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Just finished a pair of subs and they suck. Why?

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  • #61
    Re: Just finished a pair of subs and they suck. Why?

    Originally posted by generic View Post
    Try rolling up a t-shirt and stuffing the port. See if you can hear any ugly noises coming from the box.
    I think my next move if I choose to is to make a quick and dirty sealed box. No flush mounting, no port, no finishing, most likely square. A couple of dowel pieces to brace. If anyone has used this driver in a sealed enclosure, feel free to let me know what volume worked for you.

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    • #62
      Re: Just finished a pair of subs and they suck. Why?

      Your results in my mind confirm Rory's suspicion and mine. The sounds you hear while playing music are possibly just the HF content that is present in spite of the crossover. I hear that garbage when listening to subs playing a music signal even with their LPF in place all the time. The LPF isn't a brick wall. You should try this test tone and see if it sounds solid. It is a shaped LF tone burst for testing sub systems at their limit and listening for noises etc. Play this tone burst and see if you hear any noises. I'll bet you don't. That will essentially rule out box or driver noises, but to me your sine wave tone tests have mostly done that already. Have you tried playing higher frequency sine waves through the subs? Do they sound essentially normal? I'm just really convinced that all you are hearing is normal HF content being reproduced by the sub in spite of the crossover. My $.02...

      Look for the link halfway down the screen.
      http://www.synaudcon.com/site/articl...st-test-track/

      Originally posted by Exarch View Post
      .
      Anyways, that's a tangent; back to the issue.
      While playing the test tones, I tried to keep the amp's output voltage around 16.7V (70 Watts). I had both the sub amp and head unit set to 200hz 24db low-pass, and everything set to flat (No boost/eq etc)

      I played 20, 25, 31.5, 40, 50, 63, 80, 100, 120, 160hz, and a 20-160hz sweep, and everything sounded fine. There was some outdoor noise so If something was really quiet I may have missed it, but I don't think I did.

      I attempted covering the pole piece vent in each of the frequencies to see what effect it had. At 20 & 25hz, no audible effect. Starting at 31.5hz, it added a "wind noise", kinda like port chuffing. As the tone freq increase, the wind noise increased in speed, becoming a sort of buzzing until it got to the point where covering the vent hole just changed the pitch of the sub's sound. All of this sounded like stuff I should expect; I was not able to recreate the "bad" sound.

      I also covered the box port. At the lower frequency this induced chuffing, which went away as the frequency increased. Nothing to see here.

      Then I went on to playing a variety of music Some FLAC, some mp3. Immediately the bad sound presented itself, even though at this time I had the volume turned slightly below what I had it at during the test tones. I played around with the volume and crossover settings on the deck and amp, with no aha! moments. Pretty much the same results as when I used my sound card + SA70 plate amp or sound card + Emotiva UPA-500.

      .
      Loren Jones

      http://techtalk.parts-express.com/sh...-sound-drivers

      http://techtalk.parts-express.com/sh...for-live-sound

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      • #63
        Re: Just finished a pair of subs and they suck. Why?

        What's a quick test? Add cap across the woofer leads?

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        • #64
          Re: Just finished a pair of subs and they suck. Why?

          Please double check the proximity of the inside port flare RIM to the baffle inside baffle.

          Placing a flared port too close to a boundary will defeat the purpose of the flare as it will cause a change in particle velocity/direction that causes the rim of the flare to behaving like the rim of a non-flared (but perhaps a "belled") port since the new termination cross section of the port is an imaginary "cylinder" between the rim edge and baffle. The change in flow direction results in particles "wrapping" the edge of the port flare rim with high turbulence.

          Regards,
          Eric
          Pro/Fi Cinema Speaker project: "From the Ashes"

          Comment


          • #65
            Re: Just finished a pair of subs and they suck. Why?

            I was going to suggest a bottom slot port - I've been getting better results with them.
            Simple and it works. Haven't used a pvc/cardboard tube in years.
            e.g.>
            Attached Files

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            • #66
              Re: Just finished a pair of subs and they suck. Why?

              That sub hanging from the rafters? That's cool...

              Comment


              • #67
                Re: Just finished a pair of subs and they suck. Why?

                I think they (slots) work better, I'm kinda a prototype guy and do a lot of experimenting.

                The size of a slot port(s) can be worked out on WindISd (free download) 1, 2 - 6 (comb design); very easy to key different configurations.

                I don't put any damping material in sub boxes, start of empty, will add foam or wool as needed e.g. maybe a piece of foam on back wall of box.

                Never use damping in a car sub box.
                Attached Files

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                • #68
                  Re: Just finished a pair of subs and they suck. Why?

                  Hey Exarch,

                  Did you consider one of these? Also can be calculated on WinIsd:
                  http://www.parts-express.com/pe/show...number=295-494

                  Comment


                  • #69
                    Re: Just finished a pair of subs and they suck. Why?

                    FWIW I used a slot to tune an enclosure for a single RSS210HO-4. Works very well to achieve low tune (about 27Hz) in a smallish (1 cu. ft.) enclosure. This little RS sub hits clean and deep.

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                    • #70
                      Re: Just finished a pair of subs and they suck. Why?

                      Did you use an amp in your car to power the sub or the same plate amp?
                      Last edited by Navy Guy; 08-09-2013, 07:10 AM.
                      -Kerry

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                      • #71
                        Re: Just finished a pair of subs and they suck. Why?

                        Exarch, any updates?
                        Loren Jones

                        http://techtalk.parts-express.com/sh...-sound-drivers

                        http://techtalk.parts-express.com/sh...for-live-sound

                        Comment


                        • #72
                          Re: Just finished a pair of subs and they suck. Why?

                          Already tried FLAC. Although I guess those are suspect now too, along with backwards resistors and sealed boxes that are too sealed.

                          Comment


                          • #73
                            Re: Just finished a pair of subs and they suck. Why?

                            Originally posted by SirNickity View Post
                            Already tried FLAC. Although I guess those are suspect now too, along with backwards resistors and sealed boxes that are too sealed.
                            What kind of joke is this?
                            "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche

                            http://www.diy-ny.com/

                            Comment


                            • #74
                              Re: Just finished a pair of subs and they suck. Why?

                              It's not. All of those have come up in the last week. At first, genuinely honest questions from folks who didn't know -- which is absolutely fine. But then you get the inevitable audiophile back-and-forth... I swear I heard a difference, man! There's no change too small that someone can't tell. Meanwhile we consider a driver with -40dB distortion as a fine specimen, and then stick it in a room that mangles the response in terms of whole dBs. Well, at least audiophile OCD is a harmless quirk.

                              Comment


                              • #75
                                Re: Just finished a pair of subs and they suck. Why?

                                Well, while house sitting for my parent's I've finally had the opportunity to set up my complete system (OS MTM fronts, MMTMM centre, MT surrounds, and 2x RSS210HF-4's) and watch a few movies. Star Trek: Nemesis, Argo, Assassination of Jesse James, and Bourne Legacy. I didn't try too hard to get the sound right because this is just a temporary setup. I set my sound card's LFE crossover to 50hz, and the crossover on the plate amps to 60hz (essentially a 55hz-ish 24db/oct, I think) They performed well and I have no complaints.

                                I'm sure many of you, like me, would like a conclusive ending but for now I'm tired of testing things and just want to enjoy them for a bit. I may not be able to cross the subs higher than 60hz without issue but I'm fortunate I have speakers that can meet them that low.

                                For most music, I've come to the conclusion that it's better to just play my MTM's by themselves. For HT, they perform well enough that they will not be the limiting factor when I move soon (the neighbours will be).

                                ---

                                Did you use an amp in your car to power the sub or the same plate amp?
                                My car amp. A JL JX 500.1 rated at 340W RMS into 4 ohms.

                                Did you consider one of these? Also can be calculated on WinIsd:
                                http://www.parts-express.com/pe/show...number=295-494
                                Unfortunately I've already put a lot of time and money (2/3 a sheet of PSA veneer) into the two cabinets I have, which are finished, and I wouldn't be able to modify them to accomdate a PR.

                                Have you tried playing higher frequency sine waves through the subs? Do they sound essentially normal? I'm just really convinced that all you are hearing is normal HF content being reproduced by the sub in spite of the crossover. My $.02...
                                I haven't played any sine waves over 160hz recently. I may do that someday when I'm bored. Someone also suggested pink noise and taking a measurement which I may try, but I'm kinda beat right now. For what it's worth, my car's 10" JL W3v3 does not sound bad at all when getting fed a signal with the same crossovers. I don't think the W3 is known for it's ability to play as a woofer like the RS210HF, either.

                                Please double check the proximity of the inside port flare RIM to the baffle inside baffle.
                                The edge of the flare of the port is 1 3/4" away from the baffle. The flare is quite large though by that point.

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