In Search Of The Audio Abode---The Hi-fi House Page 5

If the basement is already finished when you buy the house, be prepared to unfinish it and do it all over again. Retrofitted basement partitions are purely cosmetic and are usually made of the cheapest materials obtainable. The typical wallboard is only slightly more substantial than corrugated cardboard, and will both flap and rattle, and the framing too will probably be minimally rigid. If you want finished exterior walls, use furring strips with sheetrock over them. Each exterior-wall sheet should have two additional support strips between its sides, irregularly spaced to stagger any flexing resonances. And if you plan to finish the ceiling for a decent appearance, do not use conventional ceiling tiles, as these will both lower the effective ceiling height and tend to flap in the breeze when you're reproducing bass. Install the framework for a drop ceiling, stuff the spaces between the joists with fiberglass (with the fibers exposed), and use light wooden frames covered with a neutral-colored fabric (such as beige or white "monk's cloth") as the drop-in ceiling "panels."

If the house is large and fortune shines upon you, you may find that it already has a masonry partition separating the furnace space from your proposed listening area. But if it doesn't, you should think twice before adding one yourself. An 8' wall of bricks or cinderblocks is extremely heavy, and will almost certainly crack the basement's poured-concrete floor if it isn't built on a proper footing. For details about this, consult a building contractor, but bear in mind that, if you should ever try to sell the house, a buyer who does not want his basement divided according to sound acoustical principles will look more kindly on the prospect of ripping out a wood-framed partition than a masonry one. But then, maybe you can convince him that it is the very height of trendiness to own a state-of-the-art "media room."

Climate control:
If you'll be doing your summertime listening with the windows open, the heating system of choice is hot water or electric baseboard, simply because they are the quietest when you need to operate them. But if circumstances dictate that you keep the windows shut in summer, or you just want to be more comfortable during the dog days, you'll need a climate-control system that can both cool and warm the room. And that means a forced-air system.

A central air system can deliver heated, cooled, and humidity-controlled air at the flip of a thermostat, but it can be a rather noisy delivery. Most of the noise occurs right at the duct outlets, as a result of wind turbulence, and enlarging the outlets in the listening room (fig.6) can reduce wind noise from that source by about half simply by cutting down on the exit velocity. But there is little that can be done if the main circulating fan happens to be right under your listening seat. Check this out before you buy, by turning on the heater, waiting until the blower comes on, and making a judgment as to whether you think you'll be able to stand the noise while listening.

Fig.6 Modification of a forced-air heating outlet for reduced wind noise. Enlarging the duct opening through a tapered section reduces exit turbulence by lowering the air velocity.

Air conditioning can be retrofitted to most forced-air heating systems for under $1000. A wall- or window-type conditioner in the listening room is not a sensible alternative, though, because it's just too noisy. Yes, you can always cool the room off first, then shut the unit off and listen until your butt starts sticking to the sofa, at which time you can punch up the ol' AC again for another cooling stint. But this isn't a very convenient way to go.

On the other hand, you could add a dedicated cooling and ducting system to the listening room, for about the price of a halfway-decent power amplifier. To do this right, the unit should be located far enough from the listening room that its noise is below your background limit, and connected in both directions to the room by ductwork. Standard-sized vents will be adequate here because the dedicated unit, which needs only the capacity to serve a single room, will not have as great an air-volume delivery as a central unit. But you still may want to add a baffle farm (fig.7) at some point along the delivery duct to cut down on fan noise.

Fig.7 A "baffle farm" for reducing fan noise coming through an air duct. Each baffle is 2/3 the width of the duct. Screws through the duct wall into the plywood cores fasten the baffles in place. Distances between the baffles should be different, to minimize cavity resonances.

It should go without saying that your listening room should not fill up with water from time to time, but this exigency is frequently overlooked by the househunter who has discovered what appears to be The Perfect Listening Space in the basement.

The lowest level of any home that is not at the very top of a high hill is at some risk of flooding. This may not have happened for the last 20 years, but if you put $30,000 worth of audio components on the floor in it and fail to take out adequate insurance on it, that basement will almost certainly flood again within 2 years after you move in.

A homeowner's insurance policy will often reimburse you (minus your deductible) for losses due to water damage, but not always, and usually not enough. Damage due to flooding may only be covered if you have specific flood coverage, and since the maximum allowance for unspecified "personal possessions" may only be $10,000 or so, it is prudent to make sure your insurance actually covers what you might lose. A special replacement-cost policy on your equipment is cheap, reassuring, and sensible. Even if you never get uninvited water in your home, you can always get uninvited burglars who will be delighted to take your system off your hands.

Here are some signs that a house's lowest level may have hosted a pond at one time: 1) a carpet that is cleaner or newer than all the others in the house; 2) white-edged stains around the bottoms of walls, a few inches above the floor; 3) peeling paint at the bottoms of door frames; 4) cinderblock, brick, or wooden "props" under any of the furnishings or stored cartons; and/or 5) the presence of a sump pump. If the pump is inoperative, it suggests that the last flood was a long time ago; if it works, you're covered until the power fails or unless the flood is a deluge.