Naim Unitilite amplifer and high Level connection of Rel subwoofer

It is possible, but for electrical reasons you have to connect the sub to the speakers (and not to the output terminals of the amplifier).

There is an FAQ on this
https://forums.naimaudio.com/to...nection-of-subwoofer

It's a lot easier to continue using the low level input and the performance difference is minimal (in certain ways the low level interface is actually better).

Hi Huge, yes i meant to join the speaker cable and sub cable and then to the output terminals of the amplifier. On facts would not possible enter directly to the output terminal of the amplifier if these are already occupied by cables speakers.

Thanks for your reply.

The performance difference between Hi Level and Lo Level is not minimal but there is a big difference like explain Rel Acoustic " The purpose of connecting to the speaker output terminals is one of the unique secrets of REL’s success. By connecting to the high level input on the REL from the amplifier, you build forward the sonic signature of your main system, including the tonal balance and timing cues of the entire electronics chain. In this way, the REL is fed the exact signal that is fed to the main speakers."

The link it will describe the set up in detail.

http://www.musicdirect.com/documents/pdf/ARELR218.pdf

My question is I want to connect my subwoofer Rel in Hi Level connection but speaker output terminals of the power amplifier are already busy with speaker's cables. How i can do it; can i roll up the bare lead of speakers and sub and than insert both in banana socket. I'm afraid to demage my amplifier.

is there anyone that use Rel subwoofer in Hi Level with Naim amp?

That "information" comes from REL's marketing department to give them a USP, and contains several flaws obvious to anyone who's designed an audio amplifier:

"you build forward the sonic signature of your main system..."

1  The source and pre-amp are always the same, the only difference is the presence of the power amp.

2  "including the tonal balance" Naim power amps have -3dB points at 5Hz and 69kHz, thus have no significant contribution to the "tonal balance" of a sub (15Hz to 250Hz band).

3  "and timing cues of the entire electronics chain"  As stated previously the the source and pre-amp are always the same, so this is a gross overstatement, only the presence of the power amp is different, and its group delay is going to be minor since it has to amplify HF signals as well.  In fact the group delay in the sub's amplifier is likely to be longer than the power amp; so putting them in series (by using the high-level input) will give worse timing than using the low level input.

4  By connecting to the speaker cables at either end, the back EMF created by the speaker cones will be partially 'seen' by the high level input of the sub; so the sub will be driven not just by the power amp but also by part of the reaction of the main speakers.  This reaction component will contaminate the signal sent to the sub and will vary unpredictably in both frequency response and timing, dependant on the power amp and speakers in use.

The coupling of the sub to the room acoustics (particularly the main resonance modes of the room) will have a greater effect than all those mentioned above.  Incidentally on that note:  The advice to put the sub in the corner of the room will result in the maximum amplitude of the bass, but usually also results in the least even bass response and worst timing issues as it maximises the response of the room resonances.  If you want the loudest bass achievable (irrespective of quality), corner placement is the way to achieve this; if you want bass quality, avoid the corners of the room.

If you still insist on using the high level input, use the connection scheme detailed in the Naim FAQ.

Amto69:  the best way to connect the subwoofer via high level is to connect to the back of the speaker terminals and not directly to the amplifier.