how room acoustics affects the selection of monitors

[lex125]

A question about monitor selection based on the room where they will be used:

I am a dedicated remote/location guy; I've walked away from my last "real" studio and now work out of a small control room / edit bay. I've re-arranged the room's layout a few times in the 6 months since I moved into this new room and I have decided to stick with my current layout. (this is a significant decision as I have now done a permanent wiring install and I have purchased acoustical treatment based on this layout.)

The room is very small; 14.25ft long, 8ft wide and 10ft tall with an acoustical ceiling at just over 8ft high. The good news is that the whole building was converted to studio use many years ago and my room was built as an edit bay; with floated floor, isolated walls, heavy insulation and weather stripping around the solid core door. The only significant problem that I have noticed is a strong flutter echo at my seating location. This is not a surprise with the side walls only 8ft apart, and this problem was easily solved with a 4ft x 2ft x 4" thick mineral fiber panel mounted on either side of my seated position. (mounted a few inches off of the wall)

My current monitor system is very cheap but surprisingly good for the money. (a pair of passive Tannoy Reveals with a Hafler P3000 amp.) The whole system cost me a grand total of just under $500 and I know that I will not get a significant improvement without spending a LOT more. But my work is moving towards a higher percentage of classical music and the Reveals are just not capable of reproducing that first octave C to C, 32 to 65Hz). Rather than throw money at "fixing" the Reveals with a sub, I'd rather put the money towards a pair of good monitors. My concern is that there might be a limitation imposed by the room that makes it pointless to invest in anything significantly more expensive than the Reveals. Obviously, a floor mounted three way system is not even going to fit into the room. But even a more modestly sized pair of high end monitors might be so severely restricted by the room that purchasing them makes little sense.

So, my question is "How can I determine what quality level of monitor makes sense for my room?" For example (using Tannoy as a common reference), it might make sense for me to upgrade to Tannoy System 8s, but the new Tannoy "Ellipse" monitors would be wasted in my room. Does this sort of relationship exist and how can I determine what it means in my specific situation?

[barefoot]

Hi Steve,

There are three main aspects of a small room that we need to consider here:

• 1. Room modes
  A small room is going to have more issues with standing waves, primarily because the smaller dimensions push the modal resonances up to higher frequencies, placing them into even more sensitive hearing ranges. Since these modal frequencies are typically much higher than the 40Hz to 80Hz low-end extension of most nearfield monitors, the monitor's low-end extension isn't much of a factor. You need to deal with the issue in the room, and monitor selection wont help.
  
  
  2. Low frequency loading
  There is an affect, sometimes referred to as "bass lift", where the low-end response is enhanced due to the speakers radiating into a small volume. This effect is very apparent with headphones and car stereos where small speakers can generate large amounts of bass. However, when you pull the headphones slightly away from your ears or open the car windows and drastically increase the space the speakers are radiating into, the bass disappears. You might think this is a big concern in studios, but it's not. The volumes of even small rooms like your own are just too big to make this much of a factor. Bass lift in a room your size is insignificant above 30Hz. So once again, it's unlikely that any monitor would have too much bass extension.
  
  3. Listening distance
  With a smaller room you're typically going to be constrained to shorter listening distances. This can influence your monitor selection simply because your maximum volume requirements are going to be less. As you move closer to the speakers the volume increases, so you can get away with speakers having more modest sensitivities and power handling. Furthermore, you don't want speakers with narrow listening windows (dispersion angles) because at closer listening distances any given movement of your head causes more significant deviations from the speaker axis. Big mains and midfield speakers often have fairly narrow dispersion because they use high crossover frequencies in order to increase their power handing capacities.

So, for the most part, the size of your room has little influence on monitor selection. A speaker with limited low-end response is going to have limited low-end response whether you put it in an 8'x10' room or a 16'x20' room. And the transient response and distortion of a 6" ported speaker that tries to reach much lower than 60Hz is going to suck regardless of the room. The impact of short listening distances on dispersion and maximum output level is really the only concern, and this holds true for most room sizes.

My recommendation: Get the best monitors you can afford and fit into your available space - as long as they have wide, even dispersion. If they also have high performance deep bass response, then all the better.

Thomas

[hitphy]

According to this thread , do you think ADAM S3A will be good at this room?
Length: 20.5 feet
Width: 11 feet
Height: 7.9 feet

?

Thanks.

[barefoot]

So, for the most part, the size of your room has little influence on monitor selection.