Start

Does the Klipsch R-121SW work with the Onkyo TX-NR6100?

Verdict
Yes

The R-121SW has a line-level input, and the TX-NR6100's 2 subwoofer outputs feed it.

Connection
Line-level
Sub out to its LFE input
Sub outputs
2
On the TX-NR6100
Amplifier
200 W
Built into the R-121SW

How to connect them

  1. Run a subwoofer cable from the TX-NR6100's sub out 1 to the R-121SW's line-level input.
  2. Set speakers to Small with an 80 Hz crossover.
  3. Run AccuEQ with its microphone at your seat.

Plan the R-121SW and TX-NR6100 in your own room.

Draw your room in 3D, place both, and see every connection checked and how loud they play at your seat. Designing is free.

Build it in your room

The specs that decide it

Klipsch R-121SW

Amplifier
200 W
Low end
28 Hz
Inputs
Line
MSRP
$650 each (MSRP, September 2026)
All R-121SW specs and pairings

Onkyo TX-NR6100

Amplifier channels
7
Subwoofer outputs
2
MSRP
$799 each (MSRP, May 2025)
All TX-NR6100 specs and pairings

Questions about the R-121SW and TX-NR6100

Does the R-121SW connect to the TX-NR6100?
Yes. The R-121SW has a line-level input, and the TX-NR6100's 2 subwoofer outputs feed it.
What crossover setting should I use with the R-121SW?
Set your speakers to Small with an 80 Hz crossover: the standard starting point for a receiver and subwoofer, whichever subwoofer you use.
How do I connect the R-121SW to the TX-NR6100?
Run a subwoofer cable from the TX-NR6100's sub out 1 to the R-121SW's line-level input.

Swap one of them

References

  1. Klipsch R-121SW: Spec sheet, assets.klipsch.com, retrieved September 15, 2026
  2. Klipsch R-121SW: Retailer listing, bestbuy.com, retrieved September 15, 2026
  3. Onkyo TX-NR6100: Spec sheet, assets.onkyo-av.com, retrieved September 15, 2026
  4. Onkyo TX-NR6100: Retailer listing, web.archive.org, retrieved September 15, 2026

Specs verified against the manufacturer's published data. Last checked September 15, 2026.

Brand names are trademarks of their owners. Not affiliated with or endorsed by any manufacturer. 3D models are our approximations. Prices are manufacturer list prices (MSRP) as of the month shown. How we earn from buy links: affiliate disclosure.