PROMINENT IN RECENT high-priced cassette recorders are two main design trends. One involves metering systems, with some interesting departures from the conventional needle-pointer. The other has to do with more elaborate means for adjusting the recorder to handle different kinds of tape.

How much of either trend is grnuine improvement in the basic product format or simply and effort to appeal to buyers by offering something different is very hard to say. As with most things in audio, the truth probably includes a little of both. But the novelties bear examination.

For some time, many cassette decks have sported -- in addition to conventional meter scales -- a peak level indicator in the form of an LED (light- emitting diode). This small "lamp" responds very quickly to voltage changes and thus is ideally suited to show peak levels.

Another substitute for conventional meters is the liquid-crystal readout system found in the new Sony TC-K8B. Segments of light, in the form of successive bars run horizontally across the panel in step with signal level changes. The effect visually is one of a double bar-graph. The operator can switch the display to hold the highest peak encountered during a given recording, or allow the display to reset peak levels automatically after a few seconds.

Complementing traditional VU meters on the JVC KD-85 is a spectrum display that shows relative signal peak levels for five different portions of the total frequency range covered. This display shows what portions contain the most signal energy: in addition to serving as a peak warning guide, it also provides a new insight into the relation of different frequency ranges of music and the actual demands they make on recording equipment.

For optimizing a recorder to handle different kinds of tape, the switch or switches for bias and for equalization are by now familiar. A recent embellishment here is the bias "fine adjustment" that is supposed to trim the circuit to spueeze the last drop of response from a given tape. The Yamaha TC-1000 and the Technics RS-M85 have such adjustments.

The most elaborate tape-selection system I have yet seen in a cassette recorder is that foundd in the Teac C-1. This deck uses individual plug-in circuit boards that slide into an opening on the front panel. The boards have five adjustments of their own in addition to the familiar bias and EQ switches on the panel.

Generally, these new twists are found on fairly costly cassette recorders. As a class their performance is so high that it is difficult to document that the novel features are indeed significantly responsible for the high performance or that other factors -- such as excellent transports and high- grade circuitry -- would produce the kind of test results we've been getting even if the costly embellishments had been omitted.

This difficulty seems especially germane for the extra tape-selecting adjustments. As for the novel metering systems, they can make a cassette deck look attractive or even easier to use, depending on your personal taste. No doubt, the different options will appeal in varying degree to different buyers.