This seems like a good place to put this post that I have been meaning to do for some time. It concerns the different ways to mount acrylic designs with a Speaker Light Kit behind it.
What looks best varies from each design and what style they are. Some look good with the grill directly behind the design, some look cool hidden behind the grill (and only appear when they are lit from behind). The acrylic designs that have etched details in them (ex: like the Iron Man figure) generally look much better if you mount the grill away from the acrylic design. The more etched area or details in the designs....the more important it is to mount them properly (ex: The LotR design is not as important as the Family Guy design since it has much less area etched out of it). Here is an example of different mounting orders with one of these detail etched designs.
Top pic: acrylic design, light frame, grill, speaker
2nd pic down: acrylic design, nuts installed for spacers, grill, light plate, speaker
3rd pic: acrylic design, grill, light plate, speaker
Bottom pic: grill, acrylic design, light plate, speaker
I think the top method is hands down the best looking. You can see more detail, it is lit better, you do not have the grill between the acrylic design and the light source so you are not projecting the grill holes onto the design. Plus in the back of the lit area the grill is lit instead of the speaker. This gives it a more uniform and less cluttered look back there.
If you look between the 2nd and 3rd pic you can see that even just leaving a little bit of space (with some nuts for spacers) between the acrylic design and the grill helps a bit with showing more of the designs detail and diluting the dots from the grill holes. If you are a person that doesn't want the area around the design to be open (as it would be with the top mounting method)....this is a helpful alternative.
Mounting this type of design behind the grill like the bottom picture isn't really advised. You lose a lot of detail. That mounting method is better suited for black acrylic designs or ones that are single colored with no details etched in them.
I hope this info helps to make your Speaker Light Kits look even better.