just curious...what your opinion of newer 1990+ vs older 80s etc polk quality

i was blown away in high school when i heard this new brand( new to me ) polk . by my older brothers purchase of the sda? forgive me dont recall model . with the single bass driver/tweeter and passive radiator. ... these started my fuse and curiousity in fine audio equipment. i havnt seen much use of passive radiators since ..... why???

Best Answers

  • pitdogg2
    pitdogg2 Posts: 25,571
    Answer ✓
    Ports are cheaper to design
  • K_M
    K_M Posts: 1,629
    Answer ✓
    Both have advantages.

    In a small box sometimes a passive will fit better where a port is limited in length to the inside of the box.

    A passive filters out and midrange sounds coming from the back of the woofer.

    A port is cheaper to make

    A port is slightly more efficient and allows a bit deeper bass, as a passive radiator has some sligth loss associated with it, and it rolls off faster below its resonant frequency

    Otherwise they are virtually the same thing.
  • BlueFox
    BlueFox Posts: 15,251
    Answer ✓
    K_M wrote: »
    Both have advantages.

    In a small box sometimes a passive will fit better where a port is limited in length to the inside of the box.

    A passive filters out and midrange sounds coming from the back of the woofer.

    A port is cheaper to make

    A port is slightly more efficient and allows a bit deeper bass, as a passive radiator has some sligth loss associated with it, and it rolls off faster below its resonant frequency

    Otherwise they are virtually the same thing.

    Good post. Still not sure what the original poster is looking for.
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Answers

  • BlueBirdMusic
    BlueBirdMusic Posts: 2,318
    My girlfriend and I have a set of "traveling speakers" from Definitive Technology. When we spend a week at the beach a couple of times each year, we take them. These speakers are bipolar, have a passive radiator and a built in DAC. Our laptop has all of our music ripped to FLAC and we use JRiver to play.

    The speakers are the Incline Speakers and sound quite good. The first time we took them out of the box, the volume was turned up and we shocked how loud and clear. The price was about $400 when announced in 2014. They were discontinued. We purchased them on sale for about $175.


    https://youtu.be/4LkOCFkyuiE
    https://www.crutchfield.com/S-lZcPkFSVTL0/p_735INCLINE/Definitive-Technology-Incline.html
    "Sometimes you have to look to the past to understand where you are going in the future"

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  • ericerik
    ericerik Posts: 53
    Ya sounds like they work well for ya.. I like the idea of passive radiator ever since then
  • ericerik
    ericerik Posts: 53
    Ever since I heard those Polk's in the 80s I meant... Think it's because there so efficient .
  • diverdog
    diverdog Posts: 27
    Passive radiators are still used by many speaker manufacturers. The PR are analogues to a port. They take the place of the mass of the air in a port to tune the "vented box" If you do a low frequency sweep you would see that the PR hardly moves at all until you go low enough to hit the resonant frequency, then the PR will have big excursions to support the box tuning for low bass.