When you start to audition instruments, you'll become aware that some of what you're hearing isn't the instrument, or at least not what the instrument is supposed to do. Part of what you'll be hearing is the result of room acoustics and the instrument's placement in the showroom. If there are a lot of hard surfaces nearby — uncarpeted floors and large windows — the results will be different from what you'll hear in a "softer" environment, such as a carpeted living room with drapes, bookshelves, and upholstered furniture. Placement in the room will also affect the sound. If you're serious about buying a particular instrument, asking the dealer to move it to another part of the showroom isn't an unreasonable request. Another thing to be aware of is that the voice settings of most digital pianos include some degree of reverberation. This isn't a bad thing, but it's worthwhile to listen to the piano voice, and any other voices that are important to you, with the reverb and all other effects turned off. This will allow you to judge those voices without any coloration or masking from the effects.
Evaluating Tonal Quality
Almost by definition, evaluating an instrument's tone is very subjective, and judging the tone of instruments that have a lot of voices can be overwhelming. Your best bet is to select the five or six instruments you think you'll use most and make them the standard for comparison as you shop. If you choose the piano on which those voices sound best to you, it's likely you'll find the others satisfying as well.
Digital pianos are really computers disguised as pianos, and the engineers who design them strive to develop a set of sounds and features unique to their brand. Like some features of a PC, many of the capabilities of digitals are hidden from view, accessible by pressing a sequence of buttons or through multi-screen menus. While the owner's manual will explain how to access these features or sounds, it's impractical for you to study the manuals of every instrument under consideration. Enter the salesperson! This is one of those instances where a well-trained salesperson can be invaluable.
Most manufacturers arrange trainings for their retailers' sales staffs, to enable them to demonstrate the relative advantages of that brand's features. Even if you're a proficient player, having a salesperson demonstrate and play while you listen can be a valuable part of the evaluation process. But remember that the salesperson is not going home with you! Don't be swayed by his or her talent — a really good player can make even a poor-sounding piano "sing." Focus your attention on the instrument itself.
You should make sure that you get the answers to a few key questions, either through the salesperson's demonstration or your own experimentation:
Generally, one of the instrument voices used most frequently is the piano. There is a great deal of variation in "good" piano tone. Many players like a bright, crisp sound, while others prefer a mellower tone. Some like a great deal of harmonic content, others a bell-like clarity with fewer harmonics. Whatever your preference, will you be satisfied with the piano sound of the model you're considering?
Many instruments sound slightly different as a note begins to play. For example, a flute takes a quarter of a second or so to build up enough air pressure to reach the pitch of the note, resulting in a "breathiness" to the sound. The same is true of many other wind instruments. Guitarists and other players of stringed instruments "bend" notes by varying their touch. Jazz organs often have a percussive "pop" at the beginning of the note. How well do the digital voices of the model you're evaluating emulate the actual instruments?
Even entry-level standard digitals include such effects as Reverb and Chorus. More sophisticated models have many other effects, as described in the "Digital Piano Basics" articles. Having heard them demonstrated, do you think these effects will be useful to you?
Take your time. Following the salesperson's demonstration, most dealers will let you spend time experimenting — although some may prefer that you use headphones.