DrWho Posted December 11, 2004 Share Posted December 11, 2004 Well I've been very busy plugging away and researching subwoofer drivers and all that (I had a post a while back with lots of good info from fellow members on the board) and I came to a realization the other day...A single driver in a cabinet is actually better than using two drivers in the same sized cabinet. Using two drivers in a cabinet twice the size has the same response of the single driver, but 6dB more output. I guess it really is totally obvious when you think about it because both drivers are fighting for the same air inside the cabinet. After coming to this realization, I've got me a 354L cabinet instead of a 400L one (It comes down to exact internal dimensions of 36"x24"x25" and I plan on using 1" thick wood). Using a 15" Adire Audio Tempest ($150) tuned to 20Hz gets me flat at 115dB to 20Hz. I've been looking at drivers in the $100-$300 range and the Tempest seems to be the best out there. In fact, the only better driver I found was the North Leviathan which costs $800 (http://www.northcreekmusic.com/Leviathan/LeviathanFAQ.htm). The Dayton 15" Titanic MKIII Sub is $190 and goes flat at 116dB to 20Hz. Does $50 justify a 1dB difference? They're both -3dB at 18Hz. Are there other drivers out there that I could be looking at? Quote Link to comment Share on other sites More sharing options...
prodj101 Posted December 11, 2004 Share Posted December 11, 2004 Are you on drugs? Have you heard of the Adire Audio Tumult? That will squash your Tempest to bits for a good deal less than $800. The 15 inch model Blueprint offers would also probably be more than competitive at $250 (about 9 mm more excursion). Quote Link to comment Share on other sites More sharing options...
TheEAR Posted December 12, 2004 Share Posted December 12, 2004 The Tempest is a great driver for the price,but please there are many drivers with more displacement ...for under $800.Do the research a bit ,will ya. The Tumult,the 15" Blueprint and more will outdo the Tempest. The Tempest is the best cheapo stapled steel backet woofer with very good displacement.Its no world beater And far from the best Quote Link to comment Share on other sites More sharing options...
formica Posted December 12, 2004 Share Posted December 12, 2004 ---------------- On 12/11/2004 11:17:00 PM DrWho wrote: I've been looking at drivers in the $100-$300 range and the Tempest seems to be the best out there. ---------------- Guys, you have to read sloowwwer... budget is tight with 100$ preferred and 300$ as a max. I remember you already have an amp... I don't recall how much power but I remember you'd have some to spare with the Tempest. I like the Tempest, it's a no frills Subwoofer driver, which sacrifices enclosure size for efficiency and extension. Seeing that you are willing to go a little higher... the other two drivers which jump to mind are: - Acoustic Elegance (Stryke) AV15 which should be available around x-mass. Compared to the Tempest, it offers a slighty smaller enclosure but with slightly less efficiency. It will also play louder given both it and the Tempest are excursion limited in a vented enclosure. They also have a beautiful cast frame but a little cheesy (my opinion) aluminium cone. - The PartsExpress TitanicMkIII drivers used to be similar to the AV15 but if I recall the enclosure was a little smaller still, but it traded some bass extension for it. I haven't modeled the new T/S they have. Cast frame and pulp cone... very nice looking. - The PartsExpress DVC woofers aim the Tempest and have almost identical TS parameters. Stamped frame and pulp cone. I find the blueprint 15" driver's TS parameters quirky... model it for yourself and you'll see what I mean. The BP-18" models much better but is no longer available. The are also the Lambda drivers, which the remaining stock was bought out and is being offered by Acoustic Elegance (Stryke). You will have to look up the old PB series drivers... performance was good but enclosure size was large and maximum excursion wasn't as high as the AV15s. Later... Rob Quote Link to comment Share on other sites More sharing options...
edwinr Posted December 12, 2004 Share Posted December 12, 2004 Rather than worry about two drivers in one cabinet, I would be more interested in two drivers in separate cabinets. Two subwoofers in a room to my mind would offer a better spread of sound, less liklihood of poor room interaction, less liklihood that the subwoofer would be stressed beyond it's comfortable operating limits. Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 12, 2004 Author Share Posted December 12, 2004 ---------------- On 12/12/2004 3:12:10 AM formica wrote: Guys, you have to read sloowwwer... budget is tight with 100$ preferred and 300$ as a max. I remember you already have an amp... I don't recall how much power but I remember you'd have some to spare with the Tempest. I like the Tempest, it's a no frills Subwoofer driver, which sacrifices enclosure size for efficiency and extension. Seeing that you are willing to go a little higher... the other two drivers which jump to mind are: - Acoustic Elegance (Stryke) AV15 which should be available around x-mass. Compared to the Tempest, it offers a slighty smaller enclosure but with slightly less efficiency. It will also play louder given both it and the Tempest are excursion limited in a vented enclosure. They also have a beautiful cast frame but a little cheesy (my opinion) aluminium cone. - The PartsExpress TitanicMkIII drivers used to be similar to the AV15 but if I recall the enclosure was a little smaller still, but it traded some bass extension for it. I haven't modeled the new T/S they have. Cast frame and pulp cone... very nice looking. - The PartsExpress DVC woofers aim the Tempest and have almost identical TS parameters. Stamped frame and pulp cone. I find the blueprint 15" driver's TS parameters quirky... model it for yourself and you'll see what I mean. The BP-18" models much better but is no longer available. The are also the Lambda drivers, which the remaining stock was bought out and is being offered by Acoustic Elegance (Stryke). You will have to look up the old PB series drivers... performance was good but enclosure size was large and maximum excursion wasn't as high as the AV15s. Later... Rob ---------------- lol, thx formica...i mention an $800 sub and everyone goes nuts! ahhhhhhhhhh perhaps i should have mentioned that I'm a POOR college kid with no job at the moment. I am currently rebuilding JBL 2226H driver that I acquired for free and hope to sell it and purchase a new driver with the same money. This puts me in the $100-$300 range. I just did a quick model of the Stryke AV15 in the same box tuned to 19Hz and for $50 more I can go flat at 115dB down to about 18Hz and not worry so much about the power handling of the driver (much less cone excursion). This will be something I'll have to contemplate. And here's the specs of my crown amp: Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 12, 2004 Author Share Posted December 12, 2004 ---------------- On 12/12/2004 5:04:38 AM edwinr wrote: Rather than worry about two drivers in one cabinet, I would be more interested in two drivers in separate cabinets. Two subwoofers in a room to my mind would offer a better spread of sound, less liklihood of poor room interaction, less liklihood that the subwoofer would be stressed beyond it's comfortable operating limits. ---------------- I couldn't agree more. The only reason I started out modeling two subs in the same cabinet is because I only have one good location for a sub in my room and I thought I could afford 2 drivers...and figured more was better. Obviously more cabinet is more important (as well as a better driver). I still can't get over the Leviathan specs...that thing is a beast. When I get the money, I can see myself dropping $1600 on two drivers like it Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 12, 2004 Share Posted December 12, 2004 "and I came to a realization the other day...A single driver in a cabinet is actually better than using two drivers in the same sized cabinet. Using two drivers in a cabinet twice the size has the same response of the single driver, but 6dB more output. I guess it really is totally obvious when you think about it because both drivers are fighting for the same air inside the cabinet." Putting two drivers in a cabinet effectively makes the cabinets volume half sized for each driver. To compensate you would increase the cabinet size to get back to the original tuning volume. The extra driver gives you more total output, higher efficiency and lower distortion. Along with larger cabinets and greater cost of course. And you can take advantage of that extra output ability of the multiple drivers to utilize a little EQ to boost up the low end (for a smaller cabinet size then optimum). You can do other things with multiple drivers though too. If you put them in a compound arrangement you can actually make the box tuning size HALF what would be optimum for a single driver. You do not gain the output advantages of having two drivers in this setup though... what you get is a smaller box that looks like it only has a single driver in it. Shawn Quote Link to comment Share on other sites More sharing options...
prodj101 Posted December 12, 2004 Share Posted December 12, 2004 We didn't go nuts because you mentioned an $800 sub (we didn't even really go nuts), we got on you because you said the Tempest was the best 15 inch sub around short of the $800 you mentioned, which is an extremely uninformed statement. Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 13, 2004 Author Share Posted December 13, 2004 ---------------- On 12/12/2004 10:06:15 PM prodj101 wrote: We didn't go nuts because you mentioned an $800 sub (we didn't even really go nuts), we got on you because you said the Tempest was the best 15 inch sub around short of the $800 you mentioned, which is an extremely uninformed statement. ---------------- Eek, I think you missed the "tone of voice" in my post, but no worries. I was just saying that I was interested in drivers costing $100-$300 and that in my research, the only "significantly better" driver I came across was the Leviathan which was out of my price range. However, I was sure there were more drivers out there so I was hoping to get some ideas from the rest of ya'll. I just thought it was funny that I mention $800 and all the suggestions went that high. For $150, I think it'd be very hard to beat the Tempest. For $50 more, I like the idea of the AV15 because it's less tweaked and more forgiving than the tempest (at least in the modeling stage). One thing I cannot get over is how well the JBL that I'm rebuilding models up. It has an Fs of 40Hz, but I can get better output than even the AV15 due to the sensitivity (without even coming clost to excursion limits either). All cabinets are 354L red = JBL 2226H (20Hz), blue = AV15 (19Hz), green = AV15 (14Hz). So the only real advantage I see for selling the JBL and getting the AV15 is if I want to sacrifice SPL for extension...13Hz at 110dB sounds like fun. Sadly, the driver runs out of power handling before excursion. Quote Link to comment Share on other sites More sharing options...
prodj101 Posted December 13, 2004 Share Posted December 13, 2004 both the AV-15 and Blueprint would be superior to the tempest, plus they fit in your price range. Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 13, 2004 Author Share Posted December 13, 2004 could you provide a link to the blueprint? All the hits I find say that the company is out of business... Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 13, 2004 Author Share Posted December 13, 2004 Here's a pdf with all the parameters of the JBL 2226H driver in case any of you wanted to model it for yourself: http://www.jblpro.com/pages/pub/components/2226.pdf (Notice the Xmax is defined at 7mm or so, but the cone can move 40mm P-P without damage) Quote Link to comment Share on other sites More sharing options...
michael hurd Posted December 13, 2004 Share Posted December 13, 2004 Dr.who, just because the suspension can provide 40 mm of travel doesn't mean that the voice coil will be effective at that excursions. 7 mm is not a lot of excursion, and with low frequencies, it will run out of effective travel. Once the motor strength drops, and the coil starts to come out of the gap, it is all downhill. http://www.adireaudio.com/Files/DUMAX/TempestDUMAX.PDF Here is a dumax test sheet, which shows the bl product of an Adire tempest, with respect to excursion. Quote Link to comment Share on other sites More sharing options...
michael hurd Posted December 13, 2004 Share Posted December 13, 2004 There are many variations on motor types, such as overhung and underhung types. Overhung refers to a voice coil that is longer than the gap, while an underhung motor has a shorter coil in a long gap. Some designs have a bumped back plate and a pole piece that extends above the front plate to increase the field strength at the end of the gap. Compare the motor strength curve of the Audiomobile mass 2012 with the Adire tempest above. http://www.adireaudio.com/Files/DUMAX/DUMAXMASS2012.gif Quote Link to comment Share on other sites More sharing options...
michael hurd Posted December 13, 2004 Share Posted December 13, 2004 Tom nousaine tested this for mobile electronic magazine, and you can read the 4 page review here: http://www.m-emag.com/article.asp?print_page=y§ion_id=13&article_id=183 Note the fs(23.6 hz) is fairly low, and could possibly be used in the home. Sensitivity is average for a subwoofer. Quote Link to comment Share on other sites More sharing options...
formica Posted December 13, 2004 Share Posted December 13, 2004 ---------------- On 12/13/2004 3:08:50 AM DrWho wrote: could you provide a link to the blueprint? All the hits I find say that the company is out of business... ---------------- Blueprint did close down... but Kyle at Acoustic Visions bought out the remaining parts and stock and is re-offering the Blueprint drivers for a limited time (as long as parts last). The Blueprint 1804 sold like hotcakes... and was the best of the bunch in my opinion. The AV15 biggest drawback (in my opinion) is it's loss of efficiency... but since your amplifier has enough power for two of them, it's not really a big deal. The cost premium to get a AV15 was substantially more for me given that the Adire drivers are readily available in Canada, but I still felt it provided the better value. Rob Quote Link to comment Share on other sites More sharing options...
Scp53 Posted December 13, 2004 Share Posted December 13, 2004 that sucks. i hate to see a good company go out of business... Quote Link to comment Share on other sites More sharing options...
DrWho Posted December 14, 2004 Author Share Posted December 14, 2004 Well I'm pretty much sold on the AV15. The blueprint drivers are nice, but I plan on making another sub in the future when I've got more funds. One really nice thing about the AV15 is I can get away with a smaller cabinet...in fact, a smaller cabinet gives a much flatter response. But how the heck do I fit the bloody ports in the thing? I've thought about building a slot shaped port on the front (around 18"x1")...can I have the bottom of the cabinet be one edge of the slot and the sides of the cabinet be the sides as well? ______________________ / / / / / / /_____________ ______________________ Also, do ports need to be contained inside the speaker, or can I have a "smokestack" sticking out of the cabinet? I have to work with 9 cubic feet and my cabinet should be 36" wide (I plan on placing it underneathe the TV stand...so raising my TV another 20" or so). I know Klipsch uses a "Bass-reflex via front-firing slot port" on their new THX subs...I'd have to have 4 AV15's to match the output of the THX sub system. I'd love to see the T/S parameters on their drivers Quote Link to comment Share on other sites More sharing options...
prodj101 Posted December 14, 2004 Share Posted December 14, 2004 the THX reference subs use a bit more than just a slot...if you take a look at the internal pics they look like they use some sort of fold/wave guide. Quote Link to comment Share on other sites More sharing options...
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