Harman Kardon HK550VXI Owners Manual - Page 10

APPENDIX! - Multiple Speakers in Parallel Your Harman Kardon receiver is equipped with 2 sets of speaker outputs, making it possible to add extension speakers for use in another part of your home, or for matrix surround sound. However, the total impedance of both speaker pairs can be no less than 4 ohms. If the combined impedance is lower, you will not be able to play either set of speakers very loudly without causing overload problems. Total impedance (Z) when operating 2 sets of speakers is calculated with the following formula: z= RI X R2 R1 +R2 where RI and R2 are the individual impedances of the two speaker systems. Therefore, two sets of 8-ohm speakers in parallel represents a 4-ohm total load, well within the operating parameters of your HK550Vxi / HK440Vxi receiver, providing you re-set the SPEAKER OPERATING MODE switch to the 4-ohm setting. However, two sets of 4-ohm speakers is a 2-ohm load and is NOT recommended. If you have any questions, consult your Harman Kardon Dealer before adding a second set of speakers. APPENDIX!! - Antennas for Your HK550Vxi / HK440Vxi While it may seem obvious that an antenna is critical to good reception, it is often not given sufficient consideration. The results can be significantly reduced tuner performance (a classic example of "garbage in, garbage out"). The question of just how elaborate an antenna installation you need can be determined by considering the following: 1. How good is reception in your area? If you live in an area with a moderate number of strong FM and AM stations, you may not need as large an antenna as you would if you live in a rural area or an urban area with many adjacent stations. 2. Are you interested in receiving weak or distant stations? Some very interesting programming (ethnic, classical, college formats, for example) is often on stations with very low transmitting power. Or you may simply live in an area far removed from all stations. If so, you should consider a more elaborate antenna installation. 3. Is stereo separation, bandwidth and freedom from interference critical? If you often tape broadcasts, or own a system where you can hear critical differences in broadcast quality, investing in a better antenna can increase the overall fidelity of many stations. 4. Does your living environment allow a large antenna, either indoor or outdoor? Sometimes space, physical layout (such as living in an apartment house) or even city ordinances can affect your decision in this respect. 5. Do you have access to FM through a TV cable system? The benefits of using commercial cable as a high quality FM source are many and you should investigate this option if it is available. In general, the higher the antenna, the better it will perform. Radio waves travel better in straight lines from the transmitter and if your antenna is free and clear of obstructions, it will perform better and you will enjoy greater signal strength. An indoor antenna, such as the one included with your new receiver will work well if you enjoy good "line of sight" with the area's FM transmitters or live in the upper stories of a building. Remember, however, that indoor antennas cannot provide height and may be prone to receiving interference from cars on the street or small appliances in the kitchen. If you are satisfied with the performance of an indoor antenna (or are limited in this respect), your first choice is the halfwave dipole antenna included with the HK550Vxi / HK440Vxi. It will work well in many situations and can be used until you decide whether or not you need a more extensive antenna system. Because it is basically bi-directional, it may be prone to interference or may limit your ability to "fine tune" certain stations that are not on its axis. The next choice is a pair of "rabbit ears" like the ones often used with television sets. While they have some of the same drawbacks as a flexible dipole, "rabbit ears" are easier to