Polk Monitor 10 Questions

Just curious about the design of two smaller drivers and the large passive radiator vs. the single 10" driver of my Pioneer HPM-40's of the same era. Is there better, quicker bass response and better mids from two smaller drivers and the passive radiator ?

Does the passive radiator contribute to the bass that we hear ? Unfortunately I no longer have the HPM-40's to compare sound.

Also, one of the 6" drivers on the Monitor 10 has a small tear (perhaps 3-4mm in length) in the rubber surround right next to the outer edge. Can anyone recommend a rubber cement or glue that would be suitable ? Thanks.

Comments

  • We used to recommend using bicycle inner tube repair kits to put a small patch on the tear.
  • pitdogg2
    pitdogg2 Posts: 25,412
    Best to do the repair from the inside if you can.
  • mhardy6647
    mhardy6647 Posts: 33,769
    edited February 13
    Looks like "we" covered the damaged surround question pretty well, but @redsled asked another question, too. :)
    redsled wrote: »
    Just curious about the design of two smaller drivers and the large passive radiator vs. the single 10" driver of my Pioneer HPM-40's of the same era. Is there better, quicker bass response and better mids from two smaller drivers and the passive radiator ?

    Does the passive radiator contribute to the bass that we hear ? Unfortunately I no longer have the HPM-40's to compare sound...
    So... the use of two smaller drivers has advantages of lower moving mass and was actually rather popular in the 1970s (and remains so even today in many tower loudspeakers). Braun and their US cousin, ads, e.g., made some outstanding loudspeakers using two smaller woofers in lieu of a single large one. The price of those loudspeakers was considerably higher than the Polks, though!
    Polk's choice to use a passive radiator to achieve the desired speaker system "alignment" was an interesting one. In essence, a passive radiator system is a bass reflex analogue, using the mass of the passive radiator as a substitute for the mass of air in the "port" of a bass reflex enclosure. The advantage of either bass reflex (BR) or passive radiator (PR) is better efficiency (or, more to the point, sensitivity - sound pressure level at a given distance from the speaker for a given amount of amplifier power input) compared to the then fashionable acoustic suspension alignment. Advantages of PR compared to BR include easy system tuning (just add, or remove, moving mass from the passive radiator diaphragm), no port noise ("chuffing"), and also no 'spurious midrange' emanating from the port.
    Passive radiators are still seen sometimes in modern loudspeaker design.
    The HPM-40 was a very old-fashioned bass reflex design using two cone drivers with a rather simple crossover and a "supertweeter" crossed in at a very high (nearly inaudible) frequency. Pioneer called it a three-way speaker, but it's really a two way with some ultra-treble augmentation. Yes, the midrange quality from the Polks should be substantially better than the HPM-40, although its bigger, more expensive siblings (HPM-60 and HPM-100) should fare a little better, since they do have separate midrange drivers. The hybrid cone woofers used in the Pioneer speakers were notoriously (mechanically) fragile, too.
    Really not much comparison between the HPM-40,60,100, and the Polk Monitor 7 and 10. The original HPM family was designed by a team overseen by Bart Locanthi (designer of, among other things, the hugely popular JBL L100) and share the rough and tumble "West Coast sound" coloration of the L100 and its kin. The Polk Monitor 10 and (especially) Monitor 7 were much more refined and better sounding loudspeakers, voiced much more like the British loudspeakers of the same era (but selling at much lower prices). Bass from the Polks is better defined and, in the case of the 10, should go deeper than the HPM-40 as well. Sensitivity is probably comparable.
    https://www.hifiengine.com/manual_library/pioneer/hpm-40.shtml
    EDIT: Per hifiengine, the crossover frequencies of the HPM-40 were 4000 Hz and 10,000 Hz. In other words, most of the midrange was handled by that big 10 inch woofer -- a far-from-optimal situation.

  • redsled
    redsled Posts: 21
    We used to recommend using bicycle inner tube repair kits to put a small patch on the tear.

    Thank you SeleniumFalcon !
    pitdogg2 wrote: »
    Best to do the repair from the inside if you can.
    pitdogg2 wrote: »
    Best to do the repair from the inside if you can.

    Thank you pitdogg2 !
    mhardy6647 wrote: »

    Looks like "we" covered the damaged surround question pretty well, but @redsled asked another question, too. :)
    redsled wrote: »
    Just curious about the design of two smaller drivers and the large passive radiator vs. the single 10" driver of my Pioneer HPM-40's of the same era. Is there better, quicker bass response and better mids from two smaller drivers and the passive radiator ?

    Does the passive radiator contribute to the bass that we hear ? Unfortunately I no longer have the HPM-40's to compare sound...
    So... the use of two smaller drivers has advantages of lower moving mass and was actually rather popular in the 1970s (and remains so even today in many tower loudspeakers). Braun and their US cousin, ads, e.g., made some outstanding loudspeakers using two smaller woofers in lieu of a single large one. The price of those loudspeakers was considerably higher than the Polks, though!
    Polk's choice to use a passive radiator to achieve the desired speaker system "alignment" was an interesting one. In essence, a passive radiator system is a bass reflex analogue, using the mass of the passive radiator as a substitute for the mass of air in the "port" of a bass reflex enclosure. The advantage of either bass reflex (BR) or passive radiator (PR) is better efficiency (or, more to the point, sensitivity - sound pressure level at a given distance from the speaker for a given amount of amplifier power input) compared to the then fashionable acoustic suspension alignment. Advantages of PR compared to BR include easy system tuning (just add, or remove, moving mass from the passive radiator diaphragm), no port noise ("chuffing"), and also no 'spurious midrange' emanating from the port.
    Passive radiators are still seen sometimes in modern loudspeaker design.
    The HPM-40 was a very old-fashioned bass reflex design using two cone drivers with a rather simple crossover and a "supertweeter" crossed in at a very high (nearly inaudible) frequency. Pioneer called it a three-way speaker, but it's really a two way with some ultra-treble augmentation. Yes, the midrange quality from the Polks should be substantially better than the HPM-40, although its bigger, more expensive siblings (HPM-60 and HPM-100) should fare a little better, since they do have separate midrange drivers. The hybrid cone woofers used in the Pioneer speakers were notoriously (mechanically) fragile, too.
    Really not much comparison between the HPM-40,60,100, and the Polk Monitor 7 and 10. The original HPM family was designed by a team overseen by Bart Locanthi (designer of, among other things, the hugely popular JBL L100) and share the rough and tumble "West Coast sound" coloration of the L100 and its kin. The Polk Monitor 10 and (especially) Monitor 7 were much more refined and better sounding loudspeakers, voiced much more like the British loudspeakers of the same era (but selling at much lower prices). Bass from the Polks is better defined and, in the case of the 10, should go deeper than the HPM-40 as well. Sensitivity is probably comparable.
    https://www.hifiengine.com/manual_library/pioneer/hpm-40.shtml
    EDIT: Per hifiengine, the crossover frequencies of the HPM-40 were 4000 Hz and 10,000 Hz. In other words, most of the midrange was handled by that big 10 inch woofer -- a far-from-optimal situation.
    mhardy6647 wrote: »
    Looks like "we" covered the damaged surround question pretty well, but @redsled asked another question, too. :)
    redsled wrote: »
    Just curious about the design of two smaller drivers and the large passive radiator vs. the single 10" driver of my Pioneer HPM-40's of the same era. Is there better, quicker bass response and better mids from two smaller drivers and the passive radiator ?

    Does the passive radiator contribute to the bass that we hear ? Unfortunately I no longer have the HPM-40's to compare sound...
    So... the use of two smaller drivers has advantages of lower moving mass and was actually rather popular in the 1970s (and remains so even today in many tower loudspeakers). Braun and their US cousin, ads, e.g., made some outstanding loudspeakers using two smaller woofers in lieu of a single large one. The price of those loudspeakers was considerably higher than the Polks, though!
    Polk's choice to use a passive radiator to achieve the desired speaker system "alignment" was an interesting one. In essence, a passive radiator system is a bass reflex analogue, using the mass of the passive radiator as a substitute for the mass of air in the "port" of a bass reflex enclosure. The advantage of either bass reflex (BR) or passive radiator (PR) is better efficiency (or, more to the point, sensitivity - sound pressure level at a given distance from the speaker for a given amount of amplifier power input) compared to the then fashionable acoustic suspension alignment. Advantages of PR compared to BR include easy system tuning (just add, or remove, moving mass from the passive radiator diaphragm), no port noise ("chuffing"), and also no 'spurious midrange' emanating from the port.
    Passive radiators are still seen sometimes in modern loudspeaker design.
    The HPM-40 was a very old-fashioned bass reflex design using two cone drivers with a rather simple crossover and a "supertweeter" crossed in at a very high (nearly inaudible) frequency. Pioneer called it a three-way speaker, but it's really a two way with some ultra-treble augmentation. Yes, the midrange quality from the Polks should be substantially better than the HPM-40, although its bigger, more expensive siblings (HPM-60 and HPM-100) should fare a little better, since they do have separate midrange drivers. The hybrid cone woofers used in the Pioneer speakers were notoriously (mechanically) fragile, too.
    Really not much comparison between the HPM-40,60,100, and the Polk Monitor 7 and 10. The original HPM family was designed by a team overseen by Bart Locanthi (designer of, among other things, the hugely popular JBL L100) and share the rough and tumble "West Coast sound" coloration of the L100 and its kin. The Polk Monitor 10 and (especially) Monitor 7 were much more refined and better sounding loudspeakers, voiced much more like the British loudspeakers of the same era (but selling at much lower prices). Bass from the Polks is better defined and, in the case of the 10, should go deeper than the HPM-40 as well. Sensitivity is probably comparable.

    Thank you mhardy6647 , great information !

    https://www.hifiengine.com/manual_library/pioneer/hpm-40.shtml
    EDIT: Per hifiengine, the crossover frequencies of the HPM-40 were 4000 Hz and 10,000 Hz. In other words, most of the midrange was handled by that big 10 inch woofer -- a far-from-optimal situation.

  • redsled
    redsled Posts: 21
    Woops I had trouble with quotes. Thank you too mhardy6647 for that information. Makes sense the smaller moving masses and better response. Early listening results of the Monitor 10's are quite positive at low volumes so far.

    Thanks everyone !