Dustin B

http://www.adireaudio.com/Files/VentedTempestApplications.PDF This outlines three different allignments for a vented Tempest. You can also look here for what I did: http://dustin.bunnyhug.net/sonostart.php Or another much better documented one would be from Patrick Sun: http://www.io.com/~patman/sunosub2.html Reguardless, what size sonotube you use is bounded by three considerations. It has to be large enough to fit the driver on the bottom (so nothing smaller than 18"). Can't be so wide that you can't fit it through your doors (so going over 28-30" would be a bad idea). And the the combination of the two shouldn't result in a height more than 6' (preferrably less than 5') or so short that there isn't enough room for the port to fit, in order to meet your gross volume requirement. All it takes is a little math to figure out how tall to make a particular diameter of sonotube. Pick a net volume you want to go with (personally I wouldn't go smaller than 220L and no larger than 340L). Use LspCAD to figure out how long the port needs to be to tune to what you want with that net volume (I'd recommend a 6" port with a 16-18hz tune). Then add 5L to the net volume, and the volume of the port (consider it a solid object). This is your gross volume. Use it along with some algebra and the volume of a cylinder equation to determine how tall your choosen tube diameter needs to be.

I really have no idea. Send TV an email and post his response.

Depends on what you mean by good amount of bass and how close you are to the Ultra in the room.

Look up concrete supply and contractors in your yellow pages. Phone around and see where the best deal is. There are some brands that aren't very stiff/rigid so you may end up having to check out several places in person. Also keep in mind a lot of places will only let you buy a full 12' length.

There is only one online retailer of SVS. And no stores. The only way to hear one besides eating the return shipping is to find someone local to you willing to demo (unless you deside to keep it). This site may or maynot help with that: http://www.audioenvy.com/default.asp

Without T/S for the drivers it's a craps shoot. You may get lucky, you may not. If you are willing to build several enclosures you will be more likely to find one that works well. The other thing you can do is measure the drivers yourself. I'm not versed on how to do this, but basic T/S parameters aren't hard to measure.

A passive radiator and port do the exact same thing. Just in slightly different ways, and the PR will roll off below tuning faster. You figure out how much weight to put on a PR to tune it to a particular frequency by calculating how much the air inside a similarly sized port would weigh. Take a port with the same cross sectional area as the Sd of the PR. Figure out how long it needs to be to tune to your desired tuning frequency. Then figure out how much the slug of air that would be contained in that port would weigh. This is how much the PR needs to weigh to tune to the same frequency. In smaller enclosures it is very difficult to fit ports with large enough cross sectional areas to prevent port noise and/or compression, they get way to long when you try to tune low. So PRs are a solution to this problem. I wrote this in another thread about what tuning actually means (for PRs, just replace port air speed with PR excursion). ------------------------------------------------------------------ Tuning refers to the resonance frequency of the port. It depends on the diameter/number of ports, how long they are and how much internal volume the sub has. As you approach the tuning frequency the port takes over the output taking strain off the driver and allowing the sub to play flatter lower. Maybe this picture will help (it reflects the Dharman). http://dustin.bunnyhug.net/pics/forum/dharman.jpg The bottom graph in the pic is cone excursion (how far the driver is traveling) and the top is output (solid black line is overall output, red dashed line is the ports output and the blue dot/dashed line is the drivers output). So where you tune is pretty important. If you tune higher you'll have more 30-60hz bass output but won't have much for extension. Tune lower and you'll loose some 30-60hz output but gain extension. This simplifies things a bit but is generally correct. The other thing with ports is how much cross sectional area they have. Producing bass, especially low (which is also where the port is working hardest) is mainly about moving air. But you can only move so much air through a port of a particular diameter before it starts compressing and or making noise. So the larger the ports diameter the more air can be moved before this happens (wide flares on the port can also help this). The catch is the larger the diameter, the longer the port has to be to tune to a particular frequency. And it isn't a linear relationship, ports start to needing to be really long as their diameter increases, getting longer than any box dimension really quickly. The enclosure size also effects this, the smaller the enclosure the longer a port will need to be to tune low. Enclosure size will also effect sensitivity (how much power is needed), especially down low. The bigger the enclosure the less power will be needed (but some other driver specs limit how big or small you can make the enclosure and still have decent sound). You'll want to read this to see how power relates to output. http://www.hometheaterforum.com/htf...7124#post517124 Every thing I've said also applies to passive radiator subs as well, as a passive radiator does the same thing as a port (just in a slightly different way). Sealed enclosures are different, with no port to take over output its all the driver. Avoid bandpass enclosures. ------------------------------------------------------------------

Then you want a bass horn. Will be rather tricky to build. But you won't have to worry about a pair of them keeping up with your LaScalas, you'll have to worry about your LaScalas keeping up. In fact one may be all you need. http://www.prosoundweb.com/lsp/ The driver designed for it is available from Parts Express. About $150 each I think. http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=290-570 A pair of these basshorns corner loaded should have a sensitivity around 107dB/W/m and could take up around 2 kilowatts each. So well over 130dB from 30hz on up would be possible. Mark Seaton has access to Tom Danley (guy who designed it) and knows a lot about it too. If you decide this is something you would like to persue I'm sure he'd be willing you help you get the project completed. Another option would be an infinite baffel. Throw 4-8 Tempests in an infinite baffel and you'll have some seriously nice sounding bass and some serious output too. This site has pretty much everything you wanted to know about IB subs (note the links at the top to pictures of installs and an FAQ): http://f20.parsimony.net/forum36475/ If neither of these appeal to you, then I'd say the Maelstrom would make the next best option. Send the guys at Adire an email and see what size box they recommend for the Maelstrom given your other speakers and available power.

The Maelstrom is a very nice higher efficiency 18" driver. 1000wpc is way way too much for this driver. You can get away with a 1/5th that much power. The only other issue is enclosure size. To keep efficiency up there and the Q down you will have to build a rather large enclosure. If you have, or can throw kilowatts at a sub, then you may want to consider the Tumult that should be available in a month or two. Preorder will start very soon ($350 on preorder). Almost twice the linear displacement of the Maelstrom and uses Adire's new XBL^2 motor topology, but has a very low senstivity. Also has a low Vas so it can work very well in tiny enclosures. Add a Linkwitz Transform circuit and you can have that tiny sub with a Q and F3 of whatever you want (although the more the LT modifies the response, the less overall output you'll be able to get). Either way a pair of these should be very impressive in tiny boxes.

Well, in a ~170L enclosure a pair of 15" PR would need to weigh ~1kg each to tune to 18hz. A single 18" PR would need to weigh ~1kg, and a pair of 18" PRs would need to weigh ~2kg each. The reason I like the idea of having PRs in pairs opposing each others is to cancel mechanical forces. Imagine 1kg flapping back and forth over a 3" distance 20x a second. That's some serious force. If you have the PR's opposing each other they are moving in opposite directions and will cancel out each others forces on the enclosure. The part of the driver that moves on the AV15 only weighs 1/4Kg. I'm still not sure on the 18" PR from Stryke. For a long time its' Vp was listed at just over 6L. It was listed like this when the HE15 was out, and it was listed like this when the Tumult was being talked about. Now all of a sudden its' Vp is up to 9L. The rule of thumb with PR enclosures is that the PRs should be able to displace at least twice what the active drivers can. Preferrably more than this. John J from Stryke has said the AV15 should produce very similar levels of bass to the HE15, just in a larger enclosure and with less power. The HE15 recommended design uses a pair of 18" PRs or three 15" PRs. So I don't see how the AV15 should have anything different. I also don't think 350W is enough power for the AV15. It is enough for an AV12 though. A pair of AV12 subs will outgun a single AV15. PS- Vp is the volume displaced by a stroke of the passive radiator. You calculate it by taking the radiating surface area of the passive radiator (Sp or Sd, means same thing) and multiplying it by the peak to peak Xmax (how far the cone can travel). You compare this to the Vd of the driver.

You'll find this educational I think: http://www.harman.com/wp/index.jsp?articleId=122 Adding polyfill to the subs won't help. Adding bass traps to your room will help. Changing seating and/or sub placement will help, but can also create other problems. Trying to EQ out a null is an exercise in futility. Nulls are like black holes. You can keep throwing more and more power at them, but you won't get anything back out.

Comparing power without knowing other specifics of the sub is useless. This setup is only being driven with ~300W (2ch pro amp) and yet it will be capable of truely silly output. While there are these tiny cube subs with kilowatt amps that can hardly approach it. http://t-3.cc/users/kloneaudio/page13-12Shiva1.html Without knowing the actual senstivity of the sub, you can't know what kind of SPL a certain amount of power will get you. However I am confindent in saying that the SVS will have a higher sensitivity than the KSW15 as the SVS is a smaller driver in a larger enclosure, while the KSW15 is a larger driver in a smaller enclosure (Hoffman's Iron Law). Damit, I don't want to retype how power relates to SPL and some idiot decided to get HTF Slashdotted this morning. I'll post a link to it later when I can access HTF again. But short explanation it takes a doubling of input power to cause a 3dB increase in output. So it will take twice as much power to get a 91dB/W/m speaker to the same level as a 94db/W/m speaker. Ignore the dynamic power number when comparing to other amps. The RMS one is 265W for the KSW15. Finally, 350W is more than enough power for the CS series. This is enough power to push that sub to its' limits and more power than this will gain you nothing when hooked to that sub.

Well if building the box doesn't scare you. And I assume you have the amplification already in place for the 12" drivers you were going to use. What would that amplification be anyways? There are several drivers in the $100-$400 range designed for home use that in a well built enclosure will easily be able to compete if not vastly surpass the RSW12. Let me know how you were going to power the 12" drivers (8 and 4 ohm wattage values as well as how many channels would be useful) and then I'll tell you what drivers I think would work best with the available power. If you don't mind large enclosures, even if you buy the amplification and the driver, you can complete a sub for ~$400 that should easily compete with the RSW12 (it will even destroy the RSW12 in the last octave).

What are these two 12" drivers? Without proper T/S parameters it's very difficult to determine what should be built for the enclosure. A passive radiator does the exact same thing a port does. Just in a different way. In general the only reason to go with a passive radiator is when the driver is designed to work in an enclosure that is too small to fit sufficient porting in. How much porting is required is dependant on how much volume the driver can displace. What the passive radiator or port will gain you is delaying roll off. You can maintain the subs' output level to a lower frequency before it falls off. The trade off is once it starts to fall off, it will fall off twice as fast as the sealed enclosure (when a port is used; PRs fall off even a little faster).

There are 15" drivers that do just fine acting as midbass units up to almost 3000hz. The speed difference (if it even really exists) down below 100hz won't matter. Put the BP1203 and BP1803 in the same Q sealed cabinet and I'm positive you couldn't tell them appart (as long as you weren't exceeding the 1203's output limits). It's my understanding that break up modes are the issue, not "speed" of larger drivers as frequency increases.

"What is obvious is the same voice coil used in the 12,15 and 18!As well as identical magnetic structures.The cone acceleration is faster on the 12" and a bit slower on the 18"." People significantly more knowledgable than I say this isn't the case. The 1803 has oodles of motor strength to keep that 18" cone in check. Don't forget that the 18" cone will have to move a much smaller distance than a 12" cone to displace the same amount of air. In the case of the BP 03 series the 12" will have to travel 2.35x as far to displace the same amount of air as the 18". I think it's the 130" around size limits as well as the weight limits on UPS shipping that prevent SVS from going to 15 or 18 inch drivers rather than the 12" being superior. The big hiccup with the BP 03 series and the Stryke HE15 is they have a very high inductance that results in a hump around 70hz in the subs response. You have to EQ this hump out. But since really every sub should have an EQ to tame room problems this isn't a big deal. Well unless you can go nuts with room treat-ments (well that's a lame language filter, remove the - and it will * out form the e to the e) and manage to solve all room interaction problems that way.

At a certain point dumping more power into the sub does you no good. Usually for one of two reasons. The first is the power being applied is pushing the driver past its' linear excursion limits. The second is the power you are applying is going past thermal limits; voice coils get too hot and badly change the drivers parameters making it sound bad, or they melt and you've pouched the driver. If more than 500W per sub was required to reach the clean output limits of the Ultra, I'm positive Tom would be offering it with a more powerful amp. Throwing more power at them won't gain you anything. I'm not sure what the S2000 goes for, but have you considered the Crown K1? Better amp than the S1000, 50W more per channel, no fans, and completely happy pushing 2ohm loads all day.

Venting the Tumult will be difficult. It has been designed to work best in smaller enlcosures with lots of power. You won't be able to fit adequate porting in a properly sized enclosure. So if you do build one and want to go bass reflex I'd suggest sticking with a passive radiator design. If you want everything under the sun, then I'd also suggest looking into building a folded bass horn like the ProSound Lab12 (won't use the Tumult for this though). And look into dipole sub design as well (with some EQ the Tumult could be excellent for this as well). Along with a Linkwitz transform sealed cab, the IB and a PR design. Don't even have to buy drivers and amps for them all, can just swap those between enclosures.

Well I don't think you can do a Tumult properly for under a grand (a little over a grand yes). But it will definately be interesting. The currently available HE15 and Blueprint 1503 and 1803 are also very interesting. I have a 260L Tempest tuned to 16hz with a 6" port and a 250W plate amp. By DIY standards I also built two rather tame identical subs for my roommate and parents. 120L Dayton DVC12" subs tuned to 20hz with 4" flared ports and powered by 160W plate amps. Should still give a PW2200 a run for it's money though and only cost ~$300 each. And my Tempest causes me to laugh every time I go into a stereo store and see the prices on their subs You know what I think you need theEARs. Eight Tumults (mmmm, 40L of Vd; or over 10x what a Revel B15 has ) in an infinite baffel config, powered by two Crown K2 amps with a custom linkwitz transform designed to result in a critically damped 0.5Q and flat in room response to below 16hz. Would run you over $6000 but you'd never have to try another sub again

Given the amp you have I'd be inclined to do two AV12 subs (each in a 3ft^3 enclosure with two of the 15" passive radiators, tuned around 18hz). 350W isn't enough power to push the AV15 to it's limits (should have 500+). So if you want one sub I'd go with the AV15 and give it all 700W from the amp. But I'd use a pair of 18" PRs, you can never have enough PR Vp (although a pair of the 15" ones would just cut it). Also you really want them in pairs symetrically mounted to cancel their forces on the enclosure. Having 0.5 to 2 kilograms flapping back and forth 20 times a second can generate some serious rocking forces. But two of the AV12 subs (3ft^3 enclosure with pair of 15" PRs) stacked should outgun a single AV15, and 350W per AV12 should be enough to push them to their limits. PS- is the amp stable bridged into 4ohms? The AV15 is a 4ohm driver.

No friends with the tools? Dual Tempest sonotube sub really only requires a router and drill. That could be tough then. Not much for unpowered subs in that price range that will kick *** to 30hz and below. You could see about getting one of these places to build you an enclosure, cut you a flat kit, or cut you endcaps and base plate for a sonotube sub. http://www.acoustic-visions.com/ or http://www.rutledgeaudiodesign.com In particular you may find this page at A.V. interesting: http://www.acoustic-visions.com/strykeavseries.htm Say two AV12 drivers, four 15" passive radiators and two of the 3ft^3 PR boxes.

Can you build? Two Tempests in ~500L tuned to 16-18hz with a pair of 6" ports and that amp would be very impressive (this is one box, not two). This wouldn't go as low as the first option, but K-Horns might have problems keeping up with it. It would also be rather difficult to build. http://www.prosoundweb.com/lsp/

What was the room like (dimensions)? Where were the speakers and sub placed?

Strong vote for Hsu VTF2 if you can't go over $500 (unless you can DIY). It will sound better, output is close if not better and extension is better (I don't think the KSW15 is quite as good as the KSW300 was). Nousaine test data (25-63hz 1/3octave spacing max output average, followed by max output at a the stated frequency, followed by the average with the 63hz value dropped) KLIPSCH KSW300 - 109dB / 25hz~92dB (107.25) HSU RESEARCH VTF-2 - 107.1 / 20hz~93dB(106)

Sound quality is a some what subjective matter and very dependant on room placement and integration with the rest of the system. I'll take your word for its' superiority to all other subs on sound quality (although personally I'd take an IB or Dipole sub over it without hesitation). Output wise the SW12 could not compete with the Ultra. The PC+ it might come close to, but the Ultra not likely. You can only move so much air through a single flared 4" port. Doesn't matter what tricks you play with the amp, can't cheat physics.