Newbie questions (3-Way Towers Off-Axis close to rear wall)

[Izuall]

Greetings.
Due to the lack of good retail speakers that fit my needs i`ve decided ill be going the DIY route(and because im in no hurry to finish the project maybe by the end of the year i have plenty of time to research and tune before i even start ).
For drivers i`ve decided on:
HF:VIFA NE25VTS-04
MF:SB Accoustics SB12MNRX25-04
LF:2xFountek FW168

Decided on 3 way because i want to front port and that should prevent any midrange leakage to the port my question on this regard is are there any other parameters (driver specs , box tunning etc)that i have to take into acount when designing a speaker that would work well closer to a rear wall(i dont have much space maybe 1/3ft.)?

 

[wintermute]

First the warning that a three way is much harder than a two way

Now that is out of the way. the SB mid is a very nice little driver, but if you parallel up the Fountek's (and have them close to the wall) then they are probably going to end up being more sensitive than your needs, and the mids will probably be a bit subdued, unless you pad down the woofers, which isn't a great idea).

That being said however having extra spl available in the bass range may be an advantage and allow you to start rolling off early to get a target that boosts your low low end.

Basically being close to the wall means that the baffle step effect will be much less, meaning you have less of a drop in sensitivity in the bass frequencies than you would if out from the walls. a good run down on baffle step is available here Baffle Step Compensation

Tony.

 

[Izuall]

Thank you.
As for the hard part ..I have time and lots of patience as for BSC i`ve been made aware that BSC should be aplied/fine tuned after the speakers are measured in my room.
As for the extra SPL in the bass region if its too much i can allways ad .5 to that 3 way.

 

[AllenB]

Within this region the dips and peaks are likely to be more distinct, and higher in frequency. The closer you move to the corners, the more a baffle (or equivalent) ought to be deliberate, rather than left to chance.

 

[Izuall]

Anyone know where i can find a frequency response chart for the SB12MNRX25-04 driver?