Multiple Sealed vs Multiple Ported Subwoofers for Home Theater

[jasonr93]

Hello,
I'm looking for advice for home theater subs. I'm looking for high DB and Low frequency. I know the whole thing about ported typically having more output, and sealed having more low end extension. What would be the best for both worlds, multiple ported or multiple sealed. I currently own dual SVS PB13 Ultras, but I'm interested in sub 20hz (which I know you can't hear but you can feel) with a little bit more output.

Examples:
JTR Captivator 1400 (x2)
JTR Captivator S2 (x2)
JTR Captivator S1 (x4)

Any advice, thoughts and comments would be very appreciated.
Thanks.

 

[KEW]

LOL, so you want the characteristics of a ported sub in a sealed sub!

All I have too offer is my pair of Rythmik E15HP's do a great job for HT.
My PSA XS15se's also do a great job for HT, but lose a bit of the bottom end relative to the Rythmiks.
Both put out the 17Hz signal of "live, die, repeat", but the Rythmik is much more dominating with it.
My living room is around 17x24x15h.
Both are perfect for music!!!
I suspect your options go deeper so expect you would be happy with them.

 

[jasonr93]

Yup. I'm currently thinking of selling the PB13 ultras and replacing them with S1's. I'm thinking sealed subs may be the way to go. It will offer the low end extension and if it doesn't have quite the output, add another. The S2's are 4000w RMS, I only have 120v circuits for the subs, so I'm wondering if the S2 wouldn't perform as well because it wouldn't be getting the full advantage of a 240v. Placement would also be more of an issue with the S2. The S1 on the other hand, is 2400w RMS so that may be better on a 120v and placement would also be better. I figure 2 captivator S1's on their own separate 120v may be better than 1 captivator S2 on a 120v?

 

[shadyJ]

The S2s would be better. Two drivers are more efficient than one, so you get more output per watt than with the S1. Don't worry about the 120v line. Two S2s will give you a phenomenal amount of deep bass.

 

[jasonr93]

So you think that the S2 would still perform better even though it may not pull all the wattage it needs for the drivers? I just thought that the speaker might not perform as well since it needs the 4000w RMS. I would think that the S1 would, since its getting almost all of its required 2400w RMS. S2's would obviously dominate the lower frequency, I'm wondering how the S2's compare against dual PB13 Ultras out put wise?

 

[Steve81]

I just thought that the speaker might not perform as well since it needs the 4000w RMS.

Here's the thing, a subwoofer playing dynamic real world content presents a very different load from say, a vacuum cleaner or a blow dryer. Even assuming you're running things at reference level, full power will only be demanded for some fraction of a second. This doesn't tend to trip a breaker, versus running a vacuum and blow dryer on the same circuit.

S2's would obviously dominate the lower frequency, I'm wondering how the S2's compare against dual PB13 Ultras out put wise?

One to one, I'd expect even the S1 to compare favorably in overall output to the PB13, let alone the S2.

 

[its phillip]

If I had the money the pair of S2s would be my pick.

 

[Steve81]

To toss in another idea at the S2's level, one might also consider the Deep Sea Sound 24" offerings. The base cost is a tad higher (4K vs 3.6K for the S2); however, one gets a couple form factor options (tall and shallow like the S2, or a ~28" cube), as well as a black maple or oak veneer included in the base cost.

 

[jasonr93]

I have tripped the circuit twice with the PB13Ultras. But only when when listening at much higher than normal levels. So that is why I was wondering, since together they're 2000w RMS and the S2 is 4000w RMS. I will have to look into the Deep Sea Sound sub that you mentioned. Wouldnt 2 18" drivers be more efficient than 1 24" driver?

 

[shadyJ]

I have tripped the circuit twice with the PB13Ultras. But only when when listening at much higher than normal levels. So that is why I was wondering, since together they're 2000w RMS and the S2 is 4000w RMS. I will have to look into the Deep Sea Sound sub that you mentioned. Wouldnt 2 18" drivers be more efficient than 1 24" driver?

Two 18"s are not necessarily more efficient than a 24"; the cone area is exactly the same. However, the JTR drivers are very efficient, at something like 97 dB sensitivity. The HS24 driver is something like 91 dB sensitive. But each configuration will have their respective advantages depending on frequency and drive level. Here is an Audioholics article which is a roundup of subs at this level. Something else to look at, Funk Audio has a new design called the Funk 21.0L, a $3.5k high-excursion sealed 21" with a 2.4 kW amp, which looks to be absolutely killer sub, in case their upper end $6k 21.0 is a little rich for yoru blood. I would get in contact with Nathan Funk about that.

Anyway, if you are tripping the breaker with PB13s, I would look at installing some dedicated 20 amp lines for any of the subs discussed here. The installation cost of some new circuits isn't that much compared to the price of these subs.

 

[Steve81]

However, the JTR drivers are very efficient, at something like 97 dB sensitivity.

Is there any place it's specifically stated how sensitive the new S1/S2 driver is? All I know of it is that it's based on this driver, which isn't particularly efficient.

Also worth noting, low end efficiency is largely dictated by the enclosure volume. AFAIK, the new S1 is ~3.5 cubes, with the new S2 presumably running around 7 cubes. The Deep Sea 24" subs are a bit larger at ~8.5 cubic feet.

 

[jasonr93]

So the Captivator S2 vs Deep Sea sound 24" cube. So the 24" should have more lower extension and higher output? Also wandering which sub would have lower distortion. If I remember correctly, the S2 is listed to almost single digit frequency in room. I'm guessing the deep sea would get possibly lower with more output?

 

[Steve81]

So the 24" should have more lower extension and higher output?

Couldn't say definitively. No measurements exist for the Deep Sea Sound subs or the JTR S1/S2 that I know of. What we do have is measurements of the 24" driver used by DSS in a larger box, along with a more powerful amp on tap. One presumes that even in a smalller 8.5CF box and a "mere" 4kW on tap, the DSS 24's will be extremely potent subs, with useful output down to the single digit range (contingent of course on your room's cabin gain). There's also not much question in my mind that a pair of S2s can deliver prodigious single digit output as well.

 

[shadyJ]

Is there any place it's specifically stated how sensitive the new S1/S2 driver is? All I know of it is that it's based on this driver, which isn't particularly efficient.

Also worth noting, low end efficiency is largely dictated by the enclosure volume. AFAIK, the new S1 is ~3.5 cubes, with the new S2 presumably running around 7 cubes. The Deep Sea 24" subs are a bit larger at ~8.5 cubic feet.

Jeff of JTR states that 97 dB sensitivity spec somewhere, he is a big believer in powerful motors. As for low end efficiency, suspension compliance and moving mass are big factors. It's difficult to say which one is more efficient. I know that Dave Gage of Deep Sea Sound intends to have his subs measured by Josh Ricci. It will be interesting to see how those measurements compare to the large box measurements of the HS24 there now. The existing HS24 measurements has outstanding distortion performance. Dave wants to offer an upgrade of the BHS24 driver, that should do better in a smaller cabinet as well. That sub will weigh a ton though, but, of course, they all do.

 

[jasonr93]

It seems the Deep Sea's driver has really good Low distortion. However, shipping isn't included in the $4k so it may be $100-$200 freight. So Captivator S2 ($3600) v.s. Deep Sea Mariana 24sc ($4000 - $4200). If the Deep Sea has lower distortion, higher output, and lower extension it would be the better sub in my opinion.

 

[Steve81]

However, shipping isn't included in the $4k so it may be $100-$200 freight. So Captivator S2 ($3600) v.s. Deep Sea Mariana 24sc ($4000 - $4200).

To my knowledge, JTR doesn't include shipping in their prices either.

 

[Steve81]

Jeff of JTR states that 97 dB sensitivity spec somewhere, he is a big believer in powerful motors.

I looked around but didn't see anything over at AVS. Only thing I saw from Jeff was that the S1 driver had a longer throw, lower distortion, and better power handling vs the Cap 1400 driver, with considerably less motor force.

Either way, 97dB seems awfully high for that type of driver. Data-bass has a useful list of drivers tested, and the only things that deliver that level of sensitivity are relatively short throw pro drivers with accordion surrounds. Drivers like the UXL and SI HST range from 92-89.5dB, with the aforementioned Fi driver falling in the lower end of that range. Of course, if 97dB is indeed accurate, that suggests considerable top end output when backed by a 2.4kW amp, on the order of 125dB at 2 meters. That's only 5dB off the SI 24" burst numbers being driven by 400V (20kW into an 8 ohm load!).

 

[shadyJ]

post 12 in this thread, and it is also mentioned in the Captivator thread somewhere. It is very high but not unthinkable. The Funk Audio subs also have very high sensitivity and extremely high motor force.

 

[Steve81]

post 12 in this thread, and it is also mentioned in the Captivator thread somewhere. It is very high but not unthinkable. The Funk Audio subs also have very high sensitivity and extremely high motor force.

That's for the Cap 1400 though. As noted here, the S1 driver is a completely different design. Either way, I agree that 97dB isn't unthinkable, but I'd want to see the bench results at DB to back it up.

 

[KEW]

The referenced post on Captivator efficiency quoted:

Actually, the Captivator driver is 97db/1w/1m on the topend which is why the Captivator 1400 was able to produce +121db, 2m, rms (+130db, 1m, peak) from 40hz and up with only a 1400 watt amplifier.

What does "on the top end" mean in this context? For the higher frequencies? For a sub would that be 40Hz and above (since that is his cut-off for the 121dB@2m spec.)?