If NAD has a reason to CYA, then its only true with a few of their products. Most of the A/V receivers are rated for a minimum of 4 ohms. Looks like the amp stage is NOT the same for all of their receivers.
Stereophile link is for the RS6, and speaker in question is the RX6. As stated previously, the RX6 drops to 3.9 ohms/nominal 6 ohms. Then add the RX Centre with 3.0 ohms minimum/nominal 5 ohms for home theater, and the T748s reliability is compromised.
Disagreeing with a manufacturers recommendation is just asking for trouble.
Stereophile link is for the RS6, and speaker in question is the RX6. As stated previously, the RX6 drops to 3.9 ohms/nominal 6 ohms. Then add the RX Centre with 3.0 ohms minimum/nominal 5 ohms for home theater, and the T748s reliability is compromised.
Disagreeing with a manufacturers recommendation is just asking for trouble.