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It’s that time audio enthusiasts! Registration for the 2019 Speaker Design Competition is now open! Visit midwestaudiofest.com for details and to list your speaker project. We are excited to see all returning participants, and look forward to meeting some new designers this year, as well! Be sure your plans include a visit to the Parts Express Tent Sale for the lowest prices of the year, and the Audio Swap Meet where you can buy and trade with other audio fans. We hope to see you this summer! Vivian and Jill
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NE225W+PM180+ViaWave Design & Build Thread

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  • jml
    started a topic NE225W+PM180+ViaWave Design & Build Thread

    NE225W+PM180+ViaWave Design & Build Thread

    Greetings!

    I thought that it would be good etiquette to start a single thread for all questions and progress updates on this (yet to be named) project. Hopefully this makes it easy to follow from beginning to end, and keeps my obtuse line of questions contained to a single thread HAHA!

    The next order of business is finalizing box volume(s), so that I can get the dimensions finalized before making some sawdust.

    Below is my first draft using UniBox to model the NE225Ws. The one issue that I seem to keep running into, whether I model it with 1 or 2 ports is Port Air Speed. Either way, increasing the port ID enough to reduce the air speed results in impractically long port lengths. How much of a concern is the air speed with a rear-facing port with a 1.5" round-over?

    As always, thanks to everyone for your knowledge. I look forward to learning a great deal throughout this build, and hopefully giving back to the forum throughout the process.

    Cheers!

    Joe

    Click image for larger version

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    Click image for larger version

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  • craigk
    replied
    Really nice.

    Leave a comment:


  • Vc1966
    replied
    Hello Joe those speakers are Beautiful! if you don’t mind me asking what are the inner cabinets dimensions?

    Thanks: Vince

    Leave a comment:


  • jml
    replied
    Originally posted by YaBoiMrNick View Post

    I really want to add that look to my speaker, but i don't have the tools to do so! Iv've been relying on my boss and friend to let me use their tools. I'll find a way hopefully
    Quick Question, How wide and thick are the staves?
    Nick:

    Sorry for the delay in responding. The staves are 2"x1"X16.5".

    Bast regards,

    Joe

    Leave a comment:


  • YaBoiMrNick
    replied
    Originally posted by jml View Post

    Nick:

    I'm glad that you like the look. The wood that I used was actually "builder grade" pine stair treads from Home Depot - the ones with veneered exterior. I simply ripped the bull-nose off the board on my table saw, and then broke down the boards from there. If you look closely you can see the lines of the veneer between each stave, which give the sides more visual dimension.

    I did not glue the staves to one another, as I didn't want to deal with all the squeeze-out, so they are only glued to the body of the speaker. As they were clamped together for the glue up, they're extremely tightly packed. Especially after a few coats of poly, there is no chance of vibration between the staves.

    Overall the construction seems to have come out extremely ridged and well damped - even at high volumes with strong bass, I am not able to perceive any vibration whatsoever when a hand is placed on the cabinet.

    Best regards,

    Joe
    I really want to add that look to my speaker, but i don't have the tools to do so! Iv've been relying on my boss and friend to let me use their tools. I'll find a way hopefully
    Quick Question, How wide and thick are the staves?
    Last edited by YaBoiMrNick; 11-12-2016, 07:08 PM.

    Leave a comment:


  • jml
    replied
    Originally posted by YaBoiMrNick View Post
    Hi Joe. I recently built a pair of 3 way speakers in some really crappy cabinets and i'm rebuilding them and making much better cabinets. I already have all the pieces of my cabinets cut from 3/4 inch baltic birch plywood and i want to add those staves to the side of mine too! They look stellar. I was also wondering what wood you used for the staves?

    Beautiful Build
    Nick
    Nick:

    I'm glad that you like the look. The wood that I used was actually "builder grade" pine stair treads from Home Depot - the ones with veneered exterior. I simply ripped the bull-nose off the board on my table saw, and then broke down the boards from there. If you look closely you can see the lines of the veneer between each stave, which give the sides more visual dimension.

    I did not glue the staves to one another, as I didn't want to deal with all the squeeze-out, so they are only glued to the body of the speaker. As they were clamped together for the glue up, they're extremely tightly packed. Especially after a few coats of poly, there is no chance of vibration between the staves.

    Overall the construction seems to have come out extremely ridged and well damped - even at high volumes with strong bass, I am not able to perceive any vibration whatsoever when a hand is placed on the cabinet.

    Best regards,

    Joe

    Leave a comment:


  • Chris Roemer
    replied
    I really think those look great! A very novel use of wood products.

    Leave a comment:


  • YaBoiMrNick
    replied
    Hi Joe. I recently built a pair of 3 way speakers in some really crappy cabinets and i'm rebuilding them and making much better cabinets. I already have all the pieces of my cabinets cut from 3/4 inch baltic birch plywood and i want to add those staves to the side of mine too! They look stellar. I was also wondering what wood you used for the staves?

    Beautiful Build
    Nick

    Leave a comment:


  • Wolf
    replied
    Cool! Thanks for the info! Obviously, no 'nanners applied.

    Later,
    Wolf

    Leave a comment:


  • jml
    replied
    Originally posted by Wolf View Post
    Okay, spill it- where'd you get the terminals, or what did you do to make them?
    Those are pretty cool,
    Wolf
    Necessity is the mother of invention.

    Options for purpose-made binding posts that would work with a cabinet wall that is slightly thicker than 1.5" were pretty slim. had I known this, I could have cut larger holes in the inner cabinet, so that the binding posts would only have to go through .75" of cabinet wall, but unfortunately, I didn't do that. I bought some 1/4-20 threaded brass rod, some solid brass jam nuts, and then some 1/4-20 threaded knobs. It is actually a pretty crude solution, but the knobs ended up working well with the aesthetic of the speaker - all black hardware. At some point I will have not put some lock washers into the assembly on both sides, as currently they will "slip" if you crank on the knobs too hard.

    Cheers!

    Joe

    Leave a comment:


  • Wolf
    replied
    Okay, spill it- where'd you get the terminals, or what did you do to make them?
    Those are pretty cool,
    Wolf

    Leave a comment:


  • jml
    replied
    Greetings!

    At this point I am considering the crossover design for the Treadnaughts finalized. Attached is the network schematic along with a copy of the on-axis measurements at about 1 meter. I'm sure that the more skilled among us would do a better job on the crossover design than I have done here; nonetheless, I'm very happy with the result. I won't spend a lot of time on superlatives, but to me they sound excellent - very detailed, balanced, and they image extremely well.

    The only item left to do is play around a little with the port tuning. it sounds as though the bass lost a tiny bit of definition after installing the crossovers in the cabs. The factors that changed were:
    - The box volume reduction caused by the space the crossover components take up.
    - The holes for the binding posts were open prior to installing the crossovers, and are now closed with the posts installed. Would these additional holes in the cabinet have lowered or raised the tuning frequency?

    I plan to try a few different port lengths to zero in on the optimal tuning, and then this project will be all wrapped up. Thanks to everyone for your help along the way!

    Cheers!

    Joe


    Leave a comment:


  • r-carpenter
    replied
    Originally posted by jml View Post

    I should be able to do that within the next week or so. What are you looking to see?

    Joe
    Abnormalities in the measurement process.

    I would also look at axial data. Take a few sweeps a meter away on tweeter axis 10 to 60 degrees in 10 degrees steps.
    In the process of tuning the speaker, summed up response at the listener position is basically how we evaluate the sound.
    Tonal balance is formed from both, first arrival and reflected sound. If the axial response has significant abnormalities, it may tilt the perception of the over all sound to be too bright or too dark (dull). You are border lining directivity of that mid and I'd be tiptoeing the crossover there.
    It also helps to measure each driver with the x-over attached just to see if modeled/predicted results are spot on to the actual output (on and off axis)
    Also to look at the distortion of each component with the x-over inline.

    Leave a comment:


  • jml
    replied
    Originally posted by r-carpenter View Post
    I usually just walk away from the project for couple of days. Helps to re-evaluate subjective impressions. then again, it's me. I listen to a few hours and aside from listening fatigue, I get use to the sound of the loudspeaker.
    Joe, then you get a chance, could you take a series of on-axis measurements (tweeter axis) from 20" away to 40" in incrementalists of 5".
    I should be able to do that within the next week or so. What are you looking to see?

    I also ordered a batch of different resister values, so that I can try some smaller adjustments to the tweeter and midrange levels before finalizing the design.

    Cheers!

    Joe

    Leave a comment:


  • r-carpenter
    replied
    I usually just walk away from the project for couple of days. Helps to re-evaluate subjective impressions. then again, it's me. I listen to a few hours and aside from listening fatigue, I get use to the sound of the loudspeaker.
    Joe, then you get a chance, could you take a series of on-axis measurements (tweeter axis) from 20" away to 40" in incrementalists of 5".

    Leave a comment:

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