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Newbie looking for design help from the Masters!!

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  • Newbie looking for design help from the Masters!!

    Hey Guys,

    I'll start this thread by letting you know that I'm new to DIY audio but very enthusiastic about learning the art of speaker building. I've got decent woodworking skills and the tools to match but my abilities in the areas of speaker/crossover design are non-existent.

    Now to the project:

    We are in the midst of renovation and, being an electronic enthusiast, I used this as an excuse to upgrade all my audio/video gear. After poking around on the internet a bit I came across Part Express and decided to do all custom speakers in my family room. These speakers will do double duty in home theater / music. I'll have a 5.2 system with 2 x 10" Ultimax subs (I've got one, haven't put it together yet). The front sound stage is going to be built-in, not in-wall in the truest sense, but the speakers will be sealed units set into pre-made recesses in the wall (see photos below). This room is large and is open to the kitchen / dining room.

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    Initially I had sized the opening the inside dimensions of 24" X 9.5" X 7.5" and had intended on doing a horizontal MTM design. After reading all the scathing indictments of horizontal MTM designs I went back to the drawing board, re-sized the opening to 16" X 9.5" X 7.5" and started leaning towards a 3-way T/MW design with a woofer sitting next to a tweeter over mid-woofer. Sort of like this:

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    These speakers will be my front right/left and will serve to pump out the music when I'm in the mood... I'll also build a complimentary centre channel to go above the TV position.

    As far as budget and components go I'm pretty flexible. This is what I've picked out on my own and any input regarding quality parts is welcome.

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    Any input regarding parts, design, and execution is welcome.... When I nail down the design I will post the project progress on the forums. I think I will certainly need some help from the crossover experts as that is all Greek to me.

    Thanks in advance guys and I look forward to developing my skills and being a productive member of this community!!!

    Adam

  • #2
    Re: Newbie looking for design help from the Masters!!

    Those woofers you have picked out are very nice. I just got finished with a build using the NE180W-08. It is an excellent woofer, increadibly clean and detailed. If you have the space, you might also want to consider the 8" version to get a little more bass. However, IMO, that tweeter just doesn't do those woofers justice. I would probably look at the vifa XT25 or RS28 for a reasonably priced tweeter to compliment those drivers. The layout you picked should work well. Most home speakers don't use this layout anymore, since most people don't like the way it looks, but a lot of studio monitors still due since they are often restricted in height.
    -Kerry

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    • #3
      Re: Newbie looking for design help from the Masters!!

      Thx Navy Guy, I will definitely look at your tweeter suggestions. It's good to hear that the preliminary design is valid as I am also dealing with a bit of a height issue due to the Windows

      Comment


      • #4
        Re: Newbie looking for design help from the Masters!!

        Originally posted by adam215 View Post
        Thx Navy Guy, I will definitely look at your tweeter suggestions. It's good to hear that the preliminary design is valid as I am also dealing with a bit of a height issue due to the Windows
        So I just looked at your cabinet dimensions and if those are external using 3/4" MDF with a chamber around the mid, you only have about .25 cubic feet of air space. Your dimensions listed also don't really leave anywhere to put a port, as pretty much all the front panel is used up. This is not going to work with the NE180W. It really needs at least .5 cubic feet, which is what I used, but is actually better in .75 cubic feet. I'm assuming you can't make the enclosure any deeper or taller, so you could go back to the original width and get closer to .5 cubic feet using 3/4" MDF with a small chamber on the mid.

        Also, I relized the height is going to limit you on tweeter faceplate size if you want to use the 4" Vifa NE. I would look for some small faceplate tweeters like these:

        http://www.madisoundspeakerstore.com...-dome-tweeter/
        http://www.madisoundspeakerstore.com...20-00-tweeter/
        -Kerry

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        • #5
          Re: Newbie looking for design help from the Masters!!

          I was thinking about doing these as a sealed unit... I'll have the 2 subwoofers to take care of the low low end so I thought a sealed cabinet would save on space and go low enough to cross well with the sub

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          • #6
            Re: Newbie looking for design help from the Masters!!

            Originally posted by adam215 View Post
            I was thinking about doing these as a sealed unit... I'll have the 2 subwoofers to take care of the low low end so I thought a sealed cabinet would save on space and go low enough to cross well with the sub
            Ok, well that changes things a little then. Sealed, the ideal box size for the NE180W-08 is about 9.5L, which you are just under using 3/4" material. You will still need to account for at least 2L or so for you mid chamber, as it will have to be sealed.
            -Kerry

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            • #7
              Re: Newbie looking for design help from the Masters!!

              So do you think I have the cabinet space for the 8 inch or should I revert to the 6.5?

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              • #8
                Re: Newbie looking for design help from the Masters!!

                What about a crossover? That's the most important part.

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                • #9
                  Re: Newbie looking for design help from the Masters!!

                  Totally Chris and I'm gonna need a lot of help there.

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                  • #10
                    Re: Newbie looking for design help from the Masters!!

                    Originally posted by adam215 View Post
                    So do you think I have the cabinet space for the 8 inch or should I revert to the 6.5?
                    I don't think the 8" will fit. Besides, my comment was about using the 8" for more bass. The 6.5" has an F3 of 77hz in that size box, and since you are using two subs, that should be plenty. Where are you located. There might be someone close that can help you with the crossover.
                    -Kerry

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                    • #11
                      Re: Newbie looking for design help from the Masters!!

                      I'm in Vancouver... I do have a sodering iron so if I had some help with the design of the crossover I could probably put it together

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                      • #12
                        Re: Newbie looking for design help from the Masters!!

                        I looked at the XT25... looks like a nice Tweeter. The only thing I'm unclear about is that the XT25 is 4 ohm while the woofer and mid are 8 ohm. Is this just an issue that gets sorted out in the crossover?

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                        • #13
                          Re: Newbie looking for design help from the Masters!!

                          Again, I want to say that I am pretty lost in terms of crossover design but I tried to come up with something in X-Over Pro... Am I even close?Click image for larger version

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                          • #14
                            Re: Newbie looking for design help from the Masters!!

                            You need to use drivers' actual data (curves) showing how both response (loudness) and impedance vary across the frequency spectrum. X-Over Pro doesn't (can't) make use of that data and is therefore (basically) useless as a XO design tool. It also generates horrendously complex circuits that end up with 1.5x to 2x as many components as what you'll need to do a competent job.

                            Not sure how far apart your L/Rs will be, but you might not end up needing a CC (I don't use one, and my mains are about 8' apart). Since you've got the subs covered (and you're a bit cramped for space) I strongly suggest going with just a 2-way. 3-ways get quite complicated, and aren't really necessary if you don't need them to get down to 30Hz. Also, you COULD still go vented, for listening to music when you don't fire up the sub(s). Anyway, given your space constraints, I'd probably go with a vented or sealed 2-way over any 3-way for this install.

                            Also, while your driver choices ARE top end (especially co$t-wise), you'd probably be further off looking at some 2-way designs using Dayton "Reference Series" drivers. You might not be familiar with them, buy they're very good (AND a great value) and have been designed specifically for low distortion. I'd probably go with a tweeter over a 6" or 7" woofer, with the port (if you use one) on the side.

                            Chris

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                            • #15
                              Re: Newbie looking for design help from the Masters!!

                              Interesting... Nice to know that X-Over Pro is not an overly valuable tool. What software should I be using to design crossovers? I will probably end up building a CC as I have already wired the wall for it and I could use it to further practice this new hobby.

                              I have no issue looking at a 2-way design over a 3-way. I don't think I have the vertical space to place a tweeter over a 6" woofer and that is why I was looking for some kind of side by side design. Could you do a woofer with the tweeter and port beside?

                              I have looked at the RS Dayton's... Sometimes I like to play my music LOUD so I was looking at other options with higher power ratings. I will be driving these speakers with an Emotiva XPA-5 300 watt per channel amp. I have a pretty basic understanding of speaker power ratings so in my head more power means louder...

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