Will I benefit from a subwoofer with 20Hz speakers?

My source is a minidsp shd studio with Dirac going into Denafrips Gaia DDC to Denafrips T+ DAC to McIntosh 601 Monoblocks to Cabasse Pacific 3 speakers. The speaker's published frequency response is 41-20,000Hz. I presume this is achieved in an anechoic chamber. In my room however, it goes down to 20Hz, at least according to the Dirac measurements. In fact, I needed to flatten the curve and  reduce by 5-20 DBs between 20-100Hz due to the room effect.

So, considering I already go down to 20Hz, is there anything else 1 or 2 subwoofers will do for my system?  Would it create a more consistent low frequency field? I see many people adding up to 6 subs, so I wonder what I'm missing. 

Thank you for your insight! 


Looks like the website says frequency goes down to 20hz. Where did the 41hz number come from?

Maybe RELs really are good but from my own experience their customer service sucks. Phone calls never returned. Emails answered then told they'd get back to me but never do. Text messages back and forth promising me answers that I never get. A different mfg for me next time.

Your 41HZ data is incorrect. But tell me? Do you not expect there to be dynamics in sound? Are you trying to tune out dynamic pieces so that everything plays within the same 1-2 dB range? Music is a lot different than running a tone generator through your system from 20-20KHZ at at constant decibel level and looking at the graph for peaks and valleys built into the crossover network and then trying to correct it. 

But yes! By all means, add 2 subs to your space. Everyone should, whether they know it or not. 

Here is a review of the speakers. In the 3rd paragraph it mentions the frequency range. 

I also included a couple of screenshots conforming it is 41 Hz. 









I bought the MiniDSP and returned it before the 30 day trial was up.  All the components in my system are many times the price of the Mini and it sounded like I had a really cheap preamp in the system when I put it in.  It gave me a wonderfully flat frequency response, but I hated the way it veiled the overall SQ.  I’m surprised so many people like it.