I realize that the 20-39 plus is the match for the PB12 Plus box.
I also realize that it is NOT recommended to use two port bungs to lower the tune too much.

BUT

what's the difference between a 20-39 with two port bungs and a 16-46 with one port bung (both tuned to 12hz)?

does that mean the 16-46 plus is better than the PB12 Plus? (can go lower with more output)?


oh and btw, on the AVTALK test of the 20-39 at 12hz tune ... it was still going at 10hz, at what frequency does it start to fall off? will there be a difference in the 16-46?

The lower tuned subs, native or plugged lose some mid bass impact. There is really not much movie or music content below 20 Hz. If you have a real desire to dig deeper, but don't mind losing some mid level, then I would choose the 16-46. All else equal, I would take the 20-39 over the 16-46 for general listening. If needed, you can plug a port and tune it to 16. I had a 20-39 tuned to 16 and liked it just fine.

Ribbit, the 16-46 is currently the lowest tuned tuned enclosure SVS produces, and has the largest internal volume per driver.

Whereas the 20-39's have only one 3" port open in 12Hz tune, the 16-46 has two 3" ports open -- remembering that the output comes mostly from the ports below the tuning point, it's easy to see why the 16-46 has an advantage down deep.

Ultimate low end with useful output will depend on room factors as well; email techsupport@svsound.com with your particulars and I'm sure they can tell you :)

All other things being equal, I would recommend always going with the larger enclosure with the lower native tune. You may sacrifice a db or two in total output with the 46 but the driver will not be taxed as much at the lower freqs. In other words, the more ports open at the desired extension setting, the better.
If you have the room for the 46, then go for it. You can always add a second one at a later date if the output is not enough.

thanks guys!
you guys are right, I dont need a lot of SPL ...


I wonder why SVS didn't make a lower tuned box.

Vented subs need to be large to support large port areas at low tuning points -- many folks might not want to pay the freight charges or be able to find room for much larger enclosures.

As customer acceptance of larger cabinets has grown, SVS has lowered tuning points. The new PB12-NSD has as 18Hz tuning point compared to the 22Hz tune of the model it replaced. The new Ultra13 models will feature lower tuning points of 15Hz and 10Hz, as well as 20Hz and sealed.

If you get a 16-46 Plus, you may find that operation in it's native tune of 16Hz with all ports open, corner or right-beside-you located, will give you the best performance on most bass material -- in general, tunings below about 14Hz have few advantages on most material.

thanks guys!
you guys are right, I dont need a lot of SPL ...


I wonder why SVS didn't make a lower tuned box.

For most customers there really isn't any need for lower than 20 Hz. Remember that the tuned freqs are tested in anechoic chambers or outside. Actual in room extension is usually around 2 Hz lower. There is little movie and music content below 20 Hz so even with a 20 Hz tune, you are getting good extension to 17-18 Hz or so.
The answer is most customers don't need anything below 20 Hz, in fact 99% of the content is above 25 Hz.

The 16-46 cylinder size (both PCi and PC-Plus) is unique in the SVS line-up in that it is designed from the outset to play in the 13-17 Hz bandwidth more efficiently than any other model we offer. It is usually only recommended for customers who are interested in 32' pipe organ music, or for those who simply want to capture virtually all of the infrasonic bass present on DVDs even if it only occurs for a few seconds over the entire movie.

While the 20-39PC+ and the PB12-Plus can be retuned to 16 Hz, they do sacrifice some output capability in the process because retuning involves plugging one of the three ports. So the 20-39PC+ tuned to 16 Hz will not play quite as loud/clean in the 13-17 Hz region as would the larger 16-46PC+ with all three ports still open. Conversely, the 20-39PC+ in its native tune with all three ports open will play louder than the 16-46PC+ over the more common bass regions above ~20 Hz. There are output/extension trade-offs involved when you alter Fb (the system tuning frequency).

The upshot is that either the 20-39PC-Plus or the PB12-Plus configured for the 16 Hz tune will provide a good facsimile of a 16-46PC-Plus except at very loud playback levels, where the extra port area and larger enclosure volume of the 16-46PC-Plus allow it to play louder/cleaner in the 13-18 Hz region.

We don't recommend running the 20-39PC+ or the PB12-Plus in the 12 Hz tune at high volumes - the tuning frequency is so deep that the woofer must shoulder the entire load all the way down to about 14-15 Hz before the resonators (ports) start to assist in output. The same holds true for running the 16-46PC+ in the 12 Hz tune - while it retains dual 3" ports in the 12 Hz tune, it still has the same 12 Hz tuning point, and the woofer still must handle everything down to ~14-15 Hz before the ports begin to assist.

Since woofer excursion requirements quadruple with each successively deeper octave, you can appreciate that a single 12" woofer - even one as capable as the 12.3 - will eventually run into excursion related compression at high playback volumes if asked to handle all frequencies down to ~14-15 Hz.

To answer your specific question, the 12 Hz tune has a high pass filter which kicks in around 10 Hz, so that is about the limit of the quasi-anechoic extension in the 12 Hz tune. In-room extension into the single digits is possible with the 16-46PC+ in the 12 Hz tune - just don't push it to very high playback levels unless you are planning on duals.

In Ed We Trust!!

Are you looking to talk to whales?? Why not take a 20-39 for a drive and see how you like it first? On the other hand, if my wife hadn't put a size restriction on me I would probably have a couple 16-46s myself! LOL

I agree though about not actually needing that low of a frequency ... it's just one of those, I don't have it, gotta have it mentalities.

I already have up to 15hz+- which is why I want the frequencies below that.

hopefully, I get to play with some 20hz tuned SVS subs within the next few months.

I know if I had the money I'd have a 16-46+ right now OR I'd wait to see how the new Ultra-13 (both box and PC) handles the LOW bass compared to the 16-46+

The new Ultra PC will actually be a 46inch tall PC so I would venture to guess that it will actually OUTPERFORM the 16-46+ in every mode.....Bigger Woofer, Better Woofer, More Power...

I, much like you, crave that deepest realm of bass regardless of how RARE it is. We all know there are SOME movies that have that kind of bass, and I want that too :D

I'm waiting until the summer to hear some comparision storys about these mentioned models....16-46+, PB-13Ultra, and PC-13Ultra....should be a hell of a shoot out!