Asked H/K about 4 ohm speakers this was there reply:
Hi Paul,
Good morning and thank you for your inquiry. Harman Kardon receivers are designed to work best with speakers rated at 8 ohms. All Harman Kardon Audio/Video receivers can handle MOST 4 and 6 ohm speakers on the market today. However, there are some manufacturers' speakers that have a minimum impedance WELL BELOW the 4 and 6 ohm nominal impedance, when being fed a signal. In this situation, the receiver will attempt to protect itself by having the fan turn on. In the extreme case, the unit will protect itself by shutting down, and go into standby mode. This is an indication that the speaker in question is not compatible with our receiver.
*Note: The continued use of the receiver with speakers that cause it to shut down can result in eventual failure of the receiver, which is not covered by the warranty.*
If you are concerned with using the speakers with this receiver, you can purchase an Impedance Matching Speaker Selector Box, which will allow you to connect any speakers to this box, while the receiver constantly sees a specific load (these boxes come in different values, i.e.
4/6/8/16 ohms). You can find these boxes in most electronics parts stores or online at
www.russound.com or
www.nilesaudio.com. I hope this helps.
Best Regards,
Vu Le
Internet Support Specialist
