it was better than a sealed box for sq and low as ****. tline boxes are not tuned so there is no peaky feeling to it. just what you put into it. I though it is a good box. I still have it and plan to use it later for another sq build. down fall on tline is the size.
but you might be ok since that is a slim or if you chose 8's you could do 2 subs at maybe 3/4 cubes in the main chamber . The trick is the use of polyfill. I can send you a plans for mine and you can see how you would have to make yours similar to it.