Your experience of moving to two subs

Indeed!

What sounds good to me is what’s optimal in my system.

tis true, as one of the youtube heads say... ’’ all that matters is that you like the sound of your own system’’ or something to that effect

what gets a little more complicated, and perhaps interesting, is when we get the itch to try to IMPROVE our system.... how do we go about doing that?

some ask others for advice, some tinker with their existing gear and room, some try to measure to understand what might be going on as a way to shed light on potential avenues of improvement, and some just go and buy new stuff on a trial and error basis

we all enjoy the process differently, think differently, arrive at conclusions differently on how to improve, what to do next...

... and @hilde45 ... good analogy on the hvac vents in a room... i like it, it works!!!

What sounds good to me is what's optimal in my system.

Thus, the sub’s optimal crossover setting is only at about 28hz. I have plenty of bass amplitude going on -- don’t need "more" bass.

No, not it isn't. But good luck to you. 

In our last house, I had 2 subs and it was fantastic. Everything was improved. The only hard part was spending considerable time integrated them both properly with one another and the room.  

I have three !  Remote control with ability to adjust all parameters.

I’m also now thinking that since my Rythmik is the one with the paper cone (vs aluminum) for faster response, and there must be more distortion involved because of the relative flimsiness of paper, that two subs working less hard would help increase clarity. Honestly, hard to imagine more sub-bass clarity than what I have now, but I’m sure it’s possible.

I didn’t think I would get such high quality responses here in a row! Starting with low expectations worked out well 😆 I’ve been very satisfied with the sound I’ve been getting from my Rythmik F12G in the med-large room my system is set up within, so I’ve kept putting other upgrades above getting a second one of them. But it’s helpful to get this feedback.

Thankfully, I’ve never had any difficulty integrating subs by ear using manual phase and crossover adjustments. I do have an SVS SB2000 in a different system, so I think I’ll play with trying to integrate it into my main system temporarily, just to see if I can get a general sense of this wild world of sub-bass "smoothness". I have an extra set of longer subwoofer signal cables to make it work, too.

Does anyone have an opinion on the benefits of 2 subs vs only 1 when there’s no need for more bass oompf?

yes i have had subs for over 25 years, of various brands (hsu velodyne m-l jbl and mostly/many rels) -- the answer to your question is a resounding yes, dual subs help expand the soundstage considerably and integrate better (as each sub has lower output than the single one)

Here is my take in this topic. Their is nothing wrong with one sub in a system if you implement it properly if you have the right resources. Yes dual, quad, etc, no matter how many subs you put in a room is going to improve the smoothness of the response but doing it without the use of tools and listening it not going to solve by itself especially in a room that is untreated. I have a small room where my system is and really might not require a sub but I have it for use of my listening preference, type of music, etc. My sub is set low 50s with the phase inverted. I dont have the sub in the center because I have the component rack in the area. So the sub is off center to the left about 1/4 wavelength of 1/2 of the room node, in this case around 60hz. This is almost 1/3 octave above the sub crossover frequency. The sub is low enough that localization is less noticeable and easier manageable.

REW is the norm for measurement software for this situation. I personal use Rational Acoustics for measurement in the outfield but since I have it available, it makes it easier to see what your response look like. If you are inclined with using measuring software, more power to you. Of course, you ears are the final judgement.

According to acoustics and psychoacoustics researcher Earl Geddes, the in-room bass smoothness increases in proportion to the number of independent bass sources. So two subs can theoretically be twice as smooth in-room as one sub; four subs can theoretically be twice as smooth as two, and so on. "Independent" in this context means that the subwoofer locations are acoustically completely and significantly dissimilar, and in practice that just about never actually happens; for instance even if both subwoofers are placed asymmetrically with respect to the walls, both of them are probably still on the floor, thus they are both the same distance from the floor and ceiling.

That being said, imo two subs intelligently distributed will make a very much worthwhile improvement in in-room smoothness versus only having one sub. Ime a steep-slope low-pass filter (like 4th order) can be very helpful for rapidly rolling off the top end of any subs which are positioned well away from the main speakers.

And "smoother" bass = "faster" bass, subjectively as well as literally, because it is the in-room bass peaks which take longer to decay into inaudibility and which therefore muddy the bass response.

Improvements in smoothness in the bass region pay disproportionately large dividends. This is because our ears have a heightened sensitivity to changes in SPL in the bass region, which is shown by the way equal-loudness curves bunch up south of 100 Hz. A 5 dB peak in the 40 Hz region can be comparable in perceived loudness to a 10 dB peak at 1 kHz!

The improvement in bass smoothness tends to extend throughout the room, which makes equalization more likely to be an improvement over a large listening area. With just one sub, equalization tends to fix problems in one location at the expense of making things worse elsewhere. So two (or more) subs intelligently distributed have the added benefit of making equalization beneficial across a larger area.

Duke (manufacturer of a four-subwoofer system)

@hilde45  Is 100% correct.

"The oomph is not the goal ...... The goal is evenness, tightness, naturalness."

My findings indicate that two subs are better than one and four subs are better than two. 

Two 👍👍 for two subs!

The oomph is not the goal for me, either. The goal is evenness, tightness, naturalness. It's like having a room with two vents for heating/cooling rather than one. It is about distribution of waves, in either case.

Guessing about subs is an infinite project. I suggest a umik and REW and some time spent measuring.

If your subs have adjustable phase, like my Rythmiks, that will help a lot. Sometimes subs need to interact in certain ways to create evenness. Adjustable phase makes that much easier. 

It pressurizes the room more evenly and helps avoid or minimize in-room bass anomalies.  Plus, each sub doesn’t need to work as hard to produce the same bass.  I don’t know anyone here who prefers one sub compared to two, so take that for what it’s worth.  Best of luck.