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  • [FAQ]Speaker building


    The Burdizzos Mod



    This mod was originally done on an Avatar B212. I swapped out the horn for a Galaxy Audio 5" driver. I have since used Galaxy's new Neo 5" driver and I think it sounds better than the standard driver. It has a claimed range of 150 to 18,000Hz and a claimed power handling of 100 watts RMS. If a crossover set at 500 Hz is used, it fills out the high frequency sound of the bass without being harsh, as horns often are.



    This can be done in any cab where there is room on the front baffle to fit the new speaker. It has a 4.75

  • #2
    Here's a little spiel I wrote in another thread regarding the Avatar horn modification. It could be applied to speaker building (mostly crossover use) in general as well:

    The 'Avatar horn mod' many people speak of is simply adding an appropriate high pass filter to the horn. The "crossover" that comes stock with the Avatar cabs is simply a capacitor wired inline with the foster horn, providing a 6db per octave rolloff below the crossover point (which is 3500hz if I remember correctly). Simply stated, this slope isn't steep enough to give proper protection to the horn, resulting in 'harshness' as the horn tries to produce frequencies that are at (and below) it's lower limits. With the simple capacitor acting as the HPF, the horn is only down 6db at 1725hz and is still getting a fair amount of power.

    In order to get better performance, reliability, and sound from the horn, a better HPF with a steeper slope is needed. I think something along the lines of a 3rd order (18db/oct) or 4th order (24db/oct) would suffice. If you do a search on talkbass.com you'll see that a lot of folks there have made their own linkwitz-reilly 24db/oct high pass filters for their Avatar cabs and significantly improved the performance. In fact many even lowered the crossover point to 3000hz with good results - you can do this because with such a steep rolloff you're still going to have much, much less power going to the horn at 1725hz with a 3000hz 4th order than you would with a 3500hz 1st order.

    If you're not up to building your own high pass filter, I'd suggest installing this one from Eminence:
    http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-602

    It's a 18/db per octave HPF with built-in bulb protection. Replacing the existing cap with this crossover with definitely improve the horn's performance and reduce harshness.

    Comment


    • #3
      This little page rules all when you need to design your own crossover. You plug in the impedance if your drivers, the frequencies you want and the type of crossover, and it'll give you a little diagram with the values for the components included.

      http://www.lalena.com/audio/calculator/xover/

      Comment


      • #4
        Actually, Dave is now putting real 12 dB slope crossovers in his cabs.




        Good on him, he made a great cab better and didn't jack up the prices.

        Comment


        • #5
          A few questions:

          1. Where can I download winISP?
          2. Would it be possible to convert an Avatar 115 into a 118? It looks like there's room in the enclosure to where I could just make the hole bigger.

          Official member of the HCBF DeezNuts Club
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          Drive vegetarian, biatch!

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          Come on dudes lets all just smoke some crop and watch The Magic School Bus. Ms. Frizzle is the shizzle. - DanTolen

          Playing with a pick is like throttling yourself with a belt and blowing hot air on your balls with a hairdryer while you masturbate - sometimes it's just the only way to get the job done. - FreestyleIntruder

          Comment


          • #6
            WinISD

            To download WinISD,
            click here.


            There are a couple of important things to know about WinISD.

            First, the database that comes with it isn't accurate. You will need to upload specs to get the best results.

            Second, ISD is not perfect. It is a free program that, in my experience, performs almost as well as box building programs that you have to pay for. In the speaker cab building game, approximations are almost always close enough.

            The Help menu is very good, but I

            Comment


            • #7
              When you're sizing your ports, what does the " Qes/Pe! "
              signify? I feel like since it's in red with an exclamation point, it's telling me I'm screwing something up...
              C7
              Subliminal aggression - C7 has it. -Incubitabus

              One time my gig bag and everything in it mysteriously got covered in urine while it was in my home. I want to blame the cats but my wife is crazy sometimes. -Davedblyoo


              C7... HCBF's resident pompous dick with a claw hammer. -Hearafter
              Winner!! T-Broom's Inaugural HCBF Funny MF Award 10/6/06
              Winner!! Thumper's 'HCBF Gutter Poet' Award 6/17/07

              "Oh my god...C7 You are so rock and roll, it's not even funny." -bassgirl9

              Comment


              • #8
                That implies that the port is far too short and you haven't entered a vallid value for the port diameter or size.

                When the Vent Match number is red, I think it is telling you that the port is too small and could result in port noise.

                The bigger the port, the better, in my opinion.

                Comment


                • #9
                  There's no advantage to putting an 18 in the Avatar B115 cab. It won't play any lower and it will probably be boomy.

                  Comment


                  • #10
                    Hey burdizzos, where would I find the Pe and Z on Eminence's site? Also, which SPL do you go with on their sensitivity charts? Thanks.
                    Originally Posted by bassesofalessergod


                    this is a good thread, but only nerds and creeps play 5-String.









                    Originally Posted by King Kashue


                    Yeah, Reggaton is cool for like 10 seconds, where you're thinking "hey, that's kind of a cool beat"...

                    After 10 seconds you're thinking "Hrm, is it just this same thing over and over again?"

                    And after 30 seconds you're thinking "Wow...I bet this is what is sounds like when you have an aneurysm"

                    Comment


                    • #11
                      Originally posted by burdizzos
                      That implies that the port is far too short and you haven't entered a vallid value for the port diameter or size.

                      When the Vent Match number is red, I think it is telling you that the port is too small and could result in port noise.

                      The bigger the port, the better, in my opinion.


                      The problem I have is, there are times where I can't get it to NOT be red. I can tinker with all kinds of numbers and it doesn't change...
                      C7
                      Subliminal aggression - C7 has it. -Incubitabus

                      One time my gig bag and everything in it mysteriously got covered in urine while it was in my home. I want to blame the cats but my wife is crazy sometimes. -Davedblyoo


                      C7... HCBF's resident pompous dick with a claw hammer. -Hearafter
                      Winner!! T-Broom's Inaugural HCBF Funny MF Award 10/6/06
                      Winner!! Thumper's 'HCBF Gutter Poet' Award 6/17/07

                      "Oh my god...C7 You are so rock and roll, it's not even funny." -bassgirl9

                      Comment


                      • #12
                        Originally posted by burdizzos
                        Actually, Dave is now putting real 12 dB slope crossovers in his cabs.


                        Yeah, I saw that recently. Very good on him. It's still not as good as a third or fourth order in my opinion (at least on a compression horn), but definitely a step above the first order he was using.

                        Comment


                        • #13
                          Anyone know where I can get 2x15 or 4x12 sidewinders for bass/guitar cabs? I have a 79' Marshall bass 2x15 I'd like to put in there and a 2x12 fender cab I'd like to put in there for guitar.
                          www.myspace.com/pigpawn
                          this is not a band website, it's a gear trading/networking
                          page I'm trying to do with a few buds. Add it and check out some gear! I don't spam or nothin'.

                          Wanted:
                          BASS MURF!
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                          4 12" bass speakers!

                          Comment


                          • #14
                            Could somebody post a set of diagrams describing what the different orders of crossovers are, and what their uses are?
                            C7
                            Subliminal aggression - C7 has it. -Incubitabus

                            One time my gig bag and everything in it mysteriously got covered in urine while it was in my home. I want to blame the cats but my wife is crazy sometimes. -Davedblyoo


                            C7... HCBF's resident pompous dick with a claw hammer. -Hearafter
                            Winner!! T-Broom's Inaugural HCBF Funny MF Award 10/6/06
                            Winner!! Thumper's 'HCBF Gutter Poet' Award 6/17/07

                            "Oh my god...C7 You are so rock and roll, it's not even funny." -bassgirl9

                            Comment


                            • #15
                              Originally posted by Crescent Seven
                              Could somebody post a set of diagrams describing what the different orders of crossovers are, and what their uses are?
                              C7

                              Look here...

                              and here...

                              here...

                              and here.

                              Just an elementary primer but it's a darn good start.
                              * = prone to being completely clueless.

                              *This space for rent*

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