In terms of the acoustics - yes no problem.
However as correctly pointed out by Pete bubbles are an issue since they will all act as small reflectors and give a confused near surface signal to the head unit. This is partly why epoxy is recommended as it is often low enough viscosity with slow enough cure time to allow bubbles to rise out of the mix. If you can, slow the cure of the epoxy down whilst de gassing. This can often be done by pouring it into a shallow, flat tray, rather than leaving it in the mixing pot. This stops the exotherm speeding up the cure. Vacuum degassing is best, but not everyone has access to this kind of kit
Also a member of the ebay Blue RIB cover club