Subwoofer Suggestion

@kulo
I suspect you know the truth. You’re very fortunate to have great sounding highly resolving speakers. Imagine swapping out one of the Focals mid/bass drivers for a lower quality one- you probably wouldn’t have liked the lack of cohesion/sound and wouldn’t have purchased in the first place.Another analogy is if you heard a larger Focal speaker with bigger bass drivers but these bass drivers were also sub par, you’d likely reject them also.

On the cheap, you may get away with extending linearly your bass registers such as the AudioKinesis Swarm (which I believe is an great price/performance product) while maintaining cohesion and detail, but if you want both excellent performance on par with your Focals AND increased bass power, you’re going to have to spend more $ to the level of Rel or JR Audio for instance for the larger units. Otherwise, you’ll have to compromise.

Single subwoofers can be very problematic due to room modes, and multiple subwoofers can damage your pocketbook.

If I were in your shoes, though not ideal, I’d seriously consider the Swarm. It would definitely elevate your system significantly towards both goals, level out room modes, and hopefully may be satisfying enough.

Another option is to use cheaper less fidelity subwoofers used exclusively for HT.

Also, you may consider the used market to save $ and/or upgrade.  However, I haven’t researched whether or not the wear and tear of used subwoofers should be a concern/issue.

@kennyc

If I were in your shoes, though not ideal, I’d seriously consider the Swarm.

Alright thank you very much, I’ll see if I can push the budget a bit further.

Also, you may consider the used market to save $ and/or upgrade.

I’ve actually tried looking for used subs in my place there’s not much so I think I’ll have to go brand new. Thank you for your help.

You really need to experiment with sub settings and location. You can first try setting the subs crossover to be about 10-20 Hz higher than the low frequency response of your speakers. This allows for a nice blend of the Bass from the tower speakers to me more homogenized with the subs. Of course, you will need to play around with slope, phase, etc., and just listening to get the sound right. Other methods, the one you read about, would IMO prevent the sub from doing much work at all, unless you want to hear 20hz organ music and other very low frequency notes. This would entail a lot of subwoofer processing power, size, etc. depending on room dimensions to get this aspect correct for that purpose only, not really playing any of the bass associated with the range of 30-50 hz where many speakers would need a slight boost in bass.
I use a Velodyne SMS1 EQ which I use to measure the in-room bass response with or without the subs turned on. It’s really handy to see what impact the adjustments have on the bass sound because you can see on the monitor the curve (15-200hz) and how adjusting each parameter will either smooth or cause jagged peaks. This Velodyne allows one to also adjust slope, rollover, and cutoff, phase, etc. As others also have stated, two or more subs are better than one. One thing I notice is that if you increase the bass volume too much, the soundstage collapses due to bass smearing. This is the effect of the powered bass not being perfectly time aligned with main speaker drivers. That’s why you need to experiment. You should not hear bass increases in reality, it should be a smooth transition which provides a congenial in room response. For ultra loud and excessive bass emphasis, like rock concerts volumes, forget what is stated above, and adjust the subs to just play loud because at such extreme volume levels no one cares about sound stage, just loudness and bass. 

Listen to music with drums, standup bass with and without the subs, and also listen for collapsing of the soundstage with subs in use. 

svs just introduced their new 2000 series,  i believe they are 750 each.  I would do 2.  I have sb3000 in a 14x24x8 room. Plenty of base, I will add a second because that seems to be all the rave.  But I am extremely happy with the sb3000.   I almost went rel, but svs is no brainer.  45 day trial. 

@pcc67

The svs pb2000 pro cost 1387usd here and the pb pro2000 cost1285usd here, it is almost double here 🤦🏻‍♂️