DIY Rookie: Best Driver(s) for my 1st... and last Sub?

Discussion in 'Archived Threads 2001-2004' started by John Morris, May 23, 2001.

  1. John Morris

    John Morris Guest

    I have searched and found many, many, many posts and sites on DIY subs and as I take the time to look at and read every single one... I thought I'd ask specifically what I'm looking for. I am thinking of building a subwoofer, or two, to use in my primary HT/music system. They will be crossed over (at 60Hz) off of the front three channels with the LFE channel thrown in during movies; so they will need to be musical, fast, accurate, yet rock the foundation when called upon. This sub(s) will be driven with a Crown K2 and EQ'd with a Symetrix 551-E. I am drawn to the D-I-Y sonotube with threaded rods as shown in this thread: Threaded Sonotube .
    Here are the questions I need help with in order to make a decision.
    1. In the subwoofer referenced above, does the endcap over the port negatively affect the sound?
    2. Given this design, what driver would you use in this sub and what type of performance could I expect from this sub with your suggested driver? Driver cost limit $400.
    3. Is there a best site with step by step, detailed instructions on how to build one of these?
    Thanks for all your help!!!
    ------------------
    Take Care,
    merc
    ------------------
    DTCP, DFAST, 5C, DVI, and HDCP smell like DIVX!!!
     
  2. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    0
    Hi John!
    DIY, eh? I think you'll find it more fun than the commercial offerings.
    quote: . In the subwoofer referenced above, does the endcap over the port negatively affect the sound?[/quote]
    It really shouldn't , but I'd like to see a little more room there.
    quote: Given this design, what driver would you use in this sub and what type of performance could I expect from this sub with your suggested driver? Driver cost limit $400.[/quote]
    Given the price, you've got a few options. If size is a consideration, the Audiomobile/TC Sounds Mass12 is a formidable 12" driver. The new driver from SVS appears similar to it, and I'd imagine you could expect similar performance to the new SVS series in the proper enclosure. This is just a guess, as I don't know jack about the new SVS driver.
    For the budget, though, you could purchase two 15" Tempest drivers from Adire Audio. These would need a very large enclosure, or you could build two of the sonotube subs you referenced above, which use this driver. If you did nothing more than make two exact copies of that design, driver and all, with your amp and eq, I'd say you'd have a stunning sub system capable of in-room true reference levels. Actually, I don't know the specific parameters of that design, but you get the idea...two Tempest subs will perform far beyond any commercial offerings anywhere near the cost.
    The project links at the top of this page are helpful, as I know you've seen, but Pat Sun's pages come as close to step-by-step as you'll find.
    Here's a site which shows $280 worth of Tempests in a really big box.
    There are other worthy offereings, some at a little more money. The Stryke HE15 is a $395 driver at pre-order, but it will perform like two Tempests. You'd have to figure on using passive radiators with it, so that's extra cost, plus, you'd have to build a box, not a tube.
     
  3. John Morris

    John Morris Guest

    Hi Jack! Thanks for your reply!
    I've built JL Audio based car subs but they were sealed, and the sound didn't need to be as accurate as what I'm looking for in my new sub. Also, you didn't need a big tube to get loud in a small car. [​IMG]
    I looker at the TC Sounds site, but they list their drivers as OEM with a minimum order of 500 units. Is the Audiomobile Mass 2012 the same as the TC 12 HE Woofer? If not, can you buy this bare woofer anywhere?
    Finally, what sonotube, threaded rod, design would work best with this woofer based on the listed specs?
    Thanks!
    Take Care,
    John
    ------------------
    Take Care,
    merc
    ------------------
    DTCP, DFAST, 5C, DVI, and HDCP smell like DIVX!!!
     
  4. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    0
    John,
    Yeah, TC is OEM. I don't know where you could buy a 12HE. Just from the specs, though, the Mass12 looks like an "improved" version of that TC OEM model.
    As far as an alignment for it, a quick model is looking like 5 cu.ft. tuned to 18Hz would work well, with an anechoic -3db point of 17Hz. TerryC posted some thoughts/comparisons involving the Mass12 in a vented box some time ago, over on the "old" board. He had output numbers, alignment specifics, everything. Here it is.
    You've probably seen the thread on threaded rod subs:
    http://www.hometheaterforum.com/uub/...ML/038475.html
     
  5. Brian Bunge

    Brian Bunge Producer

    Joined:
    Sep 11, 2000
    Messages:
    3,716
    Likes Received:
    0
    Jack,
    Don't forget the dual Mass12 sub TerryC built for his friend!
    That's one hellacious sub!
    http://www.audiomobileinc.com/images/richsubside.jpg
    ------------------
     
  6. John Morris

    John Morris Guest

    Where can I find details on this sub built by TerryC?
    [​IMG]
    ------------------
    Take Care,
    merc
    ------------------
    DTCP, DFAST, 5C, DVI, and HDCP smell like DIVX!!!
     
  7. Julian Data

    Julian Data Second Unit

    Joined:
    Oct 5, 1999
    Messages:
    408
    Likes Received:
    0
    I recall it's an 11FT³ NET Volume with two MASS 2012 S24 using a K1 amp. Fb is 17Hz.
    Mine 'was' 12ft³ tune to 16Hz with the same drivers using K2 amp. Yes, "was" I move the MASS drivers to the car, same with the Shivas. [​IMG] I miss the box look so I am venturing in that direction, PR Style. [​IMG]
    Be warned, the tube is pretty hefty due to the weight of the drivers 60-70Lbs! [​IMG]
    ------------------
     
  8. Julian Data

    Julian Data Second Unit

    Joined:
    Oct 5, 1999
    Messages:
    408
    Likes Received:
    0
    IF you can wait, there's a MASS 3012/3015 coming, should have more Xmax and something patented on the design.
    There's also their APEX drivers coming out.. a more affordable line up. Yes, lower than the EVO.
    ------------------
     
  9. John Morris

    John Morris Guest

    Julian: thanks for the info! When is the 3012 coming out? Also, I've built a few (3) sub boxes for my cars and I am looking forward to the tubes and their easily sealable ends... of course these will be ported anyway. As for the specs, and abbreviations, I have no idea what Fb or most of the other stuff means. I do understand cubed feet and how to use a calculator to figure internal volume. But, how exact do you have to be to meet the best specs for each driver and performance objective? If I opted for the sub you built at 12 cubic feet and tuned to 16Hz, what specifically were the measurements and the port configuration? Also, does it matter if the port exits on the same, or the opposite side as the driver?
    Gosh, I feel so stupid!!!
    Thanks for your help!
    ------------------
    Take Care,
    merc
    ------------------
    DTCP, DFAST, 5C, DVI, and HDCP smell like DIVX!!!
     
  10. Julian Data

    Julian Data Second Unit

    Joined:
    Oct 5, 1999
    Messages:
    408
    Likes Received:
    0
    Hey John,
    What's planned is this Fall, as they have been set back. It's a waiting game with the new IDX, and JL subs basically. They have more stuff coming out, like mids, tweets, alternator, amp.. etc. Price for the 3k series I think will be $499 and up. And they will come in 12" and 15". I know that the 15" has already been DUMAX'd and the 12" hasn't it.
    What's interesting, Adire is working on doing some drivers with more "stroke", so the price will go up. I don't think they will be out this year but one can always hope! [​IMG]
    Fb: Is the tuning of the enclosure.
    I do understand cubed feet and how to use a calculator to figure internal volume. But, how exact do you have to be to meet the best specs for each driver and performance objective? If I opted for the sub you built at 12 cubic feet and tuned to 16Hz, what specifically were the measurements and the port configuration? Also, does it matter if the port exits on the same, or the opposite side as the driver?

    Well, what the enclosure design is basically an EBS (Extended Bass Shelf System), you can read more about it at DIY Subwoofers . The bigger the enclosure the more efficient it is since you can use less power.
    There are always compromises when doing a design in which you will gain in some areas and lose in others. Take the EBS alignment, you gain in low extension, the GD (Group delay drops further due to Fb being low), and efficiency. Yet you'll loose some mid bass oomph but some of this loss can be picked up by the room itself. Another downfall is that you can run too much power and run into Xmax issues thus overpowering the driver - bottoming out. Hence, the addition of an PA Eq to take some of the power off from the amp. And, the F3 will be up some but room will alleviate that situation.
    With 2ks series, each VC is 4 Ohms and when wired in parallel (DVC model of course), the resistance will be 2 Ohms. So when running your K2, you'll supposedly be running 1250W/channel. Remember that power rating is at 1Khz and not 20Hz-20KHz. So it's going to be lower than what's listed. I have been comptemplating on moviing up to the Macro Tech series.
    Nevertheless, I recall my dimensions for my 24" tube was 50-52" in height and I used 2 - 6" ports. The ports were placed at the bottom with one driver. The top driver was centered. Boy, it was fun flipping this thing on it's side to play with the ports. This piano black tube is gone now as it was sold to a neighbor down the street.
    Where to put the ports?
    Keep away from the wall and the driver at least one inch. If you plan to put one port up top and one down. I wouldn't put the port directly above one another as I prefer to put each port directly positioned behind the driver.
    If you want to line the walls, go for it. I didn't as I didn't hear any differnce but I stapled a sheet of polyfill on the top endcap to break up the standing waves. Ala Greg Monfort.
    You shouldn't feel stupid as it never hurts to ask a question.
    JD
    ------------------
     
  11. John Morris

    John Morris Guest

    Ok... what if I built (with your help), a pair of sonotube ported subwoofers using the mass2012 drivers that looked like the richsubs that TerryC built. If I tuned them each to say 18Hz, what would the dimensions of the tubes be?
    Finally, am I just missing the point in that I could get the same performance from those sonotube subs using the Tempest drivers???
    Direct Me... Please!
    ------------------
    Take Care,
    merc
    ------------------
    DTCP, DFAST, 5C, DVI, and HDCP smell like DIVX!!!
     
  12. Mark Seaton

    Mark Seaton Supporting Actor

    Joined:
    Oct 10, 1999
    Messages:
    599
    Likes Received:
    0
    Real Name:
    Mark Seaton
    John,
    It seems like size isn't a huge problem for you, so I would just ante up for a pair of 15" drivers. Dual Tempests in large boxes will do quite well, and get very loud. For you budget and your overall interest in the quality and output, I would also look at the Stryke SAL 15" drivers. John Janowitz has a 7' tall sub in his home right now with 6 PRs and 2 15" drivers which could very well perform as you are hoping. The Tempests will physically out displace the Lambda made drivers by a hair, but with a pair, I don't expect this to be much of an issue. For deep bass performance per dollar, the Tempest is hard to beat, but I would look to one of the Lambda 15" drivers for the ulitimate in musicality and output. The differences definitely get into a grey area where subjectivism comes into play, so make your own decisions, but I do believe the low power compression and copper faraday motor design with very low inductance have their sonic merits.
    Understand that it's rather unlikely you would be "unhappy" with any of the options that you are considering above, or the ones I just menitoned.
    Mark Seaton
     
  13. John Morris

    John Morris Guest

    I'd also like to keep these tubed subs lower than my primary front speakers... 54"; and yet, I don't want the Mike Knapp waterheater type units. And still, they must be able to produce kick ass accurate, musical, impressive bass WITHOUT corner loading. These will go in front, between my front L,R, speakers and my RPTV. Any finally... NO boxes. Is there such a design using the MASS 2012 or Tempest 12 inch drivers??? That is... I'd like to build something like the pair of SVS 20-39cs subwoofers I used to own, yet which produces twice the output of those subs in the same footprint.
    Thanks!
    ------------------
    Take Care,
    merc
    ------------------
    DTCP, DFAST, 5C, DVI, and HDCP smell like DIVX!!!
     
  14. Patrick Sun

    Patrick Sun Moderator
    Moderator

    Joined:
    Jun 30, 1999
    Messages:
    38,680
    Likes Received:
    452
    Give your requirements, I think you have unrealistic expectations.
    I think at this point, you might want to consider a boxed solution, order the HE15 from Stryke (when it gets offered in June for around $375), and at least 1 PR. You can't use the HE15 in a downfiring configuration (only front-firing).
    ------------------
    PatCave ; HT Pix ; Gear ; Sunosub I + II + III ; DVDs ; LDs
     
  15. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    0
    John,
    All these suggestions are great!
    Look on the Projects page, download WinISD. Play with that a bit, it will give you some idea of the space requirements for a given driver. I think there's a volume calculator there for sonotube (cylinder) there, also. The Tempest will require about twice the space of a Mass12, at half the price. The Tempest should also outperform it, it has higher displacement (moves more air). A 4' high 16" diameter piece of Sonotube is over 5 cu.ft. in volume, so that should be good for the Mass.
    As far as your placement requirements, the vast majority of situations will benefit from corner loading. Having said that, if your SVS subs performed optimally in the same proposed place(s), then there's no reason to expect that a pair of Mass12 or Tempest-based subs, optimally aligned/ported, would not outperform the SVS subs. I don't know the numbers for the SVS, so I can't say if it would be "twice". If you mean 3db, that should be possible without breaking a sweat.
    With your amp, that Stryke I mentioned might be the way to go. Stryke.com
    It's common in DIY that the more you learn, by playing with software, etc., the less stringent these easthetic and placement requirements become in the face of the performance attainable. If you're serious about performance, that is. [​IMG]
    The worse thing to do is to do it halfway, then decide that it wasn't worth it. And, like Pat alluded to, keep your expectations realistic by learning all you can about what affects performance.
     
  16. Mark Seaton

    Mark Seaton Supporting Actor

    Joined:
    Oct 10, 1999
    Messages:
    599
    Likes Received:
    0
    Real Name:
    Mark Seaton
    John,
    I think we should go back to the begining, and define what you feel is acceptable in size, and what sort of low end response you are looking for? Is the $400 mark for all of the drivers?
    I think some of us also may have overlooked or forgotten the fact that you will be using a Symetrix EQ. Given the power available, this could bring your goals back into a realm of reality. The thing to remember is this: To reach specific performance goals, no matter the box size, you will need a given displacement from the drivers depending on the port tuning, and your goals. In reality, as long as the ports are large enough for the output you desire, changing the box size only alters the amount of power you will need to achieve a specific output, not how loud the sub will get (presuming tuning frequency does not change).
    That said, here is my current pick as a solution for you:
    Stryke Audio now has the SAE-1204 drivers in stock. These have a cast frame, with a 2.5" coil, and will have a flatter response in smaller enclosures. This should keep the required amount of EQ to minimal amounts, and the larger voice coil and gap height should better help with power handling where EQ is required. My proposal is for a total of 4 of the SAE-1204 drivers in 2 separate tubes, probably of 18" to 24" diameter, and as tall as you can justify. This should get you in a range of 6.5 to 10 cu.ft. per tube. Using either 3, 4" ports, or 2, 6" ports will yield nearly 40" port lengths for 18Hz tuning. The primary difference you will see between the two alignements will be in the power required for a given output between ~16Hz and ~22Hz. Put one of these subs on either side of the RPTV, and parallel the coils of the drivers together within each sub, powering each sub with a channel of the K2 which will see 2 Ohm load. This fits within your price constraints of $400, and should give you some damn impressive output. My guestimate would be for the pair of subs to produce about 123-126dB @ 1M as a minimum below 40Hz, and over 130dB above 40Hz. Dividing the power between 4 drivers will also have an advantage of keeping the operating powers well within the range where power compression won't be an issue for the majority of listening, while still giving you the headroom when you want to get really nutty. For the space and money you are talking about, I think that's one of the better options. A single Tempest in each of the same size enclosures would be a more economical way to go, with very similar performance, being edged out ever so slightly by the dual SAE-1204s in each enclosure.
    Regards,
    Mark Seaton
     
  17. John Morris

    John Morris Guest

    Jack, Brian, Julian, Mark, and Patrick: Thank you all very much for your suggestions and help! It sounds like I need to reconsider my expectations....
    Probably, KISS is the way to go at this point. So, how about if I consider building a single ported sonotube subwoofer with a single driver. 18 or 24" in diameter. No higher than 6 feet tall. Corner Loaded. Tuned to around 18Hz or so. Let's set a maximum driver cost at $500.
    What driver and configuration will give me the best flat, yet high volume response from 15Hz to 60Hz for both music and movies?
    Thank again!
    Take Care,
    John
     
  18. Mark Seaton

    Mark Seaton Supporting Actor

    Joined:
    Oct 10, 1999
    Messages:
    599
    Likes Received:
    0
    Real Name:
    Mark Seaton
    John,
    You are still in the range of about the same total volume I discussed above, and hence very similar driver options. The only thing I would consider is to keep the various Lambda 15" drivers sold by Stryke in mind. The new TD15 drivers would require some EQ for flat response, but would yeild very similar output levels, having a some advantage in the upper frequencies with their higher efficiency. Combine this with the minimal, if any, power compression and smooth high frequency response, you will never have any worries with mating these to any mains you use, with any slope that works in your room.
    Personally, I am still fond of the twin tube concept using 4 1204s.
    Mark Seaton
     
  19. DanWiggins

    DanWiggins Second Unit

    Joined:
    Aug 15, 1999
    Messages:
    324
    Likes Received:
    0
    John,
    How about a large twin-isobaric design? Use a 68" tall tube that's 24" in diameter. Use 1.5" thick endcaps. Each endcap holds an isobaric pair of Tempests, and a 6" diameter by 29" long vent for an effective 16 Hz tune.
    Wiring the voice coils of each driver in series, then wiring all drivers in parallel, you end up with a total 4 ohm load. Goosed with a good 1600W or so, and driven through a standard crossover (80 Hz LP 2nd order Butterworth) you should have an F3 on the low end of approximately 14.66 Hz. Anechoic SPLs at 1 meter should be greater than 110 dB SPL from 15 Hz and up.
    In a 5,000 cubic foot room (corner loaded), and with the listener at a typical listening position (centered left-right, head 40" from ground, 2/3rds back from the front wall) you should have an in-room F3 around 13.5 Hz, and more than 110 dB SPL from 14 Hz and up. Note this is at the listening position. At 1 meter ranges in-room, you should be comfortably above 120 dB SPL from 13 Hz and up.
    To check out this design, download our free version of LspCAD from
    http://www.adireaudio.com/Files/Adire.zip
    Then download the file describing the above setup from
    http://www.adireaudio.com/Files/JohnMorris.box
    This type of design has been semi-validated by James Johnson, who built a large sub using just twin Tempests (note that the isobaric pairs don't increase output capability per se, but reduce cabinet size). He's measured over 122 dB SPL at 16 Hz at 1 meter in his room. Additionally, several on this board have used LspCAD to develop their systems, and the predicted in-room response under power was VERY close to measured reality. This is a very accurate software package.
    Please feel free to experiment! Of most interest would be to change the room dimensions. X is the width, Y is the height, and Z is the depth. Enter your room dimensions and your listening position, and see what you get.
    Total driver cost would be $515.20 for all 4 drivers. I'll make you a deal and sell them to you for $500 complete. IMHO, this would be a world-class system, obviously capable of "full reference" output and then some. Should give you all the deep bass (extension to the low teens, and SPLs well above 110 dB) you want. And should stay within your budget - both size wise and cost wise.
    Dan Wiggins
    Adire Audio
    ------------------
     

Share This Page