Dustin B

Ultra won't go lower. Same tuning. Just more porting and a significantly better driver. A single Ultra will come really close to matching the output of a pair of properly coupled CSi subs.

It will be tough to do a Tumult in a ported box. The port requirements are higher than you can fit in the box sizes that will work well with the Tumult. You pretty much have to either go sealed or passive radiator (pair of 18" passive radiators from Stryke will just barely fit the bill). The Tumult also isn't in production yet. We will hopefully see it soon though. None the less Dan Wiggin's has stated that it would take almost 3 Tempests to equal a Tumult, but in a much much smaller enclosure (think more bass than the dual Tempest of Mike Strassburg but in 6ft^3 instead of 16ft^3). XBL^2 has been proven in their Brahma series and Adire has an excellent track record. May take a while to get everything on the Tumult right, but when it is out, you can be pretty confident it will be one hell of a driver.

Am I missing where you have pictures? The basshorn was more for fun, few people who can DIY would actually attempt building something that complex. Acoustic Visions will do fully completed Tumults. No assembly required by you at all (athough fully assembled it might push your $1500 budget a bit, especially since it will require a kilowatt or more of power). Also at 6ft^3 might be a little bit larger than you would like. However it should easily dust everything you've listed above output wise and be no slouch in sound quality either. Especially with Adire's new XBL^2 motor topology. If the objective is to keep up in output with the LaScalas you can definately drop the Sunfire and Rel. Not a hope. The HGS15 will be pretty close in output to what you currently have so that drops it too. So that leaves the other three. RSW15 can't touch the Ultra or HGS18 in the last octave. Above 30hz they should all be pretty close in output though.

Doubt you'll be able to do or fit this, but it will definately be able to keep up with Lascalas. In fact your Lascalas may have problems keeping up with it. Only problem is doesn't have a lot for below 30hz output. http://www.prosoundweb.com/lsp If you can wait a while this should also be able to keep up. http://www.acoustic-visions.com/tumult.htm

Fire SVS an email with that information, plus how close to Dobly Reference level you want to get and they won't steer you wrong.

Twin Ultra's will have 6dB more clean headroom when properly coupled than a single Ultra. If you never pass what a single Ultra can do in your room, a second one doesn't gain you anything from an output level stand point. However, two won't have to work as hard to produce the same levels as one, so you will also reduce distortion at any particular level across the board. At lower levels this won't mean much, but as you approach the limits of a single Ultra it will start to mean a lot more.

Does it help to know that the lead designer and V in SVS is a Klipsch fan. He uses Klipsch speakers in his system, well except for the subs of course. The sub is the one place you don't have to worry about tonal matches of particular brands and models.

I got this funny feeling a couple Brahma 15 drivers would walk all over this thing at a fraction of the cost.

theEARs, reread my post. That is exactly what I said. A pair of RSW15 subs would easily go louder by about 4dB (outgun, go louder, understand) than a single Ultra. One RSW15 would be a couple dB behind (using the Secrets review a single Ultra would be 112 while a RSW15 would be 110 at just over 30hz). But at 20hz a single Ultra would easily go louder than a pair of RSW15 subs. Bass reflex cabinets do not fall off gently. A sealed enclosure will fall off at 12dB/octave. A ported one will fall off at 24dB/octave and a passive radiator enclosure (RSW and Sunfire) will fall off even faster than this (depending on the parameters of the PR and the allignment of the enclosure). The Ultra is tuned to 20hz, so it will start to fall off rapidly at that point, not at 16hz (well unless you plug one of the three ports but that will hinder output). This message has been edited by Dustin B on 09-25-2002 at 01:43 AM

Above 30hz a pair of RSW15s would easily outgun a single SVS Ultra. At 20hz you'd need somewhere between 3 and 4 (closer to 3) RSW15 subs to match a single Ultra.

Keep in mind he mentioned max extension mode for the 13-15hz extension. This means one of the three ports are plugged to drop the tune down to 16hz from 20hz. This will limit maximum output. With a 250W amp it likely won't be much of an issue, but if you get up to a 500W amp it likely will become an issue if the sub is pushed.

With the software programs available free today it isn't that hard. But you do need some specific information. Namely the T/S parameters of the driver and an accurate idea of what the net internal volume of the enclosure is. I can't find the T/S on Pioneer's site for that driver. If you figure out the box volume and can post the T/S parameters from the manual I could make a suggestion.

I'm still waiting for some pics of all these subs theEARs has I went from a piece of junk Pioneer HTIB, to a Paradigm PDR10, to a Tempest in a 260L enclosure tuned to just over 16hz with a 6" port powered by a 250W plate amp. So like Mike, I evolved pretty quickly

Part of the THX spec is that the front three speakers have to be identical, and they have to have a 2nd order roll off that is 3dB down at 80hz. This is to mate up properly with THX certified processors bass management. Which has a 4th order low pass on the sub output and a 2nd order high pass that when summed with the natural roll of the speaker results in a 4th order slope that matches the sub low pass filter. So a pair of 5" drivers covering this range should be fine. Although I don't think they will be able to reach full dolby reference level in larger rooms.

I'm assuming 8' ceilings. So that would be 1500ft^3. In a room that size a single Ultra will more than likely be plenty. You'll have to ask TomV if it will be capable of true reference in a room that size though. I imagine it could come damn close if not get there though. Also square rooms are pretty bad for bass. Your length and width modes will be identical and double up on you. You'll have a major spike around 40hz in that room.

Depends on the room. Keep in mind that with LFE and the other 5 channels <80hz material a sub technically needs to be capable of over 120dB peaks all the way down to 20hz at the listening position for true reference level. Now few movies require this at 20hz and only a few more have peaks of this magnitude in the sound track anywhere. If you haven't seen this round up before it shows maximum output measurements in a 3600ft^3 room from 12feet away of various sub setups. http://www.hometheaterhifi.com/volume_8_4/subwoofers-12-2001.html

The PC+ vs the PCi. PC+ has a 525W BASH amp PCi has a 320W BASH amp. PC+ has a continously variable phase control, PCi has a 0/180 switch PC+ has a 4 different rumble filters you can select from, PCi has one PC+ uses three 3" flared ports, PCi uses a single 4" flared port (gives PC+ 70% more port cross sectional area and is the same port configuration used in the Ultra and SS). PC+ uses the DB12 driver while the PCi uses the ISD driver. SVS says the DB12 and extra power will take the PC+ ~80% of the way to the performance of a Ultra Tom and Ron have said that the PC+ will set a new price performance standard (raising the bar even higher than the PCi did) and given what you are getting with what you are paying I believe them. Still won't match the DIY ratio, but not everybody can DIY. You won't be wasting any of your $200 by getting a PC+. I would say it's the step from the + series to the Ultra where you would start to notice a point of diminishing returns. A step from the PCi to PC+ you wouldn't.

Boa, I think you are confusing standing waves with multiple source constructive/destructive interference. When two or more speakers producing the same signal interact there will be contructive/destructive interference to some degree. If the same signals meet 180 degrees out of phase they will completely cancel each other. If the same signals meet exactly in phase then will double their amplitude. And in between there will be varing degrees of cancelation or summing. Standing waves can not occur between two sources. A standing wave happens when the wave length of a frequency being played (or a factor of its' wave length) match a room dimension. In this situation when the wave reflects of a bondary it will sum with itself (peak) or cancel itself (null). Also an 80hz crossover point with the RF7 would be fine. Crossovers aren't brick walls. It's a good thing for the speaker to have a flat response to an octave below the crossover point (at 80hz that would be down to 40hz). Unless you have THX certified speakers and processor (then the speaker has a built in 2nd order roll off that is supposed to sum with the 2nd order hp filter in the bass management that will then match the 4th order low pass filter on the sub). The names choosen for the settings were very bad choices given the male ego. If people could just get past the names and understand what was going on they would see that setting big towers to the "small" setting doesn't waste anything and allows you to get the most out of them. The rest of what you've said is pretty much right on. Putting two subs as close as possible together will result in a 6dB increase in headroom. Placing two subs in different places in the room will not get you anywhere near a 6dB increase in headroom. But if done correctly (and this is very difficult to get right) they can interact in a way that will reduce the effects of standing waves. Done wrong this can makes the overall response much worse. Personally though, I'd go for the 6dB increase in headroom, play with placement until I have minimized nulls and use a parametric EQ to tame any peaks.

Cutting a hole in a cylinder and leaving that hole open will severily compromise structural integrity. Putting something in that hole weaker than the cardboard will also compromise integrity (especially if it doesn't have a cylinder shape). But replacing that hole with something stronger than what was there? Come on Jonesey, think about that one for a minute.

Properly done, mounting a plate amp to a tube style sub will in no way compromise the integrity of the tube enough to affect performance. For a DIY example of how to do it right, check this link out: http://members.optushome.com.au/wcallen/Construction.htm I haven't seen pics of how SVS has actually done the mount. But given the standards I know Tom works towards, if the amp mount adversely affected the reliability or performance of his subs in any way he wouldn't be making them.

theEARs, will you give us some pictures at least then? Considering what you claim to own for subs I'm sure the few hundred it would take to buy an Olympus D520 camera would be a complete none issue. Or you could do some research and get a kick *** high rez camera for your personal use. Then you could snap a couple photos of this guys setup, and while you are at it put your Aerial SW12, Revel B15, Sunfire Signature, Velodyne HGS18 and Klipsch RSW10 all in the same room and snap a picture of them all. If you don't want to pay for some webspace I'm sure there are several of us on this forum willing to host the pictures for you (including me).

A single RSW15 could easily outgun a PC+ above 30hz, but will get dusted below 30hz. But considering you could buy a second PC+ for the cost of an RSW you'd end up with very comparable output above 30hz and really dust the RSW below 30hz. Sound wise you'll only know if you get a chance to hear them both. Which if you can get an in home demo from your dealer on the RSW and are willing to eat the return shipping on the SVS you can do.

Here is a more direct link: http://www.prosoundweb.com/community/forum.php?board=3 Also you may want to visit this thread on HTF. Mark Seaton has access to Tom Danley and a load of knowledge himself. He seems more than willing to help people out who want to attempt this project. http://www.hometheaterforum.com/htforum/showthread.php?s=&threadid=70277&highlight=lab12 This thread may interest you as well. http://www.hometheaterforum.com/htforum/showthread.php?s=&threadid=88398&highlight=lab12

You don't necessarily have to use a Klipsch amp. Parts Express an $80 plate amp that shoudl work well. Might take a little bit of time to figure out which rumble filter/boost setting to use (which will require some soldering as well). http://www.partsexpress.com/pe/showdetl.cfm?&User_ID=8160879&St=5815&St2=62857994&St3=30949877&DS_ID=3&Product_ID=9387&DID=7 Would be a little tricky to mount the new amp on unless they are the same size, but you could always just drill a hole or run the speaker wire through the port to the PE plate amp and just have it sit on the floor outside of the sub. $550 for a replacement amp in highway robbery. That's ridiculous. I'd wouldn't be surprised if the amp cost Klipsch less than $50 and I'd bet money it was less than $100. Given what $550 can buy you in new subs getting a new one becomes a no brainer if you don't like the idea of hacking in a PE amp.

Any one know what frequency the sound of a bubble bursting is