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Discussion Starter · #1 ·
After years of tinkering with the video side of my Home Theater, I just recently turned my attention to the audio side (probably a bit overdue). To neutralize the front wall and deal with some of the room modes in the low frequencies I've added a false wall 2' from the actual wall and installed a super chunk bass trap in one corner along with 6" of mineral wool along the entire front wall. My speakers and current sub-woofer have also been relocated to the void behind the false wall. For the higher frequencies I also have 24 1" OC-703 panels arriving tomorrow which I plan to use to tame a "clap" echo that currently exists in the room.

With all that going on, I somehow got it in my head that I need to upgrade my sub. :) Only problem is, I'm having a hard time deciding exactly how much sub I need for my space. I'd like an upgrade from my current setup, but I don't want to spend a lot of money on power I'm not going to use. Here's some relevant parameters:

  • The room is roughly 15'x20'x8', or 2400 cubic feet, fully enclosed.
  • The room is used pretty much exclusively for movies (not a lot of music unless it's part of a movie)
  • I don't generally have the volume running at bone-jarring levels (my wife might disagree), but I absolutely want to feel the bass in those high impact scenes.
  • The sub (or subs) need to fit behind the false wall with enough clearance for ports to breath (if applicable) and access to the panel controls. There's not really a limitation on height or width, but with the 6" of acoustic treatments there's only about 17" available for depth if sitting flat on the floor, or about 20.5" if I raise the sub a few inches to clear the framing on the bottom of the false wall. I took some readings with REW, and there are several good locations along the front wall that are favorable for sub placement.
  • To set expectations, my current sub is an Infinity BU-120 (12" 150 Watt). Been fairly happy with the punch it offers, but it's only spec'd to 30Hz on the low end (and based on REW, it doesn't really flatten out until closer to 40Hz). Really hoping some extra extension on the low end will improve the movie experience.

Given my space limitations and budget, I think I've narrowed my choices down to either dual SB-2000's or dual PB-1000's. Just not sure if for the extra cost the sealed SB-2000's with their 12" drivers will out perform the ported SB-1000's with their 10" drivers. Looks like the SB-2000's start to roll off above 20Hz which concerns me a little (maybe it shouldn't???), but I also wonder if the SB-1000 will provide enough output to "fill" the space. Any suggestions out there on which option would work best for my situation?

Thanks!
 

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Not knowing a ton about either subwoofer, my initial feeling would be to go with the dual SB2000. Partly because I prefer sealed subs in general, and partly because of the larger driver which will be able to move more air (44% more, assuming equal excursion capabilities). You might get more output from the PB1000 at the frequencies surrounding the port tune, but as you get away from port tune (on either side), I suspect the SB2000 will equal or best it. Again, I haven't looked into this very heavily, so I would be calling SVS on this to verify.

Given your fairly small room, the output of the sealed sub will be reinforced in the very low frequencies, so even though the anechoic output of the SB2000 starts rolling off in the high 20's, room gain will probably help you stay flat to below 20 Hz. Again, this is a semi-educated guess.
 

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Discussion Starter · #3 ·
Not knowing a ton about either subwoofer, my initial feeling would be to go with the dual SB2000. Partly because I prefer sealed subs in general, and partly because of the larger driver which will be able to move more air (44% more, assuming equal excursion capabilities). You might get more output from the PB1000 at the frequencies surrounding the port tune, but as you get away from port tune (on either side), I suspect the SB2000 will equal or best it. Again, I haven't looked into this very heavily, so I would be calling SVS on this to verify.

Given your fairly small room, the output of the sealed sub will be reinforced in the very low frequencies, so even though the anechoic output of the SB2000 starts rolling off in the high 20's, room gain will probably help you stay flat to below 20 Hz. Again, this is a semi-educated guess.
Thanks for the input. I also just discovered cylindrical subwoofers. Not sure why, but I hadn't payed much attention to them before now. However, I realized that the PC12-NSD fits my footprint requirements, is ported, and sits between the PB1000 and the PB/SB2000 in term of RMS and peak output. Being ported, they are rated flat down to around 18Hz. They are a bit more expensive.

I'll probably ping SVS on their recommendations.
 

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Bkeeler has made some good points, and I would add that dual SB2k's would be better, IMO, than the PB1k. (More power/better driver etc) I was fortunate enough to win an SB2k recently, (and ironically bkeeler won aPB2k, and I think the results should have been reversed! Lol). I have around 6700 cuft without the foyer, and hallway. My SB is stuffed into the right front corner,(boundary gain) and I tested it a little with the "Darla" scene from nemo. The 2 PC+'s in the room were hardly moving at MV-10, and I thought the little SB was gonna "inchworm" itself across the carpet! I might move it to my bedroom.
If my memory serves my math, your longest wall of 24' has your room gain staring at 23.5hz. From here on down is where you'll see it.
I can say this too. When I get within 6 or 7 feet of the SB, it sounds awesome. It's all they say about sealed subs, and then some, but in my case it, even 2 wouldn't be close. I think for you, two might be enough. They would be a huge upgrade to what you have, and if they don't work you can send em back for a pair of cylinders! ...or pb2k's(only 2" larger each way than the 1000) ...or 2 more SB2k's for the back. If only choosing from your original two, I say SB2000, but as bkeeler said, call/email SVS.
 

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Discussion Starter · #5 ·
Just fired off an email to SVS asking for their recommendation. Well see what they suggest.

Thanks.
 

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Just as a point of reference . . .

The single PB2000 (not 1000) that I won has no problem filling my space with great bass. I have not pushed it beyond levels I normally listen at to test it, nor have I run more than a couple of movies on it. I will be pushing it in the coming days and weeks when I get a chance, just to see what it can do.

My room is about 17.25 x 14 x 8 and is open to a hallway -- about 3000 cubic feet of total open volume. My point is, if a single PB2000 can do the job it's doing for me, I am confident a pair of SB2000 in your room will not have an output problem unless you're one of those bassheads that likes to run at reference with your subs 6 dB hot. I usually run maybe 10 - 12 dB below reference with the subs 2-3 dB hot.

Edit: Willis, I think you're right that our fortunes should have been reversed. A single 12" sealed in 6700 cu ft -- that's a lot to ask!
 

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Jack has already responded to your email with a recommendation for you. I will add that at 20Hz you will need 2.5 SB-2000's to match the maximum output of a single PB-1000. I don't know if your room gain will be enough to compensate for this. If you really want to be sure you have that rumble/tactile feel and the full effect for slam/punch in those action/sci-fi movies, I would go with ported, especially since you suggest you like it loud. You could experiment with the direction in which they fire to see what will give you the best response... you need about 4" clearance from the front of the sub.

I currently have a pair of SB-2000's in my completely sealed room and while they are nice and offer some respectable low-end response, they don't give me what I really want for movies. They are not bad, but just not what I could live with on a permanent basis.
 

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Jack has already responded to your email with a recommendation for you. I will add that at 20Hz you will need 2.5 SB-2000's to match the maximum output of a single PB-1000. I don't know if your room gain will be enough to compensate for this. If you really want to be sure you have that rumble/tactile feel and the full effect for slam/punch in those action/sci-fi movies, I would go with ported, especially since you suggest you like it loud. You could experiment with the direction in which they fire to see what will give you the best response... you need about 4" clearance from the front of the sub.

I currently have a pair of SB-2000's in my completely sealed room and while they are nice and offer some respectable low-end response, they don't give me what I really want for movies. They are not bad, but just not what I could live with on a permanent basis.
Sonnie, remind me how big your room is again.

20 Hz is pretty close to port tune, right? One would expect a lot more output near port tune. How would the SB2000 compare to the PB1000 about half an octave to a full octave on either side of the PB1000's port tune? Just for my own enlightenment :nerd:
 

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Discussion Starter · #9 ·
Jack has already responded to your email with a recommendation for you. I will add that at 20Hz you will need 2.5 SB-2000's to match the maximum output of a single PB-1000. I don't know if your room gain will be enough to compensate for this. If you really want to be sure you have that rumble/tactile feel and the full effect for slam/punch in those action/sci-fi movies, I would go with ported, especially since you suggest you like it loud. You could experiment with the direction in which they fire to see what will give you the best response... you need about 4" clearance from the front of the sub.

I currently have a pair of SB-2000's in my completely sealed room and while they are nice and offer some respectable low-end response, they don't give me what I really want for movies. They are not bad, but just not what I could live with on a permanent basis.
I actually just sent a follow up question to Jack specifically asking about how the SB2000 would compare to the PB1000, but I think you've answered that question. Thanks!

One quick follow-up "curiosity" question. Would there be any benefit to running my current BU-120 along with duel PB1000's and having 3 sub's going?
 

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My room is 3900 cubic feet... with 9" thick walls and seriously sealed (difficult to even shut the door)... with lots of placement availability to experiment with. :bigsmile:

Port tuning is about 20Hz, although enclosure size and damping can also affect where you might see the most output. At 16Hz and 25Hz, you basically need 2 SB-2000's to match the max output of a single PB-1000, which is going to be the significant portion of rumble/feel. At 31.5Hz and up... the output is pretty close.

When you get into placing dual subs, it may be that you have to pull one of them out from the wall a good bit to even out the combined response, so you could lose room boundary gain. I don't know how that will integrate into the false wall though, which you would think would add more boundary gain too. Yet, my thinking is it would be better to play it safe and go with the ported models in this case.

Keep in mind too that we do give you a 45 day trial period. So you can try either/or and if it doesn't work out for you, we will take care of the return shipping and you can go the other route. :T
 

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Wow! 2.5 sb2k's to equal 1 pb2k. If Sonnie didn't write it, I still might not believe it. I've always been a fan of ported for their efficiency, but I may have underestimated the little PB! I haven't asked yet but since Sonnie is in this thread I will. What would you guys think about the upgrade program for my SB? Ed mentioned working something out when I first won, but WAF/budget dictated that I humbly accept my prize. I have, and I think I'll move the SB to my bedroom. I REALLY wanted to have it in my big system, but If can't figure it out, that's ok.
I'm also curios about the OP's false wall, and cabin/room gain effect here. I had an 8" Yamaha sub in a built in desk "thing" and it's output was greatly increased, but so was it's "Boominess". I did not sound treat the area though.
 

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For clarification... 2.5x at 20Hz. :T

If Ed said he would work out a trade for you, shoot us an email and I am sure he will work it out for you.
 

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Discussion Starter · #15 ·
I'm also curios about the OP's false wall, and cabin/room gain effect here. I had an 8" Yamaha sub in a built in desk "thing" and it's output was greatly increased, but so was it's "Boominess". I did not sound treat the area though.
Not much to the false wall. It's a floating wall with roughly 3' stud spacing and black acoustically transparent fabric stretched across the front surface. The height can be adjusted several inches by bolts at the bottom, which is mainly how it's held in place. It's assembled entirely with screw's and could probably be disassembled and removed in a few hours effort if necessary (though the fabric may not survive the process).

We watched "The Dark Night Returns" after the wall went up but before I installed the sound treatments. I found the bass to be very muddy. Had a hard time understanding Bane's deep booming voice and found I was constantly adjusting the volume as the dialog went from too loud to quiet. Finally got up and just turned down the bass on the woofer about half way through the movie.

After I installed the acoustic treatments and re-ran Audessey on my receiver I went back and listened to some of the scenes from DKR again and those issues were gone. That said after moving my sub and speakers behind the false wall, I didn't actually re-run Audessey until after the treatments went up, so some of the original problems could have been due to improper speaker calibration as opposed to the false wall minus sound treatments. The front speakers only moved a few inches, but the sub moved from a side wall to the front wall with Audessey still configured for the original location.

I didn't get REW up and running until after the bass traps went up, so I have no objective measurements, but my ears tell me that the bass has improved and is much more uniform across seating locations with the false wall and bass traps up.
 

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Bass trapping makes all the difference in the world, if done correctly. I really need to do some of that myself. It will be soon I hope :T
 

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Discussion Starter · #17 ·
Well, byancey, let us know what you get and how it turns out!
Just pulled the trigger on Dual SB-1000's. I was tempted to pursue more questions regarding the PC12-NBS, but I figured why spend the extra $ if I don't need it, and with the 45-day no questions asked return policy, I figured I'd start with the less expensive option, and then I can move up if I decide it's not enough. I doubt that will be the case though.

I'll report back on my impressions once they are setup.

Bass trapping makes all the difference in the world, if done correctly. I really need to do some of that myself. It will be soon I hope :T
With my sub purchase out of the way, now I'm off to deal with the higher frequencies. I have 24 1-inch OC-703 panels sitting in my basement that I need to figure out how I'm going to install. :) Got the wall figured out...still thinking through the handful that will end up on the ceiling and soffit. :ponder:
 

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byancy, congrats! Looking forward to impressions! You asked earlier about 3 subs in your system. I would add here that you can do it, and IME, if you put the time in to adjust the phase so they play nice, you'll be rewarded with more well rounded bass. This doesn't take into account exactly for the difference in capability though, between tour new, and old subs. Your new PB's will be much better. Maybe you could put your infinity near field and go from there?
 

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Discussion Starter · #20 ·
byancey, congrats! Looking forward to impressions!
Finished up my acoustic treatments last week and finally had a chance to setup the dual SVS PB-1000s and take them for a spin. I took some quick measurements and I could immediately hear and feel the difference when I ran the sweep in REW. The graphs confirmed what I felt and heard (see the attachment below). The red line is my old Infinity BU-120 and the green line is a single PB-1000 at the same location. I adjusted the input level to -18 dB FS between runs, so this doesn't reflect any difference in output capabilities between the two subs, but you can clearly see where the PB-1000 crushes my old SW below 40Hz. I'm not sure if it's the PB-1000 or a favorable contribution from my room (I suspect the room), but I'm also seeing a pretty significant bump in output between 18 and 32 Hz, which I believe will be beneficial when I set up a house curve (I picked up a BFD on ebay which arrives Friday). That said, to my untrained eye, that curve already looks pretty good even without any equalization. I ran some simulations in REW and I think I'll only need 3 or 4 filters to get a decent house curve with a 6 to 10dB drop between 30 and 80Hz.

Adding the 2nd PB-1000 into the mix gives me about a 4dB boost at my primary listening position and does a fairly good job of leveling out some of the peaks and dips in the other 9 listening positions. There are one or two spots where the negative effects from both subs are additive, but on the whole the improvements with two subs appear to be far more significant than the negative effects (from both objective and subjective measurements). I have both subs setup behind the false wall facing each other at roughly the 1/4 and 3/4 points along the wall. That 3/4 position is actually the best spot in the room, and while the 1/4 position isn't quite as good, I actually didn't find anything much better elsewhere in the room (which is good, because part of the negotiations with the wife when I proposed adding a false wall was the fact that the fronts and subs could all be hidden back there). :)

If I'm perfectly honest with myself, I think a single PB-1000 would be more than sufficient for my room...and if I had only ordered one to start with, I probably would have stopped there and been perfectly happy. However, after hearing 2 working together it would be hard to go back to a single sub. Even with the levels adjusted so that the output is roughly the same with 1 vs 2 subs, the bass just seems more "full" with the two running together. I also suspect the extra overhead will come in handy once I've inserted the BFD into the chain and added some equalization to the mix.

Once everything was setup, I sat down and watched some high impact scenes from my collection. These are scenes that always shook the room with my old sub, but with the 18Hz-30Hz frequencies added to the mix, I noticed things that simply weren't there before. In the opening scene of LotR EE, when Isuldir cuts off the finger of Souran, you can literally feel your seat sink when that finger with the "one ring" hits the ground. In The Matrix, where Neo pulls Trinity from the Helicopter just before it hits the building, you can feel the slow-motion "Whoosh, Whoosh, Whoosh" of the Huey blades as it falls past Neo on it's way down. The scene where Home Tree falls in Avatar is simply amazing. You can feel the individual shock waves as each missile impacts the tree and detonates, and the whole room seems to move as Home Tree crashes to the ground. :clap: U-571, Saving Private Ryan and a few other's are still in the queue.

You asked earlier about 3 subs in your system. I would add here that you can do it, and IME, if you put the time in to adjust the phase so they play nice, you'll be rewarded with more well rounded bass. This doesn't take into account exactly for the difference in capability though, between tour new, and old subs. Your new PB's will be much better. Maybe you could put your infinity near field and go from there?
Decided not to integrate the 3rd subwoofer with the PB-1000. Instead I swapped the BU-120 with a passive sub I had running in another room and used the passive sub in-line with my rear channels to bring their response from 150Hz down to 40Hz (that passive sub was originally bundled with those rear speakers...although at the time they were the front speakers of my first Dolby Surround setup years ago). This should give me a bit more flexibility in setting up my crossover frequencies (which are currently set to 80Hz across the board).
 

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