Best way to integrate subwoofer with RS151 + Parasound A21+

ROSE Products RS151
#1

Hello everyone,

I would like to ask for advice on the best way to integrate a subwoofer into my system.

Current setup:

  • HiFi Rose RS151
  • Parasound Halo A21+ (power amplifier)
  • KEF R3 Meta speakers

There is no preamp in the chain, so I am trying to understand the optimal signal path without degrading sound quality.

Room:

  • Speakers ~50cm from front wall
  • Distance between speakers ~2.5 m
  • Limited placement options

Goal:
Achieve tight, controlled and accurate low frequencies.

Questions:

  1. What is the best way to connect a subwoofer in this setup?

    • XLR from RS151?
    • RCA split?
    • High-level input from amplifier?

  2. Is it recommended to use an external DSP (like miniDSP) in this case?

  3. Any experience with KEF subwoofers (KC92 / KF92) in a similar system?

I would really appreciate advice based on real-world experience.

Thanks in advance!

#2

I would take the balanced out from the 151 to the balanced inputs of the A21+

A high level connection from the A21+ to the KF92.

The A21+ accepts spades, bananas and bare wire connections. I would get two sets of speaker cables one set terminated with bananas and one set with spades. Run one of the sets to the sub and the other to the R3 Metas.

Set the crossover on the sub where KEF recommends.

You might want to have a look at this thread regarding the lack of a volume limiter on the RS151 since you are not using a preamp: