John Sayers' Recording Studio Design Forum Archive

hello all,

i ve been reading up alot on this soffit/ fush mounting thing for my monitors (ADAM P22a).
Theres somethings thats not clear to me. The whole point of doing this is to use the whole " infinite baffle" principle to clean upsome acoustical problems of booth speaker response and the room.

theres basically 2 ways of doing it:
1. the real soffit thing, as in "build a box and put the speaker in it"
2. the put your speaker on a rigid(concrete) stand and decouple it from the floor, walls, and the flont baffle and mount the front of the speaker flush to the baffle.

this approach seems easier to me to construct anyway, so i would like to go with that. from what i understand theres no "compartment" whatsoever behind the baffleplate, just the stand and the speaker and the contruction to keep the baffle plate in place. no other contruction to seal anything off, right?

I also read this is not a good way to do it, because it messes up the speakers response and make it not sound accurate.

this whole thing makes me doubt the whole flush/soffit mounting again.
i don't wanna spend a lot of money and time only to find it does not improve the sound/accuracy of my monitors. that would be a waste.

sometimes the more youread the more confusiing it gets, jeez..
anyone some additional info on it?

jaye wrote:2. the put your speaker on a rigid(concrete) stand and decouple it from the floor, walls, and the flont baffle and mount the front of the speaker flush to the baffle.

this approach seems easier to me to construct anyway, so i would like to go with that. from what i understand theres no "compartment" whatsoever behind the baffleplate, just the stand and the speaker and the contruction to keep the baffle plate in place. no other contruction to seal anything off, right?

jaye,
I'm still pretty green here, so I'm sure that someone with more experience will be able to offer better information.

I'm currently building option two. Once I had determined the weight of the concrete pillar, base, form, box and speaker I worked with my local Mason Industries rep to find the product that would result in the proper compression for the total weight.

jaye wrote:from what i understand theres no "compartment" whatsoever behind the baffleplate, just the stand and the speaker and the contruction to keep the baffle plate in place. no other contruction to seal anything off, right?

The splay wall / baffle face and the front and side wall make a compartment. Perhaps I am confused on the question.
I'm also dividing the top and lower portions within the enclosure, with the lower portion holding acoustical hangers, sheets of soft fibreboard, wrapped in insulation and hung that act as a bass absorber.

jaye wrote:I also read this is not a good way to do it, because it messes up the speakers response and make it not sound accurate.

The introduction of the baffle will enhance the bass response of the monitor. I will be using a passive low shelf filter to compensate as my monitors are passive. I believe the ADAM P22a is powered and has low shelf control on the rear to compensate for corner or near wall placement.

The size of the baffle may also have an effect on the sound, as a baffle smaller than optimal may horn or narrow the sweet spot of the monitor.

Those ADAMs have an angled face and may be interesting to place flush with the baffle. I recall seeing a thread here where someone had success after a few small reworks with an angled monitor like this.

Like I said, hopefully someone with more knowledge on the subject will come and fill in the details and correct any errors I may have laid out here.

Below is my quick bastardization of John's sketch in the Soffit Mounting? thread.

Good luck, and hope I was of some help.
BF

thanks for your answer, your explanation is what i was looking for, i wondered if i needed to divide the space behind the angled face to make the principle work. i take it the dividing shelf is attached to the construction that keeps the angled face/ front baffle in place , right?

the only concern for me with this is the heat dissipation from the back, i noticed the adams run pretty hot, so i'm not gonna fill the space with isolation, just line all the insides with it. also if i use the concrete pillar, would i still need to place the adams in a box? i would like to keep the contruction as simple as possible, but still effective.

btw, i just talked to an adam rep telling me he talked to the designer, appearantly he told him it is NOT a good idea to soffit mount them..
i wonder if thats what they all say, when a speaker is not specifically designed to be build into a wall...