Your experience of moving to two subs

Thanks so much for the update. As a fan of Rhythmik subs and an owner of an SB2000 (for home theater only) I especially appreciated your observations comparing the two subs — most enlightening! Glad to hear you found benefits in using two subs, and I’d love to hear your thoughts once you get the second Rhythmic set up and dialed in. I have no doubt it’s gonna be great and color me a little jealous, and there will be a pair of Rhythmik subs in my 2-channel rig as well at some point.

I had two SVS subs but was not happy with the quality of the bass for music. I moved to one F12 and I feel the quality is better. However, like the OP, I sense its location in the room and others can too, even though I left one of the SVS subs on the other side (my two svs subs were located R and L of the speakers) and only the F12 is hooked up. If I had only 1 sub it would have to go in the middle but with my set up it can’t. I don’t know how 1 sub in the center would sound having not done that but I think two would sound better at the R and L.  I will order another F12 in time.  

Question: Does the R and L channels get different bass in songs? Thus is there is right channel low freq signal that differs from the low freq left channel in music from my DAC which outputs as line level right channel and a line level left channel.

Thanks.

@soix I’ll let ya know.

@12many Yes, bass is mixed using L and R just like anything else. But the higher frequencies certainly give much more soundstage positioning cues. Often, the low bass sounds are set evenly between L and R, which is the same as center. Like, for electronic music’s synth bass lines. But recorded upright bass, or a large tympani could be set in the mix more to one side.

One thing that could lead to being able to locate subs could be that they're causing nearby objects to resonate at higher frequencies and you're hearing that.  I'd play around with tone generator a little to see if you can isolate anything.  

Long ago in my obsessive phase I made an extremely dead sounding room in my basement.  I made dozens of insulation bass traps, got equalizers and measurement mics and found out what accurate was, at least from a frequency response perspective.  One thing I realized is that if I clapped near one of my components it made a very audible resonance sound.  If something coming out of the speakers set that off it would have been a lot more added distortion than the component put out.  

@gladmo wrote:

Hi all, I have a 2.1 system with the sub sounding best in the center between the loudspeakers. My speakers have substantial, deep, and detailed bass for their size and with the SS amp I’ve chosen. 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.

Rather than more bass it’s about added headroom via more bass capacity for a given SPL (i.e.: less excursion = lower distortion = cleaner, more effortless bass), as well as smoother frequency response from an addition of spread-out bass sources (the latter with a potential proviso, to my ears, certainly with 3 or more sources asymmetrically placed).

You always dial in the sub section for overall balance, irrespective of capacity, but when given more headroom and a smoother FR the perceived bass quality takes a leap ahead. Which is to say: oftentime poorer bass reproduction is sought counter-acted with less gain to "hide" a more obvious character of bass, but at the expense of proper, clean bass balance and fullness. So, in effect a cleaner bass can/should be dialed hotter.

I’ve taken advantage of the design of my pair of tapped horn subs, symmetrically flanking/positioned behind my mains, both with regard to smoother FR and even higher sensitivity in a single move - literally: by more effectively using boundary gain as a means of extending/enlarging the horn by firing into the concrete side walls (instead of straight ahead) at a fitting, calculated/simulated distance. That translates into a sensitivity of 108-110dB’s/1W/1M from 25Hz to >100Hz and a more even FR - win-win.

Many already lower sensitivity and direct radiating subs are only operating in a 1/2 space environment (vs. a 1/8 space ditto mentioned above from a sub principle easily 10dB’s more sensitive in itself), meaning they’ll have to work much harder for a given SPL. This is not without sonic implications, I might add, but few really consider the importance of headroom.

I’m wondering about soundstage effects of having two subs on the outsides of my speakers, though. Having my sub in the center does result in some apparent compression of the low frequencies towards the low-center area. The L and R channels from my preamp are combined at my sub. I know some people may disagree and think that the source of frequencies below 60hz can’t be located by human hearing, but my experience tells me differently.

I absolutely agree with you on this, and this is why I find a pair (and no more, unless placed on top of each other for towers) of symmetrical-to-the-mains placed subs to be paramount. It’s also one of the reasons why I’ve never fully warmed to a DBA sub setup, not least when asymmetrically placed throughout the listening space.

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

Again, it’s not (as much) about "oompf" than it is a cleaner and smoother bass response with more headroom, but to my mind the addition of radiation area only adds to the realism of sound with better physicality; you can’t really overdo capacity, it’s with you do with it and the advantages it can provide you.