Need Monitor Help

[Karl the Hermit]

I'm looking for any articles or advice on the sizes and differences of studio monitors. How do you determine what constitutes a nearfield, midfield, and farfield monitor? Is it woofer/tweeter size? Wattage? How much of what you need for monitors is based on room size? And how far away should each size of monitor be?

In my particular case, I have a pair of old, Alesis MKII's that are 50-watt, bi-amped monitors with 5" woofs and 1" tweets operating in a room that's roughly 12' x 10'. The sweet spot is set up about 3' from the monitors. Would you call these midfield? I want to buy a 2nd set of monitors for use in a different room. This room is roughly 14' x 20' and the sweet spot would be closer to 5' from the monitors. So...

Should I move my MKII's to the larger room and buy something smaller (maybe 3" woofs and 3/4" tweets) for the smaller room? Or do I need something bigger for the larger room?

[BertKoor]

I'm looking for any articles or advice on the sizes and differences of studio monitors. How do you determine what constitutes a nearfield, midfield, and farfield monitor? Is it woofer/tweeter size? Wattage?

Some articles: http://lmgtfy.com/?q=monitor+speaker+room+size+relation
And Wikipedia to the rescue:

An unqualified reference to a monitor often refers to a near-field (compact or close-field) design. This is a speaker small enough to sit on a stand or desk in proximity to the listener, so that most of the sound that the listener hears is coming directly from the speaker, rather than reflecting off of walls and ceilings (and thus picking up coloration and reverberation from the room).

So it's not one or a set of specifications like size or wattage that makes a monitor specifically "nearfield", but it's the whole intended design.
Ok then, size is a factor ofcourse. I'd say boxes measuring larger than a foot in either dimension won't be targeted as nearfield monitors. In professional studios you'd typically set nearfields on the meter bridge of the mixing console.

How much of what you need for monitors is based on room size?

My rule of thumb is 6" woofers for rooms measuring roughly 3x4m (9'x12') and 8" for 4x5m (12'x15'). For monitors that deliver more bass you need a bigger room to benefit. Putting a subwoofer in a broom closet is asking for trouble.

The sweet spot is set up about 3' from the monitors. Would you call these midfield?

Nope, 3' is about as close as you possibly can get with a desk inbetween. So this is a nearfield setup imho.

I want to buy a 2nd set of monitors for use in a different room. This room is roughly 14' x 20' and the sweet spot would be closer to 5' from the monitors. So...

Should I move my MKII's to the larger room and buy something smaller (maybe 3" woofs and 3/4" tweets) for the smaller room? Or do I need something bigger for the larger room?

My gut feeling says buy larger monitors for the larger room. 7 or 8" woofers should serve you fine...