrow Q. Something like "superchunk" bass traps in the corners, or hangers, or even just thick absorption across the corners, would probably be a much better idea.
and some gobos on the front and back wall,
I'm not quite sure what you mean by "gobo" in that context, since gobos are usually movable panels, absorbent on once side and reflective on the other, used to help isolate instruments, amps, etc. I can't see how putting those on your front and rear walls would help very much.
Your front and rear walls will most likely need some fairly thick absorption (10cm to 15cm, probably), at least in some parts. The front wall needs it because it is a first reflection point, especially if the speakers are not soffit mounted. The rear wall needs it to help deal with reflections coming back at our head from behind.
What do you mean,something is wrong with floating the wall or I dont nead to do this?
Both! If you are going to float a wall, you need to do the calculations to ensure that you are loading the neoprene correctly, with just the right amount of weight. If you put too much weight on it, then it will over-compress and will not isolate the wall from the floor, so it wont float. And if you don't put enough weight on it, then it won't be compressed at all, so it won't isolate. You have to use just the right amount of neoprene (correct dimensions, correct type, correct thickness, correct location) for the wall that you are going to put on top of it. To do it right, you have to know the technical characteristics of the neoprene that you have to use, such as exactly how much compression you need to put on it in order to load it correctly (how many kilograms per square centimeter), then you need to know exactly how heavy your wall will be, and how that weight will be distributed, then you need to calculate the surface area of neoprene that you need at each point under the wall, etc. It can be done, but it isn't easy. If you don't get it right, the wall won't float and you wasted your time. But if you aren't worried about floating it, and just want to use the neoprene to get a better seal, then that's fine: just be aware that it will not be giving you any acoustic benefit, and ordinary caulk would be much cheaper and just as good at sealing. In any event, the building code in your area might not even allow you to build a wall that is not attached to the floor: Where I live, you cannot do that, due to frequent earthquakes that we have here. Here, the wall MUST be bolted to the floor, and as soon as you put a bolt through the neoprene, then obviously you have created a flanking path, and the wall is not floating any more.
And in any event, you probably don't need to float your walls, for the same reasons that you don't need to float your floor.
- Stuart -
