Dustin B

There is absolutely no difference between a well built tube and a well built box sub with the same allignment (ie same net internal volume, same port(s)/tuning, same driver and same power). The only difference is the box is heavier and more expensive to make. The PB1 is essentially a 25-31PCi tuned to 22hz. Any minor parts cost advantage some of the major manufactures have by making their own stuff (although SVS isn't very far off that type of margin I'm sure) goes flying out the window when compared to the costs of maintaining a dealer network vs internet direct.

With the exception that there should be a least a port diameter (as the rule of thumb) between the port opening and the nearest surface, placement doesn't matter. What does matter is the air speed in the port. The more air the driver can move the higher the air speed gets, and the larger the diameter of the port the lower the air speed gets. If the air speed gets to high first you get compression (which makes it so more power is required than normal to increase the volume) and if it gets to high you get audible chuffing. Flared ports can reach higher air speeds before compression or port noise set in than straight ports. The second thing that matters is the tuning. This will greatly affect how the sub sounds and what kind of extension it will get. It's rare to find a commercial sub that is tuned well below 30hz. Most are tuned in the high 20hz to mid 30hz range. Also of note is that a port and a passive radiator do the exact same thing, just in slightly different ways.

I don't understand this comparing a dual Ultra setup to a single RSW15. A single Ultra will have no problem keeping up with a RSW15 above 30hz and easily outgun it below 30hz. $900 for an Ultra, $300 for a QSCRMX850, another $50-$75 for shipping. Total is ~$1250 to your door. Dual 20-39CS+ subs with 1000W amp are ~$1600 to your door and will easily outgun both a single Ultra and single RSW15 above and below 30hz. I'll also contend that the reason some of you like the RSW15 so much for music is the lack of below 30hz output, so don't go upgrading to an Ultra or PC+ as you likely won't like the really low bass.

Adire Allignment EBS, notice the extended bass shelf in the repsonse

Mr. Watkins did an excellent job of explaining what is also my position. Don't know where you got the idea we where saying the VTF3 wasn't better than the VTF2. I'll also add I don't share the Ear's opinion (a little abrasive and over the top in the claims in my opinion). Hsu does not use sub standard parts or construction and makes an excellent product. Comparing the VTF3 to a PC+ is like comparing a PCi to a PC+. All use excellent parts and construction, one is just a little more capable. Arguing the Hsu finish is ugly is like arguing the SVS finish it ugly (espcecially since the new SVS box subs are using the same style finish as Hsu). They are basic, understated and durable. I do believe Hsu is coming out with a much more attractive version with some nice wood detailing soon though. And in the Aerial price range SVS has some very nice wood finishes as well.

Ok James, I give. I'll take your hear say word over physics. Hsu isn't just good, it destroys all.

"No matter what the tune" If you don't understand this very simple concept of sub design and why it is very important to output this converstation is hopeless. With a 32hz tuning point the VTF2 will not be flat to below 20hz at higher output levels at all (there is a big difference between being flat with some boost to 20hz at 75dB and being flat to 20hz with some boost at over 100dB). If you get Nousaines 3rd octave results and average the 20hz to 50hz instead of the 25hz to 63hz the VTF2 will suddenly have a lower average than the Dharman (16-50 would widen the difference). Darn tune, how'd it do that. Hmm, I wonder why guys in car SPL competitions tune their subs so high and guys in sound quality competitions tune their subs so low. Why would they do that James, tune doesn't matter right? But the VTF2 is in a different price range and for that price range it is IMO the best option out there (next to DIY of course, but few people can actually DIY for various reasons). In the VTF3's price range, IMO there are equivalent options that cost less and better options that cost the same. This conversation is very reminant of conversations with BobA. He keeps flopping between the importance of lower output level flat frequency response and maximum output without reguard to frequency response (pluggin ports and modifing boosts has trade offs plain and simple, they will in the Dharman and the PC+ series as well). He also loves using max output and max extension modes as if they can be magically changed to give the sub the benefits of both modes without any trades offs. Quoting averaged max output from max output mode with the frequency response of max extension mode in the same sentence. Just like you are James.

In max output mode the VTF2 is tuned to 32hz. In max output mode, the Dharman is tuned to 22hz. You can't just flip a VTF2 back and forth from max output mode to max extension mode (and even in max extension mode the VTF2 won't go lower than a Dharman in max output mode) during a movie rapidly. You have to decide, do you want output above 30hz comparable to a Dharman, or do you want to come closer to matching it's extension.

http://www.stryke.com/prfaq.htm Bottom line is a passive radiator is just a different method for achieving the same end result as a port does. That being a bass reflex alignment. Some claim PR subs have an inferior transient response in comparison to a ported system which has an inferior transient response to a sealed system. Done properly though, all three can have excellent sound quality or done incorrectly all three can have very poor sound quality. Doing it right usually involves tuning the port or PR very low to push the rise in group delay that comes with a bass reflex system to a frequency range where it isn't really audible.

I'm not saying the VTF3 isn't a great sub, I wouldn't complain if I had one. Which one produces the better quality bass I won't say (although I doubt you or I could actually tell them appart in a blind comparison both properly setup). But output wise, there is no way a VTF3 will outgun a PC+ (and if Nousaine ever gets around to both his numbers will proof that). If it can, everything I know about sub design has to go out the window. You can't cheat Hoffman's iron law. The sub with the larger enclosure, with more vent cross sectional area, with more Vd and more power will always produce more bass. The Dharman is so similar to the VTF3. Similarily capable driver, both have twin 3" flared ports, both are tuned to 22hz, both have 250W amps. But the Dharman is around 20L larger and is $160 cheaper ($250 at the VTF3's normal price). But you are right that power doesn't mean more bass (but a watt is a watt), you have to consider the rest of the variables listed above. Which is why my 250W Tempest (9ft^3 enclosure, 6" port and 0.5-1L more Vd) will easily take both the VTF3 of PC+ in output. Sounds exceptional too, which is a nice plus

I see it competing with the Dharman and SVS PCi but not the PC+. PC+ has too much of a power (twice the power), size (25-31 roughly same size, 20-39 is larger) and venting advantage (50% more vent area). And given that the Dharman is $599 and the PCi are $550, $600 and $650 I stand by my statment.

Hsu has many advocates at avsforum.com. Hsu definately belongs in the same category as SVS and Adire. The VTF2 is almost impossible to beat at its price point. The TN series are a good value, but I think the VTF3 is priced a little high (when compared to equivalent subs from SVS or Adire).

Just about any driver is compatible Box will depend on what driver you choose. What drivers would make the best use of this amp. Stryke AV12 or AV15, Adire Tempest, Dayton Titanic would be the best choices I'd think.

That's a 50L sealed enclosure for a Tumult. The Tumult is designed for much smaller enclosures than the Tempest and pays for it by requiring significantly more power. Feed it that power though and with the XBL^2 motor and ridiculous excursion abilities, the end result will be very impressive. Sealed I woldn't go smaller than 120L for a Tempest and ported I wouldn't go smaller than 200L for a Tempest, with 260-320L being a better option. The Tumult has too much Vd to port in an enclosure of appropriate size for it. Although you could go up to 160L and a pair of 18" PRs as I said above for the Tumult.

There are any number of QSC, Crown, Crest etc pro amps that will put out the 1.5-2 kW the Tumult could use. Some for not much more than $500. Tumult in 160L with a pair of dual spider 18" PRs from stryke tuned to 16-18hz and 1.5kW. Dual Tumults in roughly twice that volume with 4 dual spider 18" PRs from stryke tuned to 16-18hz with 2.5-3kW. 2-4 Tumults in an inifnite baffle each getting about 300W. A single Tumult in about 80L with an LT transform circuit and 1.5-2kW.

Dan Wiggins has even stated that when a Tumult it pushed towards its limits, it would take 3 Tempests (well not quite, but you can't acutally use 3/4 of a Tempest ) to equal the output of a Tumult at the same THD levels.

I forget what the voltages are, but pro stuff uses a much higher voltage than the home stuff. The result is some home stuff can't provide a hot enough signal to get the Sampson to put out properly. Some searches on avsforum.com and hometheaterforum.com will bring up more specifics.

Oops, should have also clarified. US or CDN funds? If that was US, way too much, CDN, great deal. If it was US funds I'd seriously look at the Adire Dharman or the SVS 20-39PCi. There will also soon be a box style SVS that will be a chunk cheaper than $695. All of these will easily outperform a PW2200. But if you are in Canada the PW2200 does have a significant price advantage over the other three and becomes a very viable option as a result.

What price can you get it for?

Bass wavelengths are just too long. Doesn't matter what direction they are shot in, or what block of stone/concrete/wood you set the sub on, the sub will annoy the neighbors. It's the air pressure that is rattling things, not the sub directly. And with air pressure waves measured in 12-72ft lengths for bass frequencies, unless your entire floor is several inch thick concrete the sound will be transmitted. The construction techniques needed to sound proof a room to bass frequencies are quite complex and expensive and definately not an option for an appartment dweller. They involve decoupling surfaces from each other and making things air tight. The only thing you can really do in an appartment is turn it down or off. If you want more details on what is required to sound proof a room check this link out. http://www.acoustics101.com/

$2499 with the basic finish was the last I heard, more for different woods or colors. This doesn't include the amp though.

You could only get 2.5 Sadharas or 2.75 Ultras for the cost of a B4 though.

Just some clarification for some possible confusion from these quotes. The Sadhara is a modified version of the 12" Brahma. It will have about the same displacement ability as the Tempest, but at lower distortion levels and with less compression when at it's limits. It is a finished tube within a tube style passive sub that is 18" in diameter and will sell for $995. The reason for the tube within a tube is to allow a slot port (by the way, a 6" port is 15.2cm). The top has no holes, all sound exits the bottom. The Tumult is a raw stand alone 15" driver with 7mm more Xmax than the Brahma and twice the Vd of a Tempest. It has a fairly low sensitivity and is designed for use in smaller sealed boxes with a Linkwitz Transform circuit and lots of power (PR enclosure is possible also and if you don't wish to use its full potential porting is possible too). To achieve the same distortion levels at higher output levels in similar allignments would require 3 Tempests.

Stay far away from the PS series from Paradigm. Bandpass yuckyness. Also that is too much for that sub. For that price you should be able to get the Paradigm PW2200 which actually is a good sub. With some hunting you may also find a Mirage BPS400 in the $800CDN price range. The CHT10 is a little gutless for my taste, especially at that price as well. Paradigm PDR10 should come close to keeping up and I bought one a few years ago for $350CDN. Anyways, what I feel is by far the best you can do for $700 CDN is to buy this: http://www.creativesound.ca/details.php?model=Tempest and this: http://www.creativesound.ca/details.php?model=AVA250 Then build this: Doesn't have to look like that though. Here's my site where I detail its construction: http://dustin.bunnyhug.net/sonostart.php. And this site shows many more examples using a number of different drivers (but for your budget the Tempest is easily the best choice): http://members.tripod.com/~terryctheater/shivaphotoalbum/page12.html This thing will play much lower than any commercial sub at 2-3x its price point (being tuned to 16hz with a 6" port will do that; SVS being the exception) dust a PW2200 in extension, output and sound quality and make someone who payed $790 for a PS1200 cry.

You just have to get off letting the bad naming choices bruise your male ego of small equals bad. Setting either of those speakers to small in no way wastes them. Ideally a speaker should have flat response to an octave below the crossover, or in the case of an 80hz crossover 40hz. And in both the Klipschorn and KLF30 it's around 40hz where they will start to trail off when pushed. Little bookshelves on the other hand will start to trail off up around 80hz.