Something to keep in mind about the surround mix. I'm pretty sure that all of the previous surround mixes by Opeth have been 5.0, not 5.1. Even though this is on Blu-ray, it's likely no different. The LFE is channeled through the main 5 speakers as if all 5 of your speakers are full range. If all of your speakers are full range monitors and you have a good amp pushing them, the bass should be there. If you don't, you'll have to adjust your LFE to both and possibly even tweak your DSP settings to allow the dedicated powered subwoofer to pick it up. Otherwise, the 5.0 mix should be spot on.