Back wave & front wave damping

Looking for some advice here guys....
I'm using a "shared" room for a pair of Vantages so obviously wish any trapping to be as uninvasive as possible.

2 Questions :
1. Although I've positioned the MLs 4.5ft from the front wall is there anything to stop me using a portable trap (e.g. similar to a Soundlabs Sallie) at the focal point of the rear wave to make the speaker more independent of irregularities in the shape/distance of the front wall? (I'm using curtains for damping at present)

2. Recently I flattened the horizon in the outfield area (i.e. by removing cushions....not with a sledgehammer ).
This achieved good L-R balance but made the room slightly "splashy" at the top end while introducing a midband suckout.
Using a pair of damping pads on the rear wall (behind the listener) I restored the midband even though the damping only "mirrored" halfway up the panels so now I'm wondering if a panel sized pad in a mirrored position would be even better?
This would again be done using a portable trap like the Sallie. (Egg-box foam stuck onto 0.5" ply.)
That way they could be removed before Her Majesty notices

Room info:
Room size is 16(L) X 13(W)ft with a wide, square, open archway in the rear wall coupling to the next room. With the speakers on the short wall slightly toed in and firing through the arch the room is "perceived" as 27(L)ft long.

Any helpful suggestions are most appreciated.
Best regards....

Good ideas, but before I spent the kind of money they are asking for the Sallie, I would want to see a coefficient of absorption chart across frequency spectrum for it. You need an absorber that can absorb from about 250 hz. on up to 20,000 hz. If the Sallie can't do a good job absorbing the lower midband, then it wouldn't be the most effective rear wave absorber.

Many thanks for your kind input, Rich.
I agree the cost of a Sallie would be prohibitive.
I doubt that the standard egg-box foam, "as used in studios" according to the supplier, is as substantial or effective as the Soundlabs device.
On a positive note it is dirt cheap at about $4/sq metre

I recommend you look into Real Traps or GIK. Both have excellent traps that absorb well down into the lower midrange. Although they may not be quite as unobtrusive as the SALLIE. Standard egg crate foam is only going to absorb the very high frequencies and won't help you with comb filtering in the mids.

Good suggestions Rich. Had a look at those sites and they've given me some ideas.
(For example I realised I don't need to create metal stands, just a full sized wooden panel with non-slip feet placed against the rear wall.)

Price isn't really a consideration so if I had to I could spring for the manufactured item. I'm slightly concerned about the width of some of the standard offerings though. My original intention was not to "strangle" the room too much but sometimes there's no other option but to play around.

Having narrow traps at the rear focal point of the panel seems like a worthwhile possibility. Looks like it could give me the flexibility to move the RH speaker closer to the side wall without worrying about the effect of the wall contour behind it?

It would be interesting to know if anyone has tried "panel-sized" absorbers directly opposite the front of the speakers (or would I be better off with diffusers so that the energy isn't lost......?)

GIK will do custom panels. I did that with my 244s.


J

Agree with Jmschnur. Call them and ask about custom panels: 1' x 4' ought to do nicely.