The debates about separate subs, new vs used, floorstanders etc etc is all very well, but it overlooks one essential element: the significant other.
It's rare that a life partner shares the same passion for audio fidelity and will allow carte blanche on equipment selection. There are usually some compromises to be made. The three most common areas of (ahem) 'discussion' are equipment size (ahemmp as well as speakers), speaker position, and playing volume. I hear this with clients all the time...
"Do the speakers have to be so big?", "Can't you just put them in the corners of the room?" and "Does it have to be so loud?"
Sub/sat systems definitely help with the speaker size question, and there are slimline full-featured AV receivers from Marantz (NR1609 from memory) which take up about half the shelf height of normal AV receivers.
Room position for speakers is a much more thorny subject. Corners are collosally-bad places to put any speaker other than those custom-designed units which are designed for such places. The problem is what looks neat is also a sonic disaster because of the proximity of so many reflective surfaces plus the way sound gets congested where two or three room flat surfaces meet.
Keep any front speakers as close to ear height as practical, and the front L & R speakers a good 2ft/70cm away from the corner boundaries.
For the surrounds, the best place is about 1ft/35cm above head height when seated, and about in-line with the seating position.
Here's the selling point for that discussion with the significant other: Darling, the closer we can get the speakers to their ideal positions then the quieter the system can play and still give great results.
Bringing this back to speaker choices, the KEF 305 kit are good speakers, and their ace-in-the-hole is that each has a driver with very wide dispersion. As such, they're more tolerant about being put in less than ideal positions, but there's a limit to that. You'll still mess up the sound if you put them in room corners. If the KEFs have an Achilles heel it's that they only really start to work at higher volumes. That can be a bit of a problem for maintaining domestic harmony.
Q Acoustics Q7000i kit and the Monitor Audio Mass system are both more involving at lower volumes. Personally though, I find the aesthetics of the QA 7000i kit a bit of a challenge. IMO, the MA Mass kit looks classier and is more practical and acceptable. If it had a B&O badge it would be selling for five grand not £500.
Unless you have a separate budget for it, don't forget to factor in wall brackets and speaker cable. Decent speaker cable can actually save you money. This is because power is lost in cable. It's called voltage drop. Even decent all-copper cable loses some power over distance. The thinner the cable the worse the losses. 15m of 1mm cable will dump 11-12% of your amplifier's power. You can halve those losses by choosing a 1.5mm cable. It doesn't have to be fancy stuff; just bog standard 1.5 @ 40-50 strands will do just fine. £1/m should be enough budget. Put some banana plugs on the amp end to make life easy.
