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Decision: best 12" or 15" stereo subwoofer design for MUSIC listening?

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  • Decision: best 12" or 15" stereo subwoofer design for MUSIC listening?

    Thanks in advance for your review and recommendations for a,b,c,d below.

    Bummer, I found out recently my boxes are "too large" at 2.8cu ft, and should have been 1.7cu ft sealed. Apparently I'm not getting optimum performanceI've been running two of the older 12" Titanic MK3 subwoofers in two separate 2.8cu ft boxes (sealed). i.e. stereo subs. Each is powered by it's own 500w Dayton SPA500 plate amp. 1 plate amp per box. I'm trying to decide to either replace the woofers, build new boxes, or just start over completely with new/different woofers and boxes from scratch. I've never really heard the Titanics (very similar to Ultimax) in their "ideal enclosure sealed or ported". Also read some folks reporting the HF are "better for music". One customer years back stated Titanic/Ultimiax can be good too for music given the right box design, setup. Completely starting over with new woofers and new boxes, and re-using my Dayton 500w plate amps is an option if I have to. I attempted to list some options below. Looking for recommendations and feedback if anyone has a great idea either way.

    USE: 75% music


    a) PORT CURRENT BOXES: change from sealed to ported. I would end up porting my existing boxes; try again with the Titanic MKIII woofers for music. Still uncertain on tuned port spec to get to 27hz?
    b) CHANGE WOOFERS to 15 HF: since my boxes are 2.8 cu ft now, it seems close enough I could replace both Titanic 12" woofers, enlarge holes, and try Dayton 15" HF woofers, leave the boxes (sealed).
    c) CHANGE WOOFERS to 12 HF, re-do BOXES: would consider replacing the 12" Titanic woofers with the latest 12" HF series subwoofers, and run the boxes sealed (corrected box size) or ported; uncertain?
    d) OTHER? would consider other recommendations to other brand/type woofers but likely going to re-use my Dayton 500w plate amps.
    e) go buy a REL subwoofer for music. Hoping a,b,c,d can work better, instead.

  • #2
    Are you unhappy with the sound of the current setup or having power handling issues? If not then why change it?

    You could temporarily screw in chunks of 2x4 or 4x4 inside your boxes to reduce internal volume to the recommended size for the titanics and see how you like them with the recommended sealed volume. This might be my first step if I was in your shoes.*

    If you did change woofers, I have heard good things about the Dayton HFs


    • #3
      I wouldn't put too much stock in customer reviews, I've read all sorts of totally bogus and outlandish comments. Like Dynamo says,* experiment with volume if you have the software to determine optimum boxes. Trust your ears.

      People here with experience might comment on proper cabs.


      • #4
        Originally posted by decooney View Post
        Apparently I'm not getting optimum performanceI've been running two of the older 12" Titanic MK3 subwoofers in two separate 2.8cu ft boxes (sealed).*
        According to who? Is that what software modeling told you? The results of measuring your in room response?
        Still uncertain on tuned port spec to get to 27hz?
        You don't need 27Hz for music. Where did you get that figure?



        • #5
          Modeling the NLA TIT320C in WinISD shows the Titanic needs a vented box to have an F3 in the 20s. In a sealed box of 2.8 ft3 the F3 is circa 42 Hz. A smaller box doesn't make a material change in the response. Not very deep for a sub.

          However, in a 2.7 ft3 vented box (net, allowing for a 4" x 14 " port), the F3 is circa 26 Hz. Note: Vented, the sub exceeds Xmax below 20 Hz at power levels above 100 W. But that's 108 dB (each) so I wouldn't think you would be using that much power.

          Me, I'd try to shoehorn in the vent to hear the results before buying and building a different sub (or try an external vent for an easier test) - 4" PVC and elbows.

          Click image for larger version

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          • #6
            You could use inexpensive rigid foam from Home Depot to decrease the volume of the boxes to suit the existing woofers if you prefer sealed sub woofers..


            • #7
              Originally posted by Millstonemike View Post
              Modeling the NLA TIT320C in WinISD shows the Titanic ... In a sealed box of 2.8 ft the F3 is circa 42 Hz.
              That's perfect for music only, especially after you factor in cabin gain.



              • #8
                Originally posted by djg View Post
                I wouldn't put too much stock in customer reviews, I've read all sorts of totally bogus and outlandish comments....
                Consider the anonymous source; I know of guys who build based upon strong leap of faith advisement and limited quantitative data and regretted it.
                Personally the oft called "extended response" below 30Hz is desirable, but below 20Hz isn't needed. That's why I have much larger subs, though modest compared to some.
                Since I don't live in a cabin, such gain is not an expectation, so not a design consideration
                "Not a Speaker Designer - Not even on the Internet"
                “Pride is your greatest enemy, humility is your greatest friend.”
                "If the freedom of speech is taken away, then dumb and silent we may be led, like sheep to the slaughter."


                • #9
                  As Mmike said, for a closed box, there's NOthing wrong w/your current setup. The subs will definitely hit 40Hz (which ordinarily is plenty low for music).
                  Nothing would be gained by making that closed box internally smaller, except maybe a slight increase in power handling.
                  IF you feel the need for something that goes deeper, adding a 4" x 14" long port (a "Precision Port" tuned to 27Hz is what I'd go with) will break 30Hz.
                  You'd notice an increase in output at 60, 50, and 40Hz; and you'd have considerably more output at 30Hz. 1st try one box to see if it suits you.
                  Let us know.

                  Either way should be able to take 500w down into the mid 20s.


                  • #10
                    Originally posted by decooney
                    For home theater it's pretty amazing. For audio, I feel it can tend to be a bit "muddy" at times with my current box configuration
                    That's not the fault of the speakers. What does your in room measured response look like? If the answer is "I don't know" you need to find out before trying to fix what's probably not broken. Google 'Room EQ Wizard'.

                    I guess I was not so quick to believe what I read years ago about the Titanic MKIII, some saying it's really better for home theater, and the High Fidelity HF version is better for Music.
                    You shouldn't have believed it, because it's nonsense.


                    • #11
                      Originally posted by decooney

                      before I start cutting holes and reconstructing last we feel pretty confident ONE 4" diameter port at 14" long will be close enough?
                      One 4" x 14" port will handle 150 W at 26 m/s air velocity.* That's 109 dB SPL (each sub).* Upwards of 150 W and the model shows the air velocity edging up to the noisy region.* Flared port ends can help there.

                      Nothing in the model would explain "muddy" for the existing configuration (to my intermediate eyes). One hole with an external vent made of PVC pipe would allow you to hear the new configuration before ripping the box apart.


                      • #12
                        Any RSS HF driver in it's recommend sealed box will sound fantastic with music, the 10" version*
                        specs a F3 in the 50s but in practice it gets down to the high 20s in most rooms.**
                        Guess xmax's age.

                        My guess: 15. His grammar is passable. His trolling is good.


                        • #13
                          Originally posted by decooney
                          There is no real option to moving the subwoofers about, they will sit where they are.*
                          Changing their orientation where they are may help.* There's no need for them to face front.



                          • #14
                            Originally posted by decooney
                            ...I did some reading and from what I could find most indicated having a port on the side is not a big issue...
                            Correct. Just keep greater than the diameter of the port clearance from walls and furniture etc.
                            Electronics engineer, woofer enthusiast, and musician.
                            Wogg Music
                            Published projects: PPA100 Bass Guitar Amp, ISO El-Cheapo Sub, Indy 8 2.1 powered sub, MicroSat


                            • #15
                              Originally posted by billfitzmaurice View Post
                              That's perfect for music only, especially after you factor in cabin gain.

                              Look up sealed box woofer tuning. You'll find that Bill's right. Here's what to look for.*

                              I modeled the Mk3 (had the data sheet) in Unibox, and find your 2.8 cu ft. box has a Qtc of 0.57 with heavy fill. This is an "overdamped" alignment which is ideal for clean transient response, at the expense of power handling. You hit Xmax at half power below 20Hz. I'm seeing an F3 of 41 Hz, similar to Millstonemike, but I'll also mention your F10 (half as loud) is around 20Hz. This doesn't look like a bad design for someone listening to music...

                              Especially in a residential-size room... cabin gain is your friend, and is filling in a lot of the low end roll-off in your alignment.*

                              The only thing I can think that might improve transients is a woofer with a lighter cone, Mms. Mass prevents acceleration, but it's needed for strength as Vas increases and the driver can push more air. LF require a driver to push an awful lot of air. If you're mostly music, you don't need a driver designed to deliver infrasonic frequencies.*

                              But your current configuration, on paper, looks pretty much ideal for your use... be careful to make modifications reversible, in case you don't like the sound of ported alignments.*

                              BTW, your suggestion of a 1.7 cu ft. box yields a 0.708 Qtc with no fill. This is considered "critically damped" and trades some transient response and LF extension for more power handling. It's all trade-offs.*

                              Have fun,