Two quick questions about Speaker Soffit wall design...

I have two quick questions about designing a front CR wall with built in speaker soffits. The soffit plans shown on the SAE site indicate that the monitor speakers should be boxed into a sealed (airtight) MDF box that is either built into the wall and aimed (at 30 degrees) to be level to ear height when one is seated in the sweet spot of a CR, or alternatively angled downward to the sweet spot from above ear level if the height is over 1.2 meters. My questions are... 1) Is there any advantage to mounting these soffits higher than 1.2 meters and angling them downward, as opposed to a straight mount direct to seated ear level? 2) Other soffit designs I have seen posted here and on other sites and books show soffit systems which include ports that seem to lead from behind a vent in the MDF box containing the speaker, and continues down through a ported bass trap or altertatively are ported up through an upper cavity above the MDF box. If my monitor speakers do not have a rear port, must I vent or port the MDF box? If so, why? Jon E.

1) only disadvantages. The speakers' best response is on axis, and the ears localize that way best the stereo illusion. Going up can also cause strange panning effects. 2) Are you refering to cable entrances/paths? Andre

Thank you AVare, Thanks for the quick reply to my question about angled montors. I will clarify my second question with an image taken from a previous posting on this site. I realize that a small sealed hole for running cable will be necessary in each plywood (or MDF in my case!) "tight fitting" speaker enclosure box within the soffits. Although I could be wrong, the attached image seems to suggest actual rear porting via an airspace just behind each speaker enclosure, venting through and then out of each adjacent upper and lower soffit cavities. So, is it still necessary to port the enclosure as shown, if my particular monitors are not rear ported? Perhaps there is a need for this, but I just don't quite understand why... - Jon E.

Your diagram, if I am reading it properly is showing interconnections betwen the LF traps, NOT of the speaker cabinet. Otherwise the space behind the speaker would be sealed and cause not predicted acoustic effects. Nothing to do with the speaker system ports. Andre

Andre, Thanks for clearing up my mis-interpretation of that diagram. -Jon E.

Jon, There is at least one condition where you do need a rear port in the soffit. If your monitors are powered by internal amps (ie. the amps are attached to the speaker cabinets) then you will need a port to provide for cooling air. Darryl.....

That's a valid point!. In my case they are externally powered (passive) Dynaudio BM 15 monitors, so I will forgoe the porting in this case. - Jon E.