meuge Posted January 6, 2005 Author Share Posted January 6, 2005 Actually the extension is just fine. The VTF-2 that I used to own was supposed to be flat down to 25Hz, but in my room at 25Hz it was GONE. It rolled off like crazy after 31Hz or so. This sub goes substantially deeper. So while the numbers may not be impressive, they need to be understood in relative terms, rather than absolute. Furthermore, being a sealed subwoofer, and a fairly small one (relatively speaking), it will not the same extension as a ported one. Quote Link to comment Share on other sites More sharing options...
DrWho Posted January 6, 2005 Share Posted January 6, 2005 ---------------- On 1/6/2005 8:47:27 AM meuge wrote: Furthermore, being a sealed subwoofer, and a fairly small one (relatively speaking), it will not the same extension as a ported one. ---------------- Yikes! Is it actually a sealed subwoofer? I just modelled the differences and you could get an additional 4dB of output at 20 Hz simply by adding a .5" x 18" x 15" port. In the meantime, the port will greatly reduce cone excursion (an average of 10mm). The only sacrifice would be a 10ms increase in group delay (which is basically nothing). Quote Link to comment Share on other sites More sharing options...
Colin Posted January 6, 2005 Share Posted January 6, 2005 so DR, do we have actual specs yet? Quote Link to comment Share on other sites More sharing options...
meuge Posted January 6, 2005 Author Share Posted January 6, 2005 ---------------- On 1/6/2005 7:00:37 PM DrWho wrote: Yikes! Is it actually a sealed subwoofer? I just modelled the differences and you could get an additional 4dB of output at 20 Hz simply by adding a .5" x 18" x 15" port. In the meantime, the port will greatly reduce cone excursion (an average of 10mm). The only sacrifice would be a 10ms increase in group delay (which is basically nothing). ---------------- The thing is I don't need this extra output. I don't like port noise, and I enjoy the speed of the subwoofer the way it is right now. I played with some test tones and it seems as if my room doesn't like frequencies below 20Hz anyway, because the room starts shaking, and the sound is significantly blurred. I was interested in 2 things only when I got this sub: 1) 25-40Hz frequency range 2) tight, powerful, musical punch This sub satisfied both of the requirements, so I am not nearly as concerned about the extension. As for cone excursion, I haven't really seen the cone move much, so I haven't been pushing the sub much, and I doubt that will be a factor. Quote Link to comment Share on other sites More sharing options...
Scp53 Posted January 6, 2005 Share Posted January 6, 2005 xcjago said- Well I guess it's quote "musical" but I'm not very impressed by the extension. Especially for a 15 incher. ------------------------------------------------------------------ xcjago, this extension is just as impressive as the rsw15- and thats a 15" driver. hell, that even has a passive readiator and it only plays down to around 20-25hz and drops sharp after that(from what ive heard about on the forum). for a sealed 15" i think its freq response is pretty impressive(im talking about the titanic). if thats the only "bad thing" then its a d@m good sub imo. scp53 Quote Link to comment Share on other sites More sharing options...
tpg Posted January 6, 2005 Share Posted January 6, 2005 The sharp roll-off of the RSW line is because of the PR. PR designs roll-off at 18dB/octave, if I remember correctly. Most sealed designs won't play flat down to 20Hz at full power/full output. Believe me, I've been trying to make it work out. I am trying to find a driver that'll give me a fairly high (at least 105dB sustained) SPL that is flat (anechoic) from ~120Hz to 20Hz (and I mean flat as in +/-0.5dB MAX). In short, it isn't happening without the aid of a Linkwitz transform circuit, and even then it'll be limited on actual SPL to remain linear. Best I've gotten so far was 107dB flat from 19Hz-120Hz +/-0.6dB with about 100W RMS of power. I'm a poor carpenter, though, so I'm contemplating if I can actually build this thing right before I sink any money in it... If you suddenly decide you want more extension, just throw an Linkwitz transform on that thing. It'll get you lower with no trouble. EDIT: BTW- SPL at 20Hz is pretty much a moot point. According to the Fletcher-Munson curves, 105dB at 20Hz sounds about the same as 70dB at 1kHz. I will say this, though... even though I know this, I still want the next sub I build to be flat to 20Hz anyway. Quote Link to comment Share on other sites More sharing options...
meuge Posted January 6, 2005 Author Share Posted January 6, 2005 I've written this in another thread some time ago. The lowest note on the piano is the A0, which is ~27.5Hz. In my experience ,it is very difficult to tell the pitch of musical notes apart at that frequency range. Furthermore, the lowest note on a string bass or the bass guitar is the E1, which is around 41Hz. The only instruments that needs good reproduction below 20Hz are the largest organs, where the largest tubes boom all the way down to 16Hz or so. Most low-frequency output below 25Hz is only necessary for HT. Since the goal of my system is 95% music reproduction, I simply don't consider anything below 25Hz important. Also, something that I have noted about the system -> my placement is WAAAY off perfect. By the entrance to my room I can hear the most beautiful bass, which is the better than any bass I've ever heard. At some point I'll have to place the sub onto my couch and figure out whether I can place the sub elsewhere. Unfortunately there are only 2 other places where I could possibly place the sub without totally destroying any kind of decor in my room. Quote Link to comment Share on other sites More sharing options...
xcjago Posted January 7, 2005 Share Posted January 7, 2005 ---------------- 105dB at 20Hz sounds about the same as 70dB at 1kHz. ---------------- Ya, but it doesn't FEEL the same. But it's true about <25hz bass. There's not much of it in music. But there is quite a bit in movies. Quote Link to comment Share on other sites More sharing options...
tpg Posted January 7, 2005 Share Posted January 7, 2005 I thought I heard somewhere that a contra bassoon or something like that went down to the sub-20Hz level (around 14Hz maybe?). Not sure about that... As far as placement and room acoustics go... I fully agree with you. My room absolutely sucks. I've had subs in several different locations and stillg et next to nothing from them. My room eats bass like it's going out of style. However, if you leave my room and walk all the way down the hall and go into the bathroom, the bass is very loud. I am also very limited on space, so I really don't have many options for placement. So I just have to be happy with what I get... Quote Link to comment Share on other sites More sharing options...
Scp53 Posted January 7, 2005 Share Posted January 7, 2005 tpg, i have a bass sucking room too. i really should get an eq to tune down the "spikes"(a crossover setting can only do so much). scp53 Quote Link to comment Share on other sites More sharing options...
rtaylor Posted January 8, 2005 Share Posted January 8, 2005 ---------------- On 1/7/2005 7:18:55 PM tpg wrote: I thought I heard somewhere that a contra bassoon or something like that went down to the sub-20Hz level (around 14Hz maybe?). Not sure about that... As far as placement and room acoustics go... I fully agree with you. My room absolutely sucks. I've had subs in several different locations and stillg et next to nothing from them. My room eats bass like it's going out of style. However, if you leave my room and walk all the way down the hall and go into the bathroom, the bass is very loud. I am also very limited on space, so I really don't have many options for placement. So I just have to be happy with what I get... ---------------- TPG, my suggestion would be to put your subs in your bathroom,preferably under the tub for the relaxation vibes. Then they would sound great in your listening room!! Weird isn't it, in my hallway the lascala's sound the best on piano? Randy Quote Link to comment Share on other sites More sharing options...
psypathic Posted January 9, 2005 Share Posted January 9, 2005 I've owned my titanic 15 for around a year. I'm also running it with RF-7s with rebuilt networks. I think it sounds great. Quote Link to comment Share on other sites More sharing options...
Champagne taste beer budget Posted January 10, 2005 Share Posted January 10, 2005 tgp and Scp53, you both sound like good canidates to get thine hinney down to the Architectural forum and study up on bass traps. You may already have em, or know all about em, if so I apologize. (It's counterintuitive, when you suck up the bass in the corners, it gets louder in the middle of the room. Really!) Quote Link to comment Share on other sites More sharing options...
meuge Posted January 10, 2005 Author Share Posted January 10, 2005 Unfortunately for me, and perhaps for them as well, bass traps are not really an option, not really because of their price (although that's important as well), but because any bass traps that work in the lower bass range (under 50Hz) are huge. Quote Link to comment Share on other sites More sharing options...
Scp53 Posted January 10, 2005 Share Posted January 10, 2005 so the bass does get better in the middle of the room if bass traps are used? i guess i better go to the arch part of the forum. i m not well informed on acoustics as you can see. meuge, wont the parametric eq on the sub fix a lot for your room? would you really need bass traps? scp53 Quote Link to comment Share on other sites More sharing options...
meuge Posted January 10, 2005 Author Share Posted January 10, 2005 Well, it's single-band equalizer, so it's quite limited in what it can do. Because of the size of my room, and the loss in the middle, I had to use it in order to boost the low frequencies to achieve better bass extension. Also, no equalizer can ever perfectly correct a problem with acoustics. The more you equalize the 'dirtier' the sound gets. Anything that requires more than 1 band of parametric equalization is likely to be a much more complex waveform that cannot be corrected so simply, while still retaining its sonic information. If there is space, I would recommend using bass traps. Unfortunately they really must be quite large, or better yet, occupy the space within the walls. Quote Link to comment Share on other sites More sharing options...
Scp53 Posted January 10, 2005 Share Posted January 10, 2005 i agree with the "dirtier" thing. so is the BEST way to fix a frq response problems to use acoustics? where should i look for bass traps,etc. i guess these are Q's for the arch area of the board. scp53 Quote Link to comment Share on other sites More sharing options...
tpg Posted January 10, 2005 Share Posted January 10, 2005 I doubt I'll be able to pull off putting bass traps in my room. I have a fairly large room, but with everything I have packed in here, I am very limited on room and placement of objects. I have thought about treating my room several times, but I think this place is a lost cause. I need a dedicated room for that. Quote Link to comment Share on other sites More sharing options...
Mystro Posted January 12, 2005 Share Posted January 12, 2005 Great Review I have been looking at the Dayton Titanic 12" and 15" kit for sometime now. And I too like the tight, powerful, musical punch in a subwoofer. But also like a sub w/ really good extension (that a ported sub provides). Here is my newbie question: What acoustical flaws (don't know if that is the right word for it) would I get if I paired the Titanic kit w/ another sub like the SVS 16-46? Would I get the best of both world (so to speak) or is that an acoustical nightmare? What would you guys recommend? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
DrWho Posted January 12, 2005 Share Posted January 12, 2005 ---------------- On 1/12/2005 6:36:56 AM Mystro wrote: Here is my newbie question: What acoustical flaws (don't know if that is the right word for it) would I get if I paired the Titanic kit w/ another sub like the SVS 16-46? Would I get the best of both world (so to speak) or is that an acoustical nightmare? What would you guys recommend? ---------------- I think you could get more bang for the buck if you went with a single better sub than splitting the funds for two lesser subs. Quote Link to comment Share on other sites More sharing options...
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