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Question regarding subwoofers

I have an RHLabs SB-1 that’s served me pretty well for many years and use with it with my Acoustat 1+1s. (Had it refoamed a couple years back.) As well as the 1+1s image, I’ve always been slightly annoyed by having a single subwoofer between the panels. When playing something with a large sonic image like orchestral music the setup works fine. However when playing something more intimate like Jazz it’s easy to "see" where the lower frequencies are coming from: The middle. As my listening has gotten more refined it’s getting to be less acceptable to me. So I’m looking possibly at a pair of smaller, powered subwoofers. Why powered? Simple: If I do this, I’d rather the ARC VS-110 just power the panels. So, my questions:

1) The SB-1 has a single 10 or 12" driver. I’ve seen subs anywhere from 8" to huge. What folks experiences been with a pair of 8-10" powered subwoofers? Too much? Not enough?
2) Did a pair of subs affect imaging much? IOW, could you discern enough left/right to make it worthwhile?
3) How tough was it to balance them?
4) Do I run another set of interconnects from my SP11? Or do I get a set of Y adapters to feed both subs and amp?

Let me close by saying that like with most things audio there’s going to be a lot of "it depends". I get it. But I’d still like to hear of folks’ experiences as I do see a lot of systems with subs.

As always, thank you much for your time and comments!

128x128musicfan2349
turnbowm
353 posts
 
To get a reference point, listen to jazz with the subwoofer turned OFF. Is the bass still centered? If so, the sub may NOT be to blame. Regardless, the sub crossover frequency should be set no higher than 80Hz or bass localization, as mentioned by MC, will result. If you know the LF -3dB of the Acoustats is, that's where I would set the sub crossover frequency. Then, it's simply a matter of adjusting the sub gain to suit your listening tastes.

As for new subs, the number and size would depend primarily on room size and listening preferences. I would work with what I had before going that route.
atmasphere's avatar
atmasphere
11,834 posts
 
If you can tell where the woofer is, its crossed over too high as @millercarbon points out. If it does not make any output above 80Hz it won't attract attention to itself. Your Acoustats go lower than that with ease, so this should be a simple matter of resetting the crossover point.

The distributed bass array is a good tip.
rego
378 posts
 
+ 1 @turnbow, adding; a sub enclosure with two drivers ( 8" for example )
will displace as much air as a single 16 " driver.
Larger Drivers are heavier and benefit more robust motors as would any driver.
Servo feedback subs tend to be accurate IMO.
turnbowm
353 posts
 
rego199 posts10-28-2020 3:00pm
"....a sub enclosure with two drivers ( 8" for example )
will displace as much air as a single 16 " driver...."

That’s not quite correct. An 8" driver has a cone area of 50 sq.in so two 8" drivers would equal 100 sq.in. A 16" driver has a cone area of 201 sq.in. Cone area varies to the square of the radius.
musicfan2349's avatar
musicfan2349 OP
237 posts
 
Ah, for those not familiar with the SB-1 subwoofer, it is passive: The power amp's speaker output goes into the Sub where it passes through the sub's crossover. The upper and mid signals then comes out of there to the full range panels. Inside the sub there's a crossover but it has no adjustment, no internal amp. On the back of the sub, there's a volume control. Unfortunately I never had the proper manual, only the manual for the SB-2 which says it was selectable between 60 and 80Hertz so I'm guessing the SB-1 was at one of those two points. BTW the Acoustats by themselves are pretty gutless down low. 

@millercarbon: 5 subs? LOL I've visited your virtual system. Perhaps in our next home I'll have a single-purpose music room but for now, a 'swarm' of subs is out of the question. (Besides, I rather enjoy my current wife.) However I must disagree with your implication that bass is non-directional. I have moved the subwoofer in the past to different locations and please believe me when I say that I could tell you where it was (and wasn't) in the soundstage. 

@rego: I'm encourage by your statement that two 8" drivers move as much air as a single 16" driver. I will research that a bit further.
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