The space between the speakers

Essentially, all the comments above are accurate. Ideally you want nothing between the speakers but real life means most of us don't have room for a dedicated audio shrine. As suggested above, if at all possible, ensure that the speakers are at least several inches in front of the TV; this should minimize most issues if you use a blanket over the TV. Essentially, with a setup like that the only thing that you will be compromising on is depth of the center of the soundstage (it will still be deep but it won't be as deep as it will be to the sides).

I think your setup overall will be fine although you may have to treat the room but that is often the case for any setup.

I have the exact same setup as you have and I have achieved a great sound. Go for it and work with it...too often we expect to plop great gear in a room (any room) and get great results. With care and system matching you should be able to achieve more than satisfying sound.

don't waste your money if this is what your setup must be....I'd go monitor speakers on stands with a dedicated sub....but still you have to get the driver faces beyond that large cabinet as much as possible.

Larryken, a wood cabinet between speakers is far better than hard reflective surfaces...like glass french doors behind speakers perhaps? As long as the speakers are in front of the cabinet at least a foot and well spaced apart, the problems will be minimal. Irregular surfaces and soft sound absorptive materials will help as well...plants, furniture, artwork can all be part of the plan and break up reflection points and standing waves.

Thanks for all the good advice and comments. You have confinced me to give it a go. The TV is on a lift so it is stowed in the cabinet when not in use. I will read up on sound treatment at rives.com as suggested and figure out a way to make the best of what I have to work with. I just didn't want to invest a lot of money and then be very disappointed with the results. I look forward to getting into the hi end stuff and having experiences to share. thanks again for your help.