Kharma Sub Set Up- Review

I’d like to share my experience with other Kharma owners regarding integration of the new Kharma subwoofer with main speakers. I use CRM-3.2FE as my main speakers and was very excited when Kharma finally introduced a sub. With that said, I also acknowledge that I have tried numerous REL products (Stentor III and (2) Stadium III’s)
on different occasions with mixed results at best. The REL products were used with other speakers (Wilson WP7’s and Maggie 3.6’s).

My room is a finished basement approx. 18x23x7’4” with carpet over concrete.

Like most of you have seen at the recent shows (or pictures from the shows), the general consensus is to place the sub between the left and right speaker when using a single sub. The Kharma manual also states that this is a good location to start with.I initially set the crossovers in accordance with my dealer’s recommendation which proved to be a good starting point. BTW, the Kharma sub is the most tunable/adjustable subwoofer that I’ve seen. My results with this set-up were in my opinion OK and by far the best integration I’ve ever achieved with a sub. Well, that was until …….yesterday.

I called a friend in the area whom some of you may know, “Romy the Cat” and asked if he could help me with set up. I’ve known Romy for some time and trust his skills in system set-up and pointing me in the right direction in my quest for audio perfection.

Romy visited yesterday with all the tools of the trade. These included professional spectral RTA, RT60 and phase meters. His comment when first listening to my setup
was the integration was “deplorable”. Volume 8-10 db too high, phase off, peaks and valleys in the frequency response. These comments were based on his “ears” and not the test equipment. He also said the sub will never be optimized between the speakers.

Well, I insisted we measure the sub with my setup and Romy all the test substantiated Romy’s initial findings. Frequency response had peaks and valleys to plus 12db at 25 db to minus 11 db at 63 and 80 HZ. We moved the subwoofer to the corner behind the left speaker and after much experimentation/testing (3 hours) found the flattest frequency response to be with the sub driver FACING the sidewall. The driver is literally 4-5 inches from the sidewall. Our final settings on the sub were to cross it over at 17HZ and 70 HZ. with a 12 db/octave slope. This produces a relatively flat response in my room from 20-120 HZ. The worst peak or valley being –3 db around 40 HZ.

So how does it sound…………..absolutely stunning. Whether I’m playing acoustic jazz, electronica, rock or classical the sub integrates seamlessly and plays every note with weight, depth and the proper harmonic structure while completely disappearing (ala 3.2’s).

Anyone considering the purchase of this sub should take the time and effort to properly set it up. You will be rewarded handsomely.