This may have been asked before but I have been unable to find it. I am adding an active sub to my current system using the low level RCA inputs, taken from the sub out on the NAC152XS. The sub has a LFE setting, which is either in or out. The instructions suggest the out position is for AV amps only, but the sound is very different. Has anyone set this up before, and if so is the sub output of the NAC ‘processed’ similar to an AV amp? Basically, LFE in or out?
The sub outs on the 152 provide the full frequency range. You should connect them (both left and right) to the pair of phono sockets on the sub. LFE is not relevant with your 152.
Both very good questions…The sub is a BK Electrics XLS200 DF. The instructions say:-
*Figure 2. Shows a diagram on how to connect the low level input. Using the supplied RCA to RCA interconnect, plug one end into the XLS200 low level input and the other end into the dedicated sub output on your amplifier or processor. If a sub out is not available then you can use a spare set of pre-amp outputs. If you only have a single sub woofer output socket on your equipment, then connect up using one of the pairs of leads (red to red). In this instance use the (Mono) input on your XLS200 sub.
When using a source on the low level input that has built in bass management ( AV Processors) then you can switch the Filter Bypass Switch to the Out position. Your processor will manage the bass frequencies on the low level and the XLS200 will manage the bass frequencies on the High Level Input
From this, I still cannot determine if it is in or out. In essence, does the NAC152XS have built in bass management?
I have a b&w sub and it has an LFE setting which has to be set to “In” when connected to my SN2. If I set it to “out” then the sub loses it’s low frequency crossover adjustment and operates over its full range. The “out” setting is for av amps which have an inbuilt crossover.
My main speakers are specified to have a low frequency response of -3db at 43hz and I find that the best setting for the low pass filter frequency is 41hz.
If you know the low frequency response settings for your main speakers then set the sub’s low pass frequency a bit below that value and use you ears to tweek it from there.
I have a BK XXLS400 and a 152XS and prefer the sound through the high-level (neutrik) connection. The bare cable ends are connected directly to the speaker terminals.
@anon93526344 with naim amps the recommendation is to take the high-level signal from the speaker terminals on the actual speakers and not from the speaker terminals on the amplifier.