Another subwoofer connection question


I’ve looked at similar threads but feel I should get advice specific to my setup. If I wanted to connect my LM 518 integrated to a sub to augment Spatial M3 Turbo S’s, would I just run another set of speaker cables from the LM’s taps to the subs speaker inputs? Or is that going to mess up the LM? The Spatials use the 4 ohm tap; would I run the other set of speaker cables from the 8 or 16 ohm tap?
The sub in question is an ancient (2003) Velodyne CHT-8

128x128simao
Connecting a sub this way is less than optimal but with your integrated's limited facilities you have no choice. Just run cables from your speakers to the sub if that gives you the shortest cables. You might consider having a tech put the appropriate capacitor on the input of the amplifier stage internally to roll the amp off starting at 80 Hz. This will give you less distortion and more head room.
It's an old design, you might someday consider a newer design.

My old Velodyne, 12" servo controlled, new surround, adds nice extension to my office bookshelf speakers. Single sub for general centered extension

For a music system, I recommend a stereo pair of self-powered subs, front firing, no ports, located near the mains for imaging of bass fundamentals and their overtones. You will know where the bass player is standing!
that is a self-powered sub. 

great, that means: go from preamp directly to sub, it handles low bass with it's own amp; then signals with no low bass go from sub to amp, then amp to mains.

the advantage is neither the amp or mains try to make low bass, allows them to easily do a better job with less distortion.