"On-Wall" Slotted bassreflex design

[Vidi]

Hi,
I'm planning to start a new speaker design this winter. The main goal is to end up with a couple of slim speakers, made for hanging directly on the wall, beside my flat screen tv, hence the some what clumsy title "On-Wall".

I have four Seas ER15RLY and two Seas 27TFFC that I'm going to use, together with a Mini DSP 2x8 for filtering/corrections.

Since my main goal is to have a shallow "On-Wall" mounted cabinet, I have some limitations in cabinet types. Closed cabinet is not ideal for the Seas Mid/Bass elements, they tend to prefer reflex. Normal ports (round) is difficult to archive, because of the cabinet dimensions. I was hoping to aim at a slotted port design, but I am unsure of how to calculate the tuning frequency. I did some googling, and found the calculator on L-Slot Vent Bass Reflex Enclosure Calculator | DB DYNAMIX AUDIO
What I'm not getting on this calculator is the difference between the different box volumes and tuning frequencies. You have "Port Tuning", recommended Tuning" and the tuning located just below "Recommended alignment". Anyone that knows the differences of these?

Or is there any link between slotted reflex port and "normal" round port I can use together with for example Unibox408 spreadsheet?

Attaching image of parameters used in the mentioned calculation, and a box design with the suggested measurements from dbdynamixaudio. The measurements used are my maximum measurements (43inches high, 8.5inches wide and 5.5 inches deep).

Any suggestions (also regarding the usage of other cabinet types) are highly welcome!

Best Regards
Vidar

[revboden]

A slot port is basically the same as a round port, just calculate the area of the opening of a slot and convert it into a circle of the same area, if you have WinISD or some other box software you can just use the slot option. Remember to keep the width to height ratio of the port opening as close to square as possible. 1(height)/4(width) is about the maximum ratio you can use with out derating the port because of friction. Also on the inside of the cabinet where the port ends, if it uses an outside wall, add 1/2 the height of the port to calculate the effective length.

This is a good web calculator that includes friction coefficients to calculate area/lengths for a slot vent. PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES

[Vidi]

revboden, thank you very much for your swift reply!
I'll then go ahead and dimension the reflex ports as I would do with the tube ones with help from the site you suggested. Much appreciated!