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Fun with the new ND Passive's - The Passive Aggressives

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  • Mike Burke
    replied
    Looks like my next project.

    Looking at the schematic....C2 48UF is that right ? or is it a 4.8UF ?
    I hate to ask but I'm going to anyway
    Do you have a bill of matterials with part #s

    Thanks,
    Mike

    Leave a comment:


  • mattp
    replied
    Originally posted by ceiol View Post
    Cool. Gotta build these and integrate the new BTmini plate amp!

    edit: so I put the drivers and your XO into XSim. I just can't get the phase to align. Also my curve looks a bit different -- I have to change the R2 resistor from 3 Ohms to 8 Ohms to get my FR looking like yours.

    I tried using 0, 0.2, 0.4, 0.6 etc for the offset for the ND91-4, but still it does not align the phase.

    what am I doing wrong here?
    I used my own in-box measurements for my XO design. Phase still isn't perfect but that would explain why you are getting a different curve with your sims.

    Originally posted by tomzarbo View Post
    Very cool, Matt.

    They look super... I think this has to be one of the rockin'est 'tiny' speakers out there at this point.
    I can imagine that a 5.1 HT system with these and a suitable sub would really knock people's socks off.

    It's hard to tell from the pic, but what amp were you using? It kind of looks like it might be hooked up to the new DTA-2.1BT amp? How did that combo perform? I'm borrowing Kevin K's amp hooked to the Bantam speakers using the same driver, and it does have the guts to drive them plenty loud. I've found that the ND91's seem to like a fair amount of power to reach their full output potential.... seems strange for their size, but they just keep getting louder and louder without really complaining.

    I'd also love to hear these at the MWAF if possible.

    This is exciting stuff if you ask me, I love seeing PR's in motion.

    TomZ
    Yes Tom that is a DTA2.1, just what we had sitting in that little area in the office. It works well. These will take some power and not complain, I ran them for a while in the lab on an A500 and they didn't miss a beat. I will have them running on an LP1601S at home but I probably won't have them up very loud. Who knows, beer knows no bounds.

    These will be on display at MWAF for your audible pleasures.

    With tiny dual opposed passives it's especially funny, you can see them both moving if you are looking right at the speaker. The whole thing comes alive...

    Thanks for the comments guys!

    Leave a comment:


  • Wolf
    replied
    I have 4 of the nd90pr myself for some upcoming fun..

    Looks cool, Matt!

    Later,
    Wolf

    Leave a comment:


  • tomzarbo
    replied
    Very cool, Matt.

    They look super... I think this has to be one of the rockin'est 'tiny' speakers out there at this point.
    I can imagine that a 5.1 HT system with these and a suitable sub would really knock people's socks off.

    It's hard to tell from the pic, but what amp were you using? It kind of looks like it might be hooked up to the new DTA-2.1BT amp? How did that combo perform? I'm borrowing Kevin K's amp hooked to the Bantam speakers using the same driver, and it does have the guts to drive them plenty loud. I've found that the ND91's seem to like a fair amount of power to reach their full output potential.... seems strange for their size, but they just keep getting louder and louder without really complaining.

    I'd also love to hear these at the MWAF if possible.

    This is exciting stuff if you ask me, I love seeing PR's in motion.

    TomZ

    Leave a comment:


  • ceiol
    replied
    Cool. Gotta build these and integrate the new BTmini plate amp!

    edit: so I put the drivers and your XO into XSim. I just can't get the phase to align. Also my curve looks a bit different -- I have to change the R2 resistor from 3 Ohms to 8 Ohms to get my FR looking like yours.

    I tried using 0, 0.2, 0.4, 0.6 etc for the offset for the ND91-4, but still it does not align the phase.

    what am I doing wrong here?

    Last edited by ceiol; 03-27-2018, 09:28 PM.

    Leave a comment:


  • Kevin K.
    replied
    I like these little guys and I like #7 on the dry erase board too.

    Leave a comment:


  • mattp
    replied
    Originally posted by howard View Post
    Very attractive! I would like to hear them.
    Thanks!

    Originally posted by KEtheredge87 View Post
    Lookin' good sir! Do you think we might hear these at any upcoming DIY events, like InDIYana or MWAF in July?

    I'm really excited to see more projects like this that utilize the new passives. I myself would like to build some small towers for my living room using the ND series, but I can't quite reconcile my feelings on the mounting flange (personally not a fan of the shape) vs. doing a rear mount with chamfer or otherwise on the front. I know the rear mount + chamfer look is troublesome from an acoustics perspective, but it looks sleek, and having the cabinets look great is also a general requirement to satisfy high WAF
    I will try to have them on display at MWAF and see if the guys can bring them to InDIYana with them to demo. We are hoping to sell these as a kit.

    I agree about the pincushion frames. I would have liked to rear mount these but there was no way they would have fit, even just rear mounting the active woofer would've been impossible in order to fit everything in the cabinets. I encourage you to play with the ND series though. Very nice drivers for the money and the passives open up a ton of possibilities for tiny designs. Chris P did a quick model on these and determined that a 1.5" diameter port would have had to be 36" long to get the same tuning frequency.

    Leave a comment:


  • KEtheredge87
    replied
    Lookin' good sir! Do you think we might hear these at any upcoming DIY events, like InDIYana or MWAF in July?

    I'm really excited to see more projects like this that utilize the new passives. I myself would like to build some small towers for my living room using the ND series, but I can't quite reconcile my feelings on the mounting flange (personally not a fan of the shape) vs. doing a rear mount with chamfer or otherwise on the front. I know the rear mount + chamfer look is troublesome from an acoustics perspective, but it looks sleek, and having the cabinets look great is also a general requirement to satisfy high WAF

    Leave a comment:


  • howard
    replied
    Very attractive! I would like to hear them.

    Leave a comment:


  • mattp
    replied
    Electronical shenanigans.

    Simulated response:
    Click image for larger version

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    Measured response:
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    Measured impedance:
    Click image for larger version

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    Attached Files

    Leave a comment:

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