Announcement

Collapse
No announcement yet.

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

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    Re: Just finished a pair of subs and they suck. Why?

    Originally posted by Paul Carmody View Post
    Yup, sounds very bad.

    I think it's a matter of figuring out if it it's the amp or the driver. There's not much else it could be (well, the source, but honestly I think some people are making a mountain out of a molehill by claiming you can't use an mp3 to test. That distortion sounds way worse than any mp3 file I've ever heard.)
    +1
    DARPA Jr - 2015 InDIYana Winner - RS180-8 + RS100P-8 + ND25FA
    The Aria's - RS150-4 (or RS150-8) + XT25SC90
    The Mariposa's - TEBM65C20F-8 + ND16FA
    The Canzonetta's - RS100P-8 and ND16FA
    AudioSource AMP-100 Mods OR Pyle PAMP1000 Mods

    Comment


    • #32
      Re: Just finished a pair of subs and they suck. Why?

      Originally posted by Paul Carmody View Post
      Yup, sounds very bad.

      I'm breathing a slight sigh of relief that it's not the enclosure size or tuning.

      I think it's a matter of figuring out if it it's the amp or the driver. There's not much else it could be (well, the source, but honestly I think some people are making a mountain out of a molehill by claiming you can't use an mp3 to test. That distortion sounds way worse than any mp3 file I've ever heard.)
      I never claimed that you can't use an mp3 to test.

      What I do claim is that if you do have a problem then to get rid of all of the unecessary variables and arbitraries out of the equation. Like possible bad source material, possible bad soundcards and crossover settings external of the device under test.

      But that is only the sensible, logical and scientific approach to a problem.
      Don't worry, if your parachute fails, you have the rest of your life to fix it.

      If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

      Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D

      Comment


      • #33
        Re: Just finished a pair of subs and they suck. Why?

        .

        Looking at some of the solutions offered here, I think we are losing track of the fact that in the o.p. Exarch states that this problem occurs with both subwoofers.

        I am willing to bet that there is nothing wrong with either subwoofer.
        Don't worry, if your parachute fails, you have the rest of your life to fix it.

        If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

        Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D

        Comment


        • #34
          Re: Just finished a pair of subs and they suck. Why?

          at this point I'd be scrambling around for other sources, receiver amps, car xo's whatever and try to back track the problem by switching out components.

          However, that said, the amp does sound like it is running out of gas.

          Comment


          • #35
            Re: Just finished a pair of subs and they suck. Why?

            Originally posted by thekorvers View Post
            If I troubleshoot an electronic circuit I do so with a signal generator providing a clean undistorted signal.

            Same with an amp/speaker system. I don't start out with an already distorted signal (mp3) and then run it through some electronic circuit with cross-over points that may or may not be set properly (sound card) and which may add a bunch more garbage to the signal before it enters the system I am attempting to troubleshoot.
            Really? Sheesh man, have you actually ever heard an MP3 file before?

            It seems like someone instituted an audiophile-wide ban on MP3 files way back when encoders were junk and people still tried to use 96Kbps encoding for music, and the entire community has held staunchly to those beliefs ever since. THEY DON'T SOUND THAT BAD guys. Most of you probably wouldn't notice if I replaced your CDs and Folgers Crystals with a well-encoded 160Kbps MP3. There's no gross "distortion". There are differences, not for the better, but they're relatively subtle.

            Now, IF you use a really awful encoder (of which there are fewer in circulation these days -- iTunes and LAME are really quite good), and/or you use ridiculously low bitrates, you'll get a kinda watery / metallic ringing from the errors introduced by all the FFT transforms with too low precision. This can make sub-bass kinda woofy, but the mids will suffer most and the highs will be almost completely filtered out -- by design, they take more bits to encode. What you DON'T get is clipping, and chunky noises that somehow manage to pass through lowpass filters on sound cards and plate amps.

            But again, THAT'S just a sensical, logical, scientific, and most importantly, factual approach to the issue. :rolleyes:

            (No personal attacks intended here. All in good fun, with light-hearted sarcasm. We cool bro?)

            On topic: Agreed with Adam_G -- try it out of box and see if there's mechanical noise. And of course the "known good amp and source" test.

            Comment


            • #36
              Re: Just finished a pair of subs and they suck. Why?

              Originally posted by SirNickity View Post
              Really? Sheesh man, have you actually ever heard an MP3 file before?

              It seems like someone instituted an audiophile-wide ban on MP3 files way back when encoders were junk and people still tried to use 96Kbps encoding for music, and the entire community has held staunchly to those beliefs ever since. THEY DON'T SOUND THAT BAD guys. Most of you probably wouldn't notice if I replaced your CDs and Folgers Crystals with a well-encoded 160Kbps MP3. There's no gross "distortion". There are differences, not for the better, but they're relatively subtle.

              Now, IF you use a really awful encoder (of which there are fewer in circulation these days -- iTunes and LAME are really quite good), and/or you use ridiculously low bitrates, you'll get a kinda watery / metallic ringing from the errors introduced by all the FFT transforms with too low precision. This can make sub-bass kinda woofy, but the mids will suffer most and the highs will be almost completely filtered out -- by design, they take more bits to encode. What you DON'T get is clipping, and chunky noises that somehow manage to pass through lowpass filters on sound cards and plate amps.

              But again, THAT'S just a sensical, logical, scientific, and most importantly, factual approach to the issue. :rolleyes:

              (No personal attacks intended here. All in good fun, with light-hearted sarcasm. We cool bro?)

              On topic: Agreed with Adam_G -- try it out of box and see if there's mechanical noise. And of course the "known good amp and source" test.
              We are cool bro.

              You make it appear if my only issue is with the use of mp3 files. It is not. IMO more of the issue is with the use of his soundcard with the attendant cross-over settings. I suggested eliminating that.

              Having been a troubleshooter all my life, I tend to approach a problem in a very methodical, logical way. The first thing I do is to eliminate all arbitraries and variables that cloud the issue.

              Call me Mr. Spock.:D You may do things differently. Entirely up to you.
              Don't worry, if your parachute fails, you have the rest of your life to fix it.

              If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

              Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D

              Comment


              • #37
                Re: Just finished a pair of subs and they suck. Why?

                Has anyone recommended pulling the driver and running it free air? I read through the posts and am pretty sure I didn't see that mentioned. That would be my move.....
                Builds - C-Killa - Speedsters - LithMTM - Talking Sticks - Pocket Rockets - Khanspires - Dayton RS Center - RS225/28A - Kairos - Adelphos - SEOS TD12X - Dayton 8 - Needles - 871S - eD6c - Overnight Sensations - Tritrix (ported) - Lineup F4 - Stentorians - The Cheapies - Tub Thumpers - Barbells - Tuba HT - Numerous subwoofers - probably missing a few...... :p

                Comment


                • #38
                  Re: Just finished a pair of subs and they suck. Why?

                  Originally posted by Adam_G View Post
                  What you may want to do is pull the speakers from the box, and at very low wattage, while watching your excursion very very closely, play your normal signal outside of the box. If it's a mechanical noise you will very easily hear it out of the box
                  Yes.

                  Comment


                  • #39
                    Re: Just finished a pair of subs and they suck. Why?

                    Updates!

                    I took one of the subs over to my friend's house and hooked it up to his old 2-channel amp and receiver. I also hooked it up to my Emotiva UPA-500 (120W RMS). No change. So the the problem is not unique to the plate amp nor the source. That leaves the box and driver.

                    Next up, I removed the driver and played it in free air, running off my PC sound card and Emotiva. Same as in the box, I can't really hear the noise with the crossover set at 50hz, but as soon as I raise it towards 70-80, there it is, getting worse as I go up. I pick the driver up off the desk and the sound goes away. I'm not sure if it went away completely, or mostly. I put my hand over the hole (vent?) in the bottom of the magnet, and the sound comes back. Now we're getting somewhere, I hope.

                    I look inside my box and there is a brace, 3/4" x 3/4", directly behind the centre of the woofer cutout. However, the brace is 6 1/2" back from mounting surface, and the sub only extends 4 1/2" into the cabinet. Surely a single brace 2" behind that vent shouldn't cause any issues? Could there be some weird air pressure voodoo going on right there?

                    I guess the next step is reverse-mounting the driver, and if that sounds fine, cutting out the brace and trying it mounted normally again.

                    Comment


                    • #40
                      Re: Just finished a pair of subs and they suck. Why?

                      Could you just use a hole saw and put a 2" hole in it.
                      If we all reacted the same way, we'd be predictable, and there's always more than one way to view a situation.
                      What's true for the group is also true for the individual. It's simple: Overspecialize, and you breed in weakness.
                      It's slow death.

                      //Burn n' Die//Dream Weaver//Maximus//ABC Bookshelf Speakers//Dayton Twin Towers

                      Comment


                      • #41
                        Re: Just finished a pair of subs and they suck. Why?

                        Think this thru with me again. As you RAISE the XO frequency the sound gets WORSE, right? More audio information is going into the driver at this point. It's "TOPPING OUT" with higher frequencies rather than "bottoming out" from lack of excursion. Plugging the vent hole on the back of the magnet should make the sound worse in any case, but the brace 2" away from it behind shouldn't cause any issue at all.

                        Comment


                        • #42
                          Re: Just finished a pair of subs and they suck. Why?

                          Very strange - that looks to be a nice woofer (huge fan of 8" woofers also).
                          [Wish I had a pair of these 8" Daytons]

                          Still thinking you may not have enough power and also losing efficiency with all the foam.

                          Did you get these new? I know some other have asked.

                          Comment


                          • #43
                            Re: Just finished a pair of subs and they suck. Why?

                            Maybe something is loose somewhere and only resonates at a frequency above 50hz.

                            Comment


                            • #44
                              Re: Just finished a pair of subs and they suck. Why?

                              And so we await with bated breath for the next step in this odyssey.

                              One of the more interesting threads, but I guess I will not see how this plays out for a while as I am going on vacation tomorrow.
                              Don't worry, if your parachute fails, you have the rest of your life to fix it.

                              If we all did the things we are capable of doing, we would literally ASTOUND ourselves - Thomas A. Edison

                              Some people collect stamps, Imelda Marcos collected shoes. I collect speakers.:D

                              Comment


                              • #45
                                Re: Just finished a pair of subs and they suck. Why?

                                not having gone through the photos or having sound attached to this computer to watch the video, have you ruled out lead slap / rubbing, or a loose terminal plate? either of those can cause odd mechanical noises.
                                TM (RS125/TB25-302), TM RS150S / Vifa BC25SC06, RS150-4 / Vifa ML-TL, 3CR-AL Ultra Budget: Electric Blue TM, TMM, MTM, Dragonflies , Mounties: Mini HT Satellite,sub for minions

                                Comment

                                Working...
                                X