18 inch subwoofer vs multiple 12 inch subwoofers with bookshelf speakers


I am currently in the process of selecting a subwoofer system to complement my bookshelf speakers (3x KEF LS50 Metas with 5.25-inch midrange drivers, 2x KEF Q150) to achieve a balanced and immersive audio experience. Size of the room is (19.5x13x8).

After thorough research, I have narrowed down my options to two configurations: 1x Rythmik F18 18-inch subwoofer or 2x Rythmik F12 12-inch subwoofers, with the possibility of expanding to two F18 or four F12s in the future.

My primary criteria for the subwoofer system are musicality, speed, transient response and depth of bass response, particularly in the low-frequency extension below 18Hz. Additionally, I aim for seamless integration with my bookshelf speakers, ensuring a cohesive and satisfying soundstage for both music and movie content without overpowering the midrange and high frequencies produced by the bookshelf speakers.

I would greatly appreciate any insights or recommendations you may have regarding which configuration—either the single F18 or the dual F12s (possibly 2x F18 vs 4x F12) would offer better synergy with my bookshelf speakers and deliver a fuller, deeper sound with smooth and fast transient response across frequencies with 50/50 music and movie?

thxbest

viber6,

So let's say a 12 inch sub for instance Rythmik F12 does perform and blend better with KEF LS 50 Metas than an Rythmik F18 sub because of the better mid bass, no matter if servo controlled or not?  

thx best,

I don't know the Rythmik products.  Servo controlled is another factor.  Theoretically, according to Doug Blackburn, I would predict a servo 12" would still integrate better than a servo 18".  But it would be an apple/orange comparison when comparing a non servo 12 with a servo 18.  

As an aside, in 1980 I heard the HQD system--double Quad 57's, Decca ribbon tweeter, 24" Hartley woofer built into the floor whose cabinet was the room below.  The Hartley was probably not servo.  Those Quad electrostatic are still unmatched for midrange accuracy, and probably for upper bass accuracy.  I don't listen to music with much deep bass, so I couldn't comment on the quality of the bass from the Hartley.  Mark Levinson, who put together the HQD, drove it with triamped Levinson ML2 power amps and used crossovers to keep the midrange overtones from the H out of the Quad midrange.  

18” subs are a bad idea. Their motion can frequently leave pistonic and begin to wobble. The largest I recommend is 15”, but then you are dealing with large enclosures. 12” is a great compromise. If you want more than two 12” subs can give you, get another two. I use 8 12” drivers.

18” subs are a bad idea.

@mijostyn Yes, except when it is sealed and has the servo controlled drivers deployed by Rythmik (it becomes doable). Yes, it is a tad bit of a compromise compared to their 12 inch offerings, etc, but, it could put you into the infrasonic miracle territory. OP’s use case is both movies and music.

@thxbest , You could also go with Model G22, which is a force balanced, dual opposed 12 inch configuration.