PART VIII Recording Studios However, when overall convenience of access is important, this geographical isolation may be com- pletely impractical, so the only solution may lie in the choice of an inner-city site and a considerable amount of acoustic engineering. DISCUSSION AND ANALYSIS Clearly , isolation is not a simple subject to grasp, and no simple computer programs can solve the problems. Isolation is a subject for specialists, and where critical situations exist, the cost of calling in a specialist before construction will surely be less than the cost of trying to fix the problems after con- struction. In fact, the problems may lie deep within the construction, in which case total rebuilding may be required. Intuitively, leaving out a layer of fibrous material between two of many layers in an isolation system may seem insignificant, but if the cavity resonates without the lining, the air at reso- nance can be a remarkably strong coupling medium. The addition, or not, of a small component in a complex structure may thus make a disproportionate difference to the results, and even one decibel of improved isolation may be important. Experience has shown that it is better to design for inaudibility for the neighbors, rather than to legal limits, because peace with the neighbors can be crucial to their tolerance of the occasional nuisance. Nevertheless, ulti- mately the law will decide if the worse comes to the worst, and that is where that one decibel can mean make or break. In fact, if the room shown in Figure 20.4 had failed to achieve its low frequency isolation target by 1 dB, then where would one begin to look for the weakness? What would one do to plug the 1 dB leak? If the room had been completed, with all its decorations, and was considered by all concerned to