What are you guys using for the low end? One or two subs? How are you crossing over? As mentioned, the disadvantage with a monitor is the bass extension and integration.
Personally, I have both. My big system uses a pair of subs (essentially since I'm tri-amped). My little system that I am using for the speaker shootout I am using a single sub. No matter what you my read from the "experts", bass
is not omni-directional. A
pair of subs is required to pick up all of the ambiance in many,
many recordings. Loads of modern recordings are mixing stereo bass (below 100 Hz).
Don't get me wrong, a single sub sounds better than no sub at all, but a
pair blows away a single, hands down.
Honestly, actively crossing a sub provides
way more bass detail plus it's easier to integrate. Pro-sound XO's are a fair sounding, cheap alternative to integrate a sub if you want to build your own cabinets and use an old amp you may have laying around. Be careful using pro-sound XO's. They tend to use
cheap opamps and internal components (not to mention the internal circuitry is overly complicated). Cheap opamps sound like...well....cheap opamps. This is easily remidied with a soldering iron and about $40.
Pyramid makes a dirt cheap active XO for about $70. It's made for the DJ market. It's actually rebadged version of somebody elses design. It has very simple circuitry. Trouble is it uses
really crappy parts. In turn, it sounds the same way. If you are willing to spend some soldering time and about $50-$75 in parts (maybe a bit more if you get into the power supply), you could rebuild one of these and make it a killer XO. The design is pretty versitle. It can be used as a (stereo) three way or two way XO with differing XO points (dedicated xo points (click type), not a variable dial)(did that make sense?), plus it has active gain circuitry for each frequency band (you could make this passive rather than active). I've got one here but haven't found the time to mod it yet.
Pro-sound amps (on the used market, Crown, Carver, QSC's) are dirt cheap and do a good job as a sub amp. A plate amp
could be a good option too. Unfortunately I haven't had a lot of experience with these. I'm really curious to hear Dan Wiggins at Adire.
IMO, When it comes to subs, I feel they need to be forward firing, not down. A simple test for those of you using down firing subs is to turn yours on it's side then face it towards the listening position. Listen and hear all the detail you have been missing. It completely changes the character of the sub.