Do I need a subwoofer?

@jerryg123 , the QLN Prestige 5s are down 3dB at 26 Hz at 1 meter which means in a normal sized room at 3 meters they are down somewhere around 10 dB. You still need subwoofers if you want to try duplicating a live performance. 

@olfac87 , two subwoofers is the minimal requirement for decent bass. Cindyment made a very important point. Most people do the cheap and dirty method of integrating subs by using only low pass filters on the subwoofers. Using a full two way active crossover and putting a high pass filter on the main speakers will decrease distortion in the main speakers and add a significant amount of head room to the system.  The ultimate way of integrating subwoofers is with a digital bass management system such as you find in MiniDSP units and digital preamps such as the DEQX Premate, Anthem STR and Trinnov Amethyst. These allow you to adjust your speakers in time so that the sound of the subwoofers gets to your ears at exactly the same time and phase as the main speaker. Using a high pass filter and time correction allow you to put the subs where they work best, in corners or right up against a wall, and allow a higher crossover points further lowering distortion and increasing head room. With the 801s I would not want to cross over any lower than 80 Hz. 

The only commercial subs I like are the Magico Q series units. If you are decent with tools you can build a fine pair of subs from Dayton Kits (partsexpress.com) and save enough money to get a proper crossover, measurement microphone system and a vacation in Tuscany. 

@jerryg123 — I’d rethink that sub decision. Huge fan of ur speaks and ur hawks logo BTW. Lived in Chicago for a bit and sadly didn’t get to see them play in the old arena — one of my biggest sports regrets. Anyhoo, I was listening to an ultra mega system with “full-range” speaks that went down to the low 20s with stereo subs, and when he turned off the subs the whole soundstage collapsed and the dynamics and imaging of the whole thing took a huge step backwards. I was gobsmacked and didn’t wanna listen to his otherwise awesome system without the subs anymore — it was that huge of a difference and truly one of my top 3 AHA moments in audio (even surpassing the incredible impact of the oft-neglected preamp that is likewise HUGE IMHO).  I only say this to say that even with your incredibly awesome speakers I can only aspire to, you might wanna give those subs another crack crossed over suitably low that they don’t eff up all the goodness those QLNs produce. I mean, even Wilson uses subs with their Alexandras, so...

@mijostyn Thanks for the clear and logical explanation. I learn something new every time. 

 the QLN Prestige 5s are down 3dB at 26 Hz at 1 meter which means in a normal sized room at 3 meters they are down somewhere around 10 dB. You still need subwoofers if you want to try duplicating a live performance.

That is not how it works. Every frequency is "down" at 3 meters, but depending on cancellation, room response, it could be up at 26.

I have 2 sb3000.  Very happy with them.  Ht they do a fantastic job.  Looking to add another one soon.  They sound great with music, but I am 95 percent ht.  Listened to rel t9/I and jl.  Decided on svs.  Sb3000 had great reviews so I jumped in, no regrets.  I've also seen many great reviews on psa.  I have one sub in front between TV and speaker and another opposite rear corner.  One sub is OK.  But 2 is definitely needed.  I have a anthem avm 60 and used it's room correction, gave me poor results. Friend came over and used rew.  Deal breaker.  If I was going to change subs I probably would look into the psa 21 sealed.  Like I said I'm mainly HT. 

Good luck