I have a Sunn 200S and I-40 (half a 200S) and I'm not all that impressed with them. For my money, a Bag End II, if you can find one, is a much better bet. The 200S port is too big, making the low end very indistinct compared to the Bag End. Another Bag End option is this one, which I am very tempted by, despite its greater weight: https://reverb.com/item/2572036-used-ba ... er-cabinet
Or, have one made. You can do it cheaper than HT or LDS. It's a simple box. Here are my notes on dimensions from various sources:
Wall Of Sound;
25 1/2 " deep
25 3/4 " wide
21 1/2 " deep
And then there is this from Rick Turner:
"When I worked up a lot of the Wall of Sound speaker cabinet dimensions, I used the cube root of 2 (1.25992105) as the multiplier to determine the ratio of depth to width to height of the cabinets. Take your smallest dimension and multiply it by that, then take that result and multiply it again by that constant. The idea (for better or worse...) was to spread any standing waves out equal distant from one another in the audio spectrum. There are other formulae that some folks use...Golden Mean, etc.
We also used heavy rug padding with horse hair in it to damp internal reflections.
We went with closed boxes because the transient response is better than with bass reflex designs, and the deep low end extension is better way down there, though they start rolling off a bit sooner than the bass reflex. But then when stacked in the tall array, that low end comes off better because it's better directed."
What's key is having a big enough box.