I've been doing a bit of research on soundproofing, particularly with the help of www.customaudiodesigns.co.uk (which is pretty good for info). What they're suggesting makes reasonably good sense, if a little pricey, and probably worth it if doing a dedicated room from scratch (and funds permit). In addition to the absorption and isolation principles of soundproofing they also talk about ensuring the room is sealed, which all sounds logical. However, what's confusing me is that won't the seal's (and therefore soundproofing) be compromised once holes are made in the walls/ceiling for cables, power points, lights etc..? This is particularly the case as they're suggesting using soundproofing mats on the walls and ceilings, which would have to be cut to get cables through. Am I missing the point here or is this a common issue that can be easily overcome? Also, if a room is well sealed, isn't there a chance of suffocating if you're in it for a long time?